Belcher B R, Chou C-P, Nguyen-Rodriguez S T, Hsu Y-W, Byrd-Williams C E, McClain A D, Weigensberg M J, Spuijt-Metz D
Cancer Prevention Fellowship Program, Division of Cancer Prevention, National Cancer Institute, Bethesda, MD, USA.
Pediatr Obes. 2013 Feb;8(1):70-7. doi: 10.1111/j.2047-6310.2012.00091.x. Epub 2012 Sep 19.
What is already known about this subject Physical activity declines as children enter puberty. Leptin is cross-sectionally associated with physical activity, but there are conflicting findings on the magnitude and direction of this association. Leptin concentrations fluctuate during puberty, and may impact energy balance. What this study adds Leptin predicts the decline in physical activity during the start of puberty independent of central adiposity. Based on a median split of leptin, girls with low leptin levels have higher levels of physical activity than girls with high leptin levels at the start of puberty. Leptin levels at the start of puberty may provide a biological basis for the age-related physical activity decline in girls.
Leptin may influence moderate to vigorous physical activity (MVPA) at the start of puberty. The direction and magnitude of this association are unclear.
To determine the effect of baseline leptin on MVPA over 1 year in minority girls at high risk for obesity.
Data came from TRANSITIONS, a longitudinal observational study on the age-related MVPA decline. Fifty peripubertal girls aged 8-11 years at baseline participated. Baseline leptin (ng mL(-1) ) was collected via a duplicated assay using a double antibody radio immune assay. MVPA (min d(-1) ) was measured using accelerometers for at least four 10-h days on a quarterly basis for up to 1 year.
Continuous leptin was negatively related to MVPA (P = 0.001) independent of central adiposity at baseline and predicted the MVPA decline over 1 year (P = 0.002). For descriptive purposes, baseline leptin was dichotomized at the sample median into 'high leptin' and 'low leptin' categories to determine whether MVPA trajectories differed between these groups. Girls with 'low leptin' at baseline had significantly higher levels of MPVA at baseline, visit 1 and visit 2 compared to girls with 'high leptin'.
High leptin levels predicted nearly a 12.6% decline in MVPA over 1 year. These findings provide support for the biological basis of declining MVPA as girls enter puberty.
关于该主题已知的信息 随着儿童进入青春期，身体活动减少。瘦素与身体活动存在横断面关联，但关于这种关联的程度和方向存在相互矛盾的研究结果。瘦素浓度在青春期会波动，并且可能影响能量平衡。本研究的新增内容 瘦素可独立于中心性肥胖预测青春期开始时身体活动的减少。基于瘦素的中位数分割，青春期开始时瘦素水平低的女孩比瘦素水平高的女孩身体活动水平更高。青春期开始时的瘦素水平可能为女孩中与年龄相关的身体活动减少提供生物学基础。
瘦素可能会影响青春期开始时的中度至剧烈身体活动（MVPA）。这种关联的方向和程度尚不清楚。
确定基线瘦素对肥胖高风险少数族裔女孩1年内MVPA的影响。
数据来自TRANSITIONS，一项关于与年龄相关的MVPA下降的纵向观察性研究。50名基线年龄为8 - 11岁的青春期前女孩参与研究。通过双抗体放射免疫测定的重复检测收集基线瘦素（ng/mL）。使用加速度计在长达1年的时间里每季度测量至少四个10小时日的MVPA（分钟/天）。
连续瘦素与MVPA呈负相关（P = 0.001），独立于基线时的中心性肥胖，并预测了1年内MVPA的下降（P = 0.002）。为了描述目的，将基线瘦素按样本中位数分为“高瘦素”和“低瘦素”类别，以确定这些组之间MVPA轨迹是否不同。与“高瘦素”女孩相比，基线时“低瘦素”女孩在基线、第1次访视和第2次访视时的MPVA水平显著更高。
高瘦素水平预测1年内MVPA下降近12.6%。这些发现为女孩进入青春期时MVPA下降的生物学基础提供了支持。
