肾功能正常的2型糖尿病患者血肌酐与乳酸水平相关

Association of plasma creatinine with lactic acid level in type 2 diabetic patients with normal renal function

目的探讨肾功能正常的2型糖尿病患者的血肌酐与血乳酸水平的关系以及应用二甲双胍后对血乳酸的影响。方法选择肾功能正常的住院2型糖尿病患者723例，其中应用二甲双胍者（用药组）275例，未用双胍类者（对照组）448例。用酶电极法测定血乳酸水平，同时检测空腹血糖、胰岛素、HbA1C、尿素氮、肌酐和丙氨酸转氨酶（ALT）等水平。结果（1）用药组的平均血乳酸水平高于对照组[（1．33±0．57vs1．17±0．47）mmol／L，P〈0．01]；高乳酸血症的发生率显著高于对照组（9．45％vs4．91％，P〈0．01），但均未达到酸中毒的水平。（2）相关性分析结果显示，血乳酸水平与血肌酐、尿素氮、ALT、体重指数（BMI）呈明显正相关。在校正ALT和BMI后，肌酐仍与血乳酸呈正相关（r=0．345，P〈0．01）。（3）按肌酐水平进行分层后，血乳酸水平随着血肌酐水平升高而增加，肌酐〉90μmol／L后显著增高；受试者工作特征（ROC）曲线分析表明预测血乳酸水平增高的肌酐截点是95．35μmol／L。结论肾功能正常的2型糖尿病患者应用二甲双胍虽具有较好的安全性，但仍有极少数患者可出现乳酸水平的轻度升高。血肌酐〉95．35μmol／L者发生高乳酸血症的风险增加。

Objective To study the relationship between plasma creatinine and lactic acid levels in type 2 diabetic patients with normal renal function, and the effect of metformin administration on plasma lactic acid. Methods Blood samples were collected from 723 type 2 diabetic inpatients（275 cases treated with metformin as treatment group and 448 without metformin as control group ）. Plasma lactic acid was measured with enzymeelectrode assay. The fasting plasma glucose, fasting insulin, creatinine （Cr） , alanine aminotransferase （ ALT）, and HbA1c levels were also determined. Results （ 1 ） The lactic acid level in treatment group was significantly higher than that in control group [ （ 1.33±0.57 vs 1.17±0.47 ） mmol/L, P〈0.01 ] and so was the incidence of hyperlactacidemia （9. 45% vs 4. 91%, P〈0. 01 ）. No lactic acidosis was found in all patients. （2） The correlation analysis showed that Cr, blood urea nitrogen, ALT and body mass index （BMI） were positively correlated with lactic acid in control group, and the positive correlation between Cr and lactic acid still existed （r= 0. 345, P〈0.01 ） after adjustment for ALT and BMI. （3） After being divided by 20 μmol/L Cr in control group, lactic acid levels in subgroup increased with the Cr levels, especially when Cr was over 90 μmol/L. The Cr cutpoint for predicting lactatemia was 95.35 μmoL/L. Conclusion It is safe to administrate metformin in type 2 diabetic patients with normal renal function, along with low risk of lactic acidemia. The incidence of lactic acidemia may increase when plasma Cr level reaches 95.35 μmol/L.