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: 17,786 Chinese aged 50+ years were recruited from 2003-2008 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 annually mean WC increased sharply by 0.94cm (95% confidence interval 0.93-0.94) in men and 1.29cm (1.28-1.29) in women. In 77% of women and 69% of men WC increased and among them, the mean annual increase was 2.01cm and 1.70cm 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% versus 1.8%). Conversely 20.3% of generally obese individuals became non-obese and 12.8% centrally obese individuals returned to normal.
Conclusion: 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.
Funding
The Guangzhou Biobank Cohort Study was funded by The University of Hong Kong Foundation for Educational Development and Research, Hong Kong; the Guangzhou Public Health Bureau and the Guangzhou Science and Technology Bureau, Guangzhou, China; and the University of Birmingham, UK. This study was supported by the Bureau of Guangzhou Science and Technology (Grant 2013J4100031) and the Key Technology Collaboration Project funded by the Bureau of Guangzhou Science and Technology (Grant number: 2012J5100041).