Microvascular Complications in Cystic Fibrosis Related Diabetes

Abstract

OBJECTIVE: The incidence of cystic fibrosis related diabetes (CFRD) and the prevalence of diabetes microvascular complications were determined at the University of Minnesota.

RESEARCH DESIGN AND METHODS: Cystic fibrosis patients have undergone annual oral glucose tolerance testing since 1990. Database review was performed to determine diabetes duration and the results of annual urine albumin: creatinine ratio (U_alb:Cr) screening and dilated retinal exams. In addition, 59 individuals underwent detailed retinopathy, nephropathy, neuropathy, and gastroenterpathy screening.

RESULTS: During 1990-2005, 775 patients age ≥6y were followed. CFRD was diagnosed by oral glucose tolerance test or fasting hyperglycemia (FH) in 285 subjects (52% female), 64% of who had fasting hyperglycemia (FH). Most patients with CFRD without FH progressed to CFRD with FH over time. No subject with CFRD without FH had retinopathy or abnormal U_alb:Cr. In CFRD subjects with FH with diabetes ≥10yrs duration, 14% had microalbuminuria and 16% had retinopathy. Autonomic neuropathy and GI symptoms were each seen in 52% and somatic abnormalities in 22% of patients with or without FH.

CONCLUSIONS: Diabetes microvascular complications occur in CFRD, although the prevalence of retinopathy and nephropathy appears to be less than that found in other forms of diabetes. Annual complication screening should occur after known diabetes duration of 5yrs in patients with CFRD with FH.