Prevalence And Risk Of Nonalcoholic Fatty Liver Disease Among Metabolically Abnormal Normal Weight And Metabolically Healthy Obese

Objective:Nonalcoholic fatty liver disease(NAFLD)is closely associated with obesity,but this association could be influenced by the coexisting metabolic abnormalities.This study aimed to investigate the risk of present and incident NAFLD among metabolically abnormal normal-weight(MANW)and metabolically healthy obese(MHO)Chinese.Methods:A cross-sectional and subsequent longitudinal study were performed among adults who took their annual health checkups.A total of 7235 eligible participants were included at baseline,including 4905 men and 2330 women,with an average age of 40.8±9.2 years.MANW was defined as normal weight(body mass index of 18.50 to 24.99 kg/m2)with more than one metabolic abnormality,and MHO was defined as obese(body mass index ?25.00 kg/m2)with no more than one metabolic abnormality.NAFLD was diagnosed by hepatic ultrasonography,with exclusion of secondary causes.The prevalence of NAFLD was analyzed among individual of metabolically healthy normal weight(MHNW),MANW,MHO and metabolically abnormal obese(MAO).The risk of incident NAFLD was investigated by prospective analysis.Results:The prevalence of NAFLD was 16.1%at baseline,and the prevalence of NAFLD in men and women was 20.3%and 7.3%,respectively.Compared with the control group,the average age of NAFLD group was older,and male predominant(p<0.001).The metabolic parameters in NAFLD group was more disorder than that in the control group(p<0.001).The prevalence of NAFLD in MHNW,MANW,MHO and MAO participants were 4.2%,22.1%,26.6%,and 57.4%,respectively.Compared with MHNW participants,the prevalence of NAFLD in MANW,MHO and MAO participants was significantly increased(p<0.001).Logistic analysis showed that the risk factors of NAFLD in MHNW,MANW,MHO and MAO participants were different,while BMI,waist circumference and ALT are the common risk factors of present NAFLD.We enrolled 6068 eligible participants without NAFLD at baseline.During 7-year follow-up,we identified 1013 incident NAFLD cases.The incidence per 1000 person-years was 19.58,43.65,67.19,and 82.83 among MHNW,MANW,MHO,and MAO participants,respectively.Cox proportional hazards regression analyses showed that the risk for incident NAFLD was significantly increased among MANW and MHO individuals.Compared with MHNW participants,the age and gender adjusted hazard ratio(95%confidence interval)for incident NAFLD among MANW and MHO individuals was 2.18(1.84-2,57)and 2.37(1.94-2.91),respectively.Further analyses showed that weight loss during follow-up significantly attenuated the risk for incident NAFLD in both MANW and MHO individuals.Conclusion:Both MANW and MHO individuals have increased risk for present and incident NAFLD,while weight loss significantly attenuates the risk.