Objective: To explore the relationship between fasting C-peptide (F-CP) and serum uric acid (SUA) in patients with type 2 diabetes mellitus (T2DM).
Methods: A total of 347 hospitalized patients with T2DM were stratified according to F-CP level to analyze the impact of increased F-CP levels on SUA level and the incidence of hyperuricemia (HUA). The patients with an elevated SUA level (>420 µmol/L) and a normal SUA level (≤420 µmol/L) were compared for general data, fasting C-peptide and other clinical indexes. Pearson or Spearman correlation analysis was used to analyze the correlation of SUA level with F-CP levels and other parameters. The risk factors of elevated SUA were analyzed by binary logistic regression, multiple regression analysis and hierarchical interaction analysis. The ROC curve was used to analyze the independent risk factors of elevated SUA and determine the corresponding cut-off values.
Results: Compared with those with a normal SUA level, patients with elevated SUA had higher body mass index (BMI), waist-to-hip ratio, F-CP, postprandial 2hC peptide (2hP-CP), triglyceride (TG), homocysteine (HCY), serum creatinine (SCr) level (P<0.05), and a greater percentage of drinking (44.8% vs 32.6%, P=0.006), but had significantly lowered levels of HbA1c, high-density lipoprotein (HDL), and estimated glomerular filtration rate (eGFR) (P<0.05). SUA was found to be positively correlated with F-CP, 2hP-CP, BMI, waist-to-hip ratio, diastolic blood pressure, TG, HCY, SCr, smoking and drinking (P<0.05), and was negatively correlated with gender, age, age of disease onset, HbA1c, HDL and eGFR (P<0.05). SUA level and the incidence of hyperuricemia increasea significantly with F-CP level (P<0.05). F-CP was identified as an independent risk factor for elevated SUA, and gender did not affect the relationship between F-CP and SUA. ROC curve analysis showed that a F-CP level >1.260 ng/mL was associated with a significantly increased risk of hyperuricemia in T2DM patients.
Conclusion: F-CP is closely related with SUA and may be an independent risk factor of elevated SUA in patients with T2DM.
目的: 探讨2型糖尿病（T2DM）患者空腹C肽（F-CP）与血尿酸（SUA）水平之间的关系。
方法: 选取347例住院的T2DM患者，根据F-CP水平按照四分位法分为4个亚组，依次为C1（< 0.74 ng/mL）、C2（0.74~1.21 ng/mL）、C3（1.22~1.87 ng/mL）、C4（> 1.87 ng/mL），比较各亚组患者一般资料及临床指标的差异，并探讨随着F-CP亚组水平的增加，SUA的水平以及高尿酸血症（HUA）的发病率的变化。按照SUA水平分为升高组（>420 μmol/L）和正常组（≤420 μmol/L），分别比较两组患者一般资料、空腹C肽以及其他临床指标等的差异，分析两组患者SUA水平与F-CP水平等一系列指标的相关性。采用二元Logistic回归及多元回归方程分析、分层交互检验分析探讨SUA升高的危险因素。利用ROC曲线分析影响SUA升高的所有独立危险因素，观察F-CP对SUA的影响程度，寻找相应的cut-off值。
结果: 与正常组SUA相比，SUA升高组患者体质量指数（BMI）、腰臀比、F-CP、餐后2hC肽（2hP-CP）、甘油三酯（TG）、同型半胱氨酸（HCY）、血肌酐（SCr）等水平增加（均P < 0.05），合并饮酒史比率较高（44.8% vs 32.6%，P=0.006）；而糖化血红蛋白（HbA1c）、高密度脂蛋白（HDL）、估算肾小球滤过率（eGFR）水平偏低（均P < 0.05）。相关性分析结果证明，SUA与F-CP、2hP-CP、BMI、腰臀比、舒张压、TG、HCY、SCr、吸烟史、饮酒史等呈正相关（均P < 0.05），而与性别、年龄、发病年龄、HbA1c、高密度脂蛋白（HDL）、eGFR等呈负相关（均P < 0.05）。F-CP四个亚组间存在着明显差异（P < 0.0001），且随着F-CP的增加，SUA水平及高尿酸血症的发病率也随之增加（P < 0.05）。Logistic回归及多元线性回归方程分析表明，F-CP是SUA升高的独立危险因素。性别分层交互检验分析显示，性别不会影响F-CP与SUA的关系。ROC曲线表明，当F-CP在1.260 ng/mL以上时，T2DM患者出现高尿酸血症几率将明显增加。
结论: T2DM患者F-CP与SUA之间关系密切，F-CP可能是预测T2DM患者血尿酸升高的独立危险因素。