Objectives: The association between serum uric acid (SUA) and fasting plasma glucose (FPG) has not been fully outlined, in particular in hyperuricaemic population. This study aimed to address this issue, along with the exploration of the role of insulin resistance that was assessed by triglyceride-and-glucose (TyG) index.
Methods: A total of 16,297 participants without known diabetes from the SENSIBLE and SENSIBLE-Addition studies were included in the present analysis. Hyperuricaemia was defined as SUA ≥6 mg/dL. Generalised addictive model was applied to establish the relationship of SUA with FPG, and mediation analysis was performed to assess how insulin resistance affected the relationship.
Results: SUA showed an inverted U-shaped association with FPG, with the turning point of FPG at 6.1 mmol/L and 7.5 mmol/L in normouricaemic and hyperuricaemic participants, respectively. However, the significant relationship between SUA and FPG disappeared in hyperuricaemic participants (form B=3.3, 95% CI: 0.6-5.9, p=0.016 to B= -0.2, 95% CI: -3.1-2.7, p=0.894), and attenuated in normouricaemic participants (from B=9.8, 95% CI: 8.0-11.7, p<0.001 to B=7.3, 95% CI: 5.3-9.2, p<0.001) after controlling for TyG index. In the ascending segment, the relationship between SUA and FPG was partially mediated by TyG index in normouricaemic participants, but fully in hyperuricaemic participants.
Conclusions: SUA had an inverted U-shaped relationship with FPG, and their positive relationship was fully mediated by insulin resistance in participants with hyperuricaemia but not those without.