Department of Endocrinology and Metabolism, Dokkyo Medical University, Mibu, Tochigi, Japan.
Transl Res. 2013 Nov;162(5):309-16. doi: 10.1016/j.trsl.2013.07.011. Epub 2013 Aug 30.
A soluble form of CD26/dipeptidyl peptidase 4 (sCD26/DPP4) is found in serum and it has DPP4 enzymatic activity. We investigated whether the serum level of sCD26/DPP4 was influenced by the oral glucose tolerance test (OGTT) in healthy subjects. The serum sCD26/DPP4 level increased significantly from 824.5 ng/mL (interquartile range, from 699.0 to 1050 ng/mL) at baseline to a peak of 985.0 ng/mL (interquartile range, from 796.5 to 1215 ng/mL) during the OGTT (P < 0.0001). The peak sCD26/DPP4 level correlated positively with the baseline age and body mass index, and fasting plasma glucose (FPG), homeostasis model assessment of insulin resistance (HOMA-IR), triglycerides (TG), alanine aminotransferase, and γ-glutamyl transpeptidase (GGT) levels whereas it correlated negatively with high-density lipoprotein (HDL) cholesterol and the serum levels of total and high-molecular weight (HMW) adiponectin. Stepwise regression analysis was done with forward selection of variables, including age, FPG, HOMA-IR, TG, HDL cholesterol, uric acid, GGT, C-reactive protein, and HMW adiponectin. In a model that explained 57.5% of the variation of the peak sCD26/DPP4 level, GGT (β = 0.382, P = 0.007) and HOMA-IR (β = 0.307, P = 0.034) were independent determinants of the peak serum level of sCD26/DPP4. Serum HMW adiponectin decreased significantly from 4.43 μg/mL (interquartile range, from 2.80 to 6.65 μg/mL) at baseline to 4.17 μg/mL (interquartile range, from 2.48 to 6.96 μg/mL) 120 minutes after the oral glucose load (P < 0.0001). The baseline serum level of sCD26/DPP4 showed a significant negative correlation with the percent change of HMW adiponectin during the OGTT. In conclusion, the serum level of sCD26/DPP4 increased acutely after an oral glucose load in apparently healthy subjects. The abrupt increase of serum sCD26/DPP4 after a glucose load may be a marker of insulin resistance that could come from liver or muscle.
可溶性 CD26/二肽基肽酶 4（sCD26/DPP4）存在于血清中，具有 DPP4 酶活性。我们研究了健康受试者口服葡萄糖耐量试验（OGTT）是否会影响血清 sCD26/DPP4 水平。基线时血清 sCD26/DPP4 水平从 824.5ng/ml（四分位间距，699.0 至 1050ng/ml）显著升高至 985.0ng/ml（四分位间距，796.5 至 1215ng/ml）（P<0.0001）。峰值 sCD26/DPP4 水平与基线年龄、体重指数以及空腹血糖（FPG）、稳态模型评估的胰岛素抵抗（HOMA-IR）、三酰甘油（TG）、丙氨酸氨基转移酶和γ-谷氨酰转肽酶（GGT）水平呈正相关，与高密度脂蛋白（HDL）胆固醇和总、高分子量（HMW）脂联素的血清水平呈负相关。采用向前选择变量的逐步回归分析，包括年龄、FPG、HOMA-IR、TG、HDL 胆固醇、尿酸、GGT、C 反应蛋白和 HMW 脂联素。在一个可以解释峰值 sCD26/DPP4 水平 57.5%变异的模型中，GGT（β=0.382，P=0.007）和 HOMA-IR（β=0.307，P=0.034）是峰值血清 sCD26/DPP4 水平的独立决定因素。血清 HMW 脂联素从基线时的 4.43μg/ml（四分位间距，2.80 至 6.65μg/ml）显著下降至口服葡萄糖负荷后 120 分钟时的 4.17μg/ml（四分位间距，2.48 至 6.96μg/ml）（P<0.0001）。OGTT 期间，基线时血清 sCD26/DPP4 水平与 HMW 脂联素的变化百分比呈显著负相关。总之，在明显健康的受试者中，口服葡萄糖负荷后血清 sCD26/DPP4 水平会急剧升高。葡萄糖负荷后血清 sCD26/DPP4 的急剧增加可能是胰岛素抵抗的标志物，这种标志物可能来自肝脏或肌肉。
