Dynamic thiol/disulphide homeostasis and its prognostic value in patients with non-ST elevation-acute coronary syndromes

Assessment of s-nitrosothiol and thiol/disulfide levels in acute coronary syndrome patients

BACKGROUND

The level of nitric oxide (NO) is important to protect the heart from ischemic damage in acute coronary syndrome (ACS) patients. S-nitrosothiol (SNO) is a molecule that represents the main form of NO storage in the vascular structure. In addition, dynamic thiol/disulfide homeostasis (TDH) is known to play an important role in maintaining the oxidant-antioxidant balance. In this study, our aim is to evaluate the oxidative/nitrosative stress status according to SNO level and TDH in patients with ACS.

METHODS

The study included 124 patients who were admitted to the emergency service and 124 consecutive individuals who applied to the cardiology outpatient clinic with cardiac complaints and underwent coronary angiography (CAG). Blood was drawn from all participants included in the study to determine SNO, nitrite, total thiol, native thiol, and disulfide levels after 12 h of fasting.

RESULTS

Serum SNO levels were found to be significantly lower in ACS patients compared to the control group (0.3 ± 0.08 vs. 0.4 ± 0.10 μmol/L, successively, p < 0.001). In addition, while the total thiol, native thiol, and native thiol/total thiol levels were lower in the patient group compared to the control group, nitrite, disulfide/native thiol and disulfide/total thiol levels were higher. As a result of multivariate logistic regression analysis, it was determined that age, gender, smoking, low-density lipoprotein cholesterol, glycosylated haemoglobin, and SNO levels were independent predictors in predicting ACS patients.

DISCUSSION

S-nitrosothiol and thiol levels were found to be significantly lower in ACS patients. In addition, SNO molecule was independently associated with the presence of ACS diagnosis.

Prognostic value of thiol/disulfide homeostasis in symptomatic patients with heart failure

We aimed to examine the role of thiol/disulphide homeostasis (TDH) in heart failure and its stages and the prognosis of heart failure. A total of 140 subjects were included in the study. Total and native thiol levels were higher in the control group compared to the patient groups (p < .001). While the average disulphide/total thiol ratio was similar in groups 1 and 2, it was found to be significantly lower in the control group compared to other groups and significantly higher in group 3 compared to other groups (p < .05). Mean native thiol and total thiol levels were found lower in patients with mortality compared to surviving patients (p < .001). In ROC curve analysis, it was determined that the total thiol level had 81.8% sensitivity and 83.1% specificity, and native thiol level had 81.8% sensitivity and 84.3% specificity. We found that TDH was impaired in favour of disulphide in cases of heart failure.

Association between Plasma Thiol Parameters and Troponin Levels in Patients with Acute Coronary Syndrome and Prediction of In-Hospital Ventricular Arrhythmia

Fundamento

As arritmias ventriculares (AVs) são a principal causa de mortalidade e morbidade hospitalar em pacientes com síndrome coronariana aguda (SCA) e sua relação com o tiol é desconhecida.

Objetivo

Investigar a relação entre os níveis plasmáticos de tióis e os níveis de troponina em pacientes com SCA e estimar o desenvolvimento de AV intra-hospitalar durante a internação.

Método

O estudo incluiu 231 pacientes consecutivos com SCA com supradesnivelamento do segmento ST (SCA-SDST) e pacientes com SCA sem supradesnivelamento do segmento ST (SCA-SSDST). Após a aplicação dos critérios de exclusão, 191 pacientes foram incluídos na análise estatística. Os pacientes foram classificados em dois grupos: grupo SCA-SDST (n=94) e grupo SCA-SSDST (n=97). Os níveis plasmáticos de tiol, dissulfeto e troponina foram medidos e a razão de troponina para tiol nativo (RTTN) foi calculada. Considerou-se estatisticamente significativo um valor de p bilateral inferior a 0,05.

Resultados

Tiol nativo plasmático, tiol total, dissulfeto e suas razões foram semelhantes entre os grupos. A RTTN se mostrou significativamente maior no grupo SCA-SDST em comparação com o grupo SCA-SSDST. Houve correlação negativa significativa entre os níveis de troponina e tiol. Verificou-se que o tiol nativo é preditor independente do desenvolvimento de AV em pacientes com SCA-SDST e em todos os pacientes com SCA. Verificou-se que o RTTN é preditor independente do desenvolvimento de AV em pacientes com SCA-SSDST e em todos os pacientes com SCA.

Conclusão

Os níveis plasmáticos de tiol podem ser usados para identificar pacientes com alto risco de desenvolvimento de AV intra-hospitalar em pacientes com SCA. A correlação entre os níveis de troponina e tiol pode sugerir que os tióis possam ser marcadores importantes para o diagnóstico e prognóstico da SCA com a ajuda de estudos futuros.

The relationship of thiol/disulfide homeostasis in the etiology of patients with obstructive sleep apnea: a case-control study

AIM

Obstructive sleep apnea syndrome (OSAS) is a chronic and incapacitating disease that often requires lifelong care. This study aimed to evaluate the thiol/disulfide homeostasis in patients with OSAS, to compare the thiol/disulfide levels with the control group and to investigate their relationship with the severity of the disease.

MATERIAL AND METHODS

Patients who were admitted to the department of chest diseases, and diagnosed with OSAS using polysomnographic analysis (n = 186) and 144 patients who underwent polysomnography due to some reasons but ruled out of having OSAS were included in the study. Serum total thiol (TT), native thiol (SH), and disulfide thiol (SS) levels were measured from the participants; SS/SH, SS/TT, and SH/TT percent ratios were calculated and compared between the patient and control groups.

RESULTS

The mean (±SD) age of the patients and control participants was 52.0 ± 11.5 years and 44.9 ± 13.2 years, respectively. Compared to the control group, patients with OSAS had significantly lower SH (239.3 ± 56.3 μmol/L vs. 258.6 ± 65.3μmol/L, t = 2.70, p =.007) and TT levels (273.2 ± 60.1 μmol/L vs. 292.9 ± 67.5μmol/L, t = 2.64, p=.010). Age (OR = 1.04), serum albumin (OR = 12.67), ischemia-modified albumin (IMA) (OR = 0.12), SH (OR = 0.81), and TT (OR = 1.17) were independent predictors of OSAS.

CONCLUSIONS

These results support the idea that decreased ST and TT levels are related to increased oxidative stress. On the other hand, impaired thiol balance may play a significant role in the pathogenesis of OSAS.