Our study aimed to investigate the C-peptide-releasing effect associated with the risk of elevated serum uric acid (SUA) levels in patients with type 2 diabetes mellitus (T2DM). In the cross-sectional study, 345 patients with T2DM hospitalized at the First Affiliated Hospital of Harbin Medical University were consecutively enrolled, and their baseline data were collected. The study design used two parameters for C-peptide releasing effects: the multiplication effect of 1 h postprandial C-peptide to fasting C-peptide ratio (1hCp/FCp) and 2hCp/FCp; the incremental effect of 1hCp minus FCp (1hΔCp) and 2hΔCp. The patients with T2DM in the upper quartiles of SUA had higher FCp, 1hCp, 1hΔCp, 2hCp, and 2hΔCp. Multiple linear regression analysis revealed that after adjusting all the confounding factors, the serum C-peptide including 1hCp (β = 5.14, p = 0.036), 1hΔCp (β = 7.80, p = 0.010), 2hCp (β = 4.27, p = 0.009) and 2hΔCp (β = 5.20, p = 0.005) were still positively correlated with SUA levels in patients with T2DM. In female patients, only the 2hCp (β = 4.78, p = 0.017) and 2hΔCp (β = 5.28, p = 0.019) were associated with SUA level; however, in male patients, no C-peptide parameter was associated with SUA levels in T2DM (all p > 0.05). Within a certain range, the elevated SUA levels might be associated with the better C-peptide incremental effect of islet β cell function in T2DM, especially in female patients.
Keywords: C-peptide; Hyperuricemia; Serum uric acid; Type 2 diabetes mellitus.