Stratification by sample size showed HCC group had significantly higher AdipoQ levels than CFC group in small (n < 200) sample numbers (SMD = 0.76, 95% CI (0.03, 1.50), P = 0.042), but not in large (n ≥ 200) sample numbers (SMD = − 0.40, 95% CI (− 1.34, 0.54), P = 0.403). Here, ADIPOQ is linked to hepatocellular carcinoma.