The stimulation of insulin vs. inhibition of glucagon secretion in relation to the antidiabetic action of glucagon-like peptide-1 (GLP-1) is not established. Here, the influence of a 4-wk increase in circulating GLP-1 by inhibition of dipeptidyl peptidase-4 (DPP-4) on 24-h glucose and insulin and glucagon responses to breakfast was studied in subjects with dietary controlled diabetes [age: 65 +/- 8 yr (SD), body mass index: 27.3 +/- 3.3 kg/m(2), fasting plasma glucose: 9.0 +/- 1.3 mmol/liter]. Compared with placebo (n = 19), a specific DPP-4 inhibitor [(1-[[(3-hydroxy-1-adamantyl) amino] acetyl]-2-cyano-(S)-pyrrolidine) (LAF237); 100 mg daily, n = 18] reduced fasting glucose by 0.70 mmol/liter (P = 0.037), 4-h prandial glucose excursion by 1.45 mmol/liter (P < 0.001), and mean 24-h glucose by 0.93 mmol/liter (P < 0.001). Baseline and postprandial active GLP-1 were increased by LAF237. The glucagon response to breakfast was reduced by LAF237 (glucagon levels at 60 min were 88 +/- 8 pg/ml before treatment vs. 77 +/- 5 pg/ml after; P = 0.001). In contrast, the overall insulin levels were not altered. The 4-wk reduction in glucagon correlated with the reduction in 2-h glucose (r = 0.61; P = 0.008). No such association was observed for insulin. Thus, improved metabolic control by DPP-4 inhibition in type 2 diabetes is seen in association with reduced glucagon levels and, despite the lower glycemia, unaltered insulin levels.

OBJECTIVE—Glucagon-like peptide-1 (GLP-1) has been proposed as a new treatment modality for type 2 diabetes. To circumvent the drawback of the short half-life of GLP-1, inhibitors of the GLP-1–degrading enzyme dipeptidyl peptidase IV (DPP IV) have been examined. Such inhibitors improve glucose tolerance in insulin-resistant rats and mice. In this study, we examined the 4-week effect of 1-[[[2-[(5-cyanopyridin-2-yl)amino]ethyl]amino]acetyl]-2-cyano-(S)-pyrrolidine (NVP DPP728), a selective, orally active inhibitor of DPP IV, in subjects with diet-controlled type 2 diabetes in a placebo-controlled double-blind multicenter study. RESEARCH DESIGN AND METHODS—A total of 93 patients (61 men and 32 women), aged 64 ± 9 years (means ± SD) and with BMI 27.3 ± 2.7 kg/m², entered the study. Fasting blood glucose was 8.5 ± 1.5 mmol/l, and HbA_1c was 7.4 ± 0.7%. Before and after treatment with NVP DPP728 at 100 mg × 3 (n = 31) or 150 mg × 5 (n = 32) or placebo (n = 30), subjects underwent a 24-h study with standardized meals (total 2,000 kcal). RESULTS—Compared with placebo, NVP DPP728 at 100 mg t.i.d. reduced fasting glucose by 1.0 mmol/l (mean), prandial glucose excursions by 1.2 mmol/l, and mean 24-h glucose levels by 1.0 mmol/l (all P < 0.001). Similar reductions were seen in the 150-mg b.i.d. treatment group. Mean 24-h insulin was reduced by 26 pmol/l in both groups (P = 0.017 and P = 0.023). Although not an efficacy parameter foreseen in the study protocol, HbA_1c was reduced to 6.9 ± 0.7% in the combined active treatment groups (P < 0.001). Laboratory safety and tolerability was good in all groups. CONCLUSIONS—We conclude that inhibition of DPP IV is a feasible approach to the treatment of type 2 diabetes in the early stage of the disease.

Background: Different healthy food patterns may modify cardiometabolic risk. We investigated the effects of an isocaloric healthy Nordic diet on insulin sensitivity, lipid profile, blood pressure and inflammatory markers in people with metabolic syndrome.Methods: We conducted a randomized dietary study lasting for 18–24 weeks in individuals with features of metabolic syndrome (mean age 55 years, BMI 31.6 kg m⁻², 67% women). Altogether 309 individuals were screened, 200 started the intervention after 4‐week run‐in period, and 96 (proportion of dropouts 7.9%) and 70 individuals (dropouts 27%) completed the study, in the Healthy diet and Control diet groups, respectively. Healthy diet included whole‐grain products, berries, fruits and vegetables, rapeseed oil, three fish meals per week and low‐fat dairy products. An average Nordic diet served as a Control diet. Compliance was monitored by repeated 4‐day food diaries and fatty acid composition of serum phospholipids.Results: Body weight remained stable, and no significant changes were observed in insulin sensitivity or blood pressure. Significant changes between the groups were found in non‐HDL cholesterol (−0.18, mmol L⁻¹ 95% CI −0.35; −0.01, P = 0.04), LDL to HDL cholesterol (−0.15, −0.28; −0.00, P = 0.046) and apolipoprotein B to apolipoprotein A1 ratios (−0.04, −0.07; −0.00, P = 0.025) favouring the Healthy diet. IL‐1 Ra increased during the Control diet (difference −84, −133; −37 ng L⁻¹, P = 0.00053). Intakes of saturated fats (E%, beta estimate 4.28, 0.02; 8.53, P = 0.049) and magnesium (mg, −0.23, −0.41; −0.05, P = 0.012) were associated with IL‐1 Ra.Conclusions: Healthy Nordic diet improved lipid profile and had a beneficial effect on low‐grade inflammation.

OBJECTIVE—Insulin detemir is a soluble long-acting basal insulin analog designed to overcome the limitations of conventional basal insulin formulations. Accordingly, insulin detemir has been compared with NPH insulin with respect to glycemic control (HbA_1c, prebreakfast glucose levels and variability, and hypoglycemia) and timing of administration. RESEARCH DESIGN AND METHODS—People with type 1 diabetes (n = 408) were randomized in an open-label, parallel-group trial of 16-week treatment duration using either insulin detemir or NPH insulin. Insulin detemir was administered twice daily using two different regimens, either before breakfast and at bedtime (IDet_morn+bed) or at a 12-h interval (IDet_12h). NPH insulin was administered before breakfast and at bedtime. Mealtime insulin was given as the rapid-acting insulin analog insulin aspart. RESULTS—With both insulin detemir groups, clinic fasting plasma glucose was lower than with NPH insulin (IDet_12h vs. NPH, −1.5 mmol/l [95% CI −2.51 to −0.48], P = 0.004; IDet_morn+bed vs. NPH, −2.3 mmol/l (−3.32 to −1.29), P < 0.001), as was self-measured prebreakfast plasma glucose (P = 0.006 and P = 0.004, respectively). The risk of minor hypoglycemia was lower in both insulin detemir groups (25%, P = 0.046; 32%, P = 0.002; respectively) compared with NPH insulin in the last 12 weeks of treatment, this being mainly attributable to a 53% reduction in nocturnal hypoglycemia in the IDet_morn+bed group (P < 0.001). Although HbA_1c for each insulin detemir group was not different from the NPH group, HbA_1c for the pooled insulin detemir groups was significantly lower than for the NPH group (mean difference −0.18% [−0.34 to −0.02], P = 0.027). Within-person between-day variation in self-measured prebreakfast plasma glucose was lower for both detemir groups (both P < 0.001). The NPH group gained weight during the study, but there was no change in weight in either of the insulin detemir groups (IDet_12h vs. NPH, −0.8 kg [−1.44 to −0.24], P = 0.006; IDet_morn+bed vs. NPH, −0.6 kg [−1.23 to −0.03], P = 0.040). CONCLUSIONS—Overall glycemic control with insulin detemir was improved compared with NPH insulin. The data provide a basis for tailoring the timing of administration of insulin detemir to the individual person’s needs.

Age-dependent associations between type 1 diabetes risk genes HLA, INS VNTR, and CTLA-4 and autoantibodies to GAD65 (GADAs), ICA512/IA-2, insulin, and islet cells were determined by logistic regression analysis in 971 incident patients with type 1 diabetes and 702 control subjects aged 0–34 years. GADAs were associated with HLA-DQ2 in young but not in older patients (P = 0.009). Autoantibodies to insulin were negatively associated with age (P < 0.0001) but positively associated with DQ8 (P = 0.03) and with INS VNTR (P = 0.04), supporting possible immune tolerance induction. ICA512/IA-2 were negatively associated with age (P < 0.0001) and with DQ2 (P < 0.0001) but positively associated with DQ8 (P = 0.04). Males were more likely than females to be negative for GADA (P < 0.0001), autoantibodies to islet cells (P = 0.04), and all four autoantibody markers (P = 0.004). The CTLA-4 3′ end microsatellite marker was not associated with any of the autoantibodies. We conclude that age and genetic factors such as HLA-DQ and INS VNTR need to be combined with islet autoantibody markers when evaluating the risk for type 1 diabetes development.