Effects of overweight on blood pressure and incidence of hypertension: Results of an 18-year follow-up study in China

Abstract

Objectives: To investigate the effects of overweight and obesity on blood pressure (BP) tracking from adolescence to adulthood and the incidence of hypertension in young adults in a cohort from 1987 to 2005. Methods: The baseline survey was conducted in 4623 school students aged six to fifteen in 1987. According to body mass index (BMI), 260 children were enrolled and divided into the overweight group (n=42) and the control group (n=218). Overweight was defined as BMI ≥90th percentile (P90) of the same age and the same gender, with BMI <50th percentile (P50) as the control group. They were followed up 18 years later. Results: The total follow-up rate was 75.8%. In the overweight group, both baseline and follow-up BP levels were significantly higher than the control group (P<0.01), and the incidence of hypertension (≥140/90 mm Hg) was also higher after 18 years (30.0% vs 13.8%), but there was no significant difference (P>0.05). When the increments in BMI (ΔBMI) were used to replace BMI, we divided the students into ΔBMI≥P75 group (HΔBMI) and ΔBMI<P50 group (NΔBMI). We found that the development of high BP directly correlated with increments in BMI during the follow-up period. The prevalence and odds ratio of high BP were higher by 4.5-fold in individuals in HΔBMI group when compared with the NΔBMI group (37.9% vs 8.8%, P<0.01). Conclusions: Overweight during adolescence predicts higher incidence of hypertension, which is a major risk factor of youth hypertension.