Diabetes mellitus in an adult cystic fibrosis population.

Medical records of 132 patients attending an adult cystic fibrosis (CF) clinic were analysed to define the prevalence and clinical significance of diabetes mellitus (DM) in CF. Eighty four (63.6%) had normal blood glucose levels, 30 (22.8%) had hyperglycaemia only during intercurrent illness and 18 (13.6%) had DM. No significant differences were noted between the diabetic and non-diabetic groups for age, gender, height, weight, body mass index (BMI), forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) and pancreatic supplementation. Patients with hyperglycaemia during intercurrent illness had significantly lower BMI, FEV1% and FVC% than those with normal blood glucose levels. Of the diabetics four were managed on diet, three received oral hypoglycaemic agents and eleven were insulin requiring. The prevalence of DM in CF is considerable, severity of CF does not correlate with development of overt DM, and CF patients should be screened for DM by an oral glucose tolerance test on reaching adulthood.