Pilot study of resveratrol in older adults with impaired glucose tolerance.
BACKGROUND
Resveratrol, a plant-derived polyphenol, has shown promising effects on insulin sensitivity and glucose tolerance in animal models and is also reported to have cardioprotective properties, but human studies are limited. In a pilot study, we tested the hypothesis that resveratrol improves glucose metabolism and vascular function in older adults with impaired glucose tolerance (IGT).


METHODS
Ten subjects aged 72 ± 3 years (M ± SD) with IGT were enrolled in a 4-week open-label study of resveratrol (daily dose 1, 1.5, or 2 g). Following a standard mixed meal (110 g carbohydrate, 20 g protein, 20 g fat), we measured 3-hour glucose and insulin area under the curve (AUC), insulin sensitivity (Matsuda index), and secretion (corrected insulin response at 30 minutes). Endothelial function was assessed by reactive hyperemia peripheral arterial tonometry (reactive hyperemia index) before and 90 minutes postmeal. Results did not differ by dose, so data were combined for analysis.


RESULTS
At baseline, body mass index was 29 ± 5 kg/m(2), fasting plasma glucose 110 ± 13 mg/dL, and 2-hour glucose 183 ± 33 mg/dL. After 4 weeks of resveratrol, fasting plasma glucose was unchanged, but peak postmeal (185 ± 10 vs 166 ± 9 mg/dL, p = .003) and 3-hour glucose AUC (469 ± 23 vs 428 ± 19, p = .001) declined. Matsuda index improved (3.1 ± 0.5 vs 3.8 ± 0.5, p = .03), and corrected insulin response at 30 minutes was unchanged (0.6 ± 0.1 vs 0.5 ± 0.5, p = .49). There was a trend toward improved postmeal reactive hyperemia index (baseline vs resveratrol postmeal delta -0.4 ± 0.2 vs 0.2 ± 0.3, p = .06). Weight, blood pressure, and lipids were unchanged.


CONCLUSIONS
At doses between 1 and 2 g/day, resveratrol improves insulin sensitivity and postmeal plasma glucose in subjects with IGT. These preliminary findings support the conduct of larger studies to further investigate the effects of resveratrol on metabolism and vascular function.
Department of Medicine, Albert Einstein College of Medicine, Bronx, New York, USA. jill.crandall@einstein.yu.edu
Jill P
JP
Crandall
Valerie
V
Oram
Georgeta
G
Trandafirescu
Migdalia
M
Reid
Preeti
P
Kishore
Meredith
M
Hawkins
Hillel W
HW
Cohen
Nir
N
Barzilai
D000368:Aged; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology*; D001786:Blood Glucose / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000187:drug effects; D005260:Female; D018149:Glucose Intolerance / Q000188:drug therapy* / Q000378:metabolism; D006706:Homeostasis / Q000187:drug effects; D006801:Humans; D008297:Male; D010865:Pilot Projects; D000077185:Resveratrol; D013267:Stilbenes / Q000008:administration & dosage / Q000494:pharmacology*
D000975:Antioxidants; D001786:Blood Glucose; D013267:Stilbenes; D000077185:Resveratrol