Introduction:
Body mass index (BMI) and waist circumference has been reported to have a positive association with risk of coronary heart disease (CHD) and their optimal levels have been proposed. However, the association was less well described in Asian population.
Hypothesis:
This study aimed to examine the risk of developing CHD across different levels of BMI and waist circumference in a large retrospective cohort of Thai general population.
Methods:
This retrospective cohort was derived from the linkage of 2006 health checks data with diagnostic information from electronic health records of 708,544 men and women aged 20 years and above residing in Ubon Ratchathani. We examined the incidence of CHD over 6 years of follow-up in individuals with different levels of BMI defined by the WHO Asia-Pacific cut-offs and central obesity defined as waist circumference higher than half of each individual’s height. Corresponding hazard ratios were computed using Cox proportional hazards regression.
Results:
Over 3,514,681 person-years, 2,562 CHD cases developed, an overall incidence of 0.73 (95%CI 0.70-0.76) per 1,000 person-years. BMI had a J-shape association with CHD risk, with those with a BMI of 20-22.4 kg/m2 showing the lowest CHD incidence. Waist circumference had a curvilinear relationship with CHD risk, with CHD risk starting to increase after waist circumference of 80 and 85 cm in women and men respectively. CHD risk increased with higher levels of BMI and waist circumference (Table 1). Compared to those with BMI of 20.0-22.9 kg/m
2
and without central obesity, those with BMI higher than 30 kg/m
2
and with and without central obesity had a 1.8 and 2.4 fold increased risk of CHD (Adjusted hazards ratio 1.80 (1.46-2.24) and 2.39 (1.38-4.13) respectively).
Conclusions:
Different levels of BMI and waist circumference conferred different CHD risk. Change in optimal cut-off of BMI and waist circumference for the Thai population should be considered.
Body mass index, waist circumference, and risk of coronary heart disease: A prospective study among men and women