Objective: To investigate the major risk factors and their association with the dramatic increase in the prevalence of diabetes from 2001-2002 to 2006 in Qingdao, China.
Methods: Population-based cross-sectional studies on diabetes were performed in 4598 men and 7026 women aged 35-74 years. The 2006 World Health Organization diagnostic criteria for diabetes were used.
Results: The crude prevalence of diabetes was 11.3% in both men and women in urban areas and 5.3% and 8.9% in rural areas in 2001-2002. This increased to 19.2% and 16.1% in urban areas and 14.2% and 13.8% in rural areas in 2006 for men and women, respectively. The increase in diabetes prevalence from 2001-2002 to 2006 was paralleled by an increased body mass index in rural areas but not in urban areas. The major risk factors associated with diabetes were age, family history of diabetes, obesity, hypertension and high triglycerides. The multivariate adjusted odds ratio and 95% confidence interval for diabetes corresponding to a one standard deviation increase in waist circumference was 1.81 (1.47, 2.23) in urban men, 1.64 (1.26, 2.13) in rural men, 1.98 (1.66, 2.37) in urban women and 2.02 (1.63, 2.51) in rural women. Low socio-economic classes had a higher risk for diabetes in urban areas but a lower risk in rural areas, both associated with increased waist circumference.
Conclusion: Established risk factors are of great importance for the prevalence of diabetes in the urban and rural Chinese populations and changes in these factors could explain the recent dramatic increase in diabetes prevalence, particularly in rural areas. Considering the high prevalence of obesity and physical inactivity, intervention is urgently required in China.