Blaslov Kristina, Bulum Tomislav, Knežević-Ćuća Jadranka, Duvnjak Lea
Vuk Vrhovac Clinic for Diabetes, Endocrinology and Metabolic Diseases, University Hospital Merkur, School of Medicine, University of Zagreb, Croatia.
Vuk Vrhovac Clinic for Diabetes, Endocrinology and Metabolic Diseases, University Hospital Merkur, School of Medicine, University of Zagreb, Croatia.
Clin Biochem. 2015 Jan;48(1-2):39-43. doi: 10.1016/j.clinbiochem.2014.10.006. Epub 2014 Oct 28.
Dipeptidyl peptidase-4 (DPP4) was recently proposed as a novel adipokine linked to insulin resistance (IR). As IR represents a cluster of disorders in hepatic and muscle cell insulin signalisation, we aimed to assess the possible correlation between fasting serum DPP4 activity, IR and liver enzymes in order to elucidate the question of hepatic contribution to serum DPP4 activity.
This cross-sectional study comprised 44 T1DM patients aged 18 to 65years. IR was estimated using the equation derived from euglycemic-hyperinsulinemic clamp studies-estimated glucose disposal rate (eGDR). DPP4 serum activity was determined spectrophotometrically as a rate of cleavage of 7-amino-4-methyl coumarin (AMC) from H-Gly-Pro-AMC. The patients were divided into two groups according to the mean value of fasting serum DPP4 activity (31.42U/L).
The group with lower fasting serum DPP4 activity had lower mean rate of liver biomarkers alanine aminotransferase (ALT) (p=0.001) and aspartate aminotransferase (AST) (p=0.002) while higher eGDR (p=0.003) compared to group with higher DPP4 activity. DPP4 activity showed positive correlation with AST (r=0.358, p=0.017) and ALT (r=0.364, p=0.015) while negative correlation with eGDR (r=-0.612, p<0.001). ALT remained positively associated with fasting serum DPP4 activity after controlling for age, gender, diabetes duration, the use of statins and antihypertensives (p=0.025).
Fasting serum DPP4 activity might be associated with hepatic IR in T1DM patients and a part of soluble DPP4 activity might be of a hepatic origin. Further study investigation is warranted to elucidate this topic.
二肽基肽酶4（DPP4）最近被提出是一种与胰岛素抵抗（IR）相关的新型脂肪因子。由于IR代表肝和肌肉细胞胰岛素信号传导中的一系列紊乱，我们旨在评估空腹血清DPP4活性、IR和肝酶之间的可能相关性，以阐明肝脏对血清DPP4活性贡献的问题。
这项横断面研究纳入了44名年龄在18至65岁之间的1型糖尿病（T1DM）患者。使用来自正常血糖高胰岛素钳夹研究推导的方程——估计葡萄糖处置率（eGDR）来评估IR。通过分光光度法测定DPP4血清活性，即从H-甘氨酰-脯氨酰-7-氨基-4-甲基香豆素（AMC）中切割AMC的速率。根据空腹血清DPP4活性的平均值（31.42U/L）将患者分为两组。
与DPP4活性较高的组相比，空腹血清DPP4活性较低的组肝生物标志物丙氨酸氨基转移酶（ALT）的平均水平较低（p=0.001），天冬氨酸氨基转移酶（AST）的平均水平较低（p=0.002），而eGDR较高（p=0.003）。DPP4活性与AST呈正相关（r=0.358，p=0.017），与ALT呈正相关（r=0.364，p=0.015），与eGDR呈负相关（r=-0.612，p<0.001）。在控制年龄、性别、糖尿病病程、他汀类药物和抗高血压药物的使用后，ALT仍与空腹血清DPP4活性呈正相关（p=0.025）。
空腹血清DPP4活性可能与T1DM患者的肝脏IR相关，并且部分可溶性DPP4活性可能起源于肝脏。有必要进行进一步的研究调查以阐明这一主题。
