152 Influencing factors of skeletal muscle weakness in adults with cystic fibrosis

Abstract

Background Muscle weakness in cystic fibrosis (CF) is reported to be reduced. Influencing factors are still not well defined. Aim This study correlates muscle strength measurements: handgrip force (HGF), quadriceps force (QF) and 6 minute walking distance (6MWD) in adult CF patients with physical activity (PA), pulmonary function and decline, colonization status, and number of hospitalization over the past year. Methods A handheld dynamometer (HHD) was used for HGF, a knee shuttle with HHD for the isometric voluntary QF and a standard 6MWD was performed. Results are expressed as % of normal. PA is measured using Sensewear Pro® armband [Moderate PA (mPA) = 4.8–7.2 metabolic equivalents (MET), vigorous PA (vPA) MET >7.2). Pulmonary function (FVC%, FEV1%) and number of hospitalization were retrieved from the medical file. Results are given as median (interquartile range). Results 31 patients (aged 25 (22–33)years) (12 female(38.7%))(12 chronically colonized(38.7%)) with a FEV1% of 75.4(57–84.7)% participated. Muscle strength was not related to pulmonary function or pulmonary function decline or pseudomonas colonization. 21 patients measured PA. They had an average MET of 1.7 (1.55–2.1), a mPA of 26′/day (19–68.5) and a m-vPA of 40′/day (22–98). The 6MWD was 72.7% (66.9–77.8), the QF% was 46% (40.2–57.4) and the HGF 97.4% (79.8–106.5). Pseudomonas negative patients were more PA (p = 0.034). None of the muscle strength measurements correlated with the PA. The number of hospitalizations correlated with the QF (p = 0.001), the HGF (p = 0.0001) and 6MWD (p = 0.007). Conclusion Muscle weakness in CF was only influenced by the number of hospitalizations over the past year.