There is limited research on the association between the alanine aminotransferase to high-density lipoprotein cholesterol ratio (ALT/HDL-C) ratio and nonalcoholic fatty liver disease (NAFLD). The purpose of the current research was to look into the connection between the ALT/HDL-C ratio and the risk of NAFLD in lean Chinese individuals. Between January 2010 and December 2014, 11,975 non-obese people participated in this prospective cohort research. The relationship between the ALT/HDL-C ratio and the risk of developing NAFLD was assessed using the Cox proportional-hazards regression model, Cox proportional hazards regression with cubic spline functions and smooth curve fitting, sensitivity analysis, and subgroup analyses. The ALT/HDL-C ratio\'s potential value as a NAFLD prognostic marker was to be evaluated using the receiver operating characteristic curve analysis. A total of 5419 (45.253%) women comprised the research\'s participant population, and the research participants\' average age was 43.278 ± 14.941 years. The ALT/HDL-C ratio was 11.607 (7.973-17.422) at the median (interquartile ranges). 2087 (17.428%) patients had NAFLD diagnoses throughout a median follow-up of 24.967 months. The study\'s findings demonstrated a positive connection between the ALT/AHDL-C ratio and the incident NAFLD (HR = 1.037, 95% CI: 1.031-1.042) when adjusting for relevant factors. The ALT/HDL-C ratio and NAFLD risk had a nonlinear connection, with 12.963 as the ratio\'s inflection point. Effect sizes (HR) were 1.023 (95% CI: 1.017-1.029) and 1.204 (95% CI: 1.171-1.237), respectively, on the right and left sides of the inflection point. The sensitivity analysis also showed how reliable our findings were. According to subgroup analysis, those with BMI < 24 kg/m2 and DBP < 90 mmHg had a stronger correlation between the ALT/HDL-C ratio and NAFLD risk. The current study shows a positive and non-linear connection between the ALT/HDL-C ratio and NAFLD risk in lean Chinese individuals. When the ALT/HDL-C ratio is less than 12.963, it is significantly linked to NAFLD. Therefore, from a therapy standpoint, it is advised to keep the ALT/HDL-C ratio less than the inflection point.

Alanine aminotransferase (ALT) and high-density lipoprotein cholesterol (HDL-C) are important predictive factors for non-alcoholic fatty liver disease (NAFLD). The aim of this study was to analyze the association between the ALT/HDL-C ratio and NAFLD.
We conducted a retrospective analysis of data from 14,251 individuals participating in the NAGALA project\'s health screening program. The presence of NAFLD was diagnosed based on the participants\' alcohol consumption status and liver ultrasonography images. Multivariable logistic regression models were used to assess the association between the ALT/HDL-C ratio and NAFLD. Receiver operating characteristic (ROC) analysis was performed to determine and compare the effectiveness of ALT, HDL-C, the aspartate aminotransferase to HDL-C (AST/HDL-C) ratio, the gamma-glutamyl transferase to HDL-C (GGT/HDL-C) ratio and the ALT/HDL-C ratio in identifying NAFLD.
We observed a significant positive association between the ALT/HDL-C ratio and the prevalence of NAFLD. For each standard deviation (SD) increase in the ALT/HDL-C ratio, the adjusted odds ratio (OR) for NAFLD among the participants was 3.05 [95% confidence interval (CI): 2.63, 3.53], with the highest quartile of ALT/HDL-C ratio having a 9.96-fold increased risk compared to the lowest quartile. In further subgroup analyses stratified by gender, age, and waist circumference (WC), we observed a significantly higher risk of NAFLD associated with the ALT/HDL-C ratio among individuals aged ≥45 years, males, and those who were abdominal obesity. Furthermore, based on the results of ROC analysis, we found that the ALT/HDL-C ratio [area under the curves (AUC): 0.8553] was significantly superior to ALT, HDL-C, AST/HDL-C ratio and GGT/HDL-C ratio in identifying NAFLD (All Delong P<0.05); the threshold of suggested ALT/HDL-C ratio for identifying NAFLD was 15.97.
This population-based study demonstrates a positive association between the ALT/HDL-C ratio and NAFLD. The ALT/HDL-C ratio can effectively identify individuals with NAFLD.

BACKGROUND: Low levels of high-density lipoprotein cholesterol (HDL-C) and high levels of alanine aminotransferase (ALT) are related to insulin resistance, metabolic syndrome, and diabetes mellitus (DM). However, evidence on the connection between the alanine aminotransferase to high-density lipoprotein cholesterol (ALT/HDL-C) ratio and diabetes mellitus (DM) risk was limited. The study aimed to investigate the relationship between baseline ALT/HDL-C ratio and DM among Japanese individuals.
METHODS: This second analysis was based on a cohort study using open-source data. Data from 15,342 individuals who participated in the medical examination program were recorded at Murakami Memorial Hospital in Japan between 2004 and 2015. Smooth curve fitting, subgroup analysis, Cox proportional-hazards regression, and a series of sensitivity analyses were conducted to examine the relationship between ALT/HDL-C ratio and incident diabetes. The ability of the ALT/HDL-C ratio to predict diabetes was evaluated using a receiver operating characteristic curve analysis.
RESULTS: After controlling for confounding covariates, the ALT/HDL-C ratio was found to be positively correlated to the DM risk in Japanese adults (HR: 1.01, 95%CI: 1.00-1.02, P = 0.049). This study also found a stable relationship between ALT/HDL-C ratio and diabetes after employing a series of sensitivity analyses. Additionally, there was a non-linear association between the ALT/HDL-C ratio and incident diabetes, and the ALT/HDL-C ratio inflection point was 30.12. When the ALT/HDL-C ratio was below 30.12, the present study discovered a significant positive association between the ALT/HDL-C ratio and incident diabetes (HR: 1.04, 95%CI: 1.02-1.06, P = 0.001). Furthermore, among liver enzymes, blood lipids, and anthropometric indicators, the ALT/HDL-C ratio best predicts DM (AUC = 0.75, 95%CI: 0.73-0.78).
CONCLUSIONS: Increased ALT/HDL-C ratio levels at baseline correlated to incident DM. The relationship between ALT/HDL-C ratio and incident DM was also non-linear. When the ALT/HDL-C ratio is below 30.12, there is a statistically significant positive correlation between the ALT/HDL-C ratio and incident DM.