Submitted to: Journal of Clinical Endocrinology and Metabolism
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/15/2002
Publication Date: 5/15/2002
Citation: Davies, M.J., Baer, D.J., Judd, J.T., Brown, E., Campbell, W.S., Taylor, P.R. 2002. Effect of chronic moderate alcohol intake on fasting insulin and glucose concentrations and insulin sensitivity in postmenopausal women: a diet- controlled intervention study. Journal of Clinical Endocrinology and Metabolism. Interpretive Summary: Moderate alcohol consumption (1 to 2 drinks per day) is associated with certain health benefits in various population studies. It was noted that individuals who consumed moderate amounts of alcohol have reduced insulin and triglyceride concentrations and increased HDL-cholesterol. There have been no clinical trials evaluating the effects of moderate alcohol consumption on fasting insulin concentrations and insulin sensitivity. Therefore, we addressed whether chronic consumption of low to moderate amounts of alcohol influences fasting glucose and insulin and insulin sensitivity in non-diabetic, postmenopausal women who were not on hormone replacement therapy. Fifty-one women were assigned to consume one alcoholic drink per day, two alcoholic drinks per day and a non-alcoholic beverage for 8 weeks each as part of a controlled diet. Blood was collected at the end of each diet period and used to measure glucose and insulin concentrations, which were used to assess insulin sensitivity via two different indices. We found that consumption of two alcoholic drinks per day compared to the non-alcoholic beverage significantly reduced fasting insulin concentration and increased insulin sensitivity. Fasting insulin concentration and insulin sensitivity were not different after consumption of one alcoholic per day compared to non-alcoholic beverage. Fasting glucose concentration was not affected by alcohol consumption. Similar results were found after controlling for baseline body mass index, which is associated with fasting insulin concentrations and insulin sensitivity. This is the first controlled study to report that moderate alcohol consumption reduced fasting plasma insulin concentrations and enhanced insulin sensitivity in non-diabetic, postmenopausal women.
Technical Abstract: Reduced fasting insulin and improved insulin sensitivity are associated with moderate alcohol intake in cross-sectional studies. These changes may be related to the improved lipid profile associated with moderate alcohol intake and cardioprotective effects of alcohol. No controlled- feeding studies have addressed effects of chronic alcohol consumption on fasting insulin and glucose and insulin sensitivity. We examined whether chronic consumption of 1 or 2 alcohol drinks/d influenced glucose and insulin in non-diabetic, post-menopausal women, not on hormone replacement therapy. 51 women were assigned to consume either 15g alcohol/d, 30g alcohol/d or no alcohol for 8-wk as part of a controlled diet in a randomized crossover design. All foods and beverages were provided and energy intake was adjusted to maintain constant body weight. Serum was collected from fasted volunteers on three separate days at the end of each dietary period and pooled. Insulin, glucose, or triglycerides were used to assess insulin sensitivity via different indices. Fasting insulin and glucose, and insulin sensitivity were compared among treatments with and without controlling for differences in baseline BMI. Consumption of 30 g alcohol/d compared to placebo significantly reduced fasting insulin and increased insulin sensitivity. Fasting insulin and insulin sensitivity were not different after consumption of 15 g alcohol/d compared to placebo. Fasting glucose was not different across treatments. Similar results were obtained after controlling for differences in baseline BMI, except for one index of insulin sensitivity. These data demonstrate that chronic consumption of 2 alcoholic drinks per day reduces fasting insulin and improves insulin sensitivity.