Telmisartan improves vascular function independently of metabolic and antihypertensive effects in hypertensive subjects with impaired glucose tolerance.

BACKGROUND: Hypertensive patients with IGT have increased risk for cardiovascular disease and progression to diabetes mellitus. Clinical trials suggest that the ARB telmisartan uniquely possesses PPARγ agonistic properties and improves insulin resistance as well as vascular endothelial dysfunction. The aim of the present study was to compare vascular effects of telmisartan and losartan in relation to their metabolic and antihypertensive effects in hypertensive patients with IGT. MATERIALS AND METHODS: 24 patients were randomised in a double-blind, prospective, cross-over trial. At baseline and after 12 weeks of either treatment an oGTT, and endothelial function testing was performed. RESULTS: Endothelial function improved significantly by telmisartan treatment but not by losartan treatment (FMD; T: 7.9 ± 0.7%, vs B: 6.4 ± 0.8, p<0.01; vs L: 6.4 ± 0.6, p<0.001) at almost identical antihypertensive effect of both agents. Insulin resistance assessed by HOMA (T: 2.20 ± 0.47 vs B: 3.04 ± 0.60, p<0.01; vs L: 3.38 ± 0.84, T vs L p<0.05) and ISI120 (T: 0.114 ± 0.003 vs B: 0.092 ± 0.002, p<0.001; vs L: 0.090 ± 0.006, T vs L p<0.01) improved significantly after telmisartan only, as did glucose tolerance (p<0.01). The improvement of the endothelial function observed, significantly depended on pretreatment insulin resistance but was independent of improvements of insulin resistance, blood pressure or glucose tolerance. CONCLUSION: In hypertensive patients with IGT telmisartan compared to losartan improved endothelial function and insulin resistance independently, supporting the hypothesis that glucometabolic and vascular insulin resistance are differentially regulated.

Efficacy of a continuous GLP-1 infusion compared with a structured insulin infusion protocol to reach normoglycemia in nonfasted type 2 diabetic patients: a clinical pilot trial.

OBJECTIVE: Continuously administered insulin is limited by the need for frequent blood glucose measurements, dose adjustments, and risk of hypoglycemia. Regimens based on glucagon-like peptide 1 (GLP-1) could represent a less complicated treatment alternative. This alternative might be advantageous in hyperglycemic patients hospitalized for acute critical illnesses, who benefit from near normoglycemic control. RESEARCH DESIGN AND METHODS: In a prospective open randomized crossover trial, we investigated eight clinically stable type 2 diabetic patients during intravenous insulin or GLP-1 regimens to normalize blood glucose after a standardized breakfast. RESULTS: The time to reach a plasma glucose below 115 mg/dl was significantly shorter during GLP-1 administration (252 +/- 51 vs. 321 +/- 43 min, P < 0.01). Maximum glycemia (312 +/- 51 vs. 254 +/- 48 mg/dl, P < 0.01) and glycemia after 2 h (271 +/- 51 vs. 168 +/- 48 mg/dl, P = 0.012) and after 4 h (155 +/- 51 vs. 116 +/- 27 mg/dl, P = 0.02) were significantly lower during GLP-1 administration. CONCLUSIONS: GLP-1 infusion is superior to an established insulin infusion regimen with regard to effectiveness and practicability.

Endothermic heat production in honeybee winter clusters.

In order to survive cold northern winters, honeybees crowd tightly together in a winter cluster. Present models of winter cluster thermoregulation consider the insulation by the tightly packed mantle bees as the decisive factor for survival at low temperatures, mostly ignoring the possibility of endothermic heat production. We provide here direct evidence of endothermic heat production by 'shivering' thermogenesis. The abundance of endothermic bees is highest in the core and decreases towards the surface. This shows that core bees play an active role in thermal control of winter clusters. We conclude that regulation of both the insulation by the mantle bees and endothermic heat production by the inner bees is necessary to achieve thermal stability in a winter cluster.