In planning our study groups, we drew inspiration from the designs of similar studies. Using the G*Power calculator (http://www.gpower.hhu.de/), we estimated a statistical power of 0.85 and a significance level of p < 0.05 to determine the minimum necessary group size. Accordingly, we enrolled 120 hypertensive men and 70 non-cardiovascular disease (CVD) men, who underwent examinations at the Vinnytsya Regional Diagnostic and Disease Prevention Center (VRDDP) in Vinnytsya, Ukraine, as our protocol dictates. The National Pirogov Memorial Medical University's (NPMMU) ethical committee, located in Vinnytsya, Ukraine, sanctioned our research protocol. Prior to commencing any procedure, informed consent was duly obtained from all participants who signed the required documents. We set the inclusion criteria to male individuals aged 40 to 65 years, residing in the Podil region of Ukraine, and diagnosed with essential arterial hypertension (EAH). Exclusion criteria were individuals with symptomatic arterial hypertension (AH), a history of myocardial infarction or unstable angina, significant congenital heart defects, arrhythmia, non-coronary myocardial diseases, pulmonary arterial hypertension, and severe kidney or liver dysfunction, alongside known rheumatological, endocrine, or oncological diseases. Data influencing our exclusion criteria included age, sex, and concurrent diseases' impact on plasma SIRT1 levels. The primary study group had an average age of 50.93 ± 0.449 years with an EAH diagnosis. Seventy control group participants showed no CVD signs, averaging 49.03 ± 0.794 years. Diagnoses followed the 2018 and 2021 European Society of Cardiology (ESC) guidelines, segregating 120 hypertensive men based on heart failure (HF) signs into two groups of 60: one showing no HF symptoms and the other displaying NYHA class II-III HF symptoms. Participants underwent extensive evaluations, including physicals, lab tests, blood pressure measurement, electrocardiography, echocardiography, and plasma SIRT1 level and SIRT1 gene rs7069102 C/G polymorphism analysis. Body mass index (BMI) calculations used the Quetelet formula (BMI = body weight (kg)/height² (cm)), classifying obesity according to WHO guidelines.

We assessed plasma SIRT1 levels and the rs7069102 SNP variant in the SIRT1 gene from venous blood samples of all participants. The SIRT1 plasma concentration was measured using the standard ELISA method with RayBiotech, Inc. (USA) reagents and a Humareader single enzyme analyzer (Germany). This choice was backed by ELISA's proven accuracy, specificity, and widespread clinical use.

Genomic DNA extracted from whole blood was used to determine the rs7069102 C/G polymorphism in the SIRT1 gene, employing the DNA-EXTRAN-1 reagent kit for extraction. The allele-specific polymerase chain reaction (PCR), a method renown for SNP analysis effectiveness, facilitated the detection of SIRT1 gene alleles at the rs7069102 position by tracking the fluorescent signal of the amplified products (Thermo Fisher Scientific, USA).

We presented our findings as mean (M ± SEM) or percentages. Depending on the data distribution, we applied appropriate statistical methods to discern correlations or differences between groups. These included parametric (Pearson correlation, t-test) and non-parametric (Spearman correlation, Mann-Whitney U test) methods, one-way ANOVA with the Tukey criterion for parametric data, or the Kruskal–Wallis test for non-parametric data. We employed the χ2 Pearson criterion with Yates correction to assess differences in observation frequencies, especially for smaller group analyses. Differences were considered significant at p < 0.05.

Figure 1

Figure 2

Notes: BMI: body mass index, SIRT1: sirtuin 1. Data are shown as Mean.

We discovered that the plasma SIRT1 level in patients with EAH significantly differs from levels found in healthy volunteers. Research by Duman et al. suggests that in hypertensive patients, plasma peptide levels are notably higher than those in individuals with normal blood pressure19, 20, 21, 22. Conversely, other studies have indicated that hypertensive patients exhibit significantly lower plasma peptide concentrations compared to a control group9, 23. The assessment of SIRT1 in patients with heart failure (HF) showcases varied methodological approaches among researchers. Some studies have examined peptide expression levels in tissues, revealing experimental evidence that cardiomyocyte peptide expression in HF patients is nearly half that of healthy hearts8. Other analyses, focusing on SIRT1 expression in peripheral blood mononuclear cells, found significantly reduced levels in HF patients19. Despite the use of differing methodologies in these studies, our findings align closely. However, research conducted by Italian scientists reported higher peptide expression in HF patients than in healthy volunteers24. No studies were found examining plasma SIRT1 concentration in hypertensive patients with HF.

This diversity in results likely stems from the various study designs. When research includes participants of differing genders, ages, and HF etiologies, and employs varied methods for SIRT1 evaluation, interpreting or reproducing study findings becomes challenging. In planning our study, we minimized several variables by ensuring homogeneity in gender, age, and HF etiology within our groups. This approach allowed us to identify potential factors influencing plasma peptide levels: the duration of hypertension, disease severity, presence of obesity, and genetic components.

We observed that plasma SIRT1 concentration in patients with EAH and HF was significantly lower in those with early disease onset and obesity. This contrasts with findings in coronary heart disease (CHD) patients, where plasma peptide levels showed no correlation with anthropometric measures25, 26. Interestingly, Norwegian research identified a correlation between SIRT1 expression and obesity in women, but not in men14. The design of our cross-sectional study limits the generalization of our results, suggesting that men with EAH and HF may exhibit lower SIRT1 levels if obesity is present or if EAH appears early. This could impact the use of this peptide as a diagnostic marker for HF. However, our data supports a hypothesis that early EAH onset and obesity co-morbidity could accelerate HF development through more significant early hypertensive damage to the myocardium, depleting cardiomyocyte SIRT1 reserves. Experimental evidence links low SIRT1 expression in cardiomyocytes to advancing myocardial fibrosis27. Thus, reduced plasma SIRT1 levels could signal depleted myocardial functional reserves in HF development, meriting further longitudinal research.

We also explored the phenotypic significance of the rs7069102 C/G SNP in the SIRT1 gene concerning plasma activity and concentration levels. Minimal available literature exists on this topic. Kilic et al. found no significant differences in plasma peptide levels between carriers of different SNP variants in a general Turkish population12. Yet, in a CHD patient cohort, GG homozygotes exhibited significantly higher plasma SIRT1 levels compared to other variants28. In acute coronary syndrome patients, a higher plasma peptide concentration was linked to the C allele29. Little to no information exists on the rs7069102 C/G SNP's effect on plasma SIRT1 levels in HF patients. Our findings indicate low plasma peptide levels among homozygous GG variant carriers in patients with EAH and HF, offering new insights into the rs7069102 C/G polymorphism's phenotypic manifestations in Ukrainian hypertensive men. Given the minor allele G’s varying prevalence across populations, its potential impact on plasma SIRT1 levels could differ globally.

Our results lay the groundwork for further exploring plasma peptide concentrations in EAH patients, considering various heart structure and function disorders that lead to hypertensive heart and HF. The cross-sectional nature of our study precluded investigating other HF progression factors in EAH patients, such as lifestyle or treatment approaches. Consequently, our findings open avenues for detailed analysis of plasma SIRT1 level changes in patients with EH and varied HF phenotypes across different clinical scenarios. This could enhance the diagnostic and prognostic utility of SIRT1, refining the biomarker's application by accounting for significant influences and limitations.

In male patients diagnosed with exercise-associated hyponatremia (EAH), there was a significant association between lower plasma SIRT1 levels and heart failure (HF). Several factors contributing to reduced plasma peptide levels were identified, including obesity, the early onset of hypertension, and the presence of the GG variant within the rs7069102 single nucleotide polymorphism (SNP) in the SIRT1 gene. These findings enhance our understanding of SIRT1's diagnostic value and its potential limitations as a biomarker for HF in clinical settings. Furthermore, they underscore the necessity for and guide the direction of future research in this area.

BMI - Body Mass Index, CHD - Coronary Heart Disease, CVD - Cardiovascular Disease, EAH - Essential Arterial Hypertension, ELISA - Enzyme-Linked Immunosorbent Assay, ESC - European Society of Cardiology, GFR - Glomerular Filtration Rate, HF - Heart Failure, NPMMU - National Pirogov Memorial Medical University, NYHA - New York Heart Association, PCR - Polymerase Chain Reaction, SEM - Standard Error of the Mean, SIRT1 - Sirtuin 1, SNP - Single Nucleotide Polorphism, VRDDP - Vinnytsya Regional Diagnostic and Disease Prevention Center, WHO - World Health Organization

This research received no specific grant from any funding agency in the public, commercial or non-profit sectors. We thank all patients for their participation in the investigation, and the doctors, nurses, and administrative staff of VRSRPD (Vinnytsia, Ukraine) that assisted with the study.

Starzhynska O.: developed data collection and assessment tools, analysis and interpretation of data, drafting of the manuscript. Donets A.: conducted the initial analysis of the problem, coordinated and supervised data collection on the site. Maiko O.: wrote review, edited of the manuscript. Zhebel V.: developed the study concept and design, edited and approved the final manuscript. All authors read and approved the final manuscript.

None.

Data and materials used and/or analyzed during the current study are available from the corresponding author on reasonable request.

The research protocol was approved by the ethical committee of NPMM, Vinnytsya, Ukraine, which found no deviations from the requirements of the Declaration of Helsinki and the Council of Europe Convention on Human Rights and Biomedicine (1977) and requirements of the current legislation of Ukraine. Before initiating any procedures, all patients provided Informed Consent by signing the appropriate documentation.

Not applicable.

The authors declare that they have no competing interests.