Sex differences in the non-linear association between BMI and LDL cholesterol in middle-aged and older adults: findings from two nationally representative surveys in China

Lipids in Health and Disease

Jiahui Ma¹  Haibin Li²  Pixiong Su²  Jing Wang³  Deqiang Zheng⁴  Xiuhua Guo⁴  Xia Li⁵ 

[1] Department of Anesthesiology and Critical Care Medicine, Peking University First Hospital, Beijing, China;Department of Cardiac Surgery, Heart Center, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China;Beijing Key Laboratory of Hypertension, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China;Department of Clinical Laboratory, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China;Department of Epidemiology and Health Statistics, School of Public Health, Capital Medical University, Beijing, China;Department of Mathematics and Statistics, La Trobe University, Melbourne, Victoria, Australia;

关键词: BMI;    LDL-C;    Nonlinear relationship;    Sex differences;    Generalized additive models;   

DOI  :  10.1186/s12944-021-01591-w

来源: Springer

【 摘 要 】

BackgroundThe relationship between body mass index (BMI) and low-density lipoprotein cholesterol (LDL-C) has not been clearly elucidated in middle-aged and older adults. This study aimed to evaluate the non-linear dose-response relationship between BMI and LDL-C in males and females.MethodsData was obtained from two nationally representative surveys in China—the China Health and Nutrition Survey (CHNS, 2009) and China Health and Retirement Longitudinal Study (CHARLS, 2011–2012). To evaluate the sex differences in the association between BMI and LDL-C, the generalized additive models with a smooth function for continuous BMI and smooth-factor interaction for sexes with BMI were used. Segmented regressions were fitted to calculate the slopes with different estimated breakpoints among females and males.ResultsA total of 12,273 participants (47.1% male) aged 45 to 75 years were included. The generalized additive models revealed that a non-linear relationship between BMI and LDL-C level in both sexes after adjustment for age, residence, education levels, marital status, drinking, smoking status, and cohort (CHNS or CHARLS). Slopes of the association between BMI and LDL-C association changed at BMI 20.3 kg/m2 (95% CI: 18.8 to 21.8) in females and 27.1 kg/m2 (95% CI: 25. 8 to 28.4) in males. Below these BMI breakpoints, LDL-C levels increased 1.84 (95% CI: 1.45 to 2.31) in males and 3.49 (95% CI: 1.54 to 5.45) mg/dL per kg/m2 in females. However, LDL-C levels declined − 1.50 (95% CI: − 2.92 to − 0.09) mg/dL per kg/m2 above BMI of 27.1 kg/m2 in males. The non-linear association BMI and LDL-C in males and females was varied by cohort source, age groups, and the number of metabolic syndrome criteria.ConclusionsIn the Chinese middle aged and older adults, the BMI and LDL-C relationship was inverted U-shaped with a high level of LDL-C at a BMI of 27.1 kg/m2 in males, and an approximately linear association was observed in females.

【 授权许可】

CC BY