The three currently marketed long-acting insulin analogs, glargine, detemir and insulin lispro protamine suspension (ILPS), represent the most significant advances in basal insulin supplementation since the 1940s and 1950s and the introduction of the intermediate-acting NPH (neutral protamine Hagedorn) insulin. As injection of NPH insulin lacks chronic maintenance of a steady-state low-level basal insulin during fasting periods, which can also expose patients to unpredictable nocturnal hypoglycemia, long-acting insulin analogs have been developed to overcome this important limitation of NPH insulin. ILPS is a protamine-based, intermediate-acting insulin formulation of the short-acting analog insulin lispro: its pharmacokinetic and pharmacodynamic characteristics are quite similar to the other basal insulin analogs glargine and detemir. In recent head-to-head randomized controlled trials of insulin-naïve patients with type 2 diabetes, ILPS achieved similar glycemic control compared with glargine or detemir. ILPS administered once daily is an effective and safe way to maintain a steady-state low-level basal insulin during night time, not dissimilar from that currently obtained with a one-day glargine or detemir administration.

OBJECTIVE

Glucagon-like peptide 1 (GLP-1) stimulates insulin secretion. However, GLP-1 also improves endothelial function in diabetes.

RESEARCH DESIGN AND METHODS

Sixteen type 2 diabetic patients and 12 control subjects received a meal, an oral glucose tolerance test (OGTT), and two hyperglycemic clamps, with or without GLP-1. The clamps were repeated in diabetic patients after 2 months of strict glycemic control.

RESULTS

During the meal, glycemia, nitrotyrosine, and plasma 8-iso prostaglandin F2α (8-iso-PGF2a) remained unchanged in the control subjects, whereas they increased in diabetic patients. Flow-mediated vasodilation (FMD) decreased in diabetes, whereas GLP-1 increased in both groups. During the OGTT, an increase in glycemia, nitrotyrosine, and 8-iso-PGF2a and a decrease in FMD were observed at 1 h in the control subjects and at 1 and 2 h in the diabetic patients. In the same way, GLP-1 increased in both groups at the same levels of the meal. During the clamps, in both the control subjects and the diabetic patients, a significant increase in nitrotyrosine and 8-iso-PGF2a and a decrease in FMD were observed, effects that were significantly reduced by GLP-1. After improved glycemic control, hyperglycemia during the clamps was less effective in producing oxidative stress and endothelial dysfunction and the GLP-1 administration was most effective in reducing these effects.

CONCLUSIONS

Our data suggest that during the meal GLP-1 can simultaneously exert an incretin effect on insulin secretion and a protective effect on endothelial function, reasonably controlling oxidative stress generation. The ability of GLP-1 in protecting endothelial function seems to depend on the level of glycemia, a phenomenon already described for insulin secretion.

OBJECTIVE

Insulin analogs are increasingly used in patients with type 2 diabetes. We compared the effect of basal, biphasic, prandial, and basal-bolus insulin regimens with insulin analogs to reach the hemoglobin A1c (HbA1c) target of <7% in people with type 2 diabetes.

RESEARCH DESIGN AND METHODS

We conducted an electronic search for randomized controlled trials (RCTs) involving insulin analogs. RCTs were included if they lasted at least 12 weeks, reported the proportion of diabetic patients reaching the HbA1c target of <7% (primary outcome), and the number of patients in any arm was >30.

RESULTS

We found 16 RCTs, with 20 comparisons and 7,759 patients. A greater proportion of patients achieved the HbA1c goal of <7% with both biphasic (odds ratio 1.88 [95% CI 1.38–2.55]) and prandial (2.07 [1.16–3.69]) insulin compared with basal insulin; this was associated for biphasic insulin with greater hypoglycemia (event/patient/30 days, mean difference, 0.34 [range 0–0.69]) and weight gain in kg (1.0 kg [0.28–1.73]). Compared with biphasic insulin, the basal-bolus regimen was associated with a greater chance to reach the HbA1c goal (odds ratio 1.75 [95% CI 1.11–2.77]), with no greater hypoglycemia or weight gain. The effect of insulin analogs on long-term diabetes complications is still lacking.

CONCLUSIONS

A greater proportion of type 2 diabetic patients can achieve the HbA1c goal <7% with biphasic or prandial insulin compared with basal insulin; in absolute terms, the basal-bolus regimen was best for the attainment of the HbA1c goal.

We report the effects of a Mediterranean-style diet, with or without calorie restriction, on biomarkers of aging and oxidative stress in overweight men. 192 men were randomly assigned to either a Mediterranean-style diet or a conventional diet. The intervention program was based on implementation of a Mediterranean dietary pattern in the overweight group (MED diet group), associated with calorie restriction and increased physical activity in the obese group (lifestyle group). Both groups were compared with participants in two matched control groups (advice groups). After 2 years, there was a significant difference in weight loss between groups, which was −14 kg (95% CI −20 to −8) in lifestyle groups and −2.0 kg (−4.4 to 0) in the advice groups, with a difference of −11.9 kg (CI −19 to −4.7 kg, P < .001); moreover, there was a significant difference between groups at 2 years for insulin (P = .04), 8-iso-PGF2α (P = .037), glucose (P = .04), and adiponectin (P = .01). Prolonged adherence to a Mediterranean-style diet, with or without caloric restriction, in overweight or obese men is associated with significant amelioration of multiple risk factors, including a better cardiovascular risk profile, reduced oxidative stress, and improved insulin sensitivity.

Peroxisome proliferator-activated receptor gamma polymorphisms have been widely associated with type 2 diabetes, although their role in the pathogenesis of vascular complications is not yet demonstrated. In this study, a cohort of 211 type 2 diabetes, 205 obese, and 254 control individuals was genotyped for Pro12Ala, C1431T, C-2821T polymorphisms, and for a newly identified polymorphism (A-2819G). The above-mentioned polymorphisms were analyzed by gene-specific PCR and direct sequencing of all samples. A significant difference was found for -2819G frequency when patients with type 2 diabetes—particularly diabetic women with the proliferative retinopathy—were compared with healthy control individuals. In conclusion, we identified a novel polymorphism, A-2819G, in PPARG gene, and we found it to be associated with type 2 diabetes and proliferative retinopathy in diabetic females. In the analyzed population, this variant represents a genetic risk factor for developing the diabetic retinopathy, whereas Pro12Ala and C1431T do not.