Correlation between body mass index and waist circumference in individuals aged 15 years and over

Introduction: Screening and early treatment of overweight and obesity are a public health priority. Body mass index (BMI) and waist circumference (WC) are major anthropometric indices used to measure the excess of adiposity in practice. Objective: To describe the correlations between abdominal obesity measured by BMI and central obesity as measured by WC. Methods: Descriptive cross-sectional study conducted from January to March 2007, with 662 individuals aged 15 and over recruited ten health-care centers of Marrakech. Trained professionals collected data on age and gender, and anthropometric measurements (weight, height and waist circumference). The correlations between BMI and WC were calculated for both sexes and different age groups. Results: Women represented 82% of participants; the average age was 37.2 +/- 14.7 years. The prevalence of obesity and overweight were 22% and 31% respectively. Abdominal obesity was found in 67% of participants. Age and sex were significantly associated with the distribution of weight status. Overall correlations between BMI and TT were moderate to high especially among women and younger age-group. Using the current threshold values, abdominal obesity was found in 9.2% of men and 50% of women with a normal BMI. Discussion: Prevalence of overweight and obesity are alarming and concordant with previous data. BMI and WC have shown moderate to high correlations; nevertheless, classifying subjects using current thres holds has load to discordance between the two indices. Abdominal obesity was found among a high proportion of subjects having a normal BMI. Conclusions: These results underline once again the value of combining different anthropometric indices for better evaluation of weight status. They also raise the question of the appropriateness of the use of current standards in our context.