Adiponectin–leptin ratio for the early detection of lean non-alcoholic fatty liver disease independent of insulin resistance

BACKGROUND: Lean Non-alcoholic Fatty Liver Disease (NAFLD) shares a similar disease burden to those of their overweight counterparts and should be detected early. We hypothesized that the adiponectin–leptin ratio (AL ratio) could be a good marker for early detection of lean NAFLD independent of insulin resistance. MATERIALS AND METHODS: A total of 575 adults without diabetes were enrolled in a community-based study. The subjects were stratified into the lean controls, lean NAFLD, simple overweight/obesity and overweight/obesity NAFLD groups according to body mass index (BMI) and ultrasonographic fatty liver indicators. Serum adiponectin and leptin levels were measured by enzyme-linked immunosorbent assay. Multivariate logistic regression analyses were performed to estimate the odds ratio of having NAFLD in relation to the tertiles of serum AL concentration after adjustment. Receiver operating characteristic (ROC) analyses were applied to evaluate the diagnostic performance of the AL ratio for NAFLD. RESULTS: The mean age of the participants was 42.8 ± 11.5 years. Comparing with the lean controls, the odds of having lean NAFLD for the highest versus the lowest tertile of AL ratio was 0.28(95%CI: 0.12–0.69) after adjustment. Putting AL ratio, BMI, triglyceride, AST/ALT ratio to the diagnosis performance of NAFLD, the ROC was 0.85 (95% CI: 0.82–0.88), 0.83 (95% CI 0.78–0.87) and 0.86 (95% CI 081–0.91) for all NAFLD, NAFLD in women and NAFLD in men, respectively. (p < .001). CONCLUSIONS: The study revealed that the AL ratio could be a good biomarker to early distinguish lean NAFLD patients from lean controls independent of insulin resistance. [AQ3]: KEY MESSAGES: 1. The prevalence of non-alcoholic fatty liver disease (NAFLD) increases globally and is related to liver diseases and metabolic dysfunctions. Lean subset of NAFLD shares a similar disease burden to those of their overweight counterparts and should be detected early. 2. Adiponectin–leptin ratio were associated with the severity of steatosis and was a predictor of obese NAFLD better than each single adipokine. To date, there is no investigation that explores specifically for the relationship between lean NAFLD and AL ratio. 3. Our study found that adiponectin–leptin ratio is a sole independent marker regardless of insulin resistance in lean NAFLD. Having lean NAFLD for the highest versus the lowest tertile of adiponectin–leptin ratio was 0.28(95%CI: 0.12–0.69) after adjustment of age, sex, current smoking, exercise habits, HOMA-IR and AST/ALT. ROC for the NAFLD performance is good for the early detection (0.85; 95% CI: 0.82–0.88). Further rigorous investigation is necessary and should be promptly performed.