Objective: To determine whether insulin restriction increases morbidity and mortality in women with type 1 diabetes.
Research design and methods: This is an 11-year follow-up study of women with type 1 diabetes. A total of 234 women (60% of the original cohort) participated in the follow-up. Mean age was 45 years and mean diabetes duration was 28 years at follow-up. Mean BMI was 25 kg/m(2) and mean A1C was 7.9%. Measures of diabetes self-care behaviors, diabetes-specific distress, fear of hypoglycemia, psychological distress, and eating disorder symptoms were administered at baseline. At follow-up, mortality data were collected through state and national databases. Follow-up data regarding diabetes complications were gathered by self-report.
Results: Seventy-one women (30%) reported insulin restriction at baseline. Twenty-six women died during follow-up. Based on multivariate Cox regression analysis, insulin restriction conveyed a threefold increased risk of mortality after controlling for baseline age, BMI, and A1C. Mean age of death was younger for insulin restrictors (45 vs. 58 years, P < 0.01). Insulin restrictors reported higher rates of nephropathy and foot problems at follow-up. Deceased women had reported more frequent insulin restriction (P < 0.05) and reported more eating disorder symptoms (P < 0.05) at baseline than their living counterparts.
Conclusions: Our data demonstrate that insulin restriction is associated with increased rates of diabetes complications and increased mortality risk. Mortality associated with insulin restriction appeared to occur in the context of eating disorder symptoms, rather than other psychological distress. We propose a screening question appropriate for routine diabetes care to improve detection of this problem.