Abstract
BACKGROUND: The alanine aminotransferase (ALT)/aspartate aminotransferase (AST) ratio is reportedly associated with insulin resistance (IR). However, few studies have explored the relationship between the ALT/AST ratio and IR in the Chinese population. Here, we aimed to explore whether the ALT/AST ratio is associated and, if so, to what extent, with IR in the Chinese population as categorized by waist circumference (WC). METHODS: Our data were obtained from the SPECT-China study, a cross-sectional survey on the prevalence of metabolic diseases and risk factors in East China from 2014 to 2015. A total of 8398 participants aged 52.16 ± 13.16 (mean ± standard deviation) years were included in this study. Anthropometric indices, biochemical parameters and clinical characteristics were measured. IR was defined as the top quartile of the homeostasis model assessment of insulin resistance (HOMA-IR > 1.6), and central obesity was defined as a WC ≥90 cm in males or ≥80 cm in females. Linear regression and receiver operating characteristic curve analyses were conducted. RESULTS: The ALT/AST ratio was significantly correlated and associated with HOMA-IR in both non-centrally obese (r = 0.284, B = 0.509, 95% confidence interval (CI): 0.459-0.559, P < 0.001) and centrally obese subjects (r = 0.372, B = 0.607, 95%CI: 0.532-0.683, P < 0.001) after adjusting for potential confounders. The ALT/AST ratio was one of the best markers of IR, with areas under the curve (AUC) values of 0.66 (0.64-0.68) in non-centrally and 0.68 (0.66-0.70) in centrally obese subjects. In the prediction model for IR, the AUCs were significantly augmented after adding the ALT/AST ratio in both non-centrally obese [AUC 95%CI 0.69(0.67-0.71) vs 0.72(0.70-0.74), P<0.001] and central obese [AUC 95%CI 0.69(0.67-0.71) vs 0.73(0.72-0.75), P<0.001] subjects. The optimal cut-off points of the ALT/AST ratio for identifying IR were 0.80 in non-centrally obese people and 0.78 in centrally obese people, respectively. CONCLUSION: The ALT/AST ratio may be one of the best markers for IR in the Chinese population. Whether the ALT/AST ratio should be regarded as an additional metabolic syndrome component in the Chinese population warrants further investigation.