Prevalence of abdominal obesity in a population aged 20 to 70 years in urban Mazandaran (northeran Iran, 2004)

Abdominal (central) adiposity is an outcome of changes in life styles and behaviors. This study aimed at determining the prevalence of central obesity and the associated factors in a population aged 20 to 70 years in an urban area of the Mazandaran province. Methods and Materials: A population based cross-sectional study was conducted with a sample of 3600 subjects in an urban area of the Mazandaran province using cluster sampling techniques in 2004. Anthropometric measures (height, weight, waist and hip circumference) were measured with standard methods and social, demographic, and some life style data such as age, sex, education level, occupation, marital status, marriage age, parental obesity, occupational activity, leisure time physical activity, exercise level and history of pregnancy and parity for women, were collected during interviews using questionnaires. To assess central obesity, we used a standard recommended WHO method based on waist circumference (WC). In statistical analysis, the logistic regression model was used to estimate the age adjusted odds ratio and its 95% confidence interval and P-value <0.05 was considered significant. The mean (±SD) ages of men and women were 38.5±14.3, 37.5 ±13.0 years respectively. The mean (±SD) of WC was 89.3 ±11.5 for men and 87.8 ±13.6 for women. The prevalence of central obesity was 46.2% for women and 10.6% for men. The pattern of central obesity was significantly different in different age groups in both genders. The results of logistic regression model showed that the age adjusted odds ratio for central obesity was roughly 8.37, times greater in women compared with men (95% CI:7.03-10.21). The adjusted odds ratio decreased with increasing levels of education (P<0.0001) while the odds ratio was 0.20 for education at university level (95% CI: 0.14 – 0.28). The adjusted odds ratio increased 1.75 fold (95% CI: 1.55-2.05) in subjects with history of parental obesity it tended to decrease with severe occupational activities (OR=0.39: 95% CI: 0.24-0.63), high physical activity level in leisure time (OR=0.84, 95%CI: 0.58-1.21) and exercise level >5 h/w (OR=0.67, 95%CI: 0.51- 0.87). The adjusted odds ratio also decreased significalntly with marriage age and among women, it increased with parity while for >=5 parities, the age adjusted odds increased 3.3 fold (95% CI: 2.11–5.17). These results revealed an increased rate of abdominal obesity in the adult urban population in particular for women low levels of activity and low education, parity, family history of obesity, marriage at an earlier age, age and female gender are responsible for central obesity. Community-based multiple strategies are required to combat increasing rates of central obesity and the subsequent complications in the north of Iran.