Understanding The Interplay Between Factors That Influence Bone Mineral Density In CF

Background and Objectives: Multiple factors affect bone mineral density (BMD) in cystic fibrosis (CF). Our aim was to perform comprehensive analyses of parameters potentially contributing to BMD.

Methods: A prospective single center study assessing BMD, and correlations with multiple parameters including pancreatic status, lung functions, six-minute walk test (6MWT), clinical score (modified Shwachman-Kulczycki (SK) score), vitamin D, nutritional intake, hand-grip strength (HGS), habitual physical activity (smart watches) and QOL (SF-36 questionnaire).

Results: Forty CF patients, mean age 18.3±8.1 years, FEV1 74.7±17.9% predicted. Fifteen (37.5%) and 11 (27.5%) had osteopenia and osteoporosis, respectively. BMD was similar in pancreatic sufficient (PS, n=15) and insufficient (PI, n=25); median hip z-score -1.5 (-2.7-(-0.2) vs. -1.5 (-3.5-0.7), p=0.79; spine -0.8 (-2.2-2) vs. -1.2 (-4.4-1.5), p=0.39 in PS vs. PI, respectively. BMD correlated with HGS (r=0.72, p

Conclusions: A substantial number of CF patients have low BMD. Similar rates in PS and PI suggest that other factors, such as disease severity, may contribute to low BMD. SK and age, which can easily be obtained even with limited resources, were the best predictors of low BMD. Further larger multi-center studies are warranted to evaluate the contribution of multifactorial etiologies to low BMD in CF.