Association of serum gamma-glutamyltransferase with arterial stiffness in established coronary artery disease

Sexual dimorphism in glutathione metabolism and glutathione-dependent responses

Glutathione is the most abundant intracellular low molecular weight thiol in cells and tissues, and plays an essential role in numerous cellular processes, including antioxidant defenses, the regulation of protein function, protein localization and stability, DNA synthesis, gene expression, cell proliferation, and cell signaling. Sexual dimorphisms in glutathione biology, metabolism and glutathione-dependent signaling have been reported for a broad range of biological processes, spanning the human lifespan from early development to aging. Sex-depended differences with regard to glutathione and its biology have also been reported for a number of human pathologies and diseases such as neurodegeneration, cardiovascular diseases and metabolic disorders. Here we review the latest literature in this field and discuss the potential impact of these sexual dimorphisms in glutathione biology on human health and diseases.

Gamma-glutamyltransferase, possible novel biomarker in colon diverticulosis: a case-control study

The gamma-glutamyltransferase (GGT) is recognized in medical practice as a useful indicator for the detection of liver lesions, especially those induced by the excessive consumption of alcoholic or cholesterol-associated drinks. The present study, although it includes a very small number of cases diagnosed with colon diverticulosis-diverticulitis associated with polyposis at the same intestinal level, identifies the presence of increased circulating concentrations of this enzyme in the serum. Its serum levels are tracked “dynamically” throughout a year after the diagnosis and start of the therapy. The study calls into question the release of the enzyme from the edge of the enterocytes’ brush-like edge, leading to the pathogenic disturbance of regional redox homeostasis. The hypothesis gives the circulating values of GGT predictive value for cellular oxidative stress, as well as for indirectly expressing the glutathione level in cytosol.

Low alanine aminotransferase levels and higher number of cardiovascular events in people with Type 2 diabetes: analysis of the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study

AIMS

To determine whether alanine aminotransferase or gamma-glutamyltransferase levels, as markers of liver health and non-alcoholic fatty liver disease, might predict cardiovascular events in people with Type 2 diabetes.

METHODS

Data from the Fenofibrate Intervention and Event Lowering in Diabetes study were analysed to examine the relationship between liver enzymes and incident cardiovascular events (non-fatal myocardial infarction, stroke, coronary and other cardiovascular death, coronary or carotid revascularization) over 5 years.

RESULTS

Alanine aminotransferase measure had a linear inverse relationship with the first cardiovascular event occurring in participants during the study period. After adjustment, for every 1 sd higher baseline alanine aminotransferase measure (13.2 U/l), the risk of a cardiovascular event was 7% lower (95% CI 4-13; P = 0.02). Participants with alanine aminotransferase levels below and above the reference range 8-41 U/l for women and 9-59 U/l for men, had hazard ratios for a cardiovascular event of 1.86 (95% CI 1.12-3.09) and 0.65 (95% CI 0.49-0.87), respectively (P = 0.001). No relationship was found for gamma-glutamyltransferase.

CONCLUSIONS

The data may indicate that in people with Type 2 diabetes, which is associated with higher alanine aminotransferase levels because of prevalent non-alcoholic fatty liver disease, a low alanine aminotransferase level is a marker of hepatic or systemic frailty rather than health.

Comparison of the effects of metoprolol or carvedilol on serum gamma-glutamyltransferase and uric acid levels among patients with acute coronary syndrome without ST segment elevation

Objective:

Serum gamma-glutamyltransferase (GGT) and uric acid levels measured in patients with acute coronary syndrome without ST segment elevation (NSTEMI) are important in diagnosis and in predicting the prognosis of the disease. There is a limited number of clinical studies investigating the effects of beta-blockers on GGT and uric acid levels in these patients. In our study, we aimed to investigate the effects of beta-blocker therapy on GGT and uric acid levels.

Methods:

We conducted a randomized, prospective clinical study. Hundred patients with NSTEMI were included in this study, and they were divided into two groups. Fifty patients were administered metoprolol succinate treatment (1 × 50 mg), whereas the remaining 50 patients were administered carvedilol treatment (2 × 12.5 mg). Thereafter, all of the patients underwent coronary angiography. Blood samples were taken at the time of admission, at the 1^st month, and 3^rd month to detect GGT and uric acid levels.

Results:

There was no statistically significant difference among the metoprolol or carvedilol groups in terms of the GGT levels measured at the baseline, 1^st month, and 3^rd month (p=0.904 and p=0.573, respectively). In addition, there was no statistically significant difference among the metoprolol or carvedilol groups in terms of uric acid levels measured at the baseline, 1^st month, and 3^rd month (p=0.601 and p=0.601, respectively).

Conclusion:

We found that GGT and uric acid levels did not show any change compared to the baseline values, with metoprolol and carvedilol treatment initiated in the early period in patients with NSTEMI.

Assessment of machine-learning techniques on large pathology data sets to address assay redundancy in routine liver function test profiles

Routine liver function tests (LFTs) are central to serum testing profiles, particularly in community medicine. However there is concern about the redundancy of information provided to requesting clinicians. Large quantities of clinical laboratory data and advances in computational knowledge discovery methods provide opportunities to re-examine the value of individual routine laboratory results that combine for LFT profiles.

The machine learning methods recursive partitioning (decision trees) and support vector machines (SVMs) were applied to aggregate clinical chemistry data that included elevated LFT profiles. Response categories for γ-glutamyl transferase (GGT) were established based on whether the patient results were within or above the sex-specific reference interval. Single decision tree and SVMs were applied to test the accuracy of GGT prediction by the highest ranked predictors of GGT response, alkaline phosphatase (ALP) and alanine amino-transaminase (ALT).

Through interrogating more than 20,000 individual cases comprising both sexes and all ages, decision trees predicted GGT category at 90% accuracy using only ALP and ALT, with a SVM prediction accuracy of 82.6% after 10-fold training and testing. Bilirubin, lactate dehydrogenase (LD) and albumin did not enhance prediction, or reduced accuracy. Comparison of abnormal (elevated) GGT categories also supported the primacy of ALP and ALT as screening markers, with serum urate and cholesterol also useful.

Machine-learning interrogation of massive clinical chemistry data sets demonstrated a strategy to address redundancy in routine LFT screening by identifying ALT and ALP in tandem as able to accurately predict GGT elevation, suggesting that GGT can be removed from routine LFT screening.

Association between serum γ-glutamyltranspeptidase and atherosclerosis: a population-based cross-sectional study

OBJECTIVE

The purpose of this study was to determine the relationship between serum γ-glutamyltranspeptidase (GGT) and brachial-ankle pulse wave velocity (baPWV) as an indicator for atherosclerosis in Japanese men and women after adjusting for fatty liver.

DESIGN

A cross-sectional study.

SETTING

A health check-up centre in Japan.

PARTICIPANTS

912 Japanese men and women aged 24-84 years recruited from people who received a medical health check-up programme with a standardised questionnaire and an automatic waveform analyser to measure baPWV.

MAIN OUTCOME MEASURES

We measured serum GGT concentrations and baPWV. Fatty liver was diagnosed by standardised criteria using abdominal ultrasonography. The postmenopausal state was defined as beginning 1 year after the cessation of menses.

RESULTS

In women, log2 GGT was positively associated with baPWV (β=0.11, 95% CI 0.02 to 0.19, p<0.05), independent of age, body mass index, systolic blood pressure, fasting plasma glucose, triglycerides, estimated glomerular filtration rate, fatty liver, menopausal state and parameters of lifestyles. However, in men, the positive association of log2 GGT with baPWV was not significant (β=-0.04, 95% CI -0.10 to 0.03, p=0.28) in multivariable linear regression analyses.

CONCLUSIONS

The serum GGT level was associated with baPWV, independently of covariates including fatty liver or menopausal state just in women, but not in men.

Gamma Glutamyl Transferase Activity is Associated With Both Paraoxonase Activity and Aortic Stiffness in Hypertensive Patients

BACKGROUND

We aimed to investigate relationship between gamma glutamyl transferase (GGT) activity with paraoxonase 1 (PON1) activity and aortic stiffness (AS) parameters such as pulse wave velocity (PWV) and augmentation index (AIx).

METHODS

Measurements were obtained from 324 patients with newly diagnosed essential hypertension (mean age: 55.0 ± 8.2 years). The patients were divided into two groups according to their median GGT values. PWV and AIx were calculated using the single-point method via the Mobil-O-Graph® ARCsolver algorithm.

RESULTS

PWV, Aix, and high-sensitive C-reactive protein (hs-CRP) values were higher and PON1 activity values were lower in GGThigh group compared with GGTlow group (P < 0.05, for all). Multiple linear regression analysis showed that GGT activity was independently associated with PWV (β = 0.496, P < 0.001) and PON1 activity (β = -0.343, P < 0.001) as well as hs-CRP (β = 0.334, P < 0.001).

CONCLUSION

These results may support that increased GGT activity would be associated with both impaired antioxidant system and increased AS in hypertensive patients.

γ-Glutamyl transferase activity and the burden of coronary atherosclerosis in patients with ST-segment elevation myocardial infarction

The relationship between extent, severity, and complexity of coronary artery disease (CAD) in patients with ST-segment elevation myocardial infarction (STEMI) and serum γ-glutamyl transferase (GGT) activity has not been adequately studied. We evaluated the relationship between GGT activity and the burden of CAD as assessed by SYNTAX score (SXscore) in patients with STEMI. A total of 243 patients (age 67.1 ± 8.6, 77.4% male) with STEMI were divided into 2 groups. Low- and high-SXscore groups were defined as SXscore <22 and ≥22, respectively. Admission GGT activities were similar between low- and high-SXscore groups (32 ± 17 vs 33 ± 18; P = .625), and there was no significant correlation between GGT activity and SXscore. Although there was an association between high SXscore and major adverse cardiovascular events, as expected, our results did not demonstrate any relationship between admission GGT activities and complexity and extent of the coronary lesions in patients with STEMI.

Epigenetic alterations and an increased frequency of micronuclei in women with fibromyalgia

Fibromyalgia (FM), characterized by chronic widespread pain, fatigue, and cognitive/mood disturbances, leads to reduced workplace productivity and increased healthcare expenses. To determine if acquired epigenetic/genetic changes are associated with FM, we compared the frequency of spontaneously occurring micronuclei (MN) and genome-wide methylation patterns in women with FM (n = 10) to those seen in comparably aged healthy controls (n = 42 (MN); n = 8 (methylation)). The mean (sd) MN frequency of women with FM (51.4 (21.9)) was significantly higher than that of controls (15.8 (8.5)) (χ² = 45.552; df = 1; P = 1.49 × 10⁻¹¹). Significant differences (n = 69 sites) in methylation patterns were observed between cases and controls considering a 5% false discovery rate. The majority of differentially methylated (DM) sites (91%) were attributable to increased values in the women with FM. The DM sites included significant biological clusters involved in neuron differentiation/nervous system development, skeletal/organ system development, and chromatin compaction. Genes associated with DM sites whose function has particular relevance to FM included BDNF, NAT15, HDAC4, PRKCA, RTN1, and PRKG1. Results support the need for future research to further examine the potential role of epigenetic and acquired chromosomal alterations as a possible biological mechanism underlying FM.

Small artery elasticity predicts future cardiovascular events in chinese patients with angiographic coronary artery disease

Arterial elasticity has been shown to predict cardiovascular disease (CVD) in apparently healthy populations. The present study aimed to explore whether arterial elasticity could predict CVD events in Chinese patients with angiographic coronary artery disease (CAD). Arterial elasticity of 365 patients with angiographic CAD was measured. During follow-up (48 months; range 6-65), 140 CVD events occurred (including 34 deaths). Univariate Cox analysis demonstrated that both large arterial elasticity and small arterial elasticity were significant predictors of CVD events. Multivariate Cox analysis indicated that small arterial elasticity remained significant. Kaplan-Meier analysis showed that the probability of having a CVD event/CVD death increased with a decrease of small arterial elasticity (P < .001, respectively). Decreased small arterial elasticity independently predicts the risk of CVD events in Chinese patients with angiographic CAD.