Background: It is suggested that myocardial dysfunction in heart failure patients may result from increased oxidative stress-related membrane changes. Thiol/disulfide homeostasis is a new oxidative stress indicator. The aim of this study was to evaluate serum thiol levels and thiol/disulfide homeostasis in patients with heart failure with preserved ejection fraction (HFpEF).

Materials and Methods: Eighty-four overweight patients who applied to our clinic between November 2016 and February 2018 and diagnosed with hypertension and left ventricule concentric hypertrophy with normal systolic function are included in the study. Forty-two patients who were asymptomatic and had normal N terminal pro-B type natriuretic peptide (NT-proBNP) levels (≤125) were in the control group. Forty-two patients who have cardiac failure symptoms and have high NT-roBNP levels (>125) were in the patient group.

Results: Native thiol, total thiol, and disulfide values of the patient group are found to be significantly lower than the control group (P =.001; P <.001; P =.041 respectively). There is a statictically significant negative correlation between native thiol, total thiol values, and NT-proBNP. There is a statictically significant negative correlation between native thiol, total thiol values, and carbohydrate antigen 125 (CA-125) values.

Conclusion: As far as we know from literature, this is the first study on HFpEF and thiol/disulfide homeostasis. It is found that native, total thiol, and disulfide values are low in HFpEF patients and that there is a negative correlation between native, total thiol values and NT-proBNP, CA-125 values. It can be said that oxidant/antioxidant balance is impaired in patients with HFpEF and that larger, randomized studies are needed in order to use oxidant/antioxidant balance in diagnosis and treatment of HFpEF.