気管支拡張症における体組成と筋機能：比較縦断研究

Adults with bronchiectasis often present with altered body composition and muscle strength, yet prognostic value of peripheral muscle strength are not well understood. This study compared body composition and muscle function between adults with bronchiectasis and healthy controls and examined whether peripheral muscle strength estimates one-year clinical outcomes.

Adults with HRCT-confirmed bronchiectasis and controls underwent assessments including DXA (body composition), dynamometry (leg and shoulder strength), and core endurance tests. Participants with bronchiectasis were classified as having retained or impaired leg strength based on the 10^th percentile of control values and were reassessed after one year for exacerbations, dyspnoea, quality of life, anxiety and depression, and exercise capacity.

Seventy-one participants with bronchiectasis and 92 controls were included; 43 bronchiectasis participants completed follow-up. Females with bronchiectasis had lower appendicular muscle index (p = 0.018) and both sexes had lower bone mineral density compared to their control counterparts (p < 0.001). Osteopenia was 3 times more prevalent in females with bronchiectasis compared to their counterparts (54% versus 18%). Females with bronchiectasis have poorer lateral core endurance than those without (p ≤ 0.003). Leg strength was reduced in bronchiectasis compared to controls, regardless of sex (mean difference [95% CI] for males -25 [-50; -1] Kg and females -18 [-29; -7] Kg). Reduced leg strength is associated with worse dyspnoea, health related quality of life, and functional capacity over one year, explaining up to 33% of the variance (p ≤ 0.001).

Individuals with bronchiectasis exhibit impaired muscle function and bone health, with leg strength showing a significant association with clinical outcomes over one year.