Background-The short-term effects of hydroxymethylglutaryl coenzyme A reductase inhibitors (statins) on endothelial function at doses that do not affect plasma lipid levels are not known. Methods and Results-We investigated the short-term effects of cerivastatin, a hydroxymethylglutaryl coenzyme A reductase inhibitor, on endothelial function and endothelium-related products in elderly diabetic patients. Twenty-seven elderly diabetic patients (aged 69.3Ϯ3.4 years), with or without mild hypercholesterolemia, were enrolled in this study, which tested cerivastatin treatment (0.15 mg/d) for 3 days. Endothelium-dependent flow-mediated dilatation, endothelium-independent dilatation by nitroglycerin in the brachial artery, nitric oxide-related products (nitrite/nitrate and cGMP), endothelium-related products (von Willebrand Factor, soluble vascular cell adhesion molecule-1, and soluble intercellular adhesion molecule-1), and a marker of oxidant stress (8-isoprostane) were assessed. Levels of plasma lipids were not changed before and after treatment with cerivastatin. Flow-mediated dilatation was significantly increased by cerivastatin treatment, as were plasma nitrite/nitrate levels (from 16.

OBJECTIVE—We investigated the effect of glimepiride, a third-generation sulfonylurea hypoglycemic agent, on insulin resistance in elderly patients with type 2 diabetes, in connection with plasma adiponectin and 8-epi-prostagrandin F2α (8-epi-PGF2α), an oxidative stress marker. RESEARCH DESIGN AND METHODS—A total of 17 elderly patients with type 2 diabetes received 12 weeks of treatment with glimepiride. Homeostasis assessment model of insulin resistance (HOMA-IR), homeostasis assessment model of β-cell function, HbA1c, C-peptide in 24-h pooled urine (urine CPR), and plasma concentrations of 8-epi-PGF2α, tumor necrosis factor-α (TNF-α), plasminogen activator inhibitor type 1, and adiponectin were measured at various times. The metabolic clearance rate of glucose (MCR-g) was also assessed by a hyperinsulinemic-euglycemic clamp. RESULTS—After 8 weeks of glimepiride treatment, significant reductions were observed in HbA1c (from 8.4 ± 1.9 to 6.9 ± 1.0%), HOMA-IR (from 2.54 ± 2.25 to 1.69 ± 0.95%), and plasma TNF-α concentrations (from 4.0 ± 2.0 to 2.6 ± 2.5 pg/ml). MCR-g was significantly increased from 3.92 ± 1.09 to 5.73 ± 1.47 mg · kg−1 · min−1. Plasma adiponectin increased from 6.61 ± 3.06 to 10.2 ± 7.14 μg/ml. In control subjects, who maintained conventional treatment, no significant changes were observed in any of these markers. CONCLUSIONS—Glimepiride remarkably improved insulin resistance, suggested by a significant reduction in HOMA-IR, an increase in MCR-g, and a reduction in HbA1c without changing extrapancreatic β-cell function and urine CPR. Increased plasma adiponectin and decreased plasma TNF-α may underlie the improvement of insulin resistance with glimepiride.

Abstract-Dehydroepiandrosterone (DHEA) is speculated to have an antiatherosclerotic effect, although the mechanism of action remains unclear. The objective of the current study was to determine whether the antiatherosclerotic effect of DHEA is related to its conversion to estrogen and to define the role of nitric oxide (NO) in the antiatherosclerotic effect of DHEA. Forty-eight oophorectomized rabbits were divided into 5 groups and fed the following diets for 10 weeks: group 1, a regular rabbit diet plus 1% cholesterol (a high-cholesterol diet [HCD]); group 2, an HCD plus 0.3% DHEA; group 3, an HCD plus 0.3% DHEA and fadrozole (2.0 mg ⅐ kg Ϫ1 ⅐ d Ϫ1 ), a specific aromatase inhibitor; group 4, an HCD plus 17␤-estradiol (20 g ⅐ kg Ϫ1 ⅐ d Ϫ1 ); and group 5, a regular diet. Atherosclerotic lesions, lipid deposition in aortic vessels, and basal and stimulated NO release were measured in the aforementioned groups of rabbits. NO release was measured by using an NO-selective electrode as well as by measuring vascular responses and the plasma NO metabolites nitrite and nitrate. The plasma total cholesterol level was increased, but there were no significant differences in lipid profile in the 4 groups of rabbits that were fed the HCD. The area occupied by atherosclerosis in the thoracic aorta was diminished by Ϸ60% in the DHEA-treated rabbits (group 2) compared with the HCD group of rabbits (group 1); there was a corresponding 80% decrease in the estradiol group (group 4) but only a 30% decrease in the DHEA plus fadrozole group (group 3). In the aortas of rabbits from groups 1 and 3, the acetylcholine-induced and tone-related basal NO-mediated relaxations were diminished compared with those of the controls (group 5). However, these relaxations were restored in the aortas of group 2 and 4 rabbits, and an increase in NO release was observed in groups 2 and 4 compared with groups 1 and 3, as measured by an NO-selective electrode. Injection of neither solvent (20% ethanol/distilled water) nor fadrozole significantly affected the atherosclerotic area or the NO-related responses described above. We conclude that Ϸ50% of the total antiatherosclerotic effect of DHEA was achieved through the conversion of DHEA to estrogen. NO may also play a role in the antiatherosclerotic effect of DHEA and 17␤-estradiol. have not yet been determined. In plasma, where the major portion of these hormones is present in the sulfate form, it is possible that DHEA-S serves as a reservoir for DHEA, since various tissues have been shown to contain steroid sulfatases. 1 The peak plasma levels of DHEA and DHEA-S occur at approximately age 25 years, decrease progressively thereafter, and diminish by 95% around the age of 85 years. Epidemiological evidence has shown that adult men with high plasma DHEA-S levels are less likely to die of cardiovascular disease. 2 A study indicated that administration of DHEA reduced aortic fatty streak formation and cholesterol accumulation by Ϸ30% to 40% in cholesterol-fed rabbits. 3 Another report has shown a 50% reduction...

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