Department of Endocrinology and Metabolism, Peking University People's Hospital, Beijing, China.
Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing, China.
J Glob Health. 2023 Apr 7;13:04032. doi: 10.7189/jogh.13.04032.
Obesity, which has reached the scale of a global pandemic, is a leading cause of premature death. It is unclear to what extent its effect on mortality was driven by blood pressure or glucose levels in people of different ethnicities.
We conducted a causal mediation analysis to estimate the mediation effect of blood pressure and glucose between body mass index (BMI) or waist-hip ratio (WHR) on mortality based on data from the China Kadoorie Biobank (CKB) (n = 458 385) and US National Health and Nutrition Examination Survey (NHANES) (1999-2008, n = 20 726).
The WHR's effect on mortality was mediated by blood pressure and glucose in the CKB data set by 38.7% (95% confidence interval (CI) = 34.1, 43.2) and 36.4% (95% CI = 31.6, 42.8), whereas in NHANES by 6.0% (95% CI = 2.3, 8.3) and 11.2% (95% CI = 4.7, 22.7), respectively. For associations between BMI and mortality in subjects with overweight or obesity, the mediator proportion of blood glucose and pressure was 49.4% (95% CI = 40.1, 62.5) and 16.9% (95% CI = 13.6, 22.9) in CKB and 9.10% (95% CI = 2.2, 25.9) and 16.7% (95% CI = 7.3, 49.0) in NHANES, respectively. We stratified the patients by their blood glucose, blood pressure level, or both into four groups. The effect of WHR on mortality was comparable across subgroups in either cohort. The associations between BMI and mortality were stronger in patients with higher blood pressure in CKB (P = 0.011) and blood glucose in NHANES (P = 0.035) in patients with overweight and obesity.
The relationship between WHR and mortality in the CKB data set was potentially caused by blood pressure and glucose to a much greater extent than in the NHANES one. The effect of BMI influenced by blood pressure was significantly higher among Chinese individuals with overweight and obesity. These results implicate a different intervention strategy is required for blood pressure and blood glucose in China and US to prevent obesity and obesity-related premature death.
肥胖已达到全球大流行的规模，是导致过早死亡的主要原因。目前尚不清楚其对不同种族人群死亡率的影响在多大程度上是由血压或血糖水平驱动的。
我们基于中国慢性病前瞻性研究（CKB）（n=458385）和美国国家健康和营养检查调查（NHANES）（1999-2008，n=20726）的数据，采用因果中介分析来估计体重指数（BMI）或腰臀比（WHR）与死亡率之间通过血压和血糖的中介效应。
在 CKB 数据集中，WHR 对死亡率的影响通过血压和血糖介导，占 38.7%（95%置信区间（CI）=34.1，43.2）和 36.4%（95% CI=31.6，42.8），而在 NHANES 中，分别为 6.0%（95% CI=2.3，8.3）和 11.2%（95% CI=4.7，22.7）。对于超重或肥胖人群中 BMI 与死亡率之间的关联，血糖和血压的中介比例分别为 49.4%（95% CI=40.1，62.5）和 16.9%（95% CI=13.6，22.9）在 CKB 和 9.10%（95% CI=2.2，25.9）和 16.7%（95% CI=7.3，49.0）在 NHANES 中。我们根据血糖、血压水平或两者将患者分层为四组。在两个队列中，WHR 对死亡率的影响在亚组之间是相当的。在 CKB 中，超重和肥胖患者的血压较高（P=0.011）和 NHANES 中血糖较高（P=0.035）的患者中，BMI 与死亡率之间的关联更强。
CKB 数据集中 WHR 与死亡率之间的关系可能主要是由血压和血糖引起的，而 NHANES 中的关系则小得多。在中国超重和肥胖人群中，血压对 BMI 影响的作用明显更高。这些结果表明，中国和美国需要采取不同的干预策略来控制血压和血糖，以预防肥胖和肥胖相关的过早死亡。
