Neder J A, Nery L E, Silva A C, Andreoni S, Whipp B J
Department of Physiology, St. George's Hospital Medical School, University of London, UK.
Eur J Appl Physiol Occup Physiol. 1999 May;79(6):522-30. doi: 10.1007/s004210050547.
To investigate the relationships between the age-associated decline in peak oxygen uptake (peak VO2), leg muscle mass (LMM) and leg strength (LS) under the modulating effect of gender and level of physical activity (LPA, as assessed by questionnaire), we evaluated 71 sedentary subjects [males(M):females(F), 34:37], aged 20-80 years. Peak VO2 at maximum cycle ergometry was related to LMM (dual energy X-ray absorptiometry) and LS (isokinetic dynamometry) using both standard (y x x(-1)) and power function ratios (allometry). Absolute values of all variables were higher in males and declined with age (P < 0.01). Differences between the genders disappeared after peak VO2 x LS(-1.46(M)or -1.62(F)) adjustment but remained significant between peak VO2 LMM-(-0.51 (M)or -0.45(F)) and LS LMM- (-091(M) or -1.10(F)) corrected values. Allometric correction of peak VO2 and LS by LMM slowed their age-related declines; the flattening effect however, was more evident in the females. Interestingly, while no age-related decrement in peak VO2 LS(-1) was found, power function ratio values also declined with age, and at a slower rate in females. These findings are consistent with those obtained following a multiple regression analysis using LPA as an independent covariate (P < 0.01). We conclude that using adequate scaling methods and controlling by LPA: (1) no gender differences are observed in peak VO2 adjusted for LS, (2) loss of LS and LMM are important determinants of the age-associated reduction in physical fitness in both genders but (3) age per se has an LS- and LMM-independent influence on the functional decline, although this intrinsic effect of senescence is less pronounced in females.
为了研究在性别和体力活动水平（通过问卷调查评估的LPA）的调节作用下，与年龄相关的峰值摄氧量（peak VO2）下降、腿部肌肉质量（LMM）和腿部力量（LS）之间的关系，我们评估了71名久坐不动的受试者[男性（M）：女性（F），34：37]，年龄在20至80岁之间。使用标准（y x x(-1)）和幂函数比率（异速生长法），最大运动负荷时的peak VO2与LMM（双能X线吸收法）和LS（等速肌力测试法）相关。所有变量的绝对值在男性中更高，且随年龄下降（P < 0.01）。在peak VO2 x LS(-1.46（M）或 -1.62（F）)调整后，性别差异消失，但在peak VO2 LMM-(-0.51（M）或 -0.45（F）)和LS LMM- (-091（M）或 -1.10（F）)校正值之间仍存在显著差异。通过LMM对peak VO2和LS进行异速生长校正减缓了它们与年龄相关的下降；然而，这种平缓效应在女性中更明显。有趣的是，虽然未发现peak VO2 LS(-1)与年龄相关的下降，但幂函数比率值也随年龄下降，且在女性中下降速度较慢。这些发现与使用LPA作为独立协变量进行多元回归分析得到的结果一致（P < 0.01）。我们得出结论，使用适当的缩放方法并通过LPA进行控制：（1）在根据LS调整后的peak VO2中未观察到性别差异，（2）LS和LMM的丧失是两性中与年龄相关的体能下降的重要决定因素，但（3）年龄本身对功能下降有独立于LS和LMM的影响，尽管衰老的这种内在效应在女性中不太明显。
