Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA.
Division of Pulmonary & Critical Care Medicine, University of Michigan Health System, Ann Arbor, MI, USA.
Respir Res. 2018 Apr 10;19(1):62. doi: 10.1186/s12931-018-0771-6.
Low muscle mass is associated with increased mortality in the general population but its prognostic value in at-risk smokers, those without expiratory airflow obstruction, is unknown. We aimed to test the hypothesis that reduced muscle mass is associated with increased mortality in at-risk smokers.
Measures of both pectoralis and paravertebral erector spinae muscle cross-sectional area (PMA and PVMA, respectively) as well as emphysema on chest computed tomography (CT) scans were performed in 3705 current and former at-risk smokers (≥10 pack-years) aged 45-80 years enrolled into the COPDGene Study between 2008 and 2013. Vital status was ascertained through death certificate. The association between low muscle mass and mortality was assessed using Cox regression analysis.
During a median of 6.5 years of follow-up, 212 (5.7%) at-risk smokers died. At-risk smokers in the lowest (vs. highest) sex-specific quartile of PMA but not PVMA had 84% higher risk of death in adjusted models for demographics, smoking, dyspnea, comorbidities, exercise capacity, lung function, emphysema on CT, and coronary artery calcium content (hazard ratio [HR] 1.85 95% Confidence interval [1.14-3.00] P = 0.01). Results were consistent when the PMA index (PMA/height) was used instead of quartiles. The association between PMA and death was modified by smoking status (P = 0.04). Current smokers had a significantly increased risk of death (lowest vs. highest PMA quartile, HR 2.25 [1.25-4.03] P = 0.007) while former smokers did not.
Low muscle mass as measured on chest CT scans is associated with increased mortality in current smokers without airflow obstruction.
NCT00608764.
肌肉量减少与一般人群的死亡率增加有关，但在有风险的吸烟者（无呼气气流受限者）中，其预后价值尚不清楚。我们旨在检验假设，即肌肉量减少与有风险的吸烟者的死亡率增加有关。
在 2008 年至 2013 年间，对 3705 名年龄在 45-80 岁之间、有风险的当前和前吸烟者（≥10 包年）进行了胸 CT 扫描上的胸肌和椎旁竖脊肌横截面积（PMA 和 PVMA）以及肺气肿的测量。通过死亡证明确定存活状态。使用 Cox 回归分析评估低肌肉量与死亡率之间的关联。
在中位 6.5 年的随访期间，212 名（5.7%）有风险的吸烟者死亡。在调整了人口统计学、吸烟、呼吸困难、合并症、运动能力、肺功能、CT 上的肺气肿和冠状动脉钙含量等因素的模型中，PMA 最低（与最高）性别四分位数相比，风险最高的有风险吸烟者的死亡风险增加了 84%（危险比 [HR] 1.85 95%置信区间 [1.14-3.00] P = 0.01）。当使用 PMA 指数（PMA/身高）代替四分位数时，结果是一致的。PMA 与死亡的关联受吸烟状态的影响（P = 0.04）。当前吸烟者的死亡风险显著增加（最低与最高 PMA 四分位数相比，HR 2.25 [1.25-4.03] P = 0.007），而前吸烟者则没有。
在无气流受限的当前吸烟者中，胸 CT 扫描上测量的肌肉量减少与死亡率增加有关。
NCT00608764。
