Relationship between nonalcoholic fatty liver disease and metabolic syndrome

The aim of this study was to investigate the prevalence of nonalcoholic fatty liver disease (NAFLD) and metabolic syndrome (MS) in subjects who underwent a routine health checkup. We intended to establish a clinical association between NAFLD and MS as well as to compare the diagnostic criteria of MS based on the definitions set forth by the International Diabetes Federation (IDF), the US National Cholesterol Education Program Adult Treatment Panel III (2001) (NCEP/ATP-III) and the Metabolic Syndrome Study Group of Chinese Diabetes Society (CDS).

Weight, height, waist circumference, hip circumference, percentage of body fat, blood pressure and ultrasound of liver were performed on subjects undergoing routine health checkup. Serum triglyceride, total cholesterol, high density lipoprotein cholesterol and fasting plasma glucose level were measured.

A total of 2394 subjects were included in this analysis and 437 had NAFLD. The prevalence of MS in the whole sample according to IDF, NCEP/ATP-III and CDS definitions was 11.11%, 8.48% and 5.30%, respectively. The total degree of agreement between IDF, NCEP/ATP-III and CDS definition was 87.76%. The prevalence of MS in NAFLD subjects is much higher than that in non-NAFLD subjects. The prevalence of NAFLD in MS subjects is also much higher than that in non-MS subjects.

The prevalence of MS varied depending on the diagnostic criteria used. NAFLD was strongly associated with the MS, although it remains unknown whether NAFLD is a cause or effect of MS.