AST to ALT ratio and arterial stiffness in non-fatty liver Japanese population:a secondary analysis based on a cross-sectional study.

backgroundPrevious studies have revealed that triglyceride to high-density lipoprotein cholesterol (HDL-C) ratio (henceforth TG/HDL-C) is one of the major risk factors for cardiovascular disease, insulin resistance and metabolism syndrome. However, there are fewer investigations of the correlations between the aspartate aminotransferase (AST) to alanine aminotransferase (ALT) ratio and brachial ankle pulse wave velocity (baPWV). This study was undertaken to investigate the relationship between the AST to ALT ratio and brachial-ankle pulse wave velocity (baPWV) in a Japanese population.

methodsThe present study was a cross-sectional study. A total of 646 Japanese men and women without fatty liver, aged 24-84 years old, received a health medical check-up programme including the results from baPWV inspection and various standardized questionnaires in a health examination centre in Japan. Main outcome measures included AST/ALT ratio, baPWV, fatty liver and postmenopausal status. Abdominal ultrasonography was used to diagnose fatty liver. A postmenopausal state was defined as beginning 1 year following the cessation of menses.

resultsAfter adjusting for potential confounders (age, sex, BMI, SBP, DBP, AST, ALT, GGT, uric acid, fasting glucose, TC, LDL, eGFR, smoking and exercise statuses, fatty liver, alcohol consumption and ABI), a non-linear relationship was detected between AST/ALT and baPWV, which had an inflection point of 5.6. The effect sizes and the confidence intervals on the left and right sides of the inflection point were 12.7 (1.9 to 23.5) and - 16.7 (- 36.8 to 3.3), respectively. Subgroup analysis in participants with excessive alcohol consumption (more than 280 g/week) showed that AST/ALT had a negative correlation with baPWV (β = - 30.7, 95%CI (- 53.1, - 8.4)), and the P value for the interaction was less than 0.05.

conclusionThe relationship between AST/ALT and baPWV is non-linear. AST/ALT was positively correlated with baPWV when AST/ALT was less than 5.6. In addition, the trend was the opposite in subjects who consumed excessive amounts of alcohol.