Topical Area: Nutritional Epidemiology
Objectives : We aimed to investigate the association of dietary energy intake or obesity with the prevalence of hypertension, and explored the potential mediators in this relationship.
Methods : We conducted a comprehensive and in-depth assessment in the cross-sectional survey of the US National Health and Nutrition Examination Survey (NHANES) four cross-sectional cohorts (2005–2006, 2007–2008, 2009–2010, and 2011–2012) of 17746 participants aged 20–74 years, and validated the significant findings in the China Health and Nutrition Survey (CHNS, 2004-2011) of 31582 subjects. We validated whether insulin resistance (IR), fasting glucose (FG), total cholesterol (TC) or triglyceride (TG) levels could play a mediation role in the association of dietary energy intake or obesity with hypertension.
We found that the relationship between dietary energy intake and prevalence of hypertension in the NHANES is U-shaped (P for quadratic=0.002). Compared to the participants in the third quintile category of dietary energy intake, the multivariable odds radios (OR) in the first and fifth quintile category were 1.33 (1.10-1.61) and 1.13 (0.96-1.33), respectively. We observed the prevalence of hypertension in obese and abdominal obesity participants were both significantly higher than normal subjects (all P-values < 0.001), the multivariable ORs in NHANES is 3.23 (2.78-3.76) and 2.31 (2.08-2.57), in CHNS is 4.78 (4.31-5.30) and 2.71 (2.54-2.90). Mediation analyses consistently indicated that the associations between obesity and abdominal obesity with hypertension were mediated mainly by IR as measured by the homeostasis model (HOMA2-IR), followed by FG, TG and TC in the two studies. The proportions via the mediation of insulin/HOMA2-IR was 28.41~36.74%, FG was 10.43~12.63%, TG was 6.24~8.55% and TC was 0.57~0.66%, respectively.
In this study, the relationships between obesity and abdominal obesity with the risk of hypertension were both significantly positive. Meanwhile, consuming more and less dietary energy were both risk factors of hypertension.
Funding Sources :
This work was supported by funds from the National Natural Science Foundation of China (81573134, 81202282) received by Xiaoyan Wu.