Cystic Fibrosis–Related Diabetes

Abstract

OBJECTIVE—Cystic fibrosis (CF)-related diabetes has been regarded as a mild form of diabetes with a low risk of severe diabetes complications. The prevalence of CF-related diabetes increases with age, resulting in a 50% prevalence of diabetes at age 30 years. We sought to investigate whether microvascular complications in CF-related diabetes appear with a relevant frequency. RESEARCH DESIGN AND METHODS—Thirty-eight patients aged 30 (range 18–55) years with CF-related diabetes for 20 (0–31) years were screened for diabetes complications. Because of chronic pulmonary infections, the majority of patients were regularly treated with aminoglycoside and cyclosporine given frequently. RESULTS—Since the pharmacological treatment of lung transplant patients could influence metabolical regulation and renal function, the results are given separately for nontransplanted (n = 29) and transplanted (n = 9) CF patients. Nine patients (27%) had retinopathy, two of which had proliferative retinopathy and needed laser treatment. Lung transplantation did not affect the prevalence of retinopathy. In nontransplanted patients, nine had hypertension, three microalbuminuria, and one elevated creatinine. None had macroalbuminuria. In transplanted patients, eight of nine had hypertension, two had microalbuminuria, and none had macroalbuminuria. Seven of nine lung transplant patients had elevated plasma creatinine, and severely reduced glomerular filtration rate was significantly more frequent. CONCLUSIONS—A high frequency of diabetic retinopathy was found in patients with insulin-treated CF-related diabetes, stressing the need for a regular screening program as in type 1 diabetes. Severely impaired kidney function was common in lung transplant patients, probably secondary to cyclosporine treatment.