Bélanger M, O'Loughlin J, Karp I, Barnett T A, Sabiston C M
Centre de formation médicale du Nouveau-Brunswick, Moncton, NB, Canada.
Pediatr Obes. 2012 Feb;7(1):73-81. doi: 10.1111/j.2047-6310.2011.00010.x. Epub 2011 Dec 1.
The objective of the study was to test the hypothesis that greater fluctuations in physical activity lead to greater increases in body fat during adolescence.
Seven hundred fifty-six adolescents in Montreal, Canada, aged 12-13 years at baseline, completed a 7-d physical activity recall questionnaire every 3 months over 5 years. Body mass index (BMI), waist circumference, and triceps and subscapular skinfold thickness were measured at baseline and at the end of follow-up. Subject-specific linear regressions, expressing physical activity as a function of time, were fitted and physical activity fluctuation scores were obtained by averaging the absolute values of regression residuals. The association between body fat after 5 years and the physical activity fluctuation score was assessed in linear regressions adjusting for baseline body fat, average number of physical activity sessions per week, diet and sociodemographic variables.
Among boys, there were statistically significant positive associations between physical activity fluctuation and BMI (β, 95% confidence interval: 0.12, 0.02-0.21) and triceps skinfold (0.40, 0.17-0.63). The associations with waist circumference or subscapular skinfold were not statistically significant (0.22, -0.04-0.49; 0.13, -0.05-0.32, respectively). In girls, there were statistically significant negative associations between physical activity fluctuation and BMI (-0.12, -0.20 to -0.03), waist circumference (-0.54, -0.91 to -0.17), subscapular skinfold (-0.41, -0.56 to -0.26) and triceps skinfold (-0.22, -0.38 to -0.05).
Physical activity fluctuations appear to affect body fat during adolescence. Sex-specific interventions may be needed given that greater physical activity fluctuations seem unfavourable for boys and beneficial for girls.
本研究的目的是检验以下假设：青春期身体活动的较大波动会导致体脂增加更多。
加拿大蒙特利尔的756名青少年，基线年龄为12 - 13岁，在5年时间里每3个月完成一次为期7天的身体活动回忆问卷。在基线和随访结束时测量体重指数（BMI）、腰围、肱三头肌和肩胛下皮褶厚度。拟合以时间为函数表示身体活动的个体特异性线性回归，并通过平均回归残差的绝对值获得身体活动波动分数。在对基线体脂、每周身体活动次数平均值、饮食和社会人口统计学变量进行调整的线性回归中，评估5年后体脂与身体活动波动分数之间的关联。
在男孩中，身体活动波动与BMI（β，95%置信区间：0.12，0.02 - 0.21）和肱三头肌皮褶（0.40，0.17 - 0.63）之间存在统计学显著的正相关。与腰围或肩胛下皮褶的关联无统计学意义（分别为0.22， - 0.04 - 0.49；0.13， - 0.05 - 0.32）。在女孩中，身体活动波动与BMI（ - 0.12， - 0.20至 - 0.03）、腰围（ - 0.54， - 0.91至 - 0.17）、肩胛下皮褶（ - 0.41， - 0.56至 - 0.26）和肱三头肌皮褶（ - 0.22， - 0.38至 - 0.05）之间存在统计学显著的负相关。
身体活动波动似乎在青春期影响体脂。鉴于身体活动波动较大对男孩似乎不利而对女孩有益，可能需要针对性别的干预措施。
