The effect of evening alcohol consumption on next-morning glucose control in type 1 diabetes

OBJECTIVE - Alcohol is associated with acute hypoglycemia in patients with type I diabetes. After drinking alcohol in the evening, delayed hypoglycemi a has also been described, although its cause is unknown. We performed a co ntrolled study to investigate this phenomenon. RESEARCH DESIGN AND METHODS - We admitted six men With type I diabetes (age d 19-51 years, HbA(1c) 7.0-10.3%) on two occasions, from 5:00 P.M. to 12:00 noon the following day. They received regular insulin injections before st andardized meals, at 6:00 P.M. and 8:00 A.M., and a basal insulin infusion (0.15 mU - kg(-1) - min(-1)) from 11:00 P.M. They drank either dry white wi ne (0.75 g/kg alcohol) or mineral water at 9:00 P.M. over 90 min. Blood glu cose, alcohol, insulin, cortisol, growth hormone, and glucagon levels were measured. RESULTS - Blood ethanol reached a mean (SEM) peak of 19.1 (1.2) mmol/l and was undetectable by 8:00 A. M. There were no significant differences in eve ning or overnight blood glucose levels between the studies. In the morning, fasting and postprandial blood glucose levels Were significantly lower aft er consumption of wine (postprandial peak 8.9 [1.7] vs. 15 [1.5] mmol/l, P < 0.01), and from 10:00 A.M., five subjects required treatment for hypoglyc emia (nadir 1.9-2.9 mmol/l). None of the subjects had hypoglycemia after co nsumption of water. After consumption of wine, growth hormone secretion was significantly reduced between midnight and 4:00 A.M. (area under the curve 2.1 [1.1] vs. 6.5 [2.1] mug - l(-1) - h(-1), P = 0.04). There were no diff erences in insulin or other hormone levels. CONCLUSIONS - in type I diabetes, moderate consumption of alcohol in the ev ening may predispose patients to hypoglycemia after breakfast the next morn ing. This is associated with reduced nocturnal growth hormone secretion. Pa tients should be informed of this risk and advised regarding appropriate pr eventative measures.