P0148BLOOD PRESSURE CONTROL IS ASSOCIATED WITH HEALTHIER THIOL/DISULPHIDE DYNAMICS IN PRIMARY HYPERTENSION
Authors: Helvacı Özant , Helvaci Burcak , Dam Gamze , Neselioglu Salim , Erel Ozcan , Derici Ülver 
Published: June 2020

Abstract

Background and Aims
Hypertension is the most common chronic disease that leads to death. Oxidative stress plays a not yet fully understood role in the pathogenesis. OS is the result of excessive reactive oxygen species (ROS) and insufficient anti-oxidant mechanisms.
Thiol/disulphide ratio measurement is founded on the fact that ROS frequently target thiol groups of sulphur-containing amino acids on proteins. The more OS there is in the environment, there is less native or total thiols and more disulphides. Newly diagnosed hypertensive patients and those with masked hypertension have this dynamic altered towards disulphide.
In this study, we aimed to further evaluate this relation in terms of medication choice and blood pressure (BP) control in select cases with primary hypertension.

Method
This cross-sectional, multi-centre study was conducted in two tertiary referral centres between January 2018 and January 2019. Patients with diabetes, coronary artery disease, heart failure, atrial fibrillation, cerebrovascular disease, rheumatoid disease, active infection, GFR lower than 60 ml/min and microalbuminuria or proteinuria were excluded. Active smokers were also excluded.
Drug classes allowed were chosen as ACE inhibitors, ARB’s, dihydropyridine calcium channel blockers (CCB) and thiazides and their combinations. Patients on other antihypertensives were excluded from the study.
Two hundred eighty-nine patients were recruited. Demographical and clinical data were recorded. Laboratory parameters were creatinine, CKD-EPI eGFR, uric acid and cholesterol levels. Patients’ home and office BP recordings were analysed. Those with mean BP higher than 140/90 mmHg were accepted as uncontrolled.
Native thiol (NT), total thiol (TT) and disulphide (D) levels were obtained with an automated colourimetric measurement method developed by two of the authors.

Results
The study included 289 (183 female and 106 male) patients. Mean age was 56±9 (19-84). Mean duration of hypertension was 9±7 (1-38) years. Mean BMI was 29±4 (20-48). Four per cent had hypertensive retinopathy. Mean blood pressures were systolic 128±14 and diastolic 80±7 mmHg respectively.
There were nine drug schemes, including monotherapy. The most common form was ARB+thiaz (33.6% of cases) and the least common was ACE inhibitor+thiaz+CCB (1.4%). ANOVA between nine groups did not reveal any statistically significant differences in NT, TT or D levels. The analysis was repeated after combining patients on ACE inhibitors and ARB, thereby reducing the number of groups to five. Yet, the results did not change.
Forty-seven patients (16%) had uncontrolled BP. They had similar demographical data with their counterparts. Duration of hypertension, BMI and laboratory data were also identical. Patients with uncontrolled BP had lower native thiol, total thiol but higher disulphide levels (p&lt; 0,001, Table1).

Conclusion
Patients with primary hypertension have increased oxidative stress evident by altered thiol/disulphide homeostasis. BP control but not drug regimen is associated with better dynamics. Causality remains to be elucidated with prospective trials.