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Merel M Ruissen,1– 3 Jacob K Sont,2 Heidi A van Vugt,4,5 Marleen Kunneman,2,3 Guy EHM Rutten,4 Eelco JP de Koning1 1Department of Medicine, Leiden University Medical Centre, Leiden, the Netherlands; 2Department of Biomedical Data Sciences, Section of Medical Decision Making, Leiden University Medical Centre, Leiden, the Netherlands; 3Knowledge and Evaluation Research Unit, Mayo Clinic, Rochester, MN, USA; 4Julius Centre for Health Sciences and Primary Care, Department of General Practice, University Medical Centre Utrecht, Utrecht, the Netherlands; 5Dutch Diabetes Federation, Amersfoort, the NetherlandsCorrespondence: Eelco JP de Koning, Department of Medicine, Leiden University Medical Centre, Albinusdreef 2, 2333 ZA, Leiden, the Netherlands, Tel +31 71 52 62085, Fax +31 71 52 66881, Email e.j.p.de_koning@lumc.nlPurpose: Understanding which factors are important for healthcare decisions of patients with diabetes in clinical practice is important to personalise diabetes care strategies and tailor care plans to the individual. The main drivers for these healthcare decisions remain unclear. This study assessed which key factors are relevant for healthcare decisions during clinical consultations for patients with type 1 diabetes (T1DM) and type 2 diabetes (T2DM), according to healthcare professionals.Materials and Methods: Annual diabetes reviews were performed as part of a trial assessing the impact of a consultation model facilitating person-centred diabetes care in six hospital outpatient clinics. After each consultation, we asked healthcare professionals to choose a maximum of three out of 20 factors that were most relevant for healthcare decisions about treatment goals and the professional support needed during the upcoming year. Factors were characterised as either person or disease-related. Percentages reflect the number of annual diabetes reviews in which the key factor was reported.Results: Seventeen physicians and eight diabetes specialist nurses reported the key factors relevant for healthcare decisions in 285 annual diabetes reviews (T1DM n = 119, T2DM n = 166). Healthcare professionals most often reported quality of life (31.9%), motivation (27.0%) and diabetes self-management (25.6%), and to a lesser extent glycaemic control (24.2%), to be important for decisions about treatment goals. For decisions about the professional support needed during the upcoming year patient’s preferences (33.7%), diabetes self-management (33.3%), quality of life (27.0%) and motivation (25.6%) were most often considered relevant by healthcare professionals.Conclusion: According to healthcare professionals, person-related factors such as quality of life, diabetes self-management and motivation are predominantly relevant for healthcare decisions about treatment goals and the professional support needed during the upcoming year.Keywords: diabetes mellitus, person-centred, preferences, shared decision making

Heidi A van Vugt,1,2,* Anne Meike Boels,1,* Inge de Weerdt,2 Eelco JP de Koning,3 Guy EHM Rutten1 1Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht University, 3508 GA Utrecht, Utrecht, the Netherlands; 2Dutch Diabetes Federation, Amersfoort 3818 LE, the Netherlands; 3Department of Medicine, Leiden University Medical Center, 2300 RC Leiden, the Netherlands *These authors contributed equally to this work Aim: This study explored the relationship between insulin use and patient activation (a person’s internal readiness and capabilities to undertake health-promoting actions) in individuals with type 2 diabetes mellitus and aimed to identify demographic, clinical and psychosocial factors involved in patient activation.Methods: In this cross-sectional study, baseline data from a Dutch nationwide study were analyzed. Patient activation was assessed with the Patient Activation Measure 13. A linear mixed model was used to take clustering into account.Results: In total, 1,189 persons were included (310 of whom were on insulin), enrolled via 47 general practices and six hospitals. Their mean Patient Activation Measure 13 score was 59±12. We found no association between insulin therapy and patient activation. In the multivariable analysis, individuals with a better health status, very good or very poor social support (vs good social support), individuals who felt they had greater control over their illness and those with a better subjective understanding of their illness showed higher patient activation. Individuals with a lower educational level and those who expected their illness to continue showed a lower activation level.Conclusion: Patient activation does not differ between individuals with type 2 diabetes mellitus on insulin therapy and those on other therapies.Keywords: provider–patient communication, patient participation in health care, social support, patient activation, insulin therapy, psychological aspects, self-management

Objective: Limited information is available regarding the metabolic effects of high altitude trekking in patients with type 2 diabetes.Research Design and Methods: Thirteen individuals with type 2 diabetes took part in a 12-day expedition to the summit of Mount Toubkal (altitude, 4,167 m), Morocco, after 6 months of exercise training. Energy expenditure, body weight, blood glucose, fasting insulin, lipids, and HbA(1c) were assessed.Results: Training reduced fasting glucose (-0.7 ± 0.9 mmol/L, P = 0.026) and increased exercise capacity (+0.3 ± 0.3 W/kg, P = 0.005). High altitude trekking decreased fasting insulin concentrations (-3.8 ± 3.2 μU/L, P = 0.04), total cholesterol (-0.7 ± 0.8 mmol/L, P = 0.008), and LDL cholesterol (-0.5 ± 0.6 mmol/L, P = 0.007).Conclusions: High altitude trekking preceded by exercise training is feasible for patients with type 2 diabetes. It improves blood glucose, lipids, and fasting insulin concentrations, while glucose control is maintained. [ABSTRACT FROM AUTHOR]

Objectives: To describe the range of collaborative approaches to shared decision-making (SDM) observed in clinical encounters of patients with diabetes and their clinicians., Design: A secondary analysis of videorecordings obtained in a randomised trial comparing usual diabetes primary care with or without using a within-encounter conversation SDM tool., Setting: Using the purposeful SDM framework, we classified the forms of SDM observed in a random sample of 100 video-recorded clinical encounters of patients with type 2 diabetes in primary care., Main Outcome Measures: We assessed the correlation between the extent to which each form of SDM was used and patient involvement (OPTION12-scale)., Results: We observed at least one instance of SDM in 86 of 100 encounters. In 31 (36%) of these 86 encounters, we found only one form of SDM, in 25 (29%) two forms, and in 30 (35%), we found ≥3 forms of SDM. In these encounters, 196 instances of SDM were identified, with weighing alternatives (n=64 of 196, 33%), negotiating conflicting desires (n=59, 30%) and problemsolving (n=70, 36%) being similarly prevalent and developing existential insight accounting for only 1% (n=3) of instances. Only the form of SDM focused on weighing alternatives was correlated with a higher OPTION12-score. More forms of SDM were used when medications were changed (2.4 SDM forms (SD 1.48) vs 1.8 (SD 1.46); p=0.050)., Conclusions: After considering forms of SDM beyond weighing alternatives, SDM was present in most encounters. Clinicians and patients often used different forms of SDM within the same encounter. Recognising a range of SDM forms that clinicians and patients use to respond to problematic situations, as demonstrated in this study, opens new lines of research, education and practice that may advance patient-centred, evidence-based care., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Young adults living with type 1 diabetes often struggle to achieve what clinicians consider to be optimal levels of metabolic control. Despite the impact that this can have on a young person's future risk of complications, there are relatively few studies reporting new ways of organizing or delivering care to this cohort. In this article, we explore some of the reasons why young adult diabetes care is challenging, and describe approaches to "re-imagining" how care might be improved. The work is informed by the 'Making Care Fit' collaborative and by a program of research, entitled D1 Now, involving co-design of a complex person-centered intervention with young adults., (© 2022 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.)

The signal peptide of preproinsulin is a major source for HLA class I autoantigen epitopes implicated in CD8 T cell (CTL)-mediated β-cell destruction in type 1 diabetes (T1D). Among them, the 10-mer epitope located at the C-terminal end of the signal peptide was found to be the most prevalent in patients with recent-onset T1D. While the combined action of signal peptide peptidase and endoplasmic reticulum (ER) aminopeptidase 1 (ERAP1) is required for processing of the signal peptide, the mechanisms controlling signal peptide trimming and the contribution of the T1D inflammatory milieu on these mechanisms are unknown. Here, we show in human β-cells that ER stress regulates ERAP1 gene expression at posttranscriptional level via the IRE1α/miR-17-5p axis and demonstrate that inhibition of the IRE1α activity impairs processing of preproinsulin signal peptide antigen and its recognition by specific autoreactive CTLs during inflammation. These results underscore the impact of ER stress in the increased visibility of β-cells to the immune system and position the IRE1α/miR-17 pathway as a central component in β-cell destruction processes and as a potential target for the treatment of autoimmune T1D., (© 2020 by the American Diabetes Association.)

Background: Depressive symptoms and impaired physical functioning are prevalent among older adults. Supplementation with vitamin D might improve both conditions, particularly in persons with low vitamin D status., Objective: The D-Vitaal study primarily aimed to investigate the effect of vitamin D supplementation on depressive symptoms, functional limitations, and physical performance in a high-risk older population with low vitamin D status. Secondary aims included examining the effect of vitamin D supplementation on anxiety symptoms, cognitive functioning, mobility, handgrip strength, and health-related quality of life., Methods: This study was a randomized placebo-controlled trial with 155 participants aged 60-80 y who had clinically relevant depressive symptoms, ≥1 functional limitations, and serum 25-hydroxyvitamin D [25(OH)D] concentrations of 15-50/70 nmol/L (depending on season). Participants received 1200 IU/d vitamin D3 (n = 77) or placebo tablets (n = 78) for 12 mo. Serum 25(OH)D was measured at baseline and 6 mo; outcomes were assessed at baseline, 6 mo, and 12 mo. Linear mixed-models analyses were conducted to assess the effect of the intervention., Results: The supplementation increased serum 25(OH)D concentrations in the intervention group to a mean ± SD of 85 ± 16 nmol/L compared with 43 ± 18 nmol/L in the placebo group after 6 mo (P < 0.001). No relevant differences between the treatment groups were observed regarding depressive symptoms, functional limitations, physical performance, or any of the secondary outcomes., Conclusions: Supplementation with 1200 IU/d vitamin D for 12 mo had no effect on depressive symptoms and physical functioning in older persons with relatively low vitamin D status, clinically relevant depressive symptoms, and poor physical functioning. This trial is registered with the Netherlands Trial Register (www.trialregister.nl) under NTR3845., (Copyright © American Society for Nutrition 2019.)

Dysfunctional insulin secretion is a hallmark of type 2 diabetes (T2D). Interestingly, several islet microRNAs (miRNAs) are upregulated in T2D, including miR-132. We aimed to investigate whether in vivo treatment with antagomir-132 lowers expression of miR-132 in islets thereby improving insulin secretion and lowering blood glucose. Mice injected with antagomir-132 for 24 h, had reduced expression of miR-132 expression in islets, decreased blood glucose, and increased insulin secretion. In isolated human islets treated with antagomir-132, insulin secretion from four of six donors increased. Target prediction coupled with analysis of miRNA-messenger RNA expression in human islets revealed DESI2, ARIH1, SLC25A28, DIAPH1, and FOXA1 to be targets of miR-132 that are conserved in both species. Increased expression of these targets was validated in mouse islets after antagomir-132 treatment. In conclusion, we identified a post-transcriptional role for miR-132 in insulin secretion, and demonstrated that systemic antagomir-132 treatment in mice can be used to improve insulin secretion and reduce blood glucose in vivo. Our study is a first step towards utilizing antagomirs as therapeutic agents to modulate islet miRNA levels to improve beta cell function.

Vitamin D supplementation has been widely promoted to restore 25-hydroxyvitamin D concentrations; however, experimental evidence suggests a nutrient interaction with vitamin K. We assessed the effects of 1200 IU vitamin D₃ per day versus placebo for six months on vitamin K status in a randomized, double-blind, placebo-controlled trial with participants aged 60⁻80 years with depressive symptoms and ≥1 functional limitation for a secondary analysis. Stored baseline and six-month follow-up blood samples were available for 131 participants ( n = 65 placebo vs. n = 66 vitamin D supplementation). We measured dephosphorylated uncarboxylated matrix gla protein (MGP) (dp-ucMGP) concentrations-a marker of vitamin K deficiency. Mean age was 68 years, and 89 participants (68%) were women. Vitamin K antagonists were used by 16 participants and multivitamin supplements by 50 participants. No differences in change between intervention and placebo were found (-38.5 ± 389 vs. 4.5 ± 127 (pmol/L), p = 0.562). When excluding vitamin K antagonist users and multivitamin users, dp-ucMGP at follow-up was significantly higher in the vitamin D group ( n = 40) compared to placebo ( n = 30), with a difference of 92.8 (5.7, 180) pmol/L, adjusting for baseline dp-ucMGP and sex. In conclusion, vitamin D supplementation for six months did not affect vitamin K status; however, among participants without vitamin K antagonist or multivitamin use, vitamin D supplementation influenced dp-ucMGP concentrations.

Background: This study examines the association of both pain severity and within-person pain variability with physical activity (PA) in older adults with osteoarthritis (OA)., Methods: Data from the European Project on OSteoArthritis were used. At baseline, clinical classification criteria of the American College of Rheumatology were used to diagnose OA in older adults (65-85 years). At baseline and 12-18 months follow-up, frequency and duration of participation in the activities walking, cycling, gardening, light and heavy household tasks, and sports activities were assessed with the Longitudinal Aging Study Amsterdam Physical Activity Questionnaire. Physical activity was calculated in kcal/day, based on frequency, duration, body weight and the metabolic equivalent of each activity performed. At baseline and 12-18 months follow-up, pain severity was assessed using the pain subscales of the Western Ontario and McMaster Universities OA Index and the Australian/Canadian Hand OA Index. Within-person pain variability was assessed using two-week pain calendars that were completed at baseline, 6 months follow-up and 12-18 months follow-up., Results: Of all 669 participants, 70.0% were women. Sex-stratified multiple linear regression analyses showed that greater pain severity at baseline was cross-sectionally associated with less PA in women (Ratio = 0.95, 95% CI = 0.90-0.99), but not in men (Ratio = 0.99, 95% CI = 0.85-1.15). The longitudinal analyses showed a statistically significant inverse association between pain severity at baseline and PA at follow-up in women (Ratio = 0.94, 95% CI = 0.89-0.99), but not in men (Ratio = 1.00, 95% CI = 0.87-1.11). Greater pain variability over 12-18 months was associated with more PA at follow-up in men (Ratio = 1.18, 95% CI = 1.01-1.38), but not in women (Ratio = 0.94, 95% CI = 0.86-1.03)., Conclusions: Greater pain severity and less pain variability are associated with less PA in older adults with OA. These associations are different for men and women. The observed sex differences in the various associations should be studied in more detail and need replication in future research.

Objectives: Depressive symptoms and low vitamin D status are common in older persons and may be associated, but findings are inconsistent. This study investigated whether 25-hydroxyvitamin D (25(OH)D) concentrations are associated with depressive symptoms in older adults, both cross-sectionally and longitudinally. We also examined whether physical functioning could explain this relationship, to gain a better understanding of the underlying mechanisms., Methods: Data from two independent prospective cohorts of the Longitudinal Aging Study Amsterdam were used: an older cohort (≥65 years, n = 1282, assessed from 1995-2002) and a younger-old cohort (55-65 years, n = 737, assessed from 2002-2009)., Measurements: Depressive symptoms were measured at baseline and after 3 and 6 years with the Center of Epidemiological Studies Depression Scale. Cross-sectional and longitudinal linear regression techniques were used to examine the relationship between 25(OH)D and depressive symptoms. The mediating role of physical functioning was examined in the longitudinal models., Results: Cross-sectionally, associations were not significant after adjustment for confounders. Longitudinally, women in the older cohort with baseline 25(OH)D concentrations up to 75 nmol/L experienced 175 to 24% more depressive symptoms in the following 6 years, compared with women with 25(OH)D concentrations >75 nmol/L. Reduced physical performance partially mediated this relationship. In men and in the younger-old cohort, no significant associations were observed., Conclusions: Older women showed an inverse relationship between 25(OH)D and depressive symptoms over time, which may partially be explained by declining physical functioning. Replication of these findings by future studies is needed., (Copyright © 2018 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.)

Objectives: Previous prospective studies on the association between vitamin D status and depression used a single 25-hydroxyvitamin D (25(OH)D) measurement. We investigated the association between change in serum 25(OH)D and parallel change in depressive symptoms over time in Dutch older adults., Design: A population-based, prospective study in two cohorts of older men and women from the Longitudinal Aging Study Amsterdam., Methods: Serum 25(OH)D concentrations were determined at two time points: in 1995/1996 and 13 years later in the older cohort (aged 65–88y, n = 173) and in 2002/2003 and 6 years later in the younger cohort (55–65 years, n = 450). At these time points, depressive symptoms were measured with the Center for Epidemiologic Studies Depression scale (CES-D). Associations were tested by multiple linear regression analyses., Results: During follow-up, serum 25(OH)D concentrations increased in 32.4% of the older cohort and in 69.8% of the younger cohort. In the older cohort, change in 25(OH)D was not associated with change in CES-D score. In the younger cohort, no associations were observed in participants with higher baseline 25(OH)D concentrations (>58.6 nmol/L), but in those with lower baseline 25(OH)D concentrations, an increase in 25(OH)D was associated with a decrease in CES-D score (adjusted B per 10 nmol/L 25(OH)D increase: −0.62 (95% CI: −1.17, −0.07))., (© 2018 European Society of Endocrinology)

Pain is a key symptom of osteoarthritis (OA) and has been linked to poor mental health. Pain fluctuates over time within individuals, but a paucity of studies have considered day-to-day fluctuations of joint pain in relation to affective symptoms in older persons with OA. This study investigated the relationship of pain severity as well as within-person pain variability with anxiety and depression symptoms in 832 older adults with OA who participated in the European Project on OSteoArthritis (EPOSA): a 6-country cohort study. Affective symptoms were examined with the Hospital Anxiety and Depression Scale, pain severity was assessed with the Western Ontario and McMaster Universities OA Index and the Australian/Canadian Hand Osteoarthritis Index, and intraindividual pain variability was measured using pain calendars assessed at baseline, 6, and 12 to 18 months. Age-stratified multiple linear regression analyses adjusted for relevant confounders showed that more pain was associated with more affective symptoms in older-old participants (74.1-85 years). Moreover, older-old participants experienced fewer symptoms of anxiety (ratio = .85, 95% confidence interval [CI], .77-.94), depression (ratio = .90, 95% CI, .82-.98), and total affective symptoms (ratio = .87, 95% CI, .79-.94) if their pain fluctuated more. No such association was evident in younger-old participants (65-74.0 years). These findings imply that stable pain levels are more detrimental to mental health than fluctuating pain levels in older persons., Perspective: This study showed that more severe and stable joint pain levels were associated with anxiety and depressive symptoms in older persons with OA. These findings emphasize the importance of measuring pain in OA at multiple time points, because joint pain fluctuations may be an indicator for the presence of affective symptoms., (Copyright © 2018 The American Pain Society. Published by Elsevier Inc. All rights reserved.)

Objective: Low serum 25-hydroxyvitamin D levels (25(OH)D<50nmol/L) are common in older persons and associated with depressive symptoms. Depression and anxiety are highly interrelated, but only very few studies examined the association between 25(OH)D and anxiety. This study investigated whether 25(OH)D levels are related to anxiety symptoms in older persons, both cross-sectionally and over time., Methods: Data from two samples of a large population-based cohort study were used (sample 1: N=1259, 64-88years; sample 2: N=892, 60-98years). Anxiety symptoms were measured with the Hospital Anxiety and Depression Scale - Anxiety subscale at baseline and after three years; serum 25(OH)D was measured at baseline. Cross-sectional and longitudinal relationships between 25(OH)D and anxiety were examined using logistic regression analysis, taking into account relevant confounding variables., Results: Of the participants, 48.0% (sample 1) and 26.4% (sample 2) had 25(OH)D levels <50nmol/L, whereas 8.1% (sample 1) and 6.5% (sample 2) had clinically relevant anxiety symptoms. Cross-sectionally, persons with 25(OH)D<50nmol/L experienced more anxiety symptoms than persons with 25(OH)D≥50nmol/L (sample 1: OR=1.55; 95% CI: 1.03-2.32, p=0.035; sample 2: OR=1.74; 95% CI: 1.03-2.96, p=0.040). However, after adjustment for demographic and lifestyle variables and depressive symptoms, significant associations were no longer observed (p=0.25-0.72). Similarly, 25(OH)D levels were not significantly related to anxiety symptoms after three years in both samples., Conclusions: After adjustment for confounding, there was no cross-sectional or longitudinal association between 25(OH)D levels and anxiety symptoms, independently from depression, in two large samples of older persons., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Identification of epitopes that are recognized by diabetogenic T cells and cause selective beta cell destruction in type 1 diabetes (T1D) has focused on peptides originating from native beta cell proteins. Translational errors represent a major potential source of antigenic peptides to which central immune tolerance is lacking. Here, we describe an alternative open reading frame within human insulin mRNA encoding a highly immunogenic polypeptide that is targeted by T cells in T1D patients. We show that cytotoxic T cells directed against the N-terminal peptide of this nonconventional product are present in the circulation of individuals diagnosed with T1D, and we provide direct evidence that such CD8 + T cells are capable of killing human beta cells and thereby may be diabetogenic. This study reveals a new source of nonconventional polypeptides that act as self-epitopes in clinical autoimmune disease.

Objective: The aim of this study was to examine the relations between intakes of total, saturated, mono-unsaturated, poly-unsaturated and trans fatty acids (SFA, MUFA, PUFA and TFA), and their dietary sources (dairy, meat and plant) with markers of type 2 diabetes risk., Subjects/methods: This was a cross-sectional analysis of baseline data of 5675 non-diabetic, middle-aged participants of the Netherlands Epidemiology of Obesity (NEO) study. Associations between habitual dietary intake and fasting and postprandial blood glucose and insulin, Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), HOMA of β-cell function (HOMA-B) and Disposition Index were assessed through multivariable linear regression models with adjustments for demographic, lifestyle and dietary factors., Results: Mean (s.d.) intakes in percent of energy (En%) were 34.4 (5.8) for total fatty acids, 12.4 (2.9) for SFA, 12.2 (2.4) for MUFA, 6.9 (1.9) for PUFA and 0.6 (0.2) for TFA. As compared with carbohydrates, only SFA was weakly inversely associated with fasting insulin, HOMA-IR and HOMA-B. When stratified by dietary source, all fatty acids from meat were positively associated with fasting insulin - total fatty acids meat (per 5 En%: 10.0%; 95% confidence interval: 4.0, 16.3), SFA meat (per 1 En%: 3.7%; 0.4, 7.2), MUFA meat (per 1 En%: 5.0%; 2.0, 8.1), PUFA meat (per 1 En%: 17.3%; 6.0, 29.7) and TFA meat (per 0.1 En%: 10.5%; 3.2, 18.3). Similarly, all fatty acids from meat were positively associated with HOMA-IR and HOMA-B and inversely with Disposition Index., Conclusions: Our study suggests that the relations between fatty acid intakes and markers of type 2 diabetes risk may depend on the dietary sources of the fatty acids. More epidemiological studies on diet and cardiometabolic disease are needed, addressing possible interactions between nutrients and their dietary sources.

Lowering elevated plasma homocysteine (Hcy) concentrations by supplementing vitamin B 12 and folic acid may reduce depressive symptoms and improve health-related quality of life (HR-QoL) in older adults. This study aimed to test this hypothesis in a randomized controlled trial. Participants ( N = 2919, ≥65 years, Hcy concentrations ≥12 µmol/L) received either 500 µg vitamin B 12 and 400 µg folic acid daily or placebo for two years. Both tablets contained 15 µg vitamin D₃. Depressive symptoms were measured with the Geriatric Depression Scale-15 (GDS-15). HR-QoL was assessed with the SF-12 Mental and Physical component summary scores and the EQ-5D Index score and Visual Analogue Scale. Differences in two-year change scores were analyzed with Analysis of Covariance (ANCOVA). Hcy concentrations decreased more in the intervention group, but two-year change scores of the GDS-15 and three of four HR-QoL measures did not differ between groups. The EQ-5D Index score declined less in the intervention group than in the placebo group (mean change 0.00 vs. -0.02, p = 0.004). In conclusion, two-year supplementation with vitamin B 12 and folic acid in older adults with hyperhomocysteinemia showed that lowering Hcy concentrations does not reduce depressive symptoms, but it may have a small positive effect on HR-QoL., Competing Interests: The authors declare no conflict of interest. The funding sources had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, and in the decision to publish the results.

Observational studies suggest that low concentrations of serum 25-hydroxyvitamin D (25(OH)D) and high concentrations of parathyroid hormone (PTH) are associated with a higher risk of mortality. The aim of this study was to examine whether 25(OH)D and PTH concentrations are independently associated with overall and disease-specific (cardiovascular and cancer-related) mortality in a large, prospective population-based cohort of older adults. Data from 1317 men and women (65-85 years) of the Longitudinal Aging Study Amsterdam were used. Cox proportional hazard analyses were used to examine whether 25(OH)D and PTH at baseline were associated with overall mortality (with a follow-up of 18 years) and disease-specific mortality (with a follow-up of 13 years). Compared to persons in the reference category of ≥75nmol/L, persons with serum 25(OH)D <25nmol/L (HR 1.46; 95% CI: 1.12-1.91) and 25-49.9nmol/L (HR 1.24; 95% CI: 1.01-1.53) had a significantly higher risk of overall mortality, as well as men with baseline PTH concentrations ≥7pmol/L (HR 2.54 (95% CI: 1.58-4.08)), compared to the reference category of <2.33pmol/L. The relationship of 25(OH)D with overall mortality was partly mediated by PTH. Furthermore, men with PTH concentrations of ≥7pmol/L (HR 3.22; 95% CI: 1.40-7.42) had a higher risk of cardiovascular mortality, compared to the reference category. No significant associations of 25(OH)D or PTH with cancer-related mortality were observed. Both 25(OH)D and PTH should be considered as important health markers., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

To understand organ function, it is important to have an inventory of its cell types and of their corresponding marker genes. This is a particularly challenging task for human tissues like the pancreas, because reliable markers are limited. Hence, transcriptome-wide studies are typically done on pooled islets of Langerhans, obscuring contributions from rare cell types and of potential subpopulations. To overcome this challenge, we developed an automated platform that uses FACS, robotics, and the CEL-Seq2 protocol to obtain the transcriptomes of thousands of single pancreatic cells from deceased organ donors, allowing in silico purification of all main pancreatic cell types. We identify cell type-specific transcription factors and a subpopulation of REG3A-positive acinar cells. We also show that CD24 and TM4SF4 expression can be used to sort live alpha and beta cells with high purity. This resource will be useful for developing a deeper understanding of pancreatic biology and pathophysiology of diabetes mellitus., (Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.)

The initiation of type 1 diabetes (T1D) requires a break in peripheral tolerance. New insights into neoepitope formation indicate that post-translational modification of islet autoantigens, for example via deamidation, may be an important component of disease initiation or exacerbation. Indeed, deamidation of islet autoantigens increases their binding affinity to the T1D highest-risk human leucocyte antigen (HLA) haplotypes HLA-DR3/DQ2 and -DR4/DQ8, increasing the chance that T cells reactive to deamidated autoantigens can be activated upon T cell receptor ligation. Here we investigated human pancreatic islets and inflammatory and tolerogenic human dendritic cells (DC and tolDC) as potential sources of deamidated islet autoantigens and examined whether deamidation is altered in an inflammatory environment. Islets, DC and tolDC contained tissue transglutaminase, the key enzyme responsible for peptide deamidation, and enzyme activity increased following an inflammatory insult. Islets treated with inflammatory cytokines were found to contain deamidated insulin C-peptide. DC, heterozygous for the T1D highest-risk DQ2/8, pulsed with native islet autoantigens could present naturally processed deamidated neoepitopes. HLA-DQ2 or -DQ8 homozygous DC did not present deamidated islet peptides. This study identifies both human islets and DC as sources of deamidated islet autoantigens and implicates inflammatory activation of tissue transglutaminase as a potential mechanism for islet and DC deamidation., (© 2016 British Society for Immunology.)

Derailment of immune responses can lead to autoimmune type 1 diabetes, and this can be accelerated or even induced by local stress caused by inflammation or infection. Dendritic cells (DCs) shape both innate and adaptive immune responses. Here, we report on the responses of naturally occurring human myeloid BDCA1(+) DCs towards differentially stressed pancreatic β cells. Our data show that BDCA1(+) DCs in human pancreas-draining lymph node (pdLN) suspensions and blood-derived BDCA1(+) DCs both effectively engulf β cells, thus mimicking physiological conditions. Upon uptake of enterovirus-infected, but not mock-infected cells, BDCA1(+) DCs induced interferon (IFN)-α/β responses, co-stimulatory molecules and proinflammatory cytokines and chemokines. Notably, induction of stress in β cells by ultraviolet irradiation, culture in serum-free medium or cytokine-induced stress did not provoke strong DC activation, despite efficient phagocytosis. DC activation correlated with the amount of virus used to infect β cells and required RNA within virally infected cells. DCs encountering enterovirus-infected β cells, but not those incubated with mock-infected or stressed β cells, suppressed T helper type 2 (Th2) cytokines and variably induced IFN-γ in allogeneic mixed lymphocyte reaction (MLR). Thus, stressed β cells have little effect on human BDCA1(+) DC activation and function, while enterovirus-infected β cells impact these cells significantly, which could help to explain their role in development of autoimmune diabetes in individuals at risk., (© 2016 British Society for Immunology.)

Aims/hypothesis: High levels of circulating mannan-binding lectin (MBL) are associated with the development of diabetic nephropathy and hyperglycaemia-induced vasculopathy. Here, we aimed to assess the effect of glycaemic control on circulating levels of MBL and the relationship of these levels with vascular damage., Methods: We assessed MBL levels and corresponding MBL2 genotype, together with vascular endothelial growth factor (VEGF) levels as a marker of vascular damage, in type 1 diabetes patients with diabetic nephropathy before and after simultaneous pancreas-kidney (SPK) transplantation. We included diabetic nephropathy patients (n = 21), SPK patients (n = 37), healthy controls (n = 19), type 1 diabetes patients (n = 15) and diabetic nephropathy patients receiving only a kidney transplant (n = 15). Fourteen diabetic nephropathy patients were followed up for 12 months after SPK., Results: We found elevated circulating MBL levels in diabetic nephropathy patients, and a trend towards elevated circulating MBL levels in type 1 diabetes patients, compared with healthy control individuals. MBL levels in SPK patients completely normalised and our data indicate that this predominantly occurs in patients with a polymorphism in the MBL2 gene. By contrast, MBL levels in kidney transplant only patients remained elevated, suggesting that glycaemic control but not reversal of renal failure is associated with decreased MBL levels. In line, levels of glucose and HbA1c, but not creatinine levels and estimated GFR, were correlated with MBL levels. VEGF levels were associated with levels of MBL and HbA1c in an MBL-polymorphism-dependent manner., Conclusions/interpretation: Taken together, circulating MBL levels are associated with diabetic nephropathy and are dependent on glycaemic control, possibly in an MBL2-genotype-dependent manner.

Aims: To estimate prevalence and incidence of auto-immune thyroid disease and thyroid auto-antibodies in an unselected cohort of patients with DM1, including stratification by age, gender and duration of diabetes., Methods: Patients with T1D visiting our outpatient clinic between 1995 and 2011 were included. We calculated the prevalence of AITD at first screening and estimated prevalence and incidence rates during follow-up., Results: A total of 1304 patients were included, 48.9% being female. Mean age of diabetes onset was 18.7 years. Of all patients without known thyroid disorder first screened for AITD, 10.3 % (n=104) was diagnosed with hypo- or hyperthyroidism. The average prevalence of AITD in our population was 112/1000 patients. We found 128 new cases of AITD, 101 cases of hypothyroidism and 27 of hyperthyroidism between 1995 and 2011 with accompanying incidences of 11.2/1000 person-years (95% CI 9.5-13.4), 8.9/1000 person-years (95% CI, 7.3-10.8) and 2.4/1000 person-years (95% CI, 1.6-3.5), respectively. Age-stratified incidence of AITD was comparable at all ages in both males and females, with an approximately two times higher incidence in females., Conclusions: The incidence of AITD among T1D patients is high, but stable among all ages and independent of diabetes duration., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Diabetes care is shifting from disease management to personalised care. Internationally, diabetes care providers are advised to integrate the patient's preferences, wishes and possibilities into diabetes care in order to improve its efficiency. The Dutch Diabetes Federation has developed a specifically patient-centred conversation model that can be systematically applied. At an annual appraisal, the physician and the patient make decisions on the treatment goals to set, and on the treatment and professional support needed to achieve these goals. In this way person-centred and efficient care may become reality. The first results of a pilot study are promising. Currently the applicability and added value of the model are being tested on a large scale. The model is more broadly applicable, which means this could be a new perspective for everyone with a chronic disease.

Pancreatic islet transplantation is performed in a select group of patients with type 1 diabetes mellitus. Immunosuppressive regimens play an important role in long-term islet function. We aimed to investigate the efficacy of islet transplantation in patients with type 1 diabetes and a previous kidney transplantation using an alemtuzumab-based induction regimen and triple maintenance immunosuppression. Patients with type 1 diabetes, who had received a kidney transplant previously, were treated with alemtuzumab as induction therapy for their first islet transplantation and basiliximab induction therapy for subsequent islet transplantations. Maintenance immunosuppression consisted of triple immunosuppression (tacrolimus, mycophenolate mofetil, and prednisolone). Thirteen patients (age 50.9 ± 9.2 years, duration of diabetes 35 ± 9 years) received a total of 22 islet transplantations. One- and 2-year insulin independence was 62% and 42%, respectively; graft function was 100% and 92%, respectively. HbA1c dropped from 57.2 ± 13.1 (7.4 ± 1.2%) to 44.5 ± 11.8 mmol/molHb (6.2 ± 0.9%) (p = 0.003) after 2 years. Six of 13 patients suffered from severe hypoglycemia before islet transplantation. After transplantation, severe hypoglycemia was restricted to the only patient who lost graft function. Creatinine clearance was unchanged. Islet-after-kidney transplantation in patients with type 1 diabetes using an alemtuzumab-based induction regimen leads to considerable islet allograft function and improvement in glycemic control., (© Copyright 2015 The American Society of Transplantation and the American Society of Transplant Surgeons.)

Background: Depressive symptoms and decreased physical functioning are interrelated conditions and common in older persons, causing significant individual and societal burden. Evidence suggests that vitamin D supplementation may be beneficial for both mental and physical functioning. However, previous randomized controlled trials have yielded inconsistent results and often had suboptimal designs. This study examines the effect of vitamin D supplementation on both depressive symptoms and physical functioning in a high-risk population of older persons with low vitamin D status., Methods/design: The D-Vitaal study is a randomized, double-blind, placebo-controlled trial investigating the effects of a daily dose of 1200 IU vitamin D3 versus placebo for one year on depressive symptoms and physical functioning (primary outcomes) in older adults. Participants (N = 155, age 60-80 years) were recruited from the general population. Eligibility criteria included the presence of depressive symptoms, ≥1 functional limitation and serum 25-hydroxyvitamin D levels between 15 and 50/70 nmol/L (depending on season). Secondary outcomes include incidence of major depressive disorder, anxiety symptoms, health-related quality of life, cognitive function and cost-effectiveness of the intervention., Discussion: With this study, we aim to elucidate the effects of vitamin D supplementation on depressive symptoms and physical functioning in older persons who are at high risk of developing more substantial mental and physical problems. If effective, vitamin D supplementation can be a preventive intervention strategy that is easy to implement in the primary care setting., Trial Registration: Netherlands Trial Register NTR3845. Registered 6 February 2013.

Remodelling the methylome is a hallmark of mammalian development and cell differentiation. However, current knowledge of DNA methylation dynamics in human tissue specification and organ development largely stems from the extrapolation of studies in vitro and animal models. Here, we report on the DNA methylation landscape using the 450k array of four human tissues (amnion, muscle, adrenal and pancreas) during the first and second trimester of gestation (9,18 and 22 weeks). We show that a tissue-specific signature, constituted by tissue-specific hypomethylated CpG sites, was already present at 9 weeks of gestation (W9). Furthermore, we report large-scale remodelling of DNA methylation from W9 to W22. Gain of DNA methylation preferentially occurred near genes involved in general developmental processes, whereas loss of DNA methylation mapped to genes with tissue-specific functions. Dynamic DNA methylation was associated with enhancers, but not promoters. Comparison of our data with external fetal adrenal, brain and liver revealed striking similarities in the trajectory of DNA methylation during fetal development. The analysis of gene expression data indicated that dynamic DNA methylation was associated with the progressive repression of developmental programs and the activation of genes involved in tissue-specific processes. The DNA methylation landscape of human fetal development provides insight into regulatory elements that guide tissue specification and lead to organ functionality.

Background: An overview of 30 years of pancreas transplantation at a high volume center. Analysis of patient survival- and graft survival-associated risk factors., Methods: All pancreas transplantations performed in our center from January 1, 1984, till December 31, 2012, were evaluated. Covariates influencing pancreas graft survival were analyzed using both univariate and multivariate analysis and Kaplan-Meier analysis., Results: In the study period, 349 pancreas transplantations were performed. With the introduction of modern induction therapy in 1999, 5-year patient survival improved to 92.0% (P = 0.003). Five-year pancreas graft survival improved to 80.3% (P = 0.026). Pancreas graft survival was influenced by left or right donor kidney, transplant type, local origin of procurement team, pancreas cold ischemia time, recipient cerebrovascular disease. Pancreas donor risk index increased to 1.39 over the years and pancreas donor risk index 1.24 or higher is a risk factor for graft survival (P = 0.007)., Conclusions: This study has shown excellent results in patient and pancreas graft survivals after 30 years of pancreas transplantation in a high volume center. Different donor, transplant, and recipient related risk factors influence pancreas graft survival. Even with higher risk pancreas donors, good results can be achieved.

Loss of pancreatic islet β-cell mass and β-cell dysfunction are central in the development of type 2 diabetes (T2DM). We recently showed that mature human insulin-containing β-cells can convert into glucagon-containing α-cells ex vivo. This loss of β-cell identity was characterized by the presence of β-cell transcription factors (Nkx6.1, Pdx1) in glucagon(+) cells. Here, we investigated whether the loss of β-cell identity also occurs in vivo, and whether it is related to the presence of (pre)diabetes in humans and nonhuman primates. We observed an eight times increased frequency of insulin(+) cells coexpressing glucagon in donors with diabetes. Up to 5% of the cells that were Nkx6.1(+) but insulin(-) coexpressed glucagon, which represents a five times increased frequency compared with the control group. This increase in bihormonal and Nkx6.1(+)glucagon(+)insulin(-) cells was also found in islets of diabetic macaques. The higher proportion of bihormonal cells and Nkx6.1(+)glucagon(+)insulin(-) cells in macaques and humans with diabetes was correlated with the presence and extent of islet amyloidosis. These data indicate that the loss of β-cell identity occurs in T2DM and could contribute to the decrease of functional β-cell mass. Maintenance of β-cell identity is a potential novel strategy to preserve β-cell function in diabetes., (© 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.)

Patients with type 1 diabetes (T1D) suffer from beta-cell destruction by CD8+ T-cells that have preproinsulin as an important target autoantigen. It is of great importance to understand the molecular mechanism underlying the processing of preproinsulin into these CD8+ T-cell epitopes. We therefore studied a pathway that may contribute to the production of these antigenic peptides: degradation of proinsulin via ER associated protein degradation (ERAD). Analysis of the MHC class I peptide ligandome confirmed the presentation of the most relevant MHC class I-restricted diabetogenic epitopes in our cells: the signal peptide-derived sequence A15-A25 and the insulin B-chain epitopes H29-A38 and H34-V42. We demonstrate that specific silencing of Derlin-2, p97 and HRD1 by shRNAs increases steady state levels of proinsulin. This indicates that these ERAD constituents are critically involved in proinsulin degradation and may therefore also play a role in subsequent antigen generation. These ERAD proteins therefore represent interesting targets for novel therapies aiming at the reduction and possibly also prevention of beta-cell directed auto-immune reactions in T1D.

Differentiated derivatives of human pluripotent stem cells in culture are generally phenotypically immature compared to their adult counterparts. Their identity is often difficult to determine with certainty because little is known about their human fetal equivalents in vivo. Cellular identity and signaling pathways directing differentiation are usually determined by extrapolating information from either human adult tissue or model organisms, assuming conservation with humans. To resolve this, we generated a collection of human fetal transcriptional profiles at different developmental stages. Moreover, we developed an algorithm, KeyGenes, which uses this dataset to quantify the extent to which next-generation sequencing or microarray data resemble specific cell or tissue types in the human fetus. Using KeyGenes combined with the human fetal atlas, we identified multiple cell and tissue samples unambiguously on a limited set of features. We thus provide a flexible and expandable platform to monitor and evaluate the efficiency of differentiation in vitro., (Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.)

Because microvascular disease is one of the most important drivers of diabetic complications, early monitoring of microvascular integrity may be of clinical value. By assessing profiles of circulating microRNAs (miRNAs), known regulators of microvascular pathophysiology, in healthy controls and diabetic nephropathy (DN) patients before and after simultaneous pancreas-kidney transplantation (SPK), we aimed to identify differentially expressed miRNAs that associate with microvascular impairment. Following a pilot study, we selected 13 candidate miRNAs and determined their circulating levels in DN (n = 21), SPK-patients (n = 37), healthy controls (n = 19), type 1 diabetes mellitus patients (n = 15) and DN patients with a kidney transplant (n = 15). For validation of selected miRNAs, 14 DN patients were studied longitudinally up to 12 months after SPK. We demonstrated a direct association of miR-25, -27a, -126, -130b, -132, -152, -181a, -223, -320, -326, -340, -574-3p and -660 with DN. Of those, miR-25, -27a, -130b, -132, -152, -320, -326, -340, -574-3p and -660 normalized after SPK. Importantly, circulating levels of some of these miRNAs tightly associate with microvascular impairment as they relate to aberrant capillary tortuosity, angiopoietin-2/angiopoietin-1 ratios, circulating levels of soluble-thrombomodulin and insulin-like growth factor. Taken together, circulating miRNA profiles associate with DN and systemic microvascular damage, and might serve to identify individuals at risk of experiencing microvascular complications, as well as give insight into underlying pathologies., (© Copyright 2015 The American Society of Transplantation and the American Society of Transplant Surgeons.)

The second messenger cAMP is known to augment glucose-induced insulin secretion. However, its downstream targets in pancreatic β-cells have not been unequivocally determined. Therefore, we designed cAMP analogues by a structure-guided approach that act as Epac2-selective agonists both in vitro and in vivo. These analogues activate Epac2 about two orders of magnitude more potently than cAMP. The high potency arises from increased affinity as well as increased maximal activation. Crystallographic studies demonstrate that this is due to unique interactions. At least one of the Epac2-specific agonists, Sp-8-BnT-cAMPS (S-220), enhances glucose-induced insulin secretion in human pancreatic cells. Selective targeting of Epac2 is thus proven possible and may be an option in diabetes treatment.

Maturity-onset diabetes of the young (MODY) is the most common type of monogenic diabetes mellitus, estimated to account for approximately 1-4% of patients with diabetes. The predicted prevalence is, therefore, 20,000 patients in The Netherlands. Unfortunately less than 5% of these patients are confirmed by molecular genetic analysis. MODY is a clinically heterogeneous group of disorders caused by β-cell dysfunction, which is caused by mutations in multiple genes. MODY is characterized by an early onset of diabetes (often before the age of 30 years) and autosomal dominant inheritance. Patients do not usually require insulin at diagnosis. To emphasize the importance of genetic analysis we describe a 7-year-old boy and his siblings with MODY type 2. Molecular genetic testing is essential for individual patient care, as treatment options differ between the various forms of MODY; it also provides an opportunity to screen relatives.

Genetic testing for maturity-onset diabetes of the young (MODY) may be relevant for treatment and prognosis in patients with usually early-onset, non-ketotic, insulin-sensitive diabetes and for monitoring strategies in non-diabetic mutation carriers. This study describes the first 10 years of genetic testing for MODY in The Netherlands in terms of volume and test positive rate, medical setting, purpose of the test and age of patients tested. Some analyses focus on the most prevalent subtype, HNF1A MODY. Data were retrospectively extracted from a laboratory database. In total, 502 individuals were identified with a pathogenic mutation in HNF4A, GCK or HNF1A between 2001 and 2010. Although mutation scanning for MODY was used at an increasing rate, cascade testing was only used for one relative, on average, per positive index patient. Testing for HNF1A MODY was mostly requested by internists and paediatricians, often from regional hospitals. Primary care physicians and clinical geneticists rarely requested genetic testing for HNF1A MODY. Clinical geneticists requested cascade testing relatively more often than other health professionals. A substantial proportion (currently 29%) of HNF1A MODY probands was at least 40 years old at the time of testing. In conclusion, the number of individuals genetically tested for MODY so far in The Netherlands is low compared with previously predicted numbers of patients. Doctors' valuation of the test and patients' and family members' response to (an offer of) genetic testing on the other hand need to be investigated. Efforts may be needed to develop and implement translational guidelines.

Glucagon-like peptide-1-based (GLP-1-based) therapies improve glycemic control in patients with type 2 diabetes. While these agents augment insulin secretion, they do not mimic the physiological meal-related rise and fall of GLP-1 concentrations. Here, we tested the hypothesis that increasing the number of intestinal L cells, which produce GLP-1, is an alternative strategy to augment insulin responses and improve glucose tolerance. Blocking the NOTCH signaling pathway with the γ-secretase inhibitor dibenzazepine increased the number of L cells in intestinal organoid-based mouse and human culture systems and augmented glucose-stimulated GLP-1 secretion. In a high-fat diet-fed mouse model of impaired glucose tolerance and type 2 diabetes, dibenzazepine administration increased L cell numbers in the intestine, improved the early insulin response to glucose, and restored glucose tolerance. Dibenzazepine also increased K cell numbers, resulting in increased gastric inhibitory polypeptide (GIP) secretion. Using a GLP-1 receptor antagonist, we determined that the insulinotropic effect of dibenzazepine was mediated through an increase in GLP-1 signaling. Together, our data indicate that modulation of the development of incretin-producing cells in the intestine has potential as a therapeutic strategy to improve glycemic control.

Background: The complex endocrine and exocrine functionality of the human pancreas depends on an efficient fluid transport through the blood and the lymphatic vascular systems. The lymphatic vasculature has key roles in the physiology of the pancreas and in regulating the immune response, both important for developing successful transplantation and cell-replacement therapies to treat diabetes. However, little is known about how the lymphatic and blood systems develop in humans. Here, we investigated the establishment of these two vascular systems in human pancreas organogenesis in order to understand neovascularization in the context of emerging regenerative therapies., Methods: We examined angiogenesis and lymphangiogenesis during human pancreas development between 9 and 22 weeks of gestation (W9-W22) by immunohistochemistry., Results: As early as W9, the peri-pancreatic mesenchyme was populated by CD31-expressing blood vessels as well as LYVE1- and PDPN-expressing lymphatic vessels. The appearance of smooth muscle cell-coated blood vessels in the intra-pancreatic mesenchyme occurred only several weeks later and from W14.5 onwards the islets of Langerhans also became heavily irrigated by blood vessels. In contrast to blood vessels, LYVE1- and PDPN-expressing lymphatic vessels were restricted to the peri-pancreatic mesenchyme until later in development (W14.5-W17), and some of these invading lymphatic vessels contained smooth muscle cells at W17. Interestingly, between W11-W22, most large caliber lymphatic vessels were lined with a characteristic, discontinuous, collagen type IV-rich basement membrane. Whilst lymphatic vessels did not directly intrude the islets of Langerhans, three-dimensional reconstruction revealed that they were present in the vicinity of islets of Langerhans between W17-W22., Conclusion: Our data suggest that the blood and lymphatic machinery in the human pancreas is in place to support endocrine function from W17-W22 onwards. Our study provides the first systematic assessment of the progression of lymphangiogenesis during human pancreatic development.

Background: A growing number of subjects with diabetes take part in physical activities at altitude such as skiing, climbing, and trekking. Exercise under conditions of hypobaric hypoxia poses some unique challenges on subjects with diabetes, and the presence of diabetes can complicate safe and successful participation in mountain activities. Among others, altitude can alter glucoregulation. Furthermore, cold temperatures and altitude can complicate accurate reading of glucose monitoring equipment and storage of insulin. These factors potentially lead to dangerous hyperglycemia or hypoglycemia. Over the last years, more information has become available on this subject., Purpose: To provide an up-to-date overview of the pathophysiological changes during physical activity at altitude and the potential problems related to diabetes, including the use of (continuous) blood glucose monitors and insulin pumps. To propose practical recommendations for preparations and travel to altitude for subjects with diabetes., Data Sources and Synthesis: We researched PubMed, medical textbooks, and related Internet sites, and extracted human studies and data based on relevance for diabetes, exercise, and altitude., Limitations: Given the paucity of controlled trials regarding diabetes and altitude, we composed a narrative review and filled in areas lacking diabetes-specific studies with data obtained from nondiabetic subjects., Conclusions: Subjects with diabetes can take part in activities at high, and even extreme, altitude. However, careful assessment of diabetes-related complications, optimal preparation, and adequate knowledge of glycemic regulation at altitude and altitude-related complications is needed., (© 2014 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.)

The relation between atherosclerosis in the descending thoracic aortic (DTA), arterial stiffness and chronic kidney disease (CKD) in patients with diabetes mellitus (DM) remains unclear. The current aim was to evaluate associations of DTA atherosclerosis with arterial stiffness and parameters of CKD in asymptomatic patients with DM. A total of 213 asymptomatic patients with diabetes (mean age 52 years, 56% men) underwent cardiovascular risk assessment including multi-slice computed tomography (for non-invasive coronary angiography, from which DTA atherosclerosis can be derived), non-invasive assessment of arterial stiffness with applanation tonometry and assessment of renal function. Measurements of DTA atherosclerosis included assessment of DTA thickening and calcium score. Arterial stiffness was determined by the carotid-femoral pulse wave velocity (PWV), parameters of CKD included estimated glomerular filtration rate (eGFR) and urinary albumin-creatinine ratio (UACR). DTA atherosclerosis was present in 180 (84%) patients. Patients with DTA atherosclerosis had increased arterial stiffness, lower eGFR and higher UACR values. After multivariate correction, DTA calcium score was independently associated with PWV (β = 0.18, p = 0.04). Furthermore, both DTA maximal wall thickness and DTA calcium score were independently associated with eGFR (β = -7.37, p < 0.001 and β = -1.99, p < 0.003, respectively), but not with UACR. The increase in arterial stiffness by atherosclerosis seemed to be mediated by arterial calcification, while the DTA calcium score was independently associated with arterial stiffness, but not DTA maximal wall thickness. Furthermore, parameters of CKD in patients with DM had a distinct relationship with DTA atherosclerosis: DTA atherosclerosis was associated with eGFR but not with UACR.

High-fat, low-carbohydrate ketogenic diets (KD) are used for weight loss and for treatment of refractory epilepsy. Recently, short-time studies in rodents have shown that, besides their beneficial effect on body weight, KD lead to glucose intolerance and insulin resistance. However, the long-term effects on pancreatic endocrine cells are unknown. In this study we investigate the effects of long-term KD on glucose tolerance and β- and α-cell mass in mice. Despite an initial weight loss, KD did not result in weight loss after 22 wk. Plasma markers associated with dyslipidemia and inflammation (cholesterol, triglycerides, leptin, monocyte chemotactic protein-1, IL-1β, and IL-6) were increased, and KD-fed mice showed signs of hepatic steatosis after 22 wk of diet. Long-term KD resulted in glucose intolerance that was associated with insufficient insulin secretion from β-cells. After 22 wk, insulin-stimulated glucose uptake was reduced. A reduction in β-cell mass was observed in KD-fed mice together with an increased number of smaller islets. Also α-cell mass was markedly decreased, resulting in a lower α- to β-cell ratio. Our data show that long-term KD causes dyslipidemia, a proinflammatory state, signs of hepatic steatosis, glucose intolerance, and a reduction in β- and α-cell mass, but no weight loss. This indicates that long-term high-fat, low-carbohydrate KD lead to features that are also associated with the metabolic syndrome and an increased risk for type 2 diabetes in humans.

Upon a nutrient challenge, L cells produce glucagon-like peptide 1 (GLP-1), a powerful stimulant of insulin release. Strategies to augment endogenous GLP-1 production include promoting L-cell differentiation and increasing L-cell number. Here we present a novel in vitro platform to generate functional L cells from three-dimensional cultures of mouse and human intestinal crypts. We show that short-chain fatty acids selectively increase the number of L cells, resulting in an elevation of GLP-1 release. This is accompanied by the upregulation of transcription factors associated with the endocrine lineage of intestinal stem cell development. Thus, our platform allows us to study and modulate the development of L cells in mouse and human crypts as a potential basis for novel therapeutic strategies in patients with type 2 diabetes.

Purpose: To prospectively assess the effects of an exercise intervention on organ-specific fat accumulation and cardiac function in type 2 diabetes mellitus., Materials and Methods: Written informed consent was obtained from all participants, and the study protocol was approved by the medical ethics committee. The study followed 12 patients with type 2 diabetes mellitus (seven men; mean age, 46 years ± 2 [standard error]) before and after 6 months of moderate-intensity exercise, followed by a high-altitude trekking expedition with exercise of long duration. Abdominal, epicardial, and paracardial fat volume were measured by using magnetic resonance (MR) imaging. Cardiac function was quantified with cardiac MR, and images were analyzed by a researcher who was supervised by a senior researcher (4 and 21 years of respective experience in cardiac MR). Hepatic, myocardial, and intramyocellular triglyceride (TG) content relative to water were measured with proton MR spectroscopy at 1.5 and 7 T. Two-tailed paired t tests were used for statistical analysis., Results: Exercise reduced visceral abdominal fat volume from 348 mL ± 57 to 219 mL ± 33 (P < .01), and subcutaneous abdominal fat volume remained unchanged (P = .9). Exercise decreased hepatic TG content from 6.8% ± 2.3 to 4.6% ± 1.6 (P < .01) and paracardial fat volume from 4.6 mL ± 0.9 to 3.7 mL ± 0.8 (P = .02). Exercise did not change epicardial fat volume (P = .9), myocardial TG content (P = .9), intramyocellular lipid content (P = .3), or cardiac function (P = .5)., Conclusion: A 6-month exercise intervention in type 2 diabetes mellitus decreased hepatic TG content and visceral abdominal and paracardial fat volume, which are associated with increased cardiovascular risk, but cardiac function was unaffected. Tissue-specific exercise-induced changes in body fat distribution in type 2 diabetes mellitus were demonstrated in this study., (RSNA, 2013)

Aims/hypothesis: Incretin-based therapies improve glycaemic control in patients with type 2 diabetes. In animal models of diabetes, glucagon-like peptide-1 receptor agonists (GLP-1RAs) increase beta cell mass. GLP-1RAs are also evaluated in non-diabetic individuals with obesity and cardiovascular disease. However, their effect on beta cell mass in normoglycaemic conditions is not clear. Here, we investigate the effects of the GLP-1RA liraglutide on beta cell mass and function in normoglycaemic mice., Methods: C57BL/6J mice were treated with the GLP-1RA liraglutide or PBS and fed a control or high-fat diet (HFD) for 1 or 6 weeks. Glucose and insulin tolerance tests were performed after 6 weeks. BrdU was given to label proliferating cells 1 week before the animals were killed. The pancreas was taken for either histology or islet isolation followed by a glucose-induced insulin-secretion test., Results: Treatment with liraglutide for 6 weeks led to increased insulin sensitivity and attenuation of HFD-induced insulin resistance. A reduction in beta cell mass was observed in liraglutide-treated control and HFD-fed mice at 6 weeks, and was associated with a lower beta cell proliferation rate after 1 week of treatment. A similar reduction in alpha cell mass occurred, resulting in an unchanged alpha to beta cell ratio. In contrast, acinar cell proliferation was increased. Finally, islets isolated from liraglutide-treated control mice had enhanced glucose-induced insulin secretion., Conclusions/interpretation: Our data show that GLP-1RA treatment in normoglycaemic mice leads to increases in insulin sensitivity and beta cell function that are associated with reduced beta cell mass to maintain normoglycaemia.

The incretin hormone glucagon-like peptide 1 (GLP-1) promotes glucose homeostasis and enhances β-cell function. GLP-1 receptor agonists (GLP-1 RAs) and dipeptidyl peptidase-4 (DPP-4) inhibitors, which inhibit the physiological inactivation of endogenous GLP-1, are used for the treatment of type 2 diabetes. Using the Metabochip, we identified three novel genetic loci with large effects (30-40%) on GLP-1-stimulated insulin secretion during hyperglycemic clamps in nondiabetic Caucasian individuals (TMEM114; CHST3 and CTRB1/2; n = 232; all P ≤ 8.8 × 10(-7)). rs7202877 near CTRB1/2, a known diabetes risk locus, also associated with an absolute 0.51 ± 0.16% (5.6 ± 1.7 mmol/mol) lower A1C response to DPP-4 inhibitor treatment in G-allele carriers, but there was no effect on GLP-1 RA treatment in type 2 diabetic patients (n = 527). Furthermore, in pancreatic tissue, we show that rs7202877 acts as expression quantitative trait locus for CTRB1 and CTRB2, encoding chymotrypsinogen, and increases fecal chymotrypsin activity in healthy carriers. Chymotrypsin is one of the most abundant digestive enzymes in the gut where it cleaves food proteins into smaller peptide fragments. Our data identify chymotrypsin in the regulation of the incretin pathway, development of diabetes, and response to DPP-4 inhibitor treatment.

Islet transplantation is a promising therapy for type 1 diabetes, but graft function and survival are compromised by recurrent islet autoimmunity. Immunoprotection of islets will be required to improve clinical outcome. We engineered human β cells to express herpesvirus-encoded immune-evasion proteins, "immunevasins." The capacity of immunevasins to protect β cells from autoreactive T-cell killing was evaluated in vitro and in vivo in humanized mice. Lentiviral vectors were used for efficient genetic modification of primary human β cells without impairing their function. Using a novel β-cell-specific reporter gene assay, we show that autoreactive cytotoxic CD8(+) T-cell clones isolated from patients with recent onset diabetes selectively destroyed human β cells, and that coexpression of the human cytomegalovirus-encoded US2 protein and serine proteinase inhibitor 9 offers highly efficient protection in vitro. Moreover, coimplantation of these genetically modified pseudoislets with β-cell-specific cytotoxic T cells into immunodeficient mice achieves preserved human insulin production and C-peptide secretion. Collectively, our data provide proof of concept that human β cells can be efficiently genetically modified to provide protection from killing mediated by autoreactive T cells and retain their function in vitro and in vivo.