Weight gain associated with improved glycemic control in population-based sample of subjects with type I diabetes.

Previous studies have suggested that weight gain is an identifiable risk of efforts to lower blood glucose with intensive insulin therapy in type I (insulin-dependent) diabetic subjects. This study examined this relationship in a population-based sample of type I diabetic subjects participating in the Wisconsin Epidemiologic Study of Diabetic Retinopathy. Four hundred five adults (aged greater than or equal to 21 yr) with type I diabetes, who were diagnosed before age 30 yr, were studied from 1980 to 1982 and in a follow-up examination from 1984 to 1986. Weight gain over the 4-yr interval averaged 1.8 +/- 5.9 kg. Weight gain was significantly associated (r = -0.26, P less than 0.001) with improvements in glycosylated hemoglobin levels; the quartile of subjects with the greatest improvements in glycemic control gained 3.4 kg, whereas the quartile of subjects with the smallest improvements in glycemic control lost 0.6 kg. Weight gain was also correlated with increases in the number of shots of insulin per day and change in the treatment regimen from one type of insulin to a combination of short- and long-acting insulins. These results suggest that weight gain may be an adverse consequence of improved glycemic control. Efforts to better understand the mechanism explaining weight gain and to prevent weight gain are needed.