Clinical Exercise Physiology, Ball State University, Muncie, IN.
Med Sci Sports Exerc. 2020 Jul;52(7):1532-1537. doi: 10.1249/MSS.0000000000002289.
Cardiorespiratory fitness (CRF) is known to be directly related to fat-free mass (FFM), therefore, it has been suggested that normalizing CRF to FFM (V˙O2peakFFM) may be the most accurate expression of CRF as related to exercise performance and cardiorespiratory function. However, the influence of V˙O2peakFFM (mL·kg FFM·min) on predicting mortality has been largely unexplored. This study aimed to primarily assess the relationship between V˙O2peakFFM and all-cause and disease-specific mortality risk in apparently healthy adults. Further, this study sought to compare the predictive ability of V˙O2peakFFM to V˙O2peak normalized to total body weight (V˙O2peakTBW) for mortality outcomes.
Participants included 2905 adults (1555 men, 1350 women) who completed a cardiopulmonary exercise test between 1970 and 2016 to determine CRF. Body composition was assessed using the skinfold method to estimate FFM. Cardiorespiratory fitness was expressed as V˙O2peakTBW and V˙O2peakFFM. Participants were followed for 19.0 ± 11.7 yr after their cardiopulmonary exercise test for mortality outcomes. Cox-proportional hazard models were performed to determine the relationship of V˙O2peakFFM with mortality outcomes. Parameter estimates were assessed to compare the predictive ability of CRF expressed as V˙O2peakTBW and V˙O2peakFFM.
Overall, V˙O2peakFFM was inversely related to all-cause, cardiovascular disease, and cancer mortality, with a 16.2%, 8.4%, and 8.0% lower risk per 1 mL·kg FFM·min improvement, respectively (P < 0.01). Further, assessment of the parameter estimates showed V˙O2peakFFM to be a significantly stronger predictor of all-cause mortality than V˙O2peakTBW (parameter estimates, -0.49 vs -0.16).
Body composition is an important factor when considering the relationship between CRF and mortality risk. Clinicians should consider normalizing CRF to FFM when feasible, because it will strengthen the predictive power of the measure.
众所周知，心肺功能（CRF）与去脂体重（FFM）直接相关，因此，有人提出将 CRF 标准化为 FFM（V˙O2peakFFM）可能是与运动表现和心肺功能最相关的 CRF 最准确的表达。然而，V˙O2peakFFM（mL·kg FFM·min）对预测死亡率的影响在很大程度上尚未得到探索。本研究旨在主要评估在看似健康的成年人中，V˙O2peakFFM 与全因和特定疾病死亡率风险之间的关系。此外，本研究还试图比较 V˙O2peakFFM 与 V˙O2peak 标准化为总体重（V˙O2peakTBW）对死亡率结果的预测能力。
参与者包括 2905 名成年人（1555 名男性，1350 名女性），他们在 1970 年至 2016 年间完成了心肺运动测试以确定 CRF。身体成分使用皮褶法评估，以估计 FFM。心肺功能以 V˙O2peakTBW 和 V˙O2peakFFM 表示。在心肺运动测试后，参与者随访 19.0±11.7 年以确定死亡率结果。使用 Cox 比例风险模型确定 V˙O2peakFFM 与死亡率结果的关系。评估参数估计值以比较以 V˙O2peakTBW 和 V˙O2peakFFM 表示的 CRF 的预测能力。
总体而言，V˙O2peakFFM 与全因、心血管疾病和癌症死亡率呈负相关，每改善 1 mL·kg FFM·min，风险分别降低 16.2%、8.4%和 8.0%（P < 0.01）。此外，参数估计值的评估表明，V˙O2peakFFM 是全因死亡率的显著更强预测因子，而 V˙O2peakTBW 则不然（参数估计值，-0.49 与-0.16）。
身体成分是考虑 CRF 与死亡率风险之间关系的一个重要因素。临床医生应在可行的情况下考虑将 CRF 标准化为 FFM，因为这将增强该测量的预测能力。
