Type 1 diabetes mellitus (insulin-dependent diabetes mellitus) is one of the most common chronic diseases of childhood and adolescence. Previous studies suggest that as many as one third of young women with diabetes have eating disturbances. Rydall and colleagues studied the natural history of eating disorders in adolescent girls with type 1 diabetes and the association between eating disorders and microvascular complications.

In 1988, the authors contacted 121 adolescent girls aged 12 to 18 years and invited them to participate in a self-reported survey of eating attitudes and behavior. Eight did not return the questionnaire and six subsequently refused to participate. A total of 107 girls (88.4 percent) participated in the study at that time. For the present study, the authors attempted to contact these patients during 1992 and 1993 to obtain follow-up information; 91 (85 percent) of the 107 agreed to participate in the follow-up study. One of the 11 patients who did not participate in the follow-up study was in the group with highly disordered eating behavior at baseline and two of the 11 were in the group with moderately disordered eating behavior. One of the five patients lost to follow-up was in the group with highly disordered eating at baseline.

Nine of the 91 women in the current study met the criteria for highly disordered eating at baseline, and 17 met the criteria for moderately disordered eating. Ten of the 26 patients with highly or moderately disordered eating behavior at baseline were found to have improved at the time of the follow-up study. Fourteen of the 65 patients without evidence of an eating disorder at baseline had acquired disordered eating behavior in the intervening years. Patients with highly disordered eating behavior had a significantly higher mean hemoglobin A_1c value at baseline than did those in the groups with moderately disordered eating behavior or no disordered eating behavior.

Ophthalmologic examinations were performed in 71 patients who participated in the follow-up study. Diabetic retinopathy was present in 24 (33 percent) of the patients. Retinopathy was found in six (86 percent) of the seven patients with highly disordered eating behavior at baseline and in six (43 percent) of the 14 patients with moderately disordered eating behavior at baseline. In contrast, 12 (24 percent) of the 50 patients without disordered eating behavior at baseline had evidence of retinopathy. Disordered eating accounted for more of the variance in predicting retinopathy than did the duration of diabetes or the hemoglobin A_1c level.

The patients in the study demonstrated less well-recognized features of an eating disorder. Other studies have shown that such patients may not comply with diabetes treatment and may have unstable metabolic control, hyperglycemia, recurrent ketoacidosis and an earlier onset of microvascular complications. Bulimia and purging were uncommon. Aside from dieting to lose weight, intentional omission of an insulin dose and underdosing of insulin were the most common means of inducing weight loss. These two methods for losing weight were reported by one third of the women at follow-up.

The authors conclude that disordered eating behavior is common and persists in young women with type 1 diabetes. The findings suggest that routine screening for eating disturbances may be indicated in young women with diabetes.