Prevalence of overweight and obesity and their association with hypertension and diabetes mellitus in an Indo-Asian population

Background: The associations of body mass index (BMI) and chronic disease may differ between Indo-Asian and Western populations. We used Indo-Asian-specific definitions of overweight and obesity to determine the prevalence of these problems in Pakistan and studied the sensitivity and specificity of BMI cutoff values for an association with hypertension and diabetes mellitus. Methods: We analyzed data for 8972 people aged 15 years or more from the National Health Survey of Pakistan (1990-1994). People considered overweight or obese were those with a BMI of 23 kg/m(2) or greater, and those considered obese as having a BMI of 27 kg/m(2) or greater. We built multi-variable models and performed logistic regression analysis. Results: The prevalence of overweight and obesity, weighted to the general Pakistani population, was 25.0% (95% confidence interval [CI] 21.8%-28.2%). The prevalence of obesity was 10.3% (95% CI 7.0%-13.2%). The factors independently and significantly associated with overweight and obesity included greater age, being female, urban residence, being literate, and having a high (v. low) economic status and a high (v. low) intake of meat. With receiver operating characteristic curves, we found that the use of even lower BMI cutoff values (21.2 and 22.1 kg/m(2) for men and 21.2 and 22.9 kg/m(2) for women) than those recommended for an Indo-Asian population yielded the optimal areas under the curve for an association with hypertension and diabetes, respectively. Interpretation: A quarter of the population of Pakistan would be classified as overweight or obese with the use of Indo-Asian-specific BMI cutoff values. Optimal identification of those at risk of hypertension and diabetes and healthy targets may require the use of even lower BMI cutoff values than those already proposed for an Indo-Asian population.