Associations between ideal blood pressure based on different BMI categories and stroke incidence.

OBJECTIVES: The 2017 American College of Cardiology/American Heart Association (ACC/AHA) Guideline for high blood pressure (BP) in adults redefined hypertension as SBP at least 130 mmHg or DBP at least 80 mmHg. However, the optimal BP for different BMI population to reduce stroke incidence is uncertain. METHODS: A prospective cohort study was designed by four examinations: baseline (2004-2006), 2008, 2010 and 2017 follow-up. The study group composed of 36 352 individuals, to determine the ideal BP range to reduce stroke incidence of two BMI level, adjusted Cox proportional hazards models were utilized to establish the associations between SBP/DBP and the risk of stroke incident. Then, the restricted cubic spline regression was applied to find the ideal range of SBP/DBP values for two kinds of BMI categories definitions. RESULTS: During a median follow-up period of 12.5 years, 2548 (7.0%) nonstroke individuals at baseline developed incident stroke. After fully adjusting confounding factors, SBP (per 20 mmHg increase) and DBP (per 10 mmHg increase) are independently associated with the risk of stroke incidence [SBP, hazard ratio = 1.277, 95% confidence interval (95% CI), 1.217-1.340, P < 0.001; DBP, hazard ratio = 1.138, 95% CI, 1.090-1.189, P < 0.001]. CONCLUSION: Our study revealed that the ideal BP for a population with BMI less than 24 kg/m was less than 130/80 mmHg, whereas the ideal BP for BMI at least 24 kg/m was less than 120/80 mmHg. The sensitivity analyses between BMI less than 25 kg/m and BMI at least 25 kg/m showed similar findings. This finding provides more accurate primary prevention strategies based on various BMI populations.

Temporal relationship between body mass index and triglyceride-glucose index and its impact on the incident of hypertension.

BACKGROUND AND AIMS: Obesity and insulin levels can influence each other by metabolism. However, their temporal sequences and influence on hypertension are generally unknown, especially in Chinese adults. Recently, some scholars have proposed that triglycerides-glucose index (TyG) is an important indicator of insulin resistance. The study aims to describe the relationship between body mass index (BMI) and TyG index and its impact on hypertension. METHODS AND RESULTS: A total of 4081 adults (56.33% women) without antihypertensive, hypoglycemic or lipid-lowering medications were selected for the present study. Measurements of BMI and TyG index were obtained twice from 2012 to 2017. Cross-lagged panel analysis was used to describe the temporal sequences between BMI and TyG index, and the effect of their temporal relationship patterns on hypertension was explored through mediation analysis. After adjusting for confounding factors (age, sex, ethnicity et al.), the cross-lagged path coefficient from baseline BMI to follow-up TyG (ρ2 = 0.135, P < 0.001) was significantly greater than the path coefficient from baseline TyG to follow-up BMI (ρ1 = 0.043, P < 0.001), and P < 0.001 for the difference between ρ1 and ρ2. Furthermore, the sensitivity analyses between women and men revealed identical findings. In addition, TyG index mediation effect on BMI-hypertension was estimated to be 38.45% (P < 0.001) in total population, 25.24% in women and 57.35% in men. CONCLUSION: These results provided evidence that the temporal relationship between BMI and insulin resistance is reciprocal and a higher BMI precedes hyperinsulinemia in Chinese adults. This relationship plays an essential role in the development of hypertension, while there is a difference between women and men.