Bone density, body composition, and inflammatory status in cystic fibrosis

Low body weight and loss of bone mass are major problems in adults with cystic fibrosis (CF) and chronic pulmonary infection. Although these complications probably have a multifactorial origin, we hypothesized that the continuous acute-phase inflammatory and catabolic state may contribute. We determined body composition, bone turnover, physical activity, and circulating interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and their soluble receptors in 22 adults with CF and 22 age- and sex-matched healthy subjects. Comparisons were also made within patients before and after treatment of an exacerbation of respiratory symptoms. The patients had a lower mean (95% confidence interval [CI]) fat-free mass (FFM) 39.9 (36.3, 43.6) kg than healthy subjects, 49.4 (45.1, 53.7) kg, p < 0.05. The patients were in negative nitrogen balance and 20 had bone mineral density (BMD) Z scores