Study population

This cross-sectional substudy included participants of the Changfeng Study, which was a community-based cohort study of chronic diseases among middle-aged and elderly people in Shanghai, China.³⁰ Residents aged ≥40 years were consecutively screened for inclusion between May 2010 and June 2011. The exclusion criteria were (1) abnormal glucose level (impaired fasting glucose or impaired glucose tolerance) or T2DM (diagnosed diabetes or newly diagnosed diabetes) and hypertension; (2) incomplete data; (3) alcohol misuse; (4) viral hepatitis; and (5) urinary system diseases or hepatic dysfunction (defined as >1.5-fold elevation of alanine aminotransferase (ALT), aspartate aminotransferase (AST) or direct bilirubin); or (6) urinary tract infection and haematuria via routine urine test. Hypertension was defined as published in the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure.³¹ The diagnosis of diabetes mellitus was based on the 2010 criteria by the American Diabetes Association.³² MetS was defined according to the joint interim statement.³³ The study protocol was approved by the Research Ethics Committee of Shanghai Health Bureau. Written informed consent was obtained from all participants. Physical examinations, laboratory assessments and liver ultrasound scans were performed on the same morning for each individual at Changfeng Community Hospital.