Waist circumference and incidence of hypertension in Chinese adults : Observations from the Kailuan Study.

BACKGROUND

The Kailuan Study examined cardiovascular risk factors in a Chinese cohort comprising employees of the Kailuan Coal Group who underwent regular health examinations.

PATIENTS AND METHODS

Normotensive participants in the Kailuan study were enrolled in the present work and followed up for a median of 5.8 years to assess the development of hypertension (systolic blood pressure [SBP] ≥140 mmHg, diastolic blood pressure [DBP] ≥90 mmHg, or initiation of blood pressure [BP] medications).

RESULTS

This study comprised a total of 50,024 participants (age, 47.9 ± 12.0 years; male/female, 37,429/12,595), of whom 22,176 (44.3%) developed hypertension. In both male and female subjects, there was an increase in multivariable-adjusted hazard ratios for hypertension in all waist circumference (WC) groups (group 1, <70 cm; group 2, 70-79 cm; group 3, 80-89 cm; group 4, 90-99 cm; group 5, ≥100 cm). Results of a stratified analysis of subjects with normal body mass index (BMI; <24 kg/m) showed that hazard ratios for hypertension still increased across WC groups. Significant interactions were found between WC groups and gender (p <0.001), as well as between WC groups and BP categories (p <0.001). Increased WC was associated with a significantly higher risk of hypertension incidence in men compared with women and in subjects with a high-normal BP vs. those with an ideal BP.

CONCLUSION

WC is an independent predictor of hypertension incidence. The association between WC and hypertension incidence is affected by gender and baseline BP levels.