Metabolic Syndrome and Insulin Resistance Are Associated With Normal‐Range Aspartate Aminotransferase, Alanine Aminotransferase, and Their Ratio in Chinese Women With Polycystic Ovary Syndrome

ABSTRACT Aim To determine whether metabolic syndrome (MS), insulin resistance (IR), myocardial enzymes, and kidney function are related to the normal‐range of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and their ratio in Chinese women with polycystic ovary syndrome (PCOS). Methods The research, a secondary analysis of the Acupuncture and Clomiphene for Chinese Women with PCOS trial (PCOSAct), enrolled 922 participants with less than 40 U/L of AST and ALT. Linear regression and trend analyses were used to analyze the relationship between AST, ALT, AST/ALT ratio and anthropometric and metabolic characteristics. The association between AST, ALT, AST/ALT ratio and the prevalence of MS, IR was estimated by logistic regression. The diagnostic performance of AST, ALT, and AST/ALT ratio for MS and IR was determined by the receiver operating characteristics (ROC) curve. Results The results showed that AST was positively associated with body mass index (BMI), waist circumference (WC), systolic/diastole blood pressure (SBP/DBP), triacylglycerol (TG), creatine kinase (CK), lactate dehydrogenase (LDH), creatinine (Cr), urea, cystatin‐C (Cys‐C), and prevalence of MS; negatively correlated with HDL and fasting plasma glucose (FPG). ALT was positively associated with BMI, WC, SBP, DBP, total cholesterol (TC), TG, low‐density lipoprotein (LDL), fasting insulin (FINS), homeostatic model assessment values for insulin resistance (HOMA‐IR), CK, LDH, urea, Cys‐C and prevalence of MS, IR; negatively correlated with HDL and quantitative insulin sensitivity check index (QUICKI). AST/ALT ratio was positively associated with HDL, QUICKI, Cr, Cys‐C; negatively correlated with age, BMI, WC, DBP, TC, TG, LDL, FPG, FINS, HOMA‐IR, LDH and prevalence of MS and IR. Linear regression analysis showed that after adjusting for confounding factors, a positive association between AST and WC, SBP, TG, CK, LDH, Cr, urea and Cys‐C; ALT and WC, TG, FINS, HOMA‐IR, CK, LDH, urea, Cys‐C; AST/ALT ratio and HDL, QUICKI, CK, Cr and Cys‐C; a negative association between AST and HDL, FPG; ALT and HDL, QUICKI; AST/ALT ratio and TG, TC, LDL, FINS, LDH. Univariate logistic regression showed that after adjusted for confounding factors, AST (OR: 1.04; 95% CI: 1.01–1.08, p = 0.022), ALT (OR: 1.04; 95% CI: 1.01–1.07, p = 0.008), and AST/ALT ratio are related to MS (OR: 0.80; 95% CI: 0.64–0.99, p = 0.044), and AST/ALT ratio is related to IR (OR: 0.79; 95% CI: 0.67–0.93, p = 0.005). ROC curve revealed that ALT demonstrated the highest diagnostic performance for MS (AUC = 0.655, 95% CI: 0.61–0.7, cut‐off value = 7.5, Sensitive = 0.60, and Specificity = 0.63), whereas AST/ALT ratio was more strongly associated with IR (AUC = 0.619, 95% CI: 0.58–0.66, cut‐off value = 1.52, sensitive = 0.64, and specificity = 0.56). Conclusions In Chinese PCOS patients, normal‐range elevations in ALT and AST along with a lower AST/ALT ratio were associated with more severe manifestations of MS components, and ALT was more specific in predicting MS. Moreover, patients with higher ALT and lower AST/ALT ratios tend to exhibit more severe IR, and their ratio is superior to predict IR. The increased ALT and AST were associated with elevated myocardial enzymes, and ALT is the most sensitive indicator of renal impairment. It reinforces the need for PCOS‐specific enzyme reference ranges.