Regional difference in the susceptibility of non-alcoholic fatty liver disease in China

INTRODUCTION: Non-alcoholic fatty liver disease (NAFLD) is a global health problem with high geographic heterogeneity. We aimed to investigate regional-specific concomitant rate of NAFLD and quantitative relationship between liver fat content (LFC) and glucose metabolism parameters in representative clinical populations from six provinces/municipalities of China. RESEARCH DESIGN AND METHODS: A total of 2420 eligible Han Chinese were enrolled consecutively from 10 clinics of obesity, diabetes and metabolic diseases located at six provinces/municipalities of China, and divided into North (Tianjin, Shandong and Heilongjiang) and South (Shanghai, Jiangsu and Henan) groups according to their geographical latitude and proximity of NAFLD concomitant rate. LFC was assessed by a quantitative ultrasound method. Multivariate regression models and analysis of covariance were used to assess the regional difference in the risk of NAFLD. RESULTS: The concomitant rate of NAFLD was 23.3%, 44.0% and 55.3% in individuals with normal glucose tolerance (NGT), pre-diabetes and diabetes, respectively. A higher concomitant rate of NAFLD was found in the participants from the North comparing with the South group, regardless of glucose metabolism status (34.7% vs 16.2% in NGT, 61.5% vs 34.7% in pre-diabetes and 67.1% vs 48.1% in diabetes). This regional difference remained significant after adjustment for age, gender, alcohol drinking, cigarette smoking, confounding metabolic parameters and liver enzymes. For any given blood glucose, participants from the North had higher LFC than those from the South group. CONCLUSIONS: Half of Han Chinese with pre-diabetes/type 2 diabetes had NAFLD, and the individuals from the North cities were more susceptible to NAFLD.