Department of Research and Development, Ciro, Horn, The Netherlands; Department of Respiratory Medicine, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands; REVAL-Rehabilitation Research Center, Faculty of Rehabilitation Sciences, Hasselt University, Agoralaan Diepenbeek, Belgium.
Department of Medicine, Pulmonary and Critical Care Medicine, Philipps-University of Marburg (UMR), Member of the German Center for Lung Research (DZL), Marburg, Germany.
Chest. 2023 May;163(5):1071-1083. doi: 10.1016/j.chest.2022.11.040. Epub 2022 Dec 5.
Alterations in body composition, including a low fat-free mass index (FFMI), are common in patients with COPD and occur regardless of body weight.
Is the impact of low FFMI on exercise capacity, health-related quality of life (HRQL), and systemic inflammation different among patients with COPD stratified in different BMI classifications?
We analyzed baseline data of patients with COPD from the COPD and Systemic Consequences-Comorbidities Network (COSYCONET) cohort. Assessments included lung function, bioelectrical impedance analysis, 6-min walk distance (6MWD), HRQL, and inflammatory markers. Patients were stratified in underweight, normal weight (NW), preobese, and obese according to BMI and as presenting low, normal, or high FFMI using 25th and 75th percentiles of reference values. Linear mixed models were used to investigate the associations between fat-free mass (FFM) and fat mass with secondary outcomes in each BMI group.
Two thousand one hundred thirty-seven patients with COPD (Global Initiative for Chronic Obstructive Lung Disease stages 1-4; 61% men; mean ± SD age, 65 ± 8 years; mean ± SD FEV, 52.5 ± 18.8% predicted) were included. The proportions of patients in underweight, NW, preobese, and obese groups were 12.3%, 31.3%, 39.6%, and 16.8%, respectively. The frequency of low FFMI decreased from lower to higher BMI groups (underweight, 81%; NW, 53%; preobese, 42%; and obese, 39%). FFM was associated with the 6MWD in the underweight group, even when adjusting for a broad set of covariates (P < .05). HRQL was not associated with FFM after adjustment for lung function or dyspnea (P > .32). Fat mass was associated with higher systemic inflammation in the NW and preobese groups (P < .05).
In patients with COPD with lower weight, such as underweight patients, higher FFMI is associated independently with better exercise capacity. In contrast, in preobese and obese patients with COPD, a higher FFMI was not consistently associated with better outcomes.
无论体重如何，COPD 患者的身体成分改变，包括低去脂体重指数（FFMI），很常见。
在根据 BMI 分类的不同 COPD 患者中，低 FFMI 对运动能力、健康相关生活质量（HRQL）和全身炎症的影响是否不同？
我们分析了 COPD 和系统后果合并症网络（COSYCONET）队列中 COPD 患者的基线数据。评估包括肺功能、生物电阻抗分析、6 分钟步行距离（6MWD）、HRQL 和炎症标志物。根据 BMI 将患者分为体重不足、正常体重（NW）、超重和肥胖，根据参考值的 25%和 75%百分位将 FFMI 分为低、正常和高。使用线性混合模型研究每个 BMI 组中去脂体重（FFM）和脂肪量与次要结局之间的关系。
共纳入 2137 例 COPD 患者（慢性阻塞性肺疾病全球倡议分期 1-4；61%为男性；平均年龄±标准差，65±8 岁；平均预计 FEV，52.5±18.8%）。体重不足、NW、超重和肥胖组的患者比例分别为 12.3%、31.3%、39.6%和 16.8%。低 FFMI 的频率从较低 BMI 组到较高 BMI 组逐渐降低（体重不足，81%；NW，53%；超重，42%；肥胖，39%）。在调整了广泛的协变量后，FFM 与体重不足组的 6MWD 相关（P<.05）。在调整了肺功能或呼吸困难后，HRQL 与 FFM 无关（P>.32）。在 NW 和超重组中，脂肪量与更高的全身炎症相关（P<.05）。
在体重较低的 COPD 患者中，如体重不足的患者，较高的 FFMI 与更好的运动能力独立相关。相比之下，在肥胖的 COPD 患者中，较高的 FFMI 并不始终与更好的结局相关。
