MRC Epidemiology Unit, University of Cambridge School of Clinical Medicine, Institute of Metabolic Science, Cambridge Biomedical Campus, Cambridge, UK.
Int J Obes (Lond). 2017 Sep;41(9):1361-1368. doi: 10.1038/ijo.2017.122. Epub 2017 May 22.
BACKGROUND/OBJECTIVES: Fatness and fitness are associated with physical activity (PA) but less is known about the prospective associations of adiposity and muscle strength with PA. This study aimed to determine longitudinal associations of body mass index (BMI), waist circumference (WC) and grip strength (GS) with objectively measured PA.
SUBJECTS/METHODS: Data are from the UK Biobank study. At baseline (2006-2010), BMI, WC and GS were objectively measured. At follow-up (2013-2015), a sub-sample of 93 015 participants (52 161 women) wore a tri-axial accelerometer on the dominant wrist for 7 days. Linear regression was performed to investigate longitudinal associations of standardised BMI, WC and GS at baseline with moderate-to-vigorous PA (MVPA) and acceleration after a median 5.7-years follow-up (interquartile range: 4.9-6.5 years).
Linear regression revealed strong inverse associations for BMI and WC, and positive associations for GS with follow-up PA; in women, MVPA ranges from lowest to highest quintiles of GS were 42-48 min day in severely obese (BMI⩾35 kg m), 52-57 min day in obese (30⩽BMI<35 kg m), 61-65 min day in overweight (25⩽BMI<30 kg m) and 69-75 min day in normal weight (18.5⩽BMI<25 kg m). Follow-up MVPA was also lower in the lowest GS quintile (42-69 min day) compared with the highest GS quintile (48-75 min day) across BMI categories in women. The pattern of these associations was generally consistent for men, and in analyses using WC and mean acceleration as exposure and outcome, respectively.
More pronounced obesity and poor strength at baseline independently predict lower activity levels at follow-up. Interventions and policies should aim to improve body composition and muscle strength to promote active living.
背景/目的：肥胖和健康与身体活动（PA）有关，但人们对肥胖和肌肉力量与 PA 的前瞻性关联知之甚少。本研究旨在确定身体质量指数（BMI）、腰围（WC）和握力（GS）与客观测量的 PA 的纵向关联。
受试者/方法：数据来自英国生物库研究。在基线（2006-2010 年），客观测量 BMI、WC 和 GS。在随访（2013-2015 年）中，93015 名参与者（52161 名女性）的亚组佩戴三轴加速度计在优势手腕上 7 天。进行线性回归以研究基线标准化 BMI、WC 和 GS 与随访 PA（MVPA）和中位 5.7 年随访（四分位距：4.9-6.5 年）后的加速度之间的纵向关联。
线性回归显示 BMI 和 WC 与随访 PA 呈强负相关，GS 呈正相关；在女性中，GS 最低到最高五分位范围从严重肥胖（BMI≥35kg/m）的 42-48min/天，肥胖（30≤BMI<35kg/m）的 52-57min/天，超重（25≤BMI<30kg/m）的 61-65min/天，正常体重（18.5≤BMI<25kg/m）的 69-75min/天。在女性中，无论 BMI 类别如何，GS 最低五分位（42-69min/天）的随访 MVPA 也低于 GS 最高五分位（48-75min/天）。这些关联的模式在男性中基本一致，并且在分别使用 WC 和平均加速度作为暴露和结果的分析中也是如此。
基线时更明显的肥胖和较差的力量独立预测随访时较低的活动水平。干预和政策应旨在改善身体成分和肌肉力量，以促进积极的生活。
