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Aims: To identify HbA1c trajectories after the start of insulin treatment and to identify clinically applicable predictors of the response to insulin therapy., Methods: The study population comprised 1203 people with Type 2 diabetes included in the Hoorn Diabetes Care System (n = 9849). Inclusion criteria were: age ≥ 40 years; initiation of insulin during follow-up after failure to reach HbA1c levels ≤ 53 mmol/mol (7%) with oral glucose-lowering agents; and a follow up ≥ 2 years after initiating insulin. Latent class growth modelling was used to identify trajectories of HbA1c . Subjects considered to be 'off target' had HbA1c levels ≥ 53 mmol/mol (7.0%) during one-third or more of the follow-up time, and those considered to be 'on target' had HbA1c levels ≥ 53 mmol/mol (7.0%) during less than one-third of the follow-up time., Results: Four HbA1c trajectories were identified. Most people (88.7%) were classified as having a stable HbA1c trajectory of ~57 mmol/mol (7.4%). Only 24.4% of the people were on target in response to insulin; this was associated with lower HbA1c levels and a higher age at the start of insulin treatment., Conclusions: Using latent class growth modelling, four HbA1c trajectories were identified. A quarter of the people starting insulin were on target. Low HbA1c levels and advanced age at the start of insulin therapy were associated with better response to insulin therapy. Initiating insulin earlier improves the likelihood of achieving and sustaining glycaemic control., (© 2016 Diabetes UK.)

Objective: The aim of this study was to assess the time to insulin initiation in type 2 diabetes mellitus (T2DM) patients treated with oral glucose-lowering agents and to determine the baseline characteristics associated with time to insulin initiation. This was evaluated in T2DM patients with HbA1c levels consistently ≥7.0% during total follow up and in those with fluctuating HbA1c levels around 7.0%., Design and Methods: Prospective, observational study was performed, comprising 2418 persons with T2DM aged ≥40 years who entered the Diabetes Care System between 1998 and 2012 with a minimum follow up of at least 3 years, following the first HbA1c level ≥7.0%. Cox regression analyses were performed to assess the determinants of time to insulin initiation. Data related to long-term effects of insulin initiation were studied at baseline and at the end of follow up using descriptive summary statistics., Results: Two-thirds of the patients initiated insulin during follow up. The time to insulin varied from 1.2 years (range 0.3-3.1) in patients with HbA1c levels consistently ≥7.0% to 5.4 years (range 3.0-7.5) in patients with fluctuating HbA1c levels around 7.0%. Longer diabetes duration (hazard ratio (HR) 1.04 95% CI 1.03-1.05) and lower age (HR 1.00 95% CI 0.99-1.00) at baseline were associated with a shorter time to initiation. More insulin initiators had retinopathy compared with patients that remained on oral glucose-lowering agents during follow up., Conclusion: The time to insulin initiation was short, and most of the patients with HbA1c levels consistently ≥7.0% were initiating insulin. Longer diabetes duration and younger age shortened the time to insulin., (© 2016 European Society of Endocrinology.)

Aims: Modulation of dopamine receptor D2 (DRD2) activity affects insulin secretion in both rodents and isolated pancreatic β-cells. We hypothesized that single nucleotide polymorphisms in the DRD2/ANKK1 locus may affect susceptibility to type 2 diabetes in humans., Methods: Four potentially functional variants in the coding region of the DRD2/ANKK1 locus (rs1079597, rs6275, rs6277, rs1800497) were genotyped and analysed for type 2 diabetes susceptibility in up to 25 000 people (8148 with type 2 diabetes and 17687 control subjects) from two large independent Dutch cohorts and one Danish cohort. In addition, 340 Dutch subjects underwent a 2-h hyperglycaemic clamp to investigate insulin secretion. Since sexual dimorphic associations related to DRD2 polymorphisms have been previously reported, we also performed a gender-stratified analysis., Results: rs1800497 at the DRD2/ANKK1 locus was associated with a significantly increased risk for type 2 diabetes in women (odds ratio 1.14 (1.06-1.23); P = 4.1*10⁴) but not in men (odds ratio 1.00 (95% CI 0.93-1.07); P = 0.92) or the combined group. Although rs1800497 was not associated with insulin secretion, we did find another single nucleotide polymorphism in this locus, rs6275, to be associated with increased first-phase glucose-stimulated insulin secretion in women (P = 5.5*10⁴) but again not in men (P = 0.34)., Conclusion: The present data identify DRD2/ANKK1 as a potential sex-specific type 2 diabetes susceptibility gene., (© 2014 The Authors. Diabetic Medicine © 2014 Diabetes UK.)

Context: Single-nucleotide polymorphisms (SNPs) within the G6PC2 locus are associated with fasting glucose and insulin secretion. These SNPs are not associated with type 2 diabetes risk., Objective: Our objective was to investigate whether the impact of the SNP on variables of glucose-stimulated insulin secretion is influenced by glucose tolerance status., Design, Setting, Participants, and Intervention: In this cross-sectional study, we genotyped 1505 healthy Caucasian subjects [normal glucose tolerance (NGT), 1098; impaired glucose tolerance (IGT)/impaired fasting glucose (IFG), 407] for SNP rs560887 within the G6PC2 locus. A subgroup of 326 subjects underwent an iv glucose tolerance test, and 512 participants took part in a hyperinsulinemic-euglycemic clamp. For replication, SNP rs560887 was genotyped in 457 subjects (NGT, 265; IGT, 192) from four independent German and Dutch studies who underwent a hyperglycemic clamp., Main Outcome Measure: Insulin secretion was evaluated., Results: Carriers of the major G-allele exhibited increased fasting glycemia (P<0.0001). Insulin sensitivity and secretion were not associated with the SNP (P≥0.06). Glucose tolerance status and genotype interacted on insulin secretion (P=0.036), such that in NGT subjects, the minor A-allele of rs560887 was associated with decreased insulinogenic index (P=0.044), which was not the case in subjects with IFG/IGT (P=1.0). During the iv glucose tolerance test, an association of A-allele carriers with decreased first-phase insulin secretion was also observed only in NGT subjects (P=0.0053). Likewise, in the hyperglycemic clamp group, the A-allele was associated with decreased first-phase insulin secretion only in the NGT group (P=0.022) but not in the IGT group., Conclusions: The effects of hyperglycemia on insulin secretion override the more subtle effects of genetic variation in the G6PC2 locus on insulin secretion.

Objective: The objective of the present study was to investigate the effects of one-year treatment with exenatide or Insulin Glargine, followed by a 5-week off-drug period, on postprandial lipidaemia, glycaemia and measures of oxidative stress., Methods: Sixty-nine metformin-treated patients with type 2 diabetes were randomised (using apermuted block randomisation scheme stratified by site and baseline HbA(1c) stratum (< or = 8.5% or >8.5%) of which 60 completed (exenatide n=30; Insulin Glargine n=30) the pre-treatment and on-drug meal test. Postprandial glucose, lipids and lipoproteins, and oxidative stress markers were studied at week -1, 51, and after a 5-week off-drug period following a breakfast and lunch mixed-meal containing 50 g fat, 75 g carbohydrates, and 35 g protein., Results: 51-Week exenatide treatment resulted in a significant reduction of prandial glucose, triglycerides, apo-B48, calculated VLDL-C, FFA and MDA excursions whereas Insulin Glargine predominantly reduced fasting glucose, FFA and MDA. Changes in markers of oxidative stress were related to changes in postprandial glucose and triglyceride excursions, independent of treatment arm. All postprandial measures returned to pre-treatment values in both groups after 5-week cessation of study treatment., Conclusion: Exenatide showed beneficial effects on postprandial glycaemia and lipidaemia, and these effects were related to changes in the oxidative stress markers MDA and oxLDL during one year of treatment as compared to Insulin Glargine. Following cessation of both exenatide and Insulin Glargine measures returned to pre-treatment values, suggesting that ongoing treatment is necessary to maintain the beneficial effects of either therapy., (Copyright 2010. Published by Elsevier Ireland Ltd.)

Aims: Self-monitoring of blood glucose (SMBG) is an important self-management tool for insulin-treated patients with Type 2 diabetes mellitus (T2DM). Its value in estimating glycaemic control in insulin-treated T2DM patients remains unclear. The relationship between glycated haemoglobin (HbA(1c)) and SMBG measures in T2DM patients treated with premixed insulin lispro mixtures or basal insulin glargine was examined., Methods: HbA(1c) and plasma equivalent glucose (PGe) data derived from SMBG profiles were pooled from five randomized clinical trials of patients with T2DM on one or more oral glucose-lowering medication +/- 0-2 insulin injections per day switching to insulin lispro mixtures (N = 317) or glargine (N = 306). Patients generated seven-point SMBG profiles three times in a 2-week period prior to each HbA(1c) measurement. Pearson's correlation coefficients (r) were calculated for PGe values and HbA(1c). Receiver-operating characteristic (ROC) curves determined the ability of sets of PGe to estimate HbA(1c) (< or > 7.0%)., Results: Mean +/- standard deviation age was 57.5 +/- 9.5 years, body mass index 31.3 +/- 5.6 kg/m(2), 52.5% were male and HbA(1c) overall was 7.4 +/- 1.0% at end-point. Among individual SMBG measures, r for HbA(1c) ranged from 0.34 to 0.49. For means of two or more PGe measures, r for HbA(1c) ranged from 0.51 to 0.59. Correlations were similar for either regimen. ROC curves were consistent with the correlation data., Conclusions: These data provide patients and clinicians information on the relationship between HbA(1c) and SMBG measurements in patients with T2DM, and support the value of frequent blood glucose measurements for assessing overall glycaemic control.

Background: Results of intervention studies in patients with type 2 diabetes have led to concerns about the safety of aiming for normal blood glucose concentrations. We assessed survival as a function of HbA(1c) in people with type 2 diabetes., Methods: Two cohorts of patients aged 50 years and older with type 2 diabetes were generated from the UK General Practice Research Database from November 1986 to November 2008. We identified 27 965 patients whose treatment had been intensified from oral monotherapy to combination therapy with oral blood-glucose lowering agents, and 20 005 who had changed to regimens that included insulin. Those with diabetes secondary to other causes were excluded. All-cause mortality was the primary outcome. Age, sex, smoking status, cholesterol, cardiovascular risk, and general morbidity were identified as important confounding factors, and Cox survival models were adjusted for these factors accordingly., Findings: For combined cohorts, compared with the glycated haemoglobin (HbA(1c)) decile with the lowest hazard (median HbA(1c) 7.5%, IQR 7.5-7.6%), the adjusted hazard ratio (HR) of all-cause mortality in the lowest HbA(1c) decile (6.4%, 6.1-6.6) was 1.52 (95% CI 1.32-1.76), and in the highest HbA(1c) decile (median 10.5%, IQR 10.1-11.2%) was 1.79 (95% CI 1.56-2.06). Results showed a general U-shaped association, with the lowest HR at an HbA(1c) of about 7.5%. HR for all-cause mortality in people given insulin-based regimens (2834 deaths) versus those given combination oral agents (2035) was 1.49 (95% CI 1.39-1.59)., Interpretation: Low and high mean HbA(1c) values were associated with increased all-cause mortality and cardiac events. If confirmed, diabetes guidelines might need revision to include a minimum HbA(1c) value., Funding: Eli Lilly and Company., (Copyright 2010 Elsevier Ltd. All rights reserved.)

Objective: At least 20 type 2 diabetes loci have now been identified, and several of these are associated with altered beta-cell function. In this study, we have investigated the combined effects of eight known beta-cell loci on insulin secretion stimulated by three different secretagogues during hyperglycemic clamps., Research Design and Methods: A total of 447 subjects originating from four independent studies in the Netherlands and Germany (256 with normal glucose tolerance [NGT]/191 with impaired glucose tolerance [IGT]) underwent a hyperglycemic clamp. A subset had an extended clamp with additional glucagon-like peptide (GLP)-1 and arginine (n = 224). We next genotyped single nucleotide polymorphisms in TCF7L2, KCNJ11, CDKAL1, IGF2BP2, HHEX/IDE, CDKN2A/B, SLC30A8, and MTNR1B and calculated a risk allele score by risk allele counting., Results: The risk allele score was associated with lower first-phase glucose-stimulated insulin secretion (GSIS) (P = 7.1 x 10(-6)). The effect size was equal in subjects with NGT and IGT. We also noted an inverse correlation with the disposition index (P = 1.6 x 10(-3)). When we stratified the study population according to the number of risk alleles into three groups, those with a medium- or high-risk allele score had 9 and 23% lower first-phase GSIS. Second-phase GSIS, insulin sensitivity index and GLP-1, or arginine-stimulated insulin release were not significantly different., Conclusions: A combined risk allele score for eight known beta-cell genes is associated with the rapid first-phase GSIS and the disposition index. The slower second-phase GSIS, GLP-1, and arginine-stimulated insulin secretion are not associated, suggesting that especially processes involved in rapid granule recruitment and exocytosis are affected in the majority of risk loci.

Aims/hypothesis: The aim of the present study was to estimate the heritability of the beta cell insulin response to glucose and to glucose combined with glucagon-like peptide-1 (GLP-1) or with GLP-1 plus arginine., Methods: This was a twin-family study that included 54 families from the Netherlands Twin Register. The participants were healthy twin pairs and their siblings of the same sex, aged 20 to 50 years. Insulin response of the beta cell was assessed by a modified hyperglycaemic clamp with additional GLP-1 and arginine. Insulin sensitivity index (ISI) was assessed by the euglycaemic-hyperinsulinaemic clamp. Multivariate structural equation modelling was used to obtain heritabilities and the genetic factors underlying individual differences in BMI, ISI and secretory responses of the beta cell., Results: The heritability of insulin levels in response to glucose was 52% and 77% for the first and second phase, respectively, 53% in response to glucose + GLP-1 and 80% in response to an additional arginine bolus. Insulin responses to the administration of glucose, glucose + GLP-1 and glucose + GLP-1 + arginine were highly correlated (0.62< r <0.79). Heritability of BMI and ISI was 74% and 60% respectively. The genetic factors that influenced BMI and ISI explained about half of the heritability of insulin levels in response to the three secretagogues. The other half was due to genetic factors specific to the beta cell., Conclusions/interpretation: In healthy adults, genetic factors explain most of the individual differences in the secretory capacity of the beta cell. These genetic influences are partly independent from the genes that influence BMI and ISI.

Objective: Traditional blood glucose-lowering agents do not sustain adequate glycemic control in most type 2 diabetic patients. Preclinical studies with exenatide have suggested sustained improvements in beta-cell function. We investigated the effects of 52 weeks of treatment with exenatide or insulin glargine followed by an off-drug period on hyperglycemic clamp-derived measures of beta-cell function, glycemic control, and body weight., Research Design and Methods: Sixty-nine metformin-treated patients with type 2 diabetes were randomly assigned to exenatide (n = 36) or insulin glargine (n = 33). beta-Cell function was measured during an arginine-stimulated hyperglycemic clamp at week 0, at week 52, and after a 4-week off-drug period. Additional end points included effects on glycemic control, body weight, and safety., Results: Treatment-induced change in combined glucose- and arginine-stimulated C-peptide secretion was 2.46-fold (95% CI 2.09-2.90, P < 0.0001) greater after a 52-week exenatide treatment compared with insulin glargine treatment. Both exenatide and insulin glargine reduced A1C similarly: -0.8 +/- 0.1 and -0.7 +/- 0.2%, respectively (P = 0.55). Exenatide reduced body weight compared with insulin glargine (difference -4.6 kg, P < 0.0001). beta-Cell function measures returned to pretreatment values in both groups after a 4-week off-drug period. A1C and body weight rose to pretreatment values 12 weeks after discontinuation of either exenatide or insulin glargine therapy., Conclusions: Exenatide significantly improves beta-cell function during 1 year of treatment compared with titrated insulin glargine. After cessation of both exenatide and insulin glargine therapy, beta-cell function and glycemic control returned to pretreatment values, suggesting that ongoing treatment is necessary to maintain the beneficial effects of either therapy.

Background/objective: Early insulin secretion following a meal is representative for normal physiology and may depend on meal composition. To compare the effects of a fat-rich and a carbohydrate-rich mixed meal on insulinogenic index as a measure of early insulin secretion in normoglycemic women (NGM) and in women with type 2 diabetes mellitus (DM2), and to assess the relationship of anthropometric and metabolic factors with insulinogenic index., Subjects/methods: Postmenopausal women, 76 with NGM and 64 with DM2, received a fat-rich meal and a carbohydrate-rich meal on separate occasions. Early insulin response was estimated as insulinogenic index ( big up tri, Deltainsulin(0-30 min)/ big up tri, Deltaglucose(0-30 min)) for each meal. Associations of fasting and postprandial triglycerides, body mass index, waist and hip circumference and alanine aminotransferase with insulinogenic indices were determined., Results: Women with NGM present with higher insulinogenic index than women with DM2. The insulinogenic index following the fat-rich meal ( big up tri, DeltaI(30)/ big up tri, DeltaG(30) (fat)) was higher than the index following the carbohydrate-rich meal (big up tri, DeltaI(30)/ big up tri, DeltaG(30) (CH)) (P<0.05 in women with DM2, and not significant in women with NGM). In women with DM2, homeostasis model assessment for insulin resistance was positively associated with big up tri, DeltaI(30)/ big up tri, DeltaG(30) (CH). In women with NGM, waist circumference was independently and inversely associated with big up tri, DeltaI(30)/ big up tri, DeltaG(30) (fat) and with big up tri, DeltaI(30)/ big up tri, DeltaG(30) (CH); hip circumference was positively associated with big up tri, DeltaI(30)/ big up tri, DeltaG(30) (fat)., Conclusions: The insulinogenic index following the fat-rich meal was higher than following the isocaloric carbohydrate-rich meal, which might favorably affect postprandial glucose excursions, especially in women with DM2. The association between a larger waist circumference and a lower meal-induced insulinogenic index in women with NGM requires further mechanistic studies.

Aims/hypothesis: Genome-wide association studies have recently identified novel type 2 diabetes susceptibility gene regions. We assessed the effects of six of these regions on insulin secretion as determined by a hyperglycaemic clamp., Methods: Variants of the HHEX/IDE, CDKAL1, SLC30A8, IGF2BP2 and CDKN2A/CDKN2B genes were genotyped in a cohort of 146 participants with NGT and 126 with IGT from the Netherlands and Germany, who all underwent a hyperglycaemic clamp at 10 mmol/l glucose., Results: Variants of CDKAL1 and IGF2BP2 were associated with reductions in first-phase insulin secretion (34% and 28%, respectively). The disposition index was also significantly reduced. For gene regions near HHEX/IDE, SLC30A8 and CDKN2A/CDKN2B we did not find significant associations with first-phase insulin secretion (7-18% difference between genotypes; all p > 0.3). None of the variants showed a significant effect on second-phase insulin secretion in our cohorts (2-8% difference between genotypes, all p > 0.3). Furthermore, the gene variants were not associated with the insulin sensitivity index., Conclusions: Variants of CDKAL1 and IGF2BP2 attenuate the first phase of glucose-stimulated insulin secretion but show no effect on the second phase of insulin secretion. Our results, based on hyperglycaemic clamps, provide further insight into the pathogenic mechanism behind the association of these gene variants with type 2 diabetes.

Context: In persons with impaired glucose tolerance (IGT), both impaired insulin secretion and insulin resistance contribute to the conversion to type 2 diabetes mellitus (T2DM). However, few studies have used criterion standard measures to asses the predictive value of impaired insulin secretion and insulin resistance for the conversion to T2DM in a Caucasian IGT population., Objectives: The objective of the study was to determine the predictive value of measures of insulin secretion and insulin resistance derived from a hyperglycemic clamp, including the disposition index, for the development of T2DM in a Caucasian IGT population., Design, Setting, and Participants: The population-based Hoorn IGT study consisted of 101 Dutch IGT subjects (aged < 75 yr), with mean 2-h plasma glucose values, of two separate oral glucose tolerance tests, between 8.6 and 11.1 mmol/liter. A hyperglycemic clamp at baseline was performed to assess first-phase and second-phase insulin secretion and insulin sensitivity. During follow-up, conversion to T2DM was assessed by means of 6-monthly fasting glucose levels and yearly oral glucose tolerance tests., Results: The cumulative incidence of T2DM was 34.7%. Hazard ratio for T2DM development adjusted for age, sex, and body mass index was 5.74 [95% confidence interval (CI) 2.60-12.67] for absence of first insulin peak, 1.58 (95% CI 0.60-4.17) for lowest vs. highest tertile of insulin sensitivity, and 1.78 (95% CI 0.65-4.88) for lowest vs. highest tertile of the disposition index., Conclusions: In these Caucasian persons with IGT, the absence of the first insulin peak was the strongest predictor of T2DM.

Aims: We quantified the occurrence and duration of nocturnal hypoglycaemia in individuals with Type 1 diabetes treated with continuous subcutaneous insulin infusion (CSII) or multiple-injection therapy (MIT) using a continuous subcutaneous glucose sensor., Methods: A microdialysis sensor was worn at home by 24 patients on CSII (mean HbA(1c) 7.8 +/- 0.9%) and 33 patients on MIT (HbA(1c) 8.7 +/- 1.3%) for 48 h. Occurrence and duration of nocturnal hypoglycaemia were assessed and using multivariate regression analysis, the association between HbA(1c), diabetes duration, treatment type (CSII vs. MIT), fasting and bedtime blood glucose values, total daily insulin dose and mean nocturnal glucose concentrations, and hypoglycaemia occurrence and duration was investigated., Results: Nocturnal hypoglycaemia < or = 3.9 mmol/l occurred in 33.3% of both the CSII- (8/24) and MIT-treated patients (11/33). Mean (+/- sd; median, interquartile range) duration of hypoglycaemia < or = 3.9 mmol/l was 78 (+/- 76; 57, 23-120) min per night for the CSII- and 98 (+/- 80; 81, 32-158) min per night for the MIT-treated group. Multivariate regression analysis showed that bedtime glucose value had the strongest association with the occurrence (P = 0.026) and duration (P = 0.032) of nocturnal hypoglycaemia., Conclusions: Microdialysis continuous glucose monitoring has enabled more precise quantification of nocturnal hypoglycaemia occurrence and duration in Type 1 diabetic patients. Occurrence and duration of nocturnal hypoglycaemia were mainly associated with bedtime glucose value.

Many patients with diabetes mellitus view subcutaneous injections of insulin as a daily burden. Pulmonary delivery of insulin offers an alternative route of administration and may as such improve diabetes treatment. Inhaled insulin provides a rapid absorption of insulin, but with low bioavailability. Phase III clinical trials in type 1 and type 2 diabetes have disclosed clinical equivalence between three inhaled insulin products (Exubera, AErx idMs, and hIIp) and regular human insulin, both in terms of glycaemic control and hypoglycaemic risk. Inhaled insulin cannot be used to replace basal insulin requirements. The most commonly reported adverse effects of inhaled insulin are cough and insulin antibody formation, the clinical significance of which is uncertain. No or minimal deterioration in pulmonary function parameters have been recorded, although studies were typically of short duration. Patients participating in inhaled insulin trials generally expressed satisfaction with the product and chose to remain on it. The availability of inhaled insulin may increase willingness in type 2 diabetic patients to consider insulin therapy. More studies of longer duration are required to determine (pulmonary) safety and cost-effectiveness of inhaled insulin, and to disclose which patients may benefit the most.

Good glycaemic control of diabetes mellitus is still hampered by the fear of insulin injections. Particularly in patients with type 2 diabetes, inhaled insulin as a novel therapeutic option for glycaemic control could be an alternative to subcutaneous insulin. Phase III clinical studies have shown glycaemic equivalence between inhaled insulin and conventional subcutaneous insulin. However, no study comparing inhaled insulin with short-acting insulin analogues has yet been published. Thus, methodological problems preclude conclusive remarks concerning quality-of-life issues. Inhaled insulin should be reserved for selected patient groups only. Lengthier studies to evaluate the long-term (pulmonary) safety of inhaled insulin and a cost-effectiveness study are needed.

The attainment and maintenance of good glycaemic control in both type 1 and type 2 diabetes are major challenges. The main (perceived) barriers of therapy are poor compliance with prescribed medication, hypoglycaemia, fear of insulin injection and fear of self-testing by finger pricking. Another major issue is the acceptance and uptake of new insulin-delivery systems and routes of administration. Insulin therapy regimens and insulin preparations are nowadays often chosen because of the ease of delivery. The use of inhaled insulin may, because of the relative ease of administration, facilitate the transfer of type 2 diabetes patients from tablets to insulin, especially in patients with fear or phobia of needles. However, non-injectable insulin will not automatically be preferred to subcutaneous (SC) insulin injections and a proper assessment of patient acceptance and preference is of great importance. Recent studies suggest that patients may prefer inhaled insulin (Exubera) over SC insulin. Thus, the availability of inhaled insulin as a potential treatment may increase a patient's willingness to add or change to more appropriate diabetes therapy, which includes insulin. Future studies should be targeted at specific groups of patients who may benefit the most from inhaled insulin, such as those with type 2 diabetes who are delaying initiation or intensification of insulin injections.

Background: Physicians may use either insulin or exenatide injections for patients with type 2 diabetes mellitus who have poor glycemic control despite taking oral blood glucose-lowering drugs., Objective: To compare effects of exenatide and insulin glargine on glycemic control in patients with type 2 diabetes mellitus that is suboptimally controlled with metformin and a sulfonylurea., Design: 26-week multicenter, open-label, randomized, controlled trial., Setting: 82 outpatient study centers in 13 countries., Patients: 551 patients with type 2 diabetes and inadequate glycemic control (defined as hemoglobin A1c level ranging from 7.0% to 10.0%) despite combination metformin and sulfonylurea therapy., Intervention: Exenatide, 10 microg twice daily, or insulin glargine, 1 daily dose titrated to maintain fasting blood glucose levels of less than 5.6 mmol/L (<100 mg/dL)., Measurements: Hemoglobin A1c level, fasting plasma glucose level, body weight, 7-point self-monitored blood glucose, standardized test-meal challenge, safety, and tolerability., Results: Baseline mean hemoglobin A1c level was 8.2% for patients receiving exenatide and 8.3% for those receiving insulin glargine. At week 26, both exenatide and insulin glargine reduced hemoglobin A1c levels by 1.11% (difference, 0.017 percentage point [95% CI, -0.123 to 0.157 percentage point]). Exenatide reduced postprandial glucose excursions more than insulin glargine, while insulin glargine reduced fasting glucose concentrations more than exenatide. Body weight decreased 2.3 kg with exenatide and increased 1.8 kg with insulin glargine (difference, -4.1 kg [CI, -4.6 to -3.5 kg]). Rates of symptomatic hypoglycemia were similar, but nocturnal hypoglycemia occurred less frequently with exenatide (0.9 event/patient-year versus 2.4 events/patient-year; difference, -1.6 events/patient-year [CI, -2.3 to -0.9 event/patient year]). Gastrointestinal symptoms were more common in the exenatide group than in the insulin glargine group, including nausea (57.1% vs. 8.6%), vomiting (17.4% vs. 3.7%) and diarrhea (8.5% vs. 3.0%)., Limitations: The trial was open-label and did not assess clinical complications related to diabetes. Of the 551 participants, 19.4% of those receiving exenatide and 9.7% of those receiving insulin glargine withdrew from the study. Only 21.6% of the insulin glargine group and 8.6% of the exenatide group achieved the target level for fasting plasma glucose of less than 5.6 mmol/L (<100 mg/dL)., Conclusions: Exenatide and insulin glargine achieved similar improvements in overall glycemic control in patients with type 2 diabetes that was suboptimally controlled with oral combination therapy. Exenatide was associated with weight reduction and had a higher incidence of gastrointestinal adverse effects than insulin glargine.

Aims/hypothesis: Diabetic cardiomyopathy (DCM) is common in type 2 diabetes. In DCM, insulin resistance may alter cardiac substrate supply and utilisation leading to changes in myocardial metabolism and cardiac function. In rats, exposure to excessive alimentary fat, inducing a type 2 diabetic phenotype, may result in myocardial insulin resistance and cardiac functional changes resembling DCM., Materials and Methods: Rats received high-fat (HFD) or low-fat (LFD) diets for 7 weeks. Prior to killing, insulin or saline was injected i.p. Contractile function and insulin signalling were assessed in papillary muscles and ventricular lysates, respectively., Results: Fasting and post-load blood glucose levels were increased in HFD- vs LFD-rats (all p < 0.02). Mean heart weight, but not body weight, was increased in HFD-rats (p < 0.01). HFD-hearts showed structural changes and triglyceride accumulation. HFD-muscles developed higher baseline and maximum forces, but showed impaired recovery from higher workloads. Insulin-associated modulation of Ca2+-induced force augmentation was abolished in HFD-muscles. HFD reduced insulin-stimulated IRS1-associated phosphatidylinositol 3'-kinase activity and phosphorylation of protein kinase B, glycogen synthase kinase-3beta, endothelial nitric oxide synthase, and forkhead transcription factors by 40-60% (all p < 0.05). Insulin-mediated phosphorylation of phospholamban, a critical regulator of myocardial contractility, was decreased in HFD-hearts (p < 0.05)., Conclusions/interpretation: HFD induced a hypertrophy-like cardiac phenotype, characterised by a higher basal contractile force, an impaired recovery from increased workloads and decreased insulin-mediated protection against Ca2+ overload. Cardiac dysfunction was associated with myocardial insulin resistance and phospholamban hypophosphorylation. Our data suggest that myocardial insulin resistance, resulting from exposure to excessive alimentary fat, may contribute to the pathogenesis of diabetes-related heart disease.

Objective: Rapid-acting insulin analogs (insulin lispro and insulin aspart) have emerged as the meal insulin of choice in both multiple daily insulin injection (MDII) therapy and continuous subcutaneous insulin infusion (CSII) for type 1 diabetes. Thus, a comparison of efficacy between CSII and MDII should be undertaken only in studies that used rapid-acting analogs for both intensive regimens., Research Design and Methods: We performed a pooled analysis of the randomized controlled trials that compared CSII and optimized MDII therapy using rapid-acting analogs in adults with type 1 diabetes., Results: The three studies that met inclusion criteria provided data on 139 patients, representing 596 patient-months for CSII and 529 patient-months for MDII. Mean age was 38.5 years, with duration of diabetes of 18.0 years. The studies differed significantly in mean baseline A1c (7.95, 8.20, and 9.27%). The pooled estimate of treatment effect comparing the percentage reduction in A1c by CSII with that by MDII (CSII - MDII) was 0.35% (95% CI -0.10 to 0.80, P = 0.08) using a random effect to account for heterogeneity between studies. Importantly, the interaction between baseline A1c and treatment modality emerged as an independent predictor of treatment effect (CSII - MDII) (P = 0.002). The relative benefit of CSII over MDII was found to increase with higher baseline A1c. A model derived from these data predicts that in a patient with a baseline A1c of 10%, CSII would reduce the A1c by an additional 0.65% compared with MDII. Conversely, there would be no A1c benefit of CSII compared with MDII if baseline A1c were 6.5%. There was no significant difference between CSII and MDII in the rate of hypoglycemic events., Conclusions: When using rapid-acting insulin analogs in CSII and MDII regimens in adult patients with type 1 diabetes, insulin pump therapy is associated with better glycemic control, particularly in those individuals with higher baseline A1c. Thus, CSII emerges as an important modality for implementing intensive therapy and may be uniquely advantageous in patients with poor glycemic control.

IGFs are important regulators of pancreatic beta-cell development, growth, and maintenance. Mutations in the IGF genes have been found to be associated with type 2 diabetes, myocardial infarction, birth weight, and obesity. These associations could result from changes in insulin secretion. We have analyzed glucose-stimulated insulin secretion using hyperglycemic clamps in carriers of a CA repeat in the IGF-I promoter and an ApaI polymorphism in the IGF-II gene. Normal and impaired glucose-tolerant subjects (n = 237) were independently recruited from three different populations in the Netherlands and Germany to allow independent replication of associations. Both first- and second-phase insulin secretion were not significantly different between the various IGF-I or IGF-II genotypes. Remarkably, noncarriers of the IGF-I CA repeat allele had both a reduced insulin sensitivity index (ISI) and disposition index (DI), suggesting an altered balance between insulin secretion and insulin action. Other diabetes-related parameters were not significantly different for both the IGF-I and IGF-II gene variant. We conclude that gene variants in the IGF-I and IGF-II genes are not associated with detectable variations in glucose-stimulated insulin secretion in these three independent populations. Further studies are needed to examine the exact contributions of the IGF-I CA repeat alleles to variations in ISI and DI.

Mutations in mitochondrial DNA (mtDNA) associate with various disease states. A few mtDNA mutations strongly associate with diabetes, with the most common mutation being the A3243G mutation in the mitochondrial DNA-encoded tRNA(Leu,UUR) gene. This article describes clinical characteristics of mitochondrial diabetes and its molecular diagnosis. Furthermore, it outlines recent developments in the pathophysiological and molecular mechanisms leading to a diabetic state. A gradual development of pancreatic beta-cell dysfunction upon aging, rather than insulin resistance, is the main mechanism in developing glucose intolerance. Carriers of the A3243G mutation show during a hyperglycemic clamp at 10 mmol/l glucose a marked reduction in first- and second-phase insulin secretion compared with noncarriers. The molecular mechanism by which the A3243G mutation affects insulin secretion may involve an attenuation of cytosolic ADP/ATP levels leading to a resetting of the glucose sensor in the pancreatic beta-cell, such as in maturity-onset diabetes of the young (MODY)-2 patients with mutations in glucokinase. Unlike in MODY2, which is a nonprogressive form of diabetes, mitochondrial diabetes does show a pronounced age-dependent deterioration of pancreatic function indicating involvement of additional processes. Furthermore, one would expect that all mtDNA mutations that affect ATP synthesis lead to diabetes. This is in contrast to clinical observations. The origin of the age-dependent deterioration of pancreatic function in carriers of the A3243G mutation and the contribution of ATP and other mitochondrion-derived factors such as reactive oxygen species to the development of diabetes is discussed.

Objective: Epidemiological studies suggest that moderate alcohol consumers have enhanced insulin sensitivity and a reduced risk of type 2 diabetes. Adiponectin, an adipocyte-derived plasma protein, has been found to be negatively associated with adiposity and positively associated with insulin sensitivity. Moderate alcohol consumption may increase adiponectin, which in turn causes a decrease of tumor necrosis factor (TNF)-alpha. A decreased TNF-alpha level may consequently increase insulin sensitivity., Research Design and Methods: To test this hypothesis, we performed a randomized crossover partially diet-controlled study. A total of 23 healthy middle-aged male subjects consumed daily four glasses of whisky (40 g ethanol) or tap water with dinner during two successive periods of 17 days., Results: Moderate alcohol consumption increased plasma adiponectin level (11%; P = 0.0002) but did not affect plasma TNF-alpha level. An increase in insulin sensitivity index was observed in an insulin-resistant subgroup (21%; P = 0.11), which positively correlated with the relative alcohol-induced increase in plasma adiponectin level (r = 0.73, P = 0.02)., Conclusions: The experimental results are in agreement with observational data. Moderate alcohol consumption improved insulin sensitivity in relatively insulin-resistant middle-aged men, an effect that may be mediated through alcohol-induced increases in adiponectin.

Insulin secretion and sensitivity was studied in 28 prepubertal children born small for gestational age (SGA) and in 22 prepubertal children born appropriate for gestational age (AGA). The effect of body size during childhood was also assessed. Insulin sensitivity was measured using the hyperinsulinemic-euglycemic clamp (M value), and beta-cell function was studied with the hyperglycemic clamp plus arginine. First-phase insulin response (FIR) was used to calculate the disposition index (FIR x M value). Arginine-stimulated second-phase insulin response was used as a measure of beta-cell capacity. DeltaBMI(0-1 year), DeltaBMI(0-2 years), and DeltaBMI(2-9 years) were classified in tertiles. SGA children were less insulin sensitive than AGA children (P = 0.009). beta-Cell capacity and disposition indexes were similar in the two groups. In SGA children, M values were lower in the tertile with the highest DeltaBMI(2-9 years) than in the tertile with the lowest DeltaBMI(2-9 years) (P = 0.01). No association between DeltaBMI(0-2 years) and decreased insulin sensitivity was found. In conclusion, prepubertal SGA children show decreased insulin sensitivity rather than decreased beta-cell capacity. Interventions to improve fetal growth and prevent overweight after the second year of life appear to be important factors in the prevention of type 2 diabetes in children born SGA.

Aims: Insulin aspart has been shown to improve post-prandial and overall glycaemic control in people with Type 1 diabetes. We hypothesized that insulin aspart with intensified basal NPH insulin supplementation would result in better overall glycaemic control than human regular insulin with standard basal NPH insulin., Methods: The trial was conducted in 43 centres in seven countries. People with Type 1 diabetes were randomized to mealtime insulin aspart with up to four daily NPH doses if meals were > 5 h apart and a 25% increase in bedtime NPH dose (n = 187), or to mealtime human unmodified insulin with once or twice daily basal NPH insulin (n = 181). Efficacy and safety were evaluated at 12 weeks (primary evaluation period) and 64 weeks., Results: At 12 and 64 weeks there was no statistically significant difference in HbA1c between the insulin aspart and regular insulin groups: -0.09 (95% confidence interval (CI) -0.23, +0.05)% and -0.14 (-0.32, +0.04)%. Post-prandial glucose values were lower and the area under the 24-h self-monitored blood glucose curve above 7.0 mmol/l was 28% smaller with insulin aspart (35.2 +/- 3.2 vs. 48.9 +/- 3.1 mmol/l h, P = 0.0015). No significant differences were found in mild or severe hypoglycaemia, or adverse event rate. At 64 weeks treatment satisfaction was higher in the insulin aspart group (difference 1.57 (95% CI 0.49, 2.64) points, P = 0.004), while quality of life was not different., Conclusions: Improved post-prandial glycaemic control and treatment satisfaction with insulin aspart were confirmed. Intensifying basal insulin supplementation resulted in a similar HbA1c decrement as previously found with the use of insulin aspart and standard NPH insulin supplementation. This does not support routinely basal NPH insulin intensification when using rapid-acting insulin analogues in daily practice.

Objective: To assess in a randomized crossover trial the efficacy of continuous subcutaneous insulin infusion in improving glycemic control and health-related quality of life in type 1 diabetic patients with long-standing poor glycemic control., Research Design and Methods: A total of 79 patients in 11 Dutch centers were randomized to 16 weeks of continuous subcutaneous insulin infusion followed by 16 weeks intensive injection therapy or the reverse order. Glycemic control was assessed by HbA(1c), self-reported hypoglycemic events, and blood glucose memory meter read outs. Changes in quality of life were assessed by self-report questionnaires administered at baseline and 16 weeks., Results: As the drop-out rate after crossover was high (17 of 79 patients [22%]), we analyzed the trial as a parallel clinical trial, using data of the first half of the crossover phase only. At 16 weeks, mean HbA(1c) was 0.84% (95% CI -1.31 to -0.36) lower in the continuous subcutaneous insulin infusion group compared with the insulin injection group (P = 0.002). Stability of blood glucose self-measurement values, expressed as SD of the nine-point blood glucose profiles, improved in the insulin pump group by 29.3 +/- 41.1 vs. 8.2 +/- 36.5% in the injection group (P = 0.039). The number of mild hypoglycemic episodes per patient-week was 0.99 (95% CI 0.11-1.87) higher in the insulin pump group (P = 0.028). Weight gain was similar in both groups. Scores on the Short-Form 36-Item subscales 'general health' and 'mental health' improved in the continuous subcutaneous insulin infusion group, compared with stable values in the injection group (P = 0.048 and 0.050, respectively)., Conclusions: Continuous subcutaneous insulin infusion improves glycemic control and some aspects of health-related quality of life in patients with a history of long-term poor glycemic control.

An association between type 2 diabetes and genetic variation in the KIR6.2 gene has been reported in several populations. Based on in vitro studies with cell lines expressing the Glu(23)Lys (E23K) mutation, it was recently suggested that this mutation might result in altered insulin secretion. We have examined glucose-stimulated insulin secretion in relation to this KIR6.2 gene variant in two independent Dutch cohorts. Subjects with normal (n = 65) or impaired (n = 94) glucose tolerance underwent 3-h hyperglycemic clamps at 10 mmol/l glucose. We did not observe significant differences in first- or second-phase insulin secretion between carriers and noncarriers of the gene variant in either of the study populations (all P > 0.45). Furthermore, we found no evidence for a significant interaction with disease-associated gene variants in the sulfonylurea receptor (SUR1) gene. We conclude that the E23K mutation in the KIR6.2 gene is not associated with detectable alterations in glucose-stimulated insulin secretion in two independent populations from the Netherlands.

Associations between type 2 diabetes (and/or parameters contributing to glucose homeostasis) and genetic variation in the genes encoding insulin receptor substrate (IRS)-1 and -2 have been reported in several populations. Recently, it has been reported that the Gly(972)Arg variant in IRS-1 was associated with reduced insulin secretion during hyperglycemic clamps in German subjects with normal glucose tolerance. We have examined glucose-stimulated insulin secretion in relation to gene variants in the IRS-1 (Gly(972)Arg) and IRS-2 (Gly(1057)Asp) genes in two Dutch cohorts. Subjects with normal (n = 64) or impaired (n = 94) glucose tolerance underwent 3-h hyperglycemic clamps at 10 mmol/l glucose. All subjects were genotyped for the IRS-1 and IRS-2 variants by PCR-RFLP--based methods. We did not observe any significant difference in both first- and second-phase insulin secretion between carriers and noncarriers of both gene variants, nor was there evidence for an association with other diabetes-related parameters. We conclude that the common gene variants in IRS-1 and IRS-2 are not associated with altered glucose-stimulated insulin secretion in two populations from the Netherlands.

Objective: Assessing whether the initiation of insulin therapy in patients with diabetes mellitus type 2 can be delivered as effectively in a structured transmural care model as in the more usual outpatients structure., Design: Retrospective comparative cohort study., Method: In 1997 data were collected from 52 patients with diabetes mellitus type 2 all of whom were above 40 years of age and transferred to insulin therapy in 1993: 25 in a transmural care setting and 27 in an outpatients setting, both in Amsterdam, the Netherlands. Both groups were treated according to one protocol concerning the initiation and monitoring of insulin therapy, treatment goals and follow-up. Outcome measures were: percentage of glycated haemoglobin (HbA1c), health status, self-care behaviour and patient satisfaction. In 1993 the mean age was (transmural/outpatients setting): 67.5/65.3 years; percentage of men: 32%/48%; mean duration of diabetes: 7.3/10.6 years; HbA1c: 9.1%/9.3%; mean body mass index: 27.4/29.1 kg/m2., Results: In the period 1993-1997 the mean HbA1c decreased from 9.1% to 7.2% in the transmural care group and from 9.3% to 7.6% in the outpatients care group (both: p = 0.000). The percentage of patients with poor glycaemic control (HbA1c > 8%) decreased from 60 to 8 in the transmural care group and from 59 to 15 in the outpatients care group. The percentage of patients with good glycaemic control (HbA1c < 7%) increased from 4 to 52 in the transmural care group and from 11 to 30 in the outpatients care group. No statistically significant differences were found between the patient groups with respect to health status, self-care behaviour and patient satisfaction., Conclusion: The transfer of patients with diabetes mellitus type 2 insulin therapy in a shared care setting was at least as effective as in an outpatients setting.

Objective: To examine psychological functioning and self-management behaviours of Dutch adult patients with insulin-requiring diabetes mellitus suffering from extreme fear of self-injecting (FSI) and/or fear of self-testing (FST)., Methods: A cross-sectional survey was performed in a sample of insulin-treated diabetes patients (n=1275; 51.1% male; age 49.7+/-15.8 years; 58.0% Type 1 diabetes), assessing FSI and FST. Patients completed the questionnaires concerning trait/state anxiety, depression, fear of hypoglycemia, diabetes-related distress, diabetes self-care activities, and general well-being. Comparisons were made on these measures between patients with extremely high scores on FSI and/or FST (> or = 95th percentile) and the other patients. Patients with extreme scores on FSI and/or FST were invited to take part in a second survey to assess the prevalence of major depression, common fears/phobias, and psychoneuroticism., Results: People with extreme FSI/ FST scores, as compared to the other patients, reported higher levels of trait/state anxiety and depression. This group also reported more fear of hypoglycaemia and diabetes-related distress, had lower levels of general well-being, and reported less frequent self-monitoring of blood glucose. The second survey showed 11.1% of patients with extreme FSI/FST reporting scores indicating major depression. Prevalence of scores greater than or equal to the high scores on phobias (38.0-63.3%) and psychoneuroticism (27.8%) were consistently higher than norm group prevalences., Discussion: Extreme levels of FSI and/or FST are associated with high diabetes-related distress, poor general well-being, and psychological comorbidity, as well as poorer adherence to the diabetes treatment regimen. It is concluded that patients with extreme FSI/FST are often burdened with more than this specific phobia.

High levels of TSH are associated with an increased cardiovascular risk. Many cardiovascular risk factors cluster within the insulin resistance syndrome. It is not known whether levels of TSH cluster as well. We conducted this research to test the hypothesis that TSH, insulin sensitivity, and levels of low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) are interdependent in euthyroid subjects. Levels of TSH, free thyroid hormone, and serum lipids were measured in fasting serum samples taken before performance of a hyperinsulinemic euglycemic clamp to assess insulin sensitivity in 46 healthy euthyroid subjects with a mean TSH of 1.8 +/- 0.7 mU/L. Significant age- and sex-adjusted partial correlations of TSH with LDL-C (r = 0.48; P < 0.01) and HDL-C (r = -0.36; P < 0.05) were observed. TSH was not significantly correlated with insulin sensitivity or fasting triglyceride concentrations. In line with these results, we found the associations of TSH with LDL-C and HDL-C to be independent of insulin sensitivity. However, we observed significant effect-modification of the association of TSH with LDL-C by insulin sensitivity (P = 0.02). This effect-modification implies a range of associations of TSH with LDL-C that varies from absent in insulin-sensitive subjects to strongly positive in insulin-resistant subjects. We conclude that the increased cardiovascular risk associated with subclinical hypothyroidism seems to extend itself into the normal range of thyroid function. Importantly, the effect-modification of the association of TSH with LDL-C by insulin sensitivity suggests that insulin-resistant subjects are most susceptible to this increased risk.

Objective: To study the psychometric properties of the Diabetes Fear of Injecting and Self-Testing Questionnaire (D-FISQ)., Research Design and Methods: Two groups of patients were studied. Sample A consisted of 252 insulin-treated diabetes patients. Sample B incorporated 24 insulin-treated patients with high scores (> or = 95th percentile) on the D-FISQ. Test-retest correlations were assessed in both samples. Discriminant and convergent validity of the D-FISQ were assessed with questionnaires concerning fear of hypoglycemia, trait anxiety, and fear of bodily injury, illness, or death. To evaluate criterion-related validity, sample B participated in a behavioral avoidance test (BAT), in which the current level of avoidance of either self-injecting or self-testing was determined. Exploratory factor analysis (EFA) was performed to study whether 2 factors (fear of self-injecting [FSI] and fear of self-testing [FST]) could be detected., Results: Test-retest correlations ranged from 0.50 to 0.68 (P < 0.001). Correlations between D-FISQ and fear of hypoglycemia, trait anxiety, and fear of bodily injury, illness, or death ranged from 0.28 to 0.45 (P < 0.001). Patients who refused to do a BAT for self-injecting or self-testing had higher scores on FSI (P = 0.095) and FST (P = 0.01). EFA yielded 2 separate factors, FSI and FST., Conclusions: Results from this study support reliability and validity of the D-FISQ, a self-report instrument that can be used for both clinical and research purposes.

Objective: To investigate the effects of a multiple injection regimen with a mixture of 75% lispro and 25% intermediate-acting insulin (lispro high mixture [HM]) before meals on glycemic control, physiological responses to hypoglycemia, well-being, and treatment satisfaction., Research Design and Methods: We studied 35 type 1 diabetes patients. After an 8- to 10-week lead-in period, patients were randomized to HM or human regular insulin therapy for 12-14 weeks. During the lead-in and treatment periods, HbA1c levels and hypoglycemic frequencies were measured, and patients completed the Well-Being Questionnaire and the Diabetes Treatment Satisfaction Questionnaire. In 19 patients, responses to hypoglycemia were tested during stepped euglycemic-hypoglycemic clamps., Results: HM treatment improved postprandial glycemia but had no effect on HbA1c, frequency of hypoglycemia, well-being, or treatment satisfaction. During experimental hypoglycemia, HM therapy was associated with a slightly lower total adrenaline response and a higher autonomic symptom threshold (i.e., the autonomic symptom response occurred at a lower blood glucose level) than human regular insulin therapy. We speculate that this effect resulted from an accumulation of insulin during the night., Conclusions: Multiple injection therapy with HM rather than human regular insulin before meals does not offer advantages regarding glycemic control, frequency of hypoglycemia, well-being, or treatment satisfaction. In addition, this regimen causes an attenuation of the adrenaline and autonomic symptom responses to hypoglycemia.

Background: Severe hypoglycaemic episodes are an important source of morbidity in people with Type 1 diabetes. The occurrence of severe hypoglycaemia is strongly related to the frequency of low blood glucose readings. The aim of this exploratory study was to identify determinants of the frequency of mild, biochemical hypoglycaemia in patients with Type 1 diabetes treated with multiple insulin injection therapy., Methods: We studied 31 patients with Type 1 diabetes in reasonable glycaemic control (HbA(1c)

Aims/hypothesis: The sulphonylurea receptor is a subunit of the ATP-sensitive potassium channel in the pancreatic beta cell. Mutations at nt -3 of the splice acceptor site of exon 16 and a silent mutation in exon 18 of the gene for the sulphonylurea receptor (SUR1) associate with Type II (non-insulin-dependent) diabetes mellitus in several independent populations. We investigated whether these gene variants associate with changes in the pattern of glucose-stimulated insulin secretion., Methods: Subjects who had normal glucose tolerance (n = 67) and subjects with an impaired glucose tolerance (n = 94), originating from two independent studies, were included in the study. Beta-cell function and insulin sensitivity were assessed by the hyperglycaemic clamp., Results: Frequencies of the exon 16 -3t allele in the normal and impaired glucose tolerant groups were 46% and 44% respectively (p = NS). The more rare exon 18 T allele showed frequencies of 5 and 7% respectively (p = NS). We observed an approximately 25% reduced second-phase insulin secretion in carriers of the exon 16 -3t allele in both groups (p < 0.05). Estimates of insulin sensitivity did not show differences between carriers and non-carriers. The variant in exon 18 and the combined presence of variants in exon 16 and exon 18 were not associated with differences in insulin secretion or insulin sensitivity in our study groups., Conclusion/interpretation: The diabetes associated exon 16 -3t variant of the SUR1 gene associates with a functional change of the beta cell as reflected by reduced second-phase insulin secretion in response to a standardized hyperglycaemia in normal and impaired glucose tolerant subjects.

Objective: The aim of our study was to determine the agreement of two noninvasive methods, a self-report and a field study method, for the assessment of impaired hypoglycemia awareness with a gold standard criterion of hypoglycemia awareness, the autonomic symptom threshold during experimental hypoglycemia., Research Design and Methods: A total of 19 type 1 diabetic patients completed a standardized questionnaire to assess impaired hypoglycemia awareness and performed a hand-held computer (HHC) study to assess their recognition of hypoglycemic episodes occurring during 24 weeks. Patients subsequently underwent a stepped hypoglycemic clamp to study responses to standardized hypoglycemia. Diagnoses of impaired hypoglycemia awareness were based on the separate self-report questions, a composite self-report score, and three different cutoff levels for the percentage of accurately recognized hypoglycemic episodes during the field study Agreement of these noninvasive measures with the hypoglycemic clamp measure were tested by calculating kappa values, sensitivity, and specificity., Results: The composite self-report score agreed reasonably well with the hypoglycemic clamp measure (kappa 0.49, sensitivity 66.7%, and specificity 85.7%) and showed a better agreement than the separate self-report questions. The HHC criterion of impaired hypoglycemia awareness did not agree with the hypoglycemic clamp criterion at any of the cutoff levels tested., Conclusions: The composite self-report tested in this study is a reasonably reliable assessment method for the diagnosis of impaired hypoglycemia awareness, using the physiological definition of an absence of autonomic symptoms at a blood glucose level of 3 mmol/l. In contrast, the recognition of hypoglycemic events in everyday life as measured using the HHC method is not related to the hypoglycemic clamp criterion.

Background: Both HMG-CoA reductase inhibitors and fibric acid derivates are used for the treatment of dyslipidemia in Type 2 diabetes patients. The aim of this study was to compare the lipid lowering effect of 40 mg pravastatin, a HMG-CoA reductase inhibitor, and 400 mg bezafibrate, a fibric acid derivate, on serum lipids, lipoproteins and lipoprotein composition in 45 (22 men and 23 women) dyslipidemic, insulin-treated Type 2 diabetes patients., Method: The study used a double-blind, cross-over design., Results: Pravastatin treatment was more effective in reducing total cholesterol, LDL-cholesterol, LDL-triglycerides, LDL-ApoB and LDL/HDL-cholesterol ratio (all p<0.001 between groups) and total/HDL-cholesterol and ApoA1/LDL-ApoB ratios (both p<0.01) and always induced a decrease in LDL-cholesterol concentrations and LDL/HDL-cholesterol ratio irrespective of baseline triglyceride concentration. Bezafibrate was more effective in increasing HDL-cholesterol (p<0.01 between groups), ApoA1 lipoprotein and decreasing triglycerides (both p<0.001 between groups) but induced an increase in LDL-cholesterol concentration particularly in patients with baseline triglyceride concentrations exceeding 2.0 mmol/l. With bezafibrate treatment the LDL-cholesterol/LDL-ApoB ratio showed a tendency to rise, suggesting a change in the LDL particle composition to a less small and dense form, while pravastatin treatment induced a decrease in this ratio suggesting a change in the LDL particle to a more dense form. With pravastatin treatment a small rise in HbA(1c) was observed., Conclusion: Pravastatin treatment is superior in lowering cholesterol-enriched lipoprotein subpopulations and improving cardiovascular risk factors. Bezafibrate is more effective in raising HDL-cholesterol and alters LDL particle composition to a more favorable form.

Objective: Leptin is thought to play a key role in the control of body weight. There is a complex interrelationship between leptin and insulin or insulin resistance, but it is unknown how leptin is regulated. We therefore explored, in a large population-based study of 2,484 Caucasian subjects aged 50-74 years, the relationship between leptin and variables of body adiposity, energy balance, and insulin resistance., Research Design and Methods: Leptin was measured by means of a radioimmunoassay. Multiple linear regression analyses were performed with leptin as dependent variable and age, sex, BMI, waist circumference, daily energy intake, physical activity, smoking, hypertension, fasting triglyceride concentrations, HDL cholesterol, fasting plasma glucose, and fasting plasma insulin concentrations as independent variables (determinants), Results: Leptin concentrations were found to be four times higher in women than in men. Effect modification between sex and potential determinants was expected, and the analyses were performed separately for women and men. BMI was the strongest determinant of leptin in women and waist circumference the strongest determinant in men. BMI, waist circumference, insulin, and triglyceride concentrations were independently and significantly (P < 0.05) associated with leptin, while inverse associations were shown for smoking and daily energy intake (borderline significance)., Conclusions: This study confirms the relationship between insulin and leptin and, in addition, suggests a relationship between triglyceride concentrations and leptin independent of sex, BMI, waist circumference, and insulin.

Patients with type 2 diabetes mellitus often develop micro- and macrovascular complications. In 25% of them, complications are already present at the time of diagnosis. The principal objective of the United Kingdom prospective diabetes study was to determine if good blood glucose control and adequate treatment of hypertension in patients with type 2 diabetes mellitus can prevent development of diabetes-related complications. The question was also studied if they way in which this blood glucose control was achieved and the way of treating the blood pressure affected the prognosis. Blood glucose control was found to reduce the incidence of--especially--microvascular complications. Oral hypoglycaemic agents and insulin both play an important part in achieving good control. Treatment with metformin reduced mortality due to cardiovascular disease in obese patients. Strict control of the blood pressure reduced development of micro- and macrovascular complications; the mortality from diabetes-related disorders and the numbers of patients suffering a stroke or heart failure. Non of the antihypertensive drugs used (an ACE inhibitor and a beta-blocking agent) offered any advantages over the other.

The prevalence of Type 2 diabetes rises steeply with age and involves beta-cell dysfunction and diminished sensitivity to insulin. beta-cell dysfunction is important in the development of hyperglycaemia while insulin resistance seems to play a major role in the atherogenic process resulting in cardiovascular disease. Current therapeutic options include lifestyle adjustments (exercise and diet), oral hypoglycaemic agents (sulphonylureas, newer beta-cell mediated insulin releasing drugs, alpha-glucosidase inhibitors, biguanides and thiazolidinediones) and insulin treatment. Oral hypoglycaemic agents are effective only temporarily in maintaining good glycaemic control, their efficacy should be determined from changes in fasting and postprandial glucose levels. Recent studies have shown that the early initiation of insulin therapy can establish good glycaemic control.

In subjects with impaired glucose tolerance hyperproinsulinaemia has been shown to be predictive for progression to Type II (non-insulin-dependent) diabetes mellitus. These findings are often interpreted as early indicators of an impaired beta-cell function. The aim of our study was to assess the potential determinants of hyperproinsulinaemia in subjects with impaired glucose tolerance. The study group consisted of 110 subjects, 45-74 years of age with mean 2 h plasma glucose concentrations between 8.6 and 11.1 mmol/l following two oral glucose tolerance tests. Subsequently, the hyperglycaemic clamp technique (10 mmol/l, with a priming infusion of 20% glucose solution, 150 mg/kg) was used to assess the beta-cell function (time needed to reach the insulin peak) and insulin sensitivity (M/I value: glucose metabolised divided by insulin response, 150-180 min). Results showed that the intact-proinsulin:insulin ratio increased with increasing time needed to reach the insulin peak (0.065, 0.079 and 0.101; time needed to reach the insulin peak < or = 5 min, 5 to 15 min, > 15 min; p < 0.05). The split-proinsulin:insulin ratio showed a similar association with the time needed to reach the insulin peak. These associations were independent of age, sex, body mass index and waist:hip ratio. In conclusion, this study shows that relative hyperproinsulinaemia is associated with an impaired beta-cell function in a study group of subjects with impaired glucose tolerance selected after two oral glucose tolerance tests.

Objective: A randomized trial with 1-year follow-up was conducted in 23 general practices to study the relationship between target values for glycemic control and well-being in type 2 diabetes., Research Design and Methods: A total of 176 patients with type 2 diabetes, aged 40-75 years, were included. General practitioners were encouraged to make decisions according to a standardized step-up regimen until the target level of glycemic control was reached. The random allocation to a strict or a less strict target level of glycemic control (fasting capillary glucose < 6.5 or < 8.5 mmol/l), change in HbA1c and fasting glucose, and initiating insulin or treatment with oral hypoglycemic agents were studied as putative determinants of scores on a type 2 diabetes symptom checklist, a profile of mood states, an affect balance scale, and general well-being. Adjustments were made for baseline scores on the outcome at issue., Results: Positive affect (an odds ratio [OR] [95% CI] of 0.39 [0.19-0.83]) and perceived treatment burden (OR 0.48 [0.23-0.98]) were unfavorably altered in the group randomly allocated to stricter target levels (fasting capillary glucose < 6.5 mmol/l). Patients who had a decrease in HbA1c of 1% or more tended to have comparatively favorable mood (OR displeasure score 0.35 [0.13-0.94]) and general well-being scores at 1 year (ORs of having unfavorable scores ranged from 0.4 to 0.5, NS)., Conclusions: Perceived treatment burden and positive effect are unfavorably affected by random allocation to a strict target level for glycemic control. Improved glycemic control is associated with favorable mood and possibly general well-being in type 2 diabetes.

Objective: To determine the influence of insulin therapy on physical symptoms, emotional and general well-being, and treatment satisfaction in patients with type 2 diabetes., Research Design and Methods: A descriptive prospective 2-year cohort study was performed. The study population consisted of 272 eligible NIDDM patients of Dutch origin > or = 40 years of age who had a known diabetes duration > or = 3 months and who were treated with diet and/or oral hypoglycemic agents. Dependent variables in the logistic regression analysis were scores on the Type 2 Diabetes Symptom Checklist, the Profile of Mood States, and questions regarding general well-being and treatment satisfaction. Potential determinants under study were age, sex, known diabetes duration, insulin dose, duration of insulin therapy, comorbidity, baseline and change in metabolic parameters and cardiovascular risk factors., Results: A baseline and 2-year questionnaire were available for 157 patients (58%). During follow-up, 39 of them (24.8%) were treated with insulin. Initiation of insulin therapy was significantly associated with improved glycemic control (mean HbA1c 8.2 +/- 1.4 [SD] to 7.4 +/- 0.9%, P = 0.001) and weight gain (BMI 27.1 +/- 3.9 to 28.6 +/- 4.3 kg/m2, P = 0.000). Of all symptom and well-being scores, only feelings of emotional fatigue worsened significantly, although modestly (0.4-1.7 on a scale of 0.0-10.0, P = 0.02). Although diabetes management with insulin was experienced as more demanding (P = 0.04), treatment satisfaction scores were not adversely influenced (2.5-1.9, P = 0.39). High insulin doses were significantly and independently associated with high symptom scores (total score, hypoglycemic score) and with low mood (displeasure score, anger, tension, emotional fatigue) and perceived state of health., Conclusions: Initiation of insulin therapy in type 2 diabetes improves glycemic control effectively, has little influence on physical and psychological well-being dimensions, and does not affect treatment satisfaction.

In this study involving 365 non-diabetic elderly Caucasians, we examined the relationship of immuno-specific insulin (ISI), total immuno-reactive insulin (IRI), proinsulin (PI) and proinsulin-insulin ratio (PI:ISI) to serum high-density lipoprotein cholesterol (HDL-C), triglyceride (TG), systolic blood pressure (SBP) and diastolic blood pressure (DBP), mean blood pressure (MBP) and pulse pressure. In a multiple regression analysis, adjusted for age, sex and obesity, a 1.3-fold stronger inverse association with HDL-C levels was found for IRI than for ISI, with a 1.6-fold better fit of the regression equation. The positive association of insulin with TG was 1.6-fold stronger for IRI compared to ISI, with a 2.5-fold better fit. In contrast, the positive association of IRI with the various blood pressure parameters was 1.5-1.9-fold weaker than for ISI, with a 2.1-3.8-fold worse fit. Both PI:ISI ratio and PI were independently associated with TG levels, but not with HDL-C. The PI:ISI ratio but not PI, was associated with blood pressure, but dependent on glycaemia. In conclusion, compared to ISI, IRI overestimates the association of insulin with serum lipids and underestimates the association of insulin with blood pressure. The use of non-specific insulin assays may explain the inconsistencies in the findings of previous epidemiological studies.

In patients with insulin-dependent diabetes mellitus (IDDM) good glycaemic control confers an enhanced risk of hypoglycaemia. Nocturnal hypoglycaemia occurs frequently and contributes to the syndrome of hypoglycaemia unawareness. In order to avoid nocturnal hypoglycaemia we substituted night-time continuous subcutaneous insulin infusion (CSII) therapy in 14 patients with well-controlled IDDM using a multiple injection regimen for the more variable bedtime NPH insulin. During a stepwise hypoglycaemic clamp we studied the effect of this regimen on counterregulatory hormonal responses, warning symptoms and cognitive function. In addition, we investigated the incidence of daytime hypoglycaemia and the acceptability of night-time CSII treatment. CSII was associated with a lower frequency of hypoglycaemia (mean+/-SEM): 16.1+/-3.1 vs 23.6+/-3.3) episodes during the last 6 weeks of treatment, p=0.03 (CSII vs NPH)) with maintenance of good glycaemic control (HbA1c 7.2+/-0.2 vs 7.1+/-0.2 %, p=0.2). Hypoglycaemic thresholds for the growth hormone response and for autonomic symptoms were lower for CSII treatment than for NPH treatment. Of 14 patients 6 decided to continue with the nocturnal CSII treatment. In conclusion, nocturnal CSII improves warning symptoms and counterregulatory hormonal responses to hypoglycaemia and is an acceptable treatment strategy for patients suffering from hypoglycaemia unawareness, as demonstrated in this acute feasibility study.

Patients with diabetes mellitus type I usually are treated with a multiple injection regimen comprising rapid-acting insulin before meals and intermediate-acting insulin at bedtime. Recently, the rapid-acting insulin analogue insulin LISPRO was introduced on the Dutch market. This form of insulin is very rapidly taken up into the bloodstream from the subcutaneous tissue. The advantages of the use of insulin LISPRO are the comfort of injecting the insulin just before a meal, the more rapid correction of incidental hyperglycaemia and the slightly lower incidence of (nocturnal) hypoglycaemia in comparison with conventional rapid-acting insulin. There is no argument in favour of switching diabetics to insulin LISPRO if they are well-controlled with normal rapid-acting insulin and have few episodes of hypoglycaemia. In some persons the duration of action of insulin LISPRO may be too short, leading to preprandial hyperglycaemia. This can be avoided by using a second injection of intermediate-acting insulin, either before breakfast or before lunch.

The aim of this study was to investigate anthropometric and life-style determinants of insulinaemia. Specific fasting serum insulin (FI) was analysed in a general Caucasian population aged 50-74 years, not known to have diabetes mellitus (n = 2226, sample 1). The analysis was repeated some weeks later in a subgroup of sample 1 in which two individual measurements of FI were available (n = 540, sub-sample 2). Specific serum insulin 2 h after ingestion of 75 g glucose (2hI), also measured on two occasions, was analysed in this same subgroup after excluding 59 subjects with fasting plasma glucose >7 mmol l(-1) (n = 481, sub-sample 3). Multiple regression analyses were performed, stratified for sex, with 10log insulin as the dependent variable. All determinants were adjusted for each other. FI was positively associated with BMI and waist-hip ratio (men and women) and inversely associated with intake of fibre (women), moderate alcohol use (men), and current smoking (women). 2hI was positively associated with BMI and waist-hip ratio (men and women), and intake of fat (women). 2hI was inversely associated with physical activity and moderate alcohol use (men and women), and current smoking (men). Family history of diabetes was not associated with insulinaemia. In conclusion, various life-style factors are related to insulinaemia, independent of obesity.