The clinical utility of the combined use of BMI and waist circumference (WC) to indicate the cardiovascular disease (CVD) risk factors in Asians remains unclear. Using a large-scale population-based cohort from the KNHIS health checkup data from 2009 to 2015, we investigated the relationship between BMI, WC and subsequent CVD risk factors (at least one from type 2 diabetes, hypertension or dyslipidemia). BMI was categorized into 5 subgroups at 18.5, 23.0, 25.0 and 30.0kg/m2. The cut-off points of WC for central obesity were 90cm in men and 85cm in women. The participants were subdivided into a total of 10 subgroups according to the presence of central obesity in each of the 5 BMI ranges. The incidence risk of CVD risk factors in each subgroup was comparatively analyzed using a multivariable Cox's proportional hazard model. Participants were 14,170,134 adults above 20 years of age who did not have type 2 diabetes, hypertension or dyslipidemia at the baseline examinations. During a mean follow-up of 5.3 years, CVD risk factors developed in 1,857,307 participants. The HRs for CVD risk factors were increased by 8.2% per 1kg/m2 increment of BMI. The HRs (95% CI) for CVD risk factors across BMI categories were 0.573, 1.0, 1.479, 1.962 and 3.03, respectively, after adjusting for age, sex, smoking, alcohol drinking, physical activity, and monthly income. Compared to the group with BMI of 18.5 to 23 kg/m2 without central obesity, which served as the reference group, the multivariable-adjusted HRs in those with central obesity was significantly increased from 1.00 to 1.27 with a BMI of 18.5 to 23.0 kg/m2, from 1.45 to 1.64 with a BMI of 23.0 to 25.0 kg/m2, from 1.83 to 2.10 with a BMI of 25.0 to 30.0 kg/m2, and from 2.56 to 3.08 with a BMI of 30.0 kg/m2 or over. These findings show that assessment of central obesity provided additional clinical utility beyond BMI for reclassifying the risk of CVD risk factors in Korean populations, even those with a low BMI.
J. Son: None. S. Lee: None. H. Kwon: None. S. Yoo: None.