Aim: The increase in life expectancy of cystic fibrosis (CF) patients has brought about a rise in new clinical problems in these patients, such as a decrease in bone mineral density (BMD). The cause of diminished BMD in CF is multi-factorial.
Methods: The aim of this cross-sectional study, conducted on 39 CF patients under the age of 18 years, was to evaluate the degree of bone mineralization and the prevalence of low BMD in these patients during a follow-up at the Cystic Fibrosis Regional Center of Tuscany, using a dual energy X-ray absorptiometry (DXA) scan, and to then study the factors correlated with low BMD.
Results: Areas BMD values (g/cm2) and Z-score values were determined. Eighteen patients (46%) out of the our sample had decreased BMD, while 21 patients (54%) had normal values. A statistically significant association was found between BMD Z-score values and pancreatic insufficiency, BMI<5th percentile and DeltaF508 homozygosis. Subjects treated with oral steroid therapy had a 3.9 times greater risk of developing osteoporosis compared to non-treated subjects (95% C.I.: 1.07-22.6; R.R. 4.9). An association was found between BMD Z-score values and FEV1 values (r=0.29; P=0.06), physical activity total score values (r=0.22; P=0.19) and the Chrispin-Norman chest radiographic score (r=-0.31; P=0.06).
Conclusion: Early identification of reduced bone mass values would permit early intervention to prevent the development of osteoporosis. Maintaining pulmonary function, guaranteeing optimal nutritional status, following an adequate program of physical activity and controlling steroid intake could maintain BMD over time.