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Objective: Beta-cell function in type 1 diabetes clinical trials is commonly measured by C-peptide response to a secretagogue in either a mixed-meal tolerance test (MMTT) or a glucagon stimulation test (GST). The Type 1 Diabetes TrialNet Research Group and the European C-peptide Trial (ECPT) Study Group conducted parallel randomized studies to compare the sensitivity, reproducibility, and tolerability of these procedures.Research Design and Methods: In randomized sequences, 148 TrialNet subjects completed 549 tests with up to 2 MMTT and 2 GST tests on separate days, and 118 ECPT subjects completed 348 tests (up to 3 each) with either two MMTTs or two GSTs.Results: Among individuals with up to 4 years' duration of type 1 diabetes, >85% had measurable stimulated C-peptide values. The MMTT stimulus produced significantly higher concentrations of C-peptide than the GST. Whereas both tests were highly reproducible, the MMTT was significantly more so (R(2) = 0.96 for peak C-peptide response). Overall, the majority of subjects preferred the MMTT, and there were few adverse events. Some older subjects preferred the shorter duration of the GST. Nausea was reported in the majority of GST studies, particularly in the young age-group.Conclusions: The MMTT is preferred for the assessment of beta-cell function in therapeutic trials in type 1 diabetes. [ABSTRACT FROM AUTHOR]

Objective: We tested the hypothesis that elevated transferrin saturation is associated with an increased risk of any form of diabetes, as well as type 1 or type 2 diabetes separately.Research Design and Methods: We used two general population studies, The Copenhagen City Heart Study (CCHS, N = 9,121) and The Copenhagen General Population Study (CGPS, N = 24,195), as well as a 1:1 age- and sex-matched population-based case-control study with 6,129 patients with diabetes from the Steno Diabetes Centre and 6,129 control subjects, totaling 8,535 patients with diabetes and 37,039 control subjects.Results: In the combined studies, odds ratios in those with transferrin saturation ≥50% vs. <50% were 2.1 (95% CI 1.3-3.4; P = 0.003) for any form of diabetes; 2.6 (1.2-5.6; P = 0.01) for type 1 diabetes; and 1.7 (1.4-2.1; P = 0.001) for type 2 diabetes.Conclusions: Elevated transferrin saturation confers a two- to threefold increased risk of developing any form of diabetes, as well as type 1 and type 2 diabetes separately. [ABSTRACT FROM AUTHOR]

Objective: To examine whether iron intake and genetically determined iron overload interact in predisposing to the development of childhood islet autoimmunity (IA) and type 1 diabetes (T1D)., Research Design and Methods: In The Environmental Determinants of Diabetes in the Young (TEDDY) study, 7,770 genetically high-risk children were followed from birth until the development of IA and progression to T1D. Exposures included energy-adjusted iron intake in the first 3 years of life and a genetic risk score (GRS) for increased circulating iron., Results: We found a U-shaped association between iron intake and risk of GAD antibody as the first autoantibody. In children with GRS ≥2 iron risk alleles, high iron intake was associated with an increased risk of IA, with insulin as first autoantibody (adjusted hazard ratio 1.71 [95% CI 1.14; 2.58]) compared with moderate iron intake., Conclusions: Iron intake may alter the risk of IA in children with high-risk HLA haplogenotypes., (© 2023 by the American Diabetes Association.)

Objective: Cardiovascular mortality risk remains high among patients with type 2 diabetes. Oxidative stress indicated by high urinary excretion of the biomarker for RNA oxidation, 8-oxo-7,8-dihydroguanosine (8-oxoGuo), is associated with an increased risk of death in newly diagnosed and treated patients. We assessed whether 8-oxoGuo is associated with specific cardiovascular and all-cause mortality risk., Research Design and Methods: Urinary biomarkers for nucleic acid oxidation were measured in a cohort of patients with type 2 diabetes aged ≥60 years ( n = 1,863), along with biochemical measurements, questionnaire findings, and Central Person Registry information to estimate the hazard ratios (HRs) for log2-transformed RNA oxidation using Cox regression., Results: During the 5-year follow-up, 173 of 1,863 patients had died (9.3%), including 73 patients who died of cardiovascular disease (42.2%). Doubling of RNA oxidation was associated with an HR of all-cause mortality of 2.10 (95% CI 1.63-2.71; P < 0.001) and an HR of cardiovascular death of 1.82 (95% CI 1.20-2.77; P = 0.005) after multiple adjustments. The 5-year absolute risks (ARs) of all-cause mortality (AR 13.9 [95% CI 10.8-17.0] vs. AR 6.10 [95% CI 4.00-8.30]) and cardiovascular mortality (AR 5.49 [95% CI 3.44-7.55] vs. AR 3.16 [95% CI 1.59-4.73]) were approximately two times higher in the highest quartile of RNA oxidation than in the lowest quartile., Conclusions: We conclude that high RNA oxidation is associated with all-cause and cardiovascular mortality risk in patients with type 2 diabetes. Targeting oxidative stress via interventions with long-term follow-up may reveal the predictive potential of the biomarker 8-oxoGuo., (© 2017 by the American Diabetes Association.)

Objective: Mortality is increased in patients with hereditary hemochromatosis, in individuals from the general population with increased transferrin saturation (TS), and also in patients with type 1 diabetes and increased TS from a highly specialized diabetes clinic. Thus, we have recommended targeted screening for TS in specialized diabetes clinics. Whether mortality is also increased in individuals from the general population with diabetes and increased TS is unknown., Research Design and Methods: In two Danish population studies (N = 84,865), we examined mortality according to baseline levels of TS and hemochromatosis genotype (HFE) G → A substitution at nucleotide 845 in codon 282 (C282Y/C282Y) in individuals with diabetes (type 1, N = 118; type 2, N = 3,228; total, N = 3,346)., Results: The cumulative survival rate was reduced in individuals with diabetes with TS ≥50% vs. <50% (log-rank; P < 0.0001), with median survival ages of 66 and 79 years, respectively. The hazard ratio (HR) for TS ≥50% vs. <50% was 2.0 (95% CI 1.3-2.8; P = 0.0004) for total mortality overall (and similar for men and women separately); 2.6 (1.3-5.4; P = 0.008) for neoplasms; and 3.4 (2.0-6.0; P = 0.00002) for endocrinological causes. A stepwise increased risk of total mortality was observed for stepwise increasing TS (log-rank test, P = 0.0001), with an HR for TS ≥70% vs. TS <20% of 4.8 (2.0-12; P = 0.0006). The HR for total mortality in individuals with diabetes for C282Y/C282Y versus wild type/wild type was 3.3 (1.04-10; P = 0.04), and for C282Y/C282Y and TS ≥50% versus wild type/wild type and TS <50% was 6.0 (1.5-24; P = 0.01). Six percent of these premature deaths can possibly be avoided by early screening for TS or HFE genotype., Conclusions: Individuals with diabetes, ascertained in the general population, with increased TS or HFE genotype have a twofold to sixfold increased risk of premature death.

Objective: It is not known to what extent iron overload predicts prognosis in patients with diabetes after diagnosis or whether iron overload is a risk factor independent of the HFE genotype. We investigated total and cause-specific mortality according to increased transferrin saturation (≥ 50 vs. <50%), whether mortality is driven by the HFE genotype, and whether early measurement of transferrin saturation helps to predict mortality outcome., Research Design and Methods: Cohort 1 included patients with late-onset type 1 diabetes (n = 716) with a cross-sectional measurement of transferrin saturation and HFE genotype. Cohort 2 included consecutively recruited patients with any diabetes (n = 6,120), transferrin saturation measurement at referral, and HFE genotype if transferrin saturation was above 50%., Results: In cohort 1, the hazard ratio for total mortality was 2.3 (95% CI 1.3-3.9; P = 0.002) and for cause-specific mortality by neoplasms was 5.8 (2.4-14; P = 0.00007) in patients with transferrin saturation ≥ 50 vs. <50%. Excluding genotypes C282Y/C282Y and C282Y/H63D gave similar results. The hazard ratio for total mortality was 4.0 (1.2-13; P = 0.01) and for cause-specific mortality by neoplasms was 13 (3.6-49; P = 0.0001) in patients with C282Y/C282Y versus wild type. In cohort 2, total mortality was not different in patients with transferrin saturation ≥ 50 vs. <50%. In patients with late-onset type 1 diabetes and transferrin saturation ≥ 50%, the hazard ratio for total mortality was 0.4 (0.2-0.9; P = 0.03) in cohort 2 versus cohort 1., Conclusions: Increased transferrin saturation and HFE genotype C282Y/C282Y predict total mortality in patients with late-onset type 1 diabetes, and increased transferrin saturation after diagnosis is an independent risk factor. Early measurement of transferrin saturation in these patients leading to early intervention improves life expectancy.

Objective: Metabolic activation of the innate immune system governed by interleukin (IL)-1β contributes to β-cell failure in type 2 diabetes. Gevokizumab is a novel, human-engineered monoclonal anti-IL-1β antibody. We evaluated the safety and biological activity of gevokizumab in patients with type 2 diabetes., Research Design and Methods: In a placebo-controlled, dose-escalation study, a total of 98 patients were randomly assigned to placebo (17 subjects) or gevokizumab (81 subjects) at increasing doses and dosing schedules. The primary objective of the study was to evaluate the safety profile of gevokizumab in type 2 diabetes. The secondary objectives were to assess pharmacokinetics for different dose levels, routes of administration, and regimens and to assess biological activity., Results: The study drug was well tolerated with no serious adverse events. There was one hypoglycemic event whereupon concomitant insulin treatment had to be reduced. Clearance of gevokizumab was consistent with that for a human IgG(2), with a half-life of 22 days. In the combined intermediate-dose group (single doses of 0.03 and 0.1 mg/kg), the mean placebo-corrected decrease in glycated hemoglobin was 0.11, 0.44, and 0.85% after 1, 2 (P = 0.017), and 3 (P = 0.049) months, respectively, along with enhanced C-peptide secretion, increased insulin sensitivity, and a reduction in C-reactive protein and spontaneous and inducible cytokines., Conclusions: This novel IL-1β-neutralizing antibody improved glycemia, possibly via restored insulin production and action, and reduced inflammation in patients with type 2 diabetes. This therapeutic agent may be able to be used on a once-every-month or longer schedule.

Objective: Interleukin (IL)-1 impairs insulin secretion and induces beta-cell apoptosis. Pancreatic beta-cell IL-1 expression is increased and interleukin-1 receptor antagonist (IL-1Ra) expression reduced in patients with type 2 diabetes. Treatment with recombinant IL-1Ra improves glycemia and beta-cell function and reduces inflammatory markers in patients with type 2 diabetes. Here we investigated the durability of these responses., Research Design and Methods: Among 70 ambulatory patients who had type 2 diabetes, A1C >7.5%, and BMI >27 kg/m(2) and were randomly assigned to receive 13 weeks of anakinra, a recombinant human IL-1Ra, or placebo, 67 completed treatment and were included in this double-blind 39-week follow-up study. Primary outcome was change in beta-cell function after anakinra withdrawal. Analysis was done by intention to treat., Results: Thirty-nine weeks after anakinra withdrawal, the proinsulin-to-insulin (PI/I) ratio but not stimulated C-peptide remained improved (by -0.07 [95% CI -0.14 to -0.02], P = 0.011) compared with values in placebo-treated patients. Interestingly, a subgroup characterized by genetically determined low baseline IL-1Ra serum levels maintained the improved stimulated C-peptide obtained by 13 weeks of IL-1Ra treatment. Reductions in C-reactive protein (-3.2 mg/l [-6.2 to -1.1], P = 0.014) and in IL-6 (-1.4 ng/l [-2.6 to -0.3], P = 0.036) were maintained until the end of study., Conclusions: IL-1 blockade with anakinra induces improvement of the PI/I ratio and markers of systemic inflammation lasting 39 weeks after treatment withdrawal.

Objective: To evaluate the perinatal outcome and the frequency of maternal complications in pregnancies of women with type 2 diabetes during 1996-2001., Research Design and Methods: Medical records of 61 consecutive singleton pregnancies in women with type 2 diabetes from 1996 to 2001 were studied. Pregnancy outcome was compared with that of pregnant women with type 1 diabetes during 1996-2000, the background population, and pregnant women with type 2 diabetes during 1980-1992 from the same department., Results: The perinatal mortality in pregnancies complicated by type 2 diabetes (4/61, 6.6%) was increased four- and ninefold, respectively, and the rate of major congenital malformations (4/60, 6.7%) was more than doubled, although not statistically significant, compared with type 1 diabetic pregnancies and the background population. The glycemic control was similar or better in women with type 2 diabetes compared with women with type 1 diabetes. Multivariate logistic regression analysis in the pooled group of pregnancies with pregestational diabetes from 1996 to 2001 showed that high HbA(1c) at admission and type 2 diabetes were independently associated with a serious adverse fetal outcome (perinatal mortality and/or major congenital malformations). The perinatal mortality and the rate of major congenital malformations in type 2 diabetic pregnancies have increased during the last decade., Conclusions: The perinatal outcome of pregnancies in women with type 2 diabetes during 1996-2001 is poor. It is worse than the outcome of pregnancies in women with type 1 diabetes and the background population in the same period, as well as in women with type 2 diabetes studied during 1982-1990.

Objective: The use of cyclosporin in recent-onset type 1 diabetes has demonstrated the potential for immune intervention in the treatment and prevention of the disease. However, a proportion of patients failed to respond to cyclosporin treatment. Indicators of resistance to immune intervention would be valuable for the most effective use of such therapies in disease prevention. The aim of this study was to determine whether presence of IA-2 antibodies is such a marker., Research Design and Methods: IA-2 antibodies were determined by radioligand binding assay in sera from patients recruited into the Canadian-European cyclosporin trial. Insulin dose requirements and glucagon-stimulated C-peptide secretion were analyzed in patients grouped according to IA-2 antibody status at entry., Results: Cyclosporin treatment had no significant effect on frequency of IA-2 antibodies during the 1 year of treatment. Cyclosporin caused significant reduction in insulin requirements and significant increases in C-peptide secretion mainly in patients negative for IA-2 antibodies. Analysis of GAD antibodies in combination with antibodies to IA-2 indicated that the group most resistant to cyclosporin were IA-2 antibody positive, GAD antibody negative., Conclusions: The results demonstrate that IA-2 antibody analysis is valuable in identifying individuals for whom immunosuppressive treatment would be most effective.

The pathogenetic mechanisms leading to beta-cell destruction and insulin-dependent diabetes mellitus (IDDM) are major histocompatibility complex (MHC) nonrestricted and are MHC associated and beta-cell specific. The macrophage peptide hormone interleukin 1 (IL-1) may be the primary MHC-nonrestricted beta-cell-destructive molecule. Beta-Cell death most likely results from free radical induction by IL-1. Thus, islet cell-specific antibodies and cytotoxic T-lymphocytes are secondary in importance and time. The potentiation of IL-1 effects on beta-cells by tumor necrosis factor alpha (TNF), another macrophage hormone controlled by a gene in the HLA region on chromosome 6, may account for the MHC association of IDDM. In the experimental model of IDDM etiopathogenesis described, release of beta-cell antigen, processed and presented by macrophages to helper T-lymphocytes, initiates a self-perpetuating and self-limiting circuit of cytokine production of which IL-1 is beta-cell cytotoxic. As postulated, the IL-1 effect is potentiated by TNF, whereas IL-1 and/or TNF production is controlled in a quantitative way by HLA-D genes.