Changes in adiposity in an older Chinese population in rapid economic transition

Objective: To examine the changes in body mass index (BMI) and waist circumference (WC) in Guangzhou, South China, which is probably experiencing the most rapid economic transition in history. Methods: In this study, 17,786 Chinese aged 50+ years were recruited from 2003 to 2008 and followed up until 2012. BMI and WC were measured at two time points. Results: During the mean follow-up of 3.6 years (median = 3, interquartile = 1), age-adjusted mean BMI increased only slightly. By contrast, mean WC increased sharply by 0.94 cm (95% confidence interval 0.93-0.94) annually in men and 1.29 cm (1.28-1.29) annually in women. In 77% of women and 69% of men, WC increased, and among them, the mean annual increase was 2.01 cm and 1.70 cm, respectively. Among healthy, never-smoking participants, the incidence of central obesity was 29.0% (36.4% in women and 14.2% in men). The incidence of general obesity was 1.9% and was similarly low in both men and women (2.1% vs. 1.8%). Conversely, 20.3% of individuals with general obesity became nonobese, and 12.8% of individuals with central obesity returned to normal. Conclusions: Central obesity has risen sharply in this cohort. Such increases may have been greatly underestimated previously and should form the basis of an even stronger warning for regions undergoing economic transitions in China and elsewhere.