Center on Translational Neuroscience, College of Life and Environment Sciences, Minzu University of China, Beijing, China.
Department of Epidemiology, School of Public Health, Harbin Medical University, Harbin, China.
Pediatr Obes. 2021 Mar;16(3):e12716. doi: 10.1111/ijpo.12716. Epub 2020 Aug 25.
It has been controversial whether to adjust for current body weight while examining the relationship between birthweight and blood pressure (BP).
The present study aims to partition the total effect of birthweight on BP into its direct effect and indirect effect through current body mass index (BMI).
The study cohort consisted of 6251 participants who had birthweight information with 13 443 observations on BMI and BP in pre-adolescence (4-11 years), adolescence (12-19 years), young adulthood (20-30 years) and mid-adulthood (31-58 years). General third-variable models were used to distinguish the mediation and suppression effects of current BMI on the birthweight-BP association at different ages.
The total effect of birthweight on systolic BP measured as standardized regression coefficient (β) without current BMI included in the model was 0.003 (P = .810) in pre-adolescents, -0.032 (P = .029) in adolescents, -0.066 (P = .002) in young adults and -0.051 (P = .023) in midlife adults. With additional adjustment for BMI, the direct effect of birthweight on systolic BP was strengthened to β = -0.066 (P = .013), β = -0.058 (P = .014), β = -0.094 (P = .020), β = -0.066 (P = .023); the suppression effects of BMI were calculated at 0.070, 0.027, 0.028 and 0.015 in the respective age groups. The decreasing trend of suppression effects with increasing age mimicked the trends of birthweight-BMI and BMI-BP correlations.
Current body weight has a suppression effect, not a mediation effect, on the birthweight-BP association, with pre-adolescents having the greatest suppression effect. The suppression effect is predominantly determined by birthweight-BMI and BMI-BP correlations.
在研究出生体重与血压（BP）之间的关系时，是否需要根据当前体重进行调整一直存在争议。
本研究旨在通过当前的体重指数（BMI）将出生体重对 BP 的总效应分为直接效应和间接效应。
该研究队列包括 6251 名参与者，他们在青春期前（4-11 岁）、青春期（12-19 岁）、青年期（20-30 岁）和中年期（31-58 岁）有出生体重信息，共 13443 次 BMI 和 BP 测量值。采用一般三变量模型来区分当前 BMI 对不同年龄出生体重与 BP 关联的中介和抑制作用。
未纳入模型的当前 BMI 出生体重对收缩压的总效应（标准化回归系数β）为 0.003（P =.810）在青春期前，-0.032（P =.029）在青春期，-0.066（P =.002）在青年期和-0.051（P =.023）在中年。通过进一步调整 BMI，出生体重对收缩压的直接效应增强至β=-0.066（P =.013），β=-0.058（P =.014），β=-0.094（P =.020），β=-0.066（P =.023）；在各自的年龄组中，BMI 的抑制作用分别为 0.070、0.027、0.028 和 0.015。抑制作用随年龄的增加而减小的趋势与出生体重-BMI 和 BMI-BP 相关性的趋势相似。
当前体重对出生体重与 BP 之间的关联有抑制作用，而不是中介作用，青春期前的抑制作用最大。抑制作用主要由出生体重-BMI 和 BMI-BP 相关性决定。
