PS-P13-5: ASSOCIATION BETWEEN G-GLUTAMYL TRANSPEPTIDASE WITH BLOOD PRESSURE IN APPARENTLY HEALTHY SUBJECTS
Authors: Murakami Kazuo 
Published: January 2023

Objective:
γ-glutamyl transpeptidase (γ-GTP) increases intracellular reduced glutathione (GSH) synthesis to scavenge increased intracellular ROSs. And oxidative stress is reported to be involved in the pathogenesis of hypertension recently. The aim of this study is to investigate whether oxidative stress is taking some part in the pathogenesis of hypertension using γ-GTP as a marker.

Design and method:
Apparently healthy 1259 cases who visited our department for the medical check-up examinations including BMI, TG, LDL-cholesterol, fasting plasma glucose (FPG), uric acid, blood pressure, tobacco habits, having metabolic syndrome according to Japanese criteria or not and γ-GTP were assessed. Subjects were not on medical treatment such as malignancy, hyperlipidemia, hypertension, diabetes, hyperuricemia, liver dysfunction or chronic viral infection. Simple correlations between blood pressure and these risk factors or γ-GTP were estimated by Pearson correlation coefficient (CC). Difference between blood pressure and gender, tobacco or metabolic groups were estimated by unpaired t-test. Then multiple regression analysis was estimated, adopting positively associated risk factors or γ-GTP as independent variables to explain the response variable of blood pressure.

Results:
Systolic blood pressure (SBP) correlated with gender (P < 0.001), age (CC; 0.341, P < 0.001), BMI (CC; 0.342, P < 0.001), metabolic syndrome (P < 0.001), uric acid (CC; 0.253, P < 0.001), TG (CC; 0.204, P < 0.001), LDL-cholesterol (CC; 0.194, P < 0.001), HDL-cholesterol (CC; -0.131, P < 0.001), FPG (CC; 0.311, P < 0.001), γ-GTP (CC; 0.164, P < 0.001). And multiple regression analysis revealed significant effect of gender (standardizedβ;; -0.062, P < 0.05), age (standardizedβ;; 0.302, P < 0.001), BMI (standardizedβ;; 0.243, P < 0.001), metabolic syndrome (standardizedβ;; -0.128, P < 0.001), LDL-cholesterol (standardizedβ;; 0.060, P < 0.05), HDL-cholesterol (standardizedβ;; 0.062, P < 0.05), FPG (standardizedβ;; 0.086, P < 0.005), and γ-GTP (standardizedβ;; 0.071, P < 0.01) on SBP. Similarly, Diastolic blood pressure (DBP) correlated with gender (P < 0.001), age (CC; 0.203, P < 0.001), BMI (CC; 0.333, P < 0.001), metabolic syndrome (P < 0.001), uric acid (CC; 0.315, P < 0.001), TG (CC; 0.253, P < 0.001), LDL-cholesterol (CC; 0.165, P < 0.001), HDL-cholesterol (CC; -0.162, P < 0.001), FPG (CC; 0.295, P < 0.001), γ-GTP (CC; 0.226, P < 0.001). Multiple regression analysis adopting diastolic blood pressure (DBP) as response variable revealed significant effect of gender (standardizedβ;; -0.161, P < 0.001), age (standardizedβ;; 0.159, P < 0.001), BMI (standardizedβ;; 0.193, P < 0.001), metabolic syndrome (standardizedβ;; -0.120, P < 0.001), uric acid (standardizedβ;; 0.067, P < 0.05), LDL-cholesterol (standardizedβ;; 0.058, P < 0.05), HDL-cholesterol (standardizedβ;; 0.078, P < 0.05), FPG (standardizedβ;; 0.082, P < 0.005), and γ-GTP (standardizedβ;; 0.099, P < 0.001) on DBP.

Conclusion:
Elevated blood γ-GTP level associated with blood pressure positively, significantly and independently of other risk factors of hypertension, indicating oxidative stress may take some part in pathophysiology of hypertension as cause or result.