Background: The study estimated the association between NAFLD and SUA/Cr in Chinese non-obese patients with type 2 diabetes mellitus (T2DM) and also investigated mediating effect of TG.
Methods: All patients were divided into NAFLD group (n = 420) and non-NAFLD group (n = 347). The differences of biochemical indicators between the two groups were compared. The link between SUA/Cr and other parameters was checked through Spearman correlation analysis. Differences in the incidence rate of NAFLD between SUA/Cr and TG 3 tertile subgroups were tested by chi-squared. To explore the independent influence of SUA/Cr and TG on NAFLD, logistic regression was performed. The predictive value of SUA/Cr and SUA/Cr combined with BMI for NAFLD was analyzed using ROC curves. In addition, to confirm whether TG has a mediating effect on the link of SUA/Cr and NAFLD, we conducted a mediating analysis.
Results: NAFLD group had higher SUA/Cr values than individuals without NAFLD (P < 0.01). SUA/Cr was linked with TC and TG (r = 0.081, 0.215 respectively). NAFLD prevalence increased progressively from quartile 1 to quartile 3 of SUA/Cr (44% vs 57% vs 62%). Prevalence of NAFLD increased from quartile 1 to quartile 3 of TG (35.8% vs 58.7% vs 69.9%). Analysis of the logistic regression revealed that SUA/Cr and TG were statistically linked with NAFLD. The ROC curve pointed out that the area under the curve (AUC), sensitivity and specificity of SUA/Cr were 0.59, 0.629 and 0.522, respectively. The AUC, sensitivity and specificity for SUA/Cr combined with BMI were 0.719, 0.644 and 0.677, separately. The mediation analysis showed a statistically direct effect of SUA/Cr on NAFLD (β=0.148, 95% CI: 0.0393, 0.2585). The function of SUA/Cr on NAFLD partially mediated by TG (β=0.1571, 95% CI: 0.0704, 0.2869).
Conclusion: SUA/Cr was significantly associated with NAFLD in non-obese T2DM patients, and TG partially mediated this association. SUA/Cr can be applied to predict for NAFLD.

Keywords: nonalcoholic fatty liver disease, type 2 diabetes mellitus, serum uric acid to creatinine ratio