Mehra Ayush, Snarr Ronald L, Park Kyung-Shin, Krok-Schoen Jessica L, Czerwinski Stefan A, Nickerson Brett S
School of Health and Rehabilitation Sciences, The Ohio State University, Columbus, OH, USA.
Department of Kinesiology, Texas A&M University-Corpus Christi, Corpus Christi, TX, USA.
Eur J Clin Nutr. 2024 Dec;78(12):1064-1071. doi: 10.1038/s41430-024-01484-y. Epub 2024 Aug 8.
BACKGROUND & AIMS: Muscle quality index (MQI) can be computed in various ways. Also, many studies have evaluated MQI in older adults and non-Hispanic populations. The aim of this study was to compare various muscle quality indexes between Hispanics and non-Hispanic Caucasians when stratifying grip strength and appendicular lean mass measurements.
235 participants (aged 25.5 ± 9.5 for males and 26.4 ± 9.9 for females) completed a dual energy X-ray absorptiometry (DXA) scan to assess appendicular lean mass (ALM). Handgrip strength (HGS) was assessed using a handheld dynamometer. MQI was computed using four different models: 1). MQI: ALM and HGS of right arm and hand, respectively; 2). MQI: ALM and HGS of left arm and hand, respectively; 3). MQI: ALM and HGS of both arms and hands, respectively; and 4). MQI: ALM of upper and lower-limbs and HGS of left and right hand.
Hispanic males and females exhibited lower HGS compared to Caucasians with effect sizes ranging from trivial (d = 0.17) to moderate (d = 0.80). Females demonstrated higher MQI values compared to males for MQI (d = 0.70), MQI (d = 0.75), and MQI (d = 0.57). However, MQI yielded a small practical effect (d = 0.33) in favor of males (3.2 ± 0.5 kg/kg vs. 3.1 ± 0.5 kg/kg). After factoring by sex and ethnicity, Hispanic males and females, compared to non-Hispanic Caucasians males and females, showed trivial-to-small practical differences (d values ranging from 0.03 to 0.39).
These results demonstrate MQI models vary across sex, particularly when utilizing models that account for upper extremity strength and ALM (i.e., MQI, MQI, and MQI). Lastly, to establish consistency in future research, the present study recommends using MQI models that account for ALM of upper- and lower-limbs (i.e., MQI). However, research measuring muscular strength via one upper-limb (e.g., left hand) might consider measuring ALM of the corresponding arm (e.g., left arm) when computing muscle quality (e.g., MQI).
肌肉质量指数（MQI）可以通过多种方式计算。此外，许多研究已经评估了老年人和非西班牙裔人群的MQI。本研究的目的是在分层握力和附属瘦体重测量时，比较西班牙裔和非西班牙裔白种人之间的各种肌肉质量指数。
235名参与者（男性年龄25.5±9.5岁，女性年龄26.4±9.9岁）完成了双能X线吸收法（DXA）扫描以评估附属瘦体重（ALM）。使用手持式测力计评估握力（HGS）。MQI使用四种不同模型计算：1）. MQI：分别为右臂和右手的ALM和HGS；2）. MQI：分别为左臂和左手的ALM和HGS；3）. MQI：分别为双臂和双手的ALM和HGS；4）. MQI：上肢和下肢的ALM以及左手和右手的HGS。
与白种人相比，西班牙裔男性和女性的HGS较低，效应大小范围从微小（d = 0.17）到中等（d = 0.80）。对于MQI（d = 0.70）、MQI（d = 0.75）和MQI（d = 0.57），女性的MQI值高于男性。然而，MQI对男性有一个小的实际效应（d = 0.33）（3.2±0.5 kg/kg对3.1±0.5 kg/kg）。在按性别和种族进行因素分析后，与非西班牙裔白种人男性和女性相比，西班牙裔男性和女性显示出微小到小的实际差异（d值范围从0.03到0.39）。
这些结果表明MQI模型因性别而异，特别是在使用考虑上肢力量和ALM的模型时（即MQI、MQI和MQI）。最后，为了在未来研究中建立一致性，本研究建议使用考虑上肢和下肢ALM的MQI模型（即MQI）。然而，通过一个上肢（例如左手）测量肌肉力量的研究在计算肌肉质量（例如MQI）时可能考虑测量相应手臂（例如左臂）的ALM。
