Prevalence and significance of generalized and central body obesity in an urban Asian Indian population in Chennai, India (CURES: 47).

OBJECTIVES: To determine the prevalence of generalized and abdominal obesity in urban Asian Indians and compare the association of body mass index (BMI) and waist circumference (WC) with metabolic risk variables.

METHODS: Subjects were recruited from the Chennai Urban Rural Epidemiology Study (CURES) carried out between 2001 and 2004 and involved 2350/2600 eligible subjects (response rate 90.4%). Anthropometric measurements, lipids and oral glucose tolerance tests were carried out. Generalized obesity (BMI>or=23 kg m(-2)) and abdominal obesity (WC>or=90 cm in men and >or=80 cm in women) were defined using WHO Asia Pacific guidelines.

RESULTS: The age standardized prevalence of generalized obesity was 45.9% (95% CI: 43.9-47.9%), (women: 47.4%; men: 43.2%, P=0.210), while that of abdominal obesity was 46.6% (95% CI: 44.6-48.6%), (women: 56.2%> men: 35.1%, P<0.001). Area under the curve for identifying subjects with any three metabolic risk factors using BMI was 0.66, 95% CI: 0.63-0.69, P<0.001, while, for WC, it was 0.70, 95% CI: 0.66-0.74, P<0.001 for men, and 0.69, 95% CI: 0.65-0.74, P<0.001 for women. Isolated generalized obesity (normal WC, increased BMI) was present in 12.7% of men and 6.1% of women. Isolated abdominal obesity (increased WC, normal BMI) was present in 4.7% of men and 14% of women. Combined obesity was present in 32.6% of men and 43.3% of women.

CONCLUSIONS: In Asian Indians, the prevalence of combined obesity is high among both sexes, while isolated generalized obesity is more common in men and isolated abdominal obesity more common in women. However, these prevalence rates vary markedly depending on cut points used. WC is a better marker of obesity-related metabolic risk than BMI in women compared to men in this population.