High blood pressure in Chinese youth across categories of BMI and waist circumference

Background BMI and waist circumference (WC) have commonly been used to identify obesity in practice. The aim of the present study was to assess the blood pressure (BP) status among Chinese college students categorized by BMI and WC. Methods A total of 4226 college students (2107 males and 2119 females) aged 19–22 years included in the study. The WHO BMI cutoffs were used to define underweight, normal weight and overweight. The WC cutoffs (90 cm for man and 80 cm for woman) were used to define central obesity. High BP was defined as SBP/DBP ≥140/90 mmHg. The BP status of subjects within each category across BMI and WC were assessed. Results When subjects were categorized by BMI, overweight males and females had a higher prevalence of high BP than their nonoverweight counterparts. When WC was used to diagnose central obesity, subjects with central obesity had a higher prevalence of high BP than those with normal WC. A positive association between BMI, WC and BP was also observed even in normal-weight subjects, with ‘high normal BMI’ subgroup (BMI = 23.7–24.9) had a higher BP level and prevalence of high BP than ‘low normal BMI’ subgroups (BMI = 18.5–19.7 and BMI = 19.8–21.0, P < 0.05). Conclusion Prevention of overweight/obesity in youth may be an effective approach for preventing the development of hypertension in the future; for normal-weight youth, it is essential to keep their BMI at a lower level within normal range.