RESUMO
OBJECTIVES: To determine the modifiable factors affecting glucose variability in people with cystic fibrosis (CF). CF-related diabetes (CFRD) is the most common complication of CF, and its presence increases morbidity and mortality in patients. Patients with CF (with and without CFRD) have potentially harmful glucose fluctuations and glucose excursions when compared to healthy adults. Carbohydrate intake and exercise have been shown to affect glycemia. Therefore, our hypothesis was that the proportion of energy from carbohydrates and total energy expenditure (TEE) would influence glucose fluctuations in adults with CF. METHODS: A cross-sectional study involved 36 patients with CF, in whom continuous glucose monitoring systems were installed. Glucose fluctuations were then quantified using 3 indexes: mean amplitude of glucose excursions, standard deviation and coefficient of variation. Patients filled out a 3-day food diary to quantify energy intake and the proportions of calories from carbohydrates, fats and proteins, and they wore Sensewear Armbands to estimate spontaneous TEE and footsteps walked. Glucose tolerance status was determined using oral glucose tolerance tests. RESULTS: Patients with CF with normal and impaired glucose tolerance had fewer glucose fluctuations than patients with CFRD (p<0.05). However, linear regression models used to determine whether nutrition or energy expenditure affects glucose fluctuations demonstrated that energy, the proportion of carbohydrates, of fat and of protein, TEE or the number of footsteps walked did not affect glucose fluctuation indexes (p>0.05). CONCLUSIONS: TEE and the proportion of energy from carbohydrates did not affect glucose fluctuations in adults with CF.