Association of serum alanine aminotransferase with metabolic syndrome in middle-aged and elderly Chinese

Abstract

Objective To investigate the association between levels of serum alanine aminotransferase (ALT) and the risks of metabolic syndrome in middle-aged and elderly Chinese. Methods After excluding subjects with known liver disease, excess alcohol consumption and serum ALT≥40 IU/L,1 664 subjects aged 40 years or older from Baoshan Community, Shanghai were recruited to undergo questionnaire interview, anthropometric measurements, and fasting blood sampling. Biochemical features were evaluated and the metabolic syndrome was defined according to the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) criteria with modification on waist circumference cutoff which is more appropriate for an Asian population. Results Increased ALT levels were associated with more unfavorable metabolic risk profiles. The prevalence rates of the metabolic syndrome in participants with increasing ALT quartiles were 29. 2% , 38. 0% , 44.9% , and 62. 9% , respectively (P for trend <0. 01 ). ALT concentrations were significantly elevated with increasing number of the metabolic syndrome components (P for trend<0.01). Serum ALT levels were significantly associated with the risks of metabolic syndrome and most of its components in a dose-response manner. As compared with participants in the first ALT quartile, the risks of metabolic syndrome were increased by 146% , central obesity by 204% , hypertension by 35% , high triglycerides by 133% , and hyperglycemia by 72% in participants of the fourth ALT quartile. Conclusions A high-normal serum ALT level was significantly associated with an increased risk of the metabolic syndrome in middle-aged and elderly Chinese. Key words: Alanine aminotransferase; Metabolic syndrome; Middle-aged and elderly people