Dynamic thiol and disulphide homoeostasis in fibromyalgia.

INTRODUCTION: Thiol and disulphide levels are biomarkers that provide useful information about oxidative stress and antioxidant capacity, showing a different homoeostasis in inflammatory and proliferative diseases. We aimed to clarify the possible aetiology of this disease by using thiol and disulphide levels in patients with fibromyalgia, the basis of which has not yet been clearly elucidated. MATERIAL AND METHODS: A total of 156 individuals: 86 patients with fibromyalgia and 70 age-matched controls were included in this prospective non-randomised case-control study. Demographic characteristics including smoking status, body mass index (BMI), the duration of complaints, and pain levels were carefully recorded. Dynamic thiol-disulphide homoeostasis in blood samples was determined by an automatic-spectrophotometric method. The Mann-Whitney U and Student's t-test were used to determine the differences between the groups. RESULTS: Sex, BMI, and smoking status were similar between the groups (p = 0.62, p = 0.09, and p = 0.64, respectively). While native thiol levels were found to be high in patients with fibromyalgia (p = 0.018), disulphide levels and the rates of disulphide/native thiol and disulphide/total thiol were significantly low (p = 0.049, p = 0.007, and p = 0.007, respectively). Correlation analysis showed no significant relationship between thiol-disulphide levels and duration of complaints or pain level. CONCLUSIONS: Thiol-disulphide balance in fibromyalgia was found to be similar to benign proliferative diseases, suggesting that the underlying mechanism is more likely to be of proliferative pattern rather than inflammatory. Additionally, fibromyalgia is not directly associated with increase in oxidative stress. The molecular mechanisms need to be elucidated.

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.

Fibulins: a new biomarker for pulmonary thromboembolism?

OBJECTIVES: Fibulin-1, -2, -4, and -5 have important role in several vascular diseases. We aimed to investigate if fibulin-4 and -5 can be used as a biomarker for pulmonary thromboembolism (PTE). METHODS: This is a prospective case control study. Thirthy patients diagnosed with PTE and 31 in the control group. Data on demographic characteristics, length of hospital stay, blood cell counts, troponin and BNP levels, arterial blood gases, radiological reports, indication for thromboembolitic treatment, intensive care unit (ICU) requirement, and loss of life were recorded for the patients group. Serum Fibulin-4 and Fibulin-5 levels were measured. RESULTS: Fibulin 4 levels correlated positively with female gender (p < .01, r = 0.433). Positive results were found in 14 (46.7%) patients for PESI.0.1; in 7 (23.3%) patients for D-dimer; in 7 (23.3%) patients for troponin-I; in 7(23.3%) patients for BNP. Median values for Fibulin 4 level were significantly higher in patients positive for BNP. Fibulin-5 level was found to be correlated with the presence of embolism (p = .041, r = 0.263). CONCLUSIONS: Fibulin-4 and -5 have been shown to be relevant to cardiovascular biology and diseases. Experimental studies and observations in humans show that they may play a role in several cardiovascular diseases particularly pulmonary embolism.

The prognostic and predictive significance of serum thiols and disulfide levels in advanced non-small cell lung cancer.

Serum Total Thiol (TT), Native Thiol (NT), and Disulfide (SS) levels were found significantly lower in benign proliferative pathologies and cancer disease compared to healthy subjects. We conducted this prospective study to investigate the possible predictive and prognostic significance of these markers in non-small cell lung cancer (NSCLC), which is one of the most associated cancers with oxidative stress. This was a non-randomized, prospective, and case-control study of 120 subjects, including 60 patients with metastatic or inoperable NSCLC at the time of diagnosis and 60 demographically-matched controls. Morning fasting venous blood serum samples from both NSCLC and control group were stored at -80 °C for equal periods and then TT, NT, and SS levels were measured spectrophotometrically. Serum TT, NT, and SS levels were compared between groups and their relationships with demographic features and survival of NSCLC patients were analyzed. In results, Serum TT, NT, and SS levels were significantly lower in NSCLC patients than those in control group, with a low SS level being an independent indicator of poor survival.

Dynamic thiol/disulphide homeostasis in patients with Uterine Myoma.

BACKGROUND: The aim of this study is to measure and compare the dynamic thiol and disulphide homeostasis between patients with Uterine Myoma (UM) and healthy subjects. MATERIAL AND METHOD: A total of 54 patients with UM who were diagnosed by transvaginal ultrasonography and 37 age- and body mass index-matched healthy individuals were included in this study. Thiol/disulphide homeostasis was measured by a novel automatic spectrophotometric method. RESULTS: The mean serum native thiol, disulphide, and thiol levels were statistically lower in UM group than those in the control group [(284.66±59.41µmol/L vs. 320.98±56.17µmol/L, P<0.0001), (17.27±5.59µmol/L vs. 22.38±6.93µmol/L, P<0.0001) and (319.21±61.69 vs. 365.76±61.46µmol/L, P<0.0001), respectively]. There were no statistically significant differences in ratios of the disulphide/native thiol, native thiol/total thiol, and disulphide/total thiol among patients with UM versus healthy control group (P=0.096, 0.092, 0.092, respectively). CONCLUSION: It was found that the native thiol, total thiol, and disulphide levels in patients with UM decreased while the ratio of native thiol/disulphide remained unchanged.It is necessary to investigate whether these findings have a role in the etiology and clinical course of the UM.