Prevalence and Risk Factors of Central Obesity Among Adults With Normal Bmi in Shaanxi, China: A Cross-sectional Study

Abstract Background: Defined by normal body mass index (BMI) and higher waist-to-height ratio, normal weight with central obesity (NWCO) has been recognised as a risk factor for cardio-metabolic diseases. The study aims to estimate the prevalence of NWCO and to examine the relationship between NWCO and cardiovascular disease risk factors in adults of Shaanxi Province.Methods: A population-based cross-sectional survey was conducted among residents who were aged 18–80 years and had been living in Zhenba County, Shaanxi Province, for over six months in 2018. The multistage stratified cluster sampling method was used to enroll the study participants. Six towns (districts) in Zhenba County, Shaanxi Province, were randomly selected, and then six villages (communities) were randomly selected from each town (district). All residents in the villages (communities) were face-to-face interviewed. Descriptive data analysis and 95% confidence intervals (CIs) of prevalence/frequency were conducted. Logistic regression analyses were used to detect the corresponding factors associated with central obesity. Results: A total of 2312 participants (936 men and 1376 women) were analyzed. The prevalence of NWCO was 58.3%. NWCO was significantly associated with hypertension and dyslipidemia. Compared with normal weight non-central obesity (NWNO), the adjusted odds ratios (ORs) for hypertension were 1.47, (95% CI 1.10–1.98) in men and 1.55(1.14–2.10) in women, and the corresponding ones for dyslipidemia were 2.71 (1.77–4.13) in men and 1.84 (1.29–2.61) in women. Female sex, age over 58 years, and lower education level were also significantly predictors of abdominal obesity. In males, comparison with no cigarette smoking, daily cigarette smoking was less likely to lead to normal weight central obesity. Conclusion: In people with normal BMI, the prevalence of central obesity was 58.3%. Female, age over 58 years, hypertension and dyslipidemia indicate a higher risk. Body mass index alone as a measure of obesity is not enough to assess health risks. Central obesity index should be used together for clinical assessment.