High frequency of cardiovascular risk factors in overweight adult Japanese subjects.

Background: It has been suggested that Japanese subjects categorized as having normal weight (body mass index [BMI]<25.0) as defined by WHO (2000) have a tendency toward increased incidence of dyslipidemia and diabetes. Our objective was to assess the suitability for Japanese subjects of the Regional Office for the Western Pacific Region of WHO criteria pertaining to obesity (WPRO criteria, 2000) by analyzing cardiovascular risk factors relative to gender and age in overweight Japanese with BMI of 23.0-24.9.

Methods: There were 3,608 subjects (2,387 men: 42.3+/-0.2 years and 1,221 women: 41.6+/-0.3 years) who participated in a community setting and cross-sectional study and were not using any prescription drugs for obesity-related diseases. BMI and cardiovascular risk factors (blood pressure, plasma levels of total cholesterol, LDL-cholesterol, HDL-cholesterol, triglyceride, Lp(a), glucose, HbA1C, uric acid, white blood cell count, AST, ALT and gamma-GTP) were compared by BMI classes and by gender and age group.

Results: The subjects were categorized as 21% "overweight" (23.0-24.9 BMI), 17% "obese I" (25.0-29.9 BMI) and 2% "obese II" (over 30.0 BMI), all based on WPRO criteria. Graded increases in BMI classes based on these WPRO criteria were positively associated with frequency and values of cardiovascular risk factors, and the "overweight" had a significantly higher risk of cardiovascular disease than did the "normal" subjects.

Conclusion: While a relationship between BMI and cardiovascular risk factors is gender and age specific, our investigation, highlighting the increasing risks of "overweight" with a BMI of 23.0-24.9, suggests that WPRO criteria are more relevant and therefore suitable for Japanese subjects.