The Effect of Alcohol Intake on Insulin Sensitivity in Men

Abstract

OBJECTIVE—Population data suggest that alcohol consumption may influence the risk of diabetes in a biphasic manner, but this has not been tested by any controlled interventions. The object of this study was to determine whether reducing alcohol intake in moderate-to-heavy drinkers (40–110 g/day) results in improvement in insulin sensitivity. RESEARCH DESIGN AND METHODS—A 4-week run-in period where subjects maintained their usual drinking pattern was followed by randomization to a two-way cross-over intervention study. In each of two 4-week treatment interventions, subjects either substituted their usual alcohol intake with a 0.9% alcohol beer or maintained their usual alcohol intake. At the end of each 4-week period, insulin sensitivity as determined by the low-dose insulin glucose infusion test and the homeostasis model assessment (HOMA) score, and biomarkers of alcohol consumption (γ-glutamyl transpeptidase [γ-GT] and HDL cholesterol) were measured. RESULTS—A total of 16 healthy men aged 51.0 ± 2.7 (mean ± SEM) years with a BMI of 26.4 ± 0.61 kg/m2 completed the study. There was a large reduction in alcohol intake (72.4 ± 5.0 vs. 7.9 ± 1.6 g/day, P < 0.001) and significant reductions in γ-GT (geometric mean 24.4 units/l [95% CI 19.7–30.2] vs. 18.6 units/l [15.5–22.2], P < 0.01) and HDL cholesterol (1.36 ± 0.07 vs. 1.13 ± 0.07 mmol/l, P < 0.001). There was no effect of alcohol on insulin sensitivity index (ISI), fasting insulin, glucose, or HOMA score. CONCLUSIONS—A substantial reduction in alcohol intake from 7.2 to 0.8 standard drinks per day in healthy men did not change insulin sensitivity as measured by ISI or HOMA score.