Associations between body fat variability and later onset of cardiovascular disease risk factors

Objective
There is current debate regarding whether body weight variability is associated with cardiovascular events. Recently, high body fat percentage (BF%) has been shown to be a cardiovascular risk factor. We therefore hypothesized that BF% variability would present a stronger cardiovascular risk than body weight variability.
Methods
A single-center retrospective cohort study of medical check-up examinees aged 20 years or older at baseline (2005) was performed. Examinees were followed in 2007, 2009, and 2013–2014. BF% variability in 2005, 2007 and 2009 was calculated as the root-mean square error (RMSE) using a simple linear regression model. Multiple logistic regression models estimated the association between BF%-RMSE and new diagnoses of cardiovascular risk factors occurring between the 2009 and 2013–2014 visits.
Results
In total, 11,281 participants (mean age: 51.3 years old, 48.8% were male) were included in this study. The average BF%-RMSE of our subjects was 0.63, and the average BMI-RMSE was 0.24. The high BF%-RMSE group (76-100th percentile) had a higher incidence of hypertension and a lower incidence of diabetes mellitus than the low BF%-RMSE group (1-25th percentile). This tendency was particularly evident in male participants. BMI-RMSE was not associated with any cardiovascular risks in our study.
Conclusions
This study indicates that body fat variability has contrasting effects on cardiovascular risk factors, while body weight variability has no significant effects.

研究目标
当前学界关于体质量波动是否与心血管事件存在关联尚存争议。近期研究证实，高体脂百分比（body fat percentage, BF%）是心血管疾病风险因素。据此，本研究提出假设：体脂百分比波动相较于体质量波动，可带来更强的心血管疾病风险。
研究方法
本研究为单中心回顾性队列研究，纳入2005年基线时年龄≥20岁的体检受检者，分别于2007年、2009年及2013-2014年开展随访。以2005、2007与2009年的体脂百分比数据，通过简单线性回归模型计算均方根误差（root-mean square error, RMSE），以此表征体脂百分比波动水平。采用多重logistic回归模型，分析2009年至2013-2014年随访期间新诊断的心血管疾病风险因素与体脂百分比均方根误差（BF%-RMSE）之间的关联。
研究结果
本研究共纳入11281名参与者（平均年龄51.3岁，男性占比48.8%）。受试者的平均BF%-RMSE为0.63，平均身体质量指数（Body Mass Index, BMI）均方根误差（BMI-RMSE）为0.24。与低BF%-RMSE组（1-25百分位数）相比，高BF%-RMSE组（76-100百分位数）的高血压发病率更高，而糖尿病发病率更低，该趋势在男性参与者中尤为显著。本研究未发现BMI-RMSE与任何心血管疾病风险因素存在显著关联。
研究结论
本研究表明，体脂波动对心血管疾病风险因素存在相悖的影响，而体质量波动未表现出显著关联。