Presence of cystic fibrosis-related diabetes mellitus is tightly linked to poor lung function in patients with cystic fibrosis: data from the European Epidemiologic Registry of Cystic Fibrosis.

Data derived from a cross-sectional analysis of 7,566 patients stratified into six age groups were used to compare lung function, body mass index (BMI), and weight for age in patients with and without cystic fibrosis-related diabetes mellitus (CFDM). The presence of CFDM was tightly linked to poor lung function, regardless of age. The mean value of FEV(1) % predicted in the age groups < 10, 10-< 15, 15-< 20, 20-< 25, 25-< 30, and 30 years or older were 87%, 77%, 69%, 58%, 55%, and 53% in the nondiabetic cystic fibrosis (CF) patients as compared to 79%, 66%, 55%, 49%, 46%, and 44% in the diabetic CF patients. BMI and weight for age were also lower in diabetic than nondiabetic CF patients in all age groups, except for BMI in the youngest patients. The difference in lung function and in nutritional parameters between diabetic and nondiabetic CF patients was not linked to presence or absence of any specific pathogen in the lower respiratory tract. These results confirm and extend those of earlier studies in smaller numbers of patients, and they clearly identify CFDM as a powerful determinant of severe lung disease and reduced survival in patients with CF and diabetes mellitus.