The relationship between gamma-glutamyl transferase levels and coronary plaque burdens and plaque structures in young adults with coronary atherosclerosis

Systematic interrogation of functional genes underlying cholesterol and lipid homeostasis

BACKGROUND

Dyslipidemia or hypercholesterolemia are among the main risk factors for cardiovascular diseases. Unraveling the molecular basis of lipid or cholesterol homeostasis would help to identify novel drug targets and develop effective therapeutics.

RESULTS

Here, we adopt a systematic approach to catalog the genes underlying lipid and cholesterol homeostasis by combinatorial use of high-throughput CRISPR screening, RNA sequencing, human genetic variant association analysis, and proteomic and metabolomic profiling. Such integrative multi-omics efforts identify gamma-glutamyltransferase GGT7 as an intriguing potential cholesterol and lipid regulator. As a SREBP2-dependent target, GGT7 positively regulates cellular cholesterol levels and affects the expression of several cholesterol metabolism genes. Furthermore, GGT7 interacts with actin-dependent motor protein MYH10 to control low-density lipoprotein cholesterol (LDL-C) uptake into the cells. Genetic ablation of Ggt7 in mice leads to reduced serum cholesterol levels, supporting an in vivo role of Ggt7 during cholesterol homeostasis.

CONCLUSIONS

Our study not only provides a repertoire of lipid or cholesterol regulatory genes from multiple angles but also reveals a causal link between a gamma-glutamyltransferase and cholesterol metabolism.

Association of Serum Gamma-Glutamyltransferase with In-hospital Heart Failure in Patients with ST-segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

Background

To explore the association between gamma-glutamyltransferase (GGT) and in-hospital heart failure (HF) in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI).

Methods

A total of 412 patients diagnosed with STEMI and treated with primary PCI were included in our study. Univariate and multivariate logistic regression models were used to evaluate the association between GGT and the risk of in-hospital HF in STEMI patients. The receiver operating characteristic (ROC) curve was used to assess the accuracy of GGT in predicting in-hospital HF.

Results

The incidence of HF after STEMI increased significantly with increasing GGT tertiles (the first, second, and third tertile groups were 7.97%, 14.49%, and 18.38%, respectively; p = 0.039). Multivariate logistic regression analysis revealed that the risk of HF in the second and third GGT tertile groups was 2.51 times greater (95% CI, 1.06-5.96) and 2.77 times greater (95% CI, 1.13-6.81), respectively, than that in the first GGT tertile group. Each 1-unit increase in the lnGGT level was related to a 1.88-fold increased risk of HF (odds ratio, OR, 1.88; 95% CI, 1.19-2.96; p = 0.007). Restricted cubic splines suggested a linear relationship between GGT and in-hospital HF (p for nonlinearity = 0.158). The area under the curve was 0.607 (95% CI, 0.558-0.654; p = 0.007) when GGT was used to predict in-hospital HF, with a sensitivity of 57.14% and a specificity of 64.04%. Moreover, the incidence of HF significantly increased in-hospital death risk (OR, 7.75; 95% CI, 1.87-32.12; p = 0.005).

Conclusions

GGT is positively associated with in-hospital HF and is an independent risk factor for in-hospital HF in STEMI patients.

In Vivo Imaging of γ-Glutamyl Transferase in Cardiovascular Diseases with a Photoacoustic Probe

In this work, a photoacoustic (PA) probe, HDS-GGT, was developed for the in vivo imaging of cardiovascular diseases by monitoring the γ-glutamyl transferase (GGT) dynamics. HDS-GGT exhibited a stable PA signal with auxiliary absorbance and NIRF variation after the trigger by GGT. In all three modalities of absorbance, NIRF, and PA, HDS-GGT could quantitatively reflect the GGT level. In PA modality, HDS-GGT indicated the practical advantages including high sensitivity, high stability, and high specificity. In living oxidized low-density lipoprotein-induced RAW264.7 cells, HDS-GGT indicated proper capability for imaging the plaques by visualizing the GGT dynamics. Moreover, during imaging in living model mice, HDS-GGT was achieved to distinguish the plaques from healthy blood vessels via a multiview PA presentation. HDS-GGT could also suggest the severity of plaques in the extracted aorta from the model mice, which was consistent with the histological staining results. The information herein might be useful for future investigations on cardiovascular diseases.

Serum Gamma Glutamyltransferase Is Associated with 25-Hydroxyvitamin D Status in Elderly Patients with Stable Coronary Artery Disease

Background: No previous study has investigated the association between gamma glutamyltransferase (GGT) and vitamin D in patients with stable coronary artery disease (CAD). We investigated the cross-sectional associations between vitamin D status as assessed by serum 25(OH)D and GGT. Methods: 169 patients were enrolled. Study population was divided into three groups: 1: 25(OH)D < 10 ng/mL (n = 59); 2: 25(OH)D 10–20 ng/mL (n = 82), and 3: 25(OH)D > 20 ng/mL (n = 28). Based on a cut-off GGT value identified in ROC analysis, we also divided the study population to compare the following groups: GGT ≤19 (n = 66) and GGT >19 (n = 103). Results: GGT activity was the highest in vitamin D severely deficient patients and the lowest in vitamin D insufficient patients. GGT was inversely correlated with 25(OH)D concentrations (R = −0.23; p = 0.002). The receiver operating characteristics curve identified the discrimination threshold of GGT of >19 U/L in predicting vitamin D deficiency. Higher leukocyte and neutrophil counts and lower 25(OH)D concentration were found in patients with GGT > 19 U/L. Conclusions: We identified an interaction between declining 25(OH)D levels and rising GGT levels with increasing age, which resulted in an unfavorable 25(OH)D-to-GGT ratio in stable CAD patients. These results suggest that these changes might further contribute to a high cardiovascular risk in the elderly.

Association of High-Intensity Binge Drinking With Lipid and Liver Function Enzyme Levels

Importance

The prevalence of high-intensity binge drinking (HIBD), defined as consuming 2 or more times the binge threshold defined by the National Institute on Alcohol Abuse and Alcoholism (NIAAA), is rapidly increasing in the United States. While the relationship between alcohol consumption and lipid and liver function enzyme (LFT) biomarkers has been previously examined, the associations of HIBD with those biomarkers remain unknown.

Objective

To examine associations of HIBD with lipid and LFT levels in a cross-sectional sample enriched with participants who engage in HIBD.

Design, Setting, and Participants

Cross-sectional study using data from the NIAAA clinical sample collected from March 3, 2005, to August 21, 2017, with participants recruited for either the NIAAA screening protocols or inpatient alcohol treatment program. For this study, participants were stratified by self-reported alcohol consumption into 4 sex-specific binge levels: nonbinge and 1, 2, and 3 or more times the binge threshold (levels I, II, and III). Multivariable analyses examined the odds of clinically high levels of lipids and LFTs across binge levels. Analyses were performed from December 3, 2018, to January 30, 2019.

Main Outcomes and Measures

Serum levels of high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol, total cholesterol, triglycerides, alanine aminotransferase, aspartate aminotransferase, and γ-glutamyltransferase.

Results

A total of 2065 participants underwent protocol screening; 1519 with data available on alcohol consumption, body mass index, lipid levels, and LFT levels were included in the final analyses. Mean (SD) age was 39.7 (12.1) years; mean (SD) body mass index was 26.6 (5.1); 978 (64.4%) were male; 718 (47.3%) were white; and 578 (31.1%) consumed alcohol at the nonbinge level, 321 (21.2%) at level I, 239 (15.7%) at level II, and 318 (25.1%) at level III. High-intensity binge drinking was associated with 2- to 8-fold increased odds for clinically high levels of HDL-C, total cholesterol, triglycerides, and all LFTs (eg, for HDL-C: level III odds ratio [OR], 8.65; 95% CI, 4.75-15.77 and for γ-glutamyltransferase: level III OR, 8.21; 95% CI, 5.90-11.43). Increased HIBD frequency (days consuming at levels II and III) was associated with increased odds for clinically high levels of HDL-C, total cholesterol, and all LFTs (per unit increase in days consuming at the respective binge level) (eg, for HDL-C: level II OR, 1.025; 95% CI, 1.014-1.036 and level III OR, 1.033; 95% CI, 1.019-1.047 and for γ-glutamyltransferase: level II OR, 1.028; 95% CI, 1.019-1.037 and level III OR, 1.033; 95% CI, 1.019-1.047).

Conclusions and Relevance

High-impact binge drinking was significantly associated with increased odds for clinically high levels of lipids and LFTs. Given that HIBD is increasingly common among US adults, targeted interventions aimed at reducing HIBD may have important health benefits.

Serum level of gamma-glutamyl transferase as a biomarker for predicting stenosis severity in patients with coronary artery disease

BACKGROUND

Gamma glutamyl transferase (GGT) is associated with pathogenesis of various diseases such as coronary artery disease (CAD). GGT activity displays an essential role in the catabolism of glutathione which is reported as a major antioxidant. The aim of this study was to explore the association of GGT activity with obstruction severity of artery in 500 CAD patients.

RESULTS

Our finding showed a significant association between serum GGT activity and CAD patients. In particular, the level of GGT in patients who had ≥50% obstruction was higher, compared to healthy and patients with less than 50% obstruction in their coronary arteries (the level of GGT in patients with at least one (1 SVD), two (2VD), three (3VD) coronary artery obstruction were 55.6±9.7, 71.7±12.7 and 84.7±13.4, while these values in patients with negative angio or control group were 28±10 and 17±4.6). Furthermore, the activity of this marker was associated with increased the risk of CAD (Odd ratio of GGT in 3VD group: 2, 95%CI: 1.8-2.3), which was also related with HDL-C. Of note, the level of GGT was enhanced progressively with increasing the obstruction severity of arteries.

CONCLUSION

We demonstrate the prognostic value of serum level of GGT as a biomarker for predicting obstruction severity in patients with CAD.

Gamma-Glutamyltransferase and Risk of Acute Coronary Syndrome in Young Chinese Patients: A Case-Control Study

BACKGROUND

Serum gamma-glutamyltransferase (GGT) is a biomarker of hepatic disease. Recent studies have shown that GGT may also associate with the risk of coronary artery disease. However, the underlying mechanisms of this association are still unclear.

METHODS

This study included 216 young patients with acute coronary syndrome (aged ≤55years) and 227 age-matched controls with normal findings by coronary angiography or coronary computed tomography angiography. We use standard colorimetric techniques and sandwich enzyme-linked immunosorbent assay to measure the levels of GGT and oxidized low-density lipoprotein (ox-LDL), respectively. Traditional risk factors of coronary artery disease, including smoking, diabetes mellitus, hypertension, dyslipidemia, and obesity/overweight, were evaluated according to the current guidelines.

RESULTS

The levels of GGT were significantly correlated with body mass index and levels of triglyceride, fasting plasma glucose, aspartate aminotransferase, and ox-LDL (all P < 0.05). Multivariate logistic regression analysis showed that GGT was significantly associated with the risk of acute coronary syndrome in young Chinese patients (OR = 1.53, 95% CI = 1.09-2.15) after adjusting for traditional risk factors, including sex, age, quantity of smoking, hypertension, diabetes, body mass index, dyslipidemia, and high-sensitivity C-reactive protein. However, this association was significantly attenuated (OR = 1.20, 95% CI = 0.91-1.58) after further adjusting for the levels of ox-LDL.

CONCLUSIONS

GGT was associated with the risk of ACS in relatively young patients. The link between GGT and the risk of ACS may be dependent on ox-LDL levels, indicating that the prooxidant action is an important pathway for GGT in the development of cardiovascular disease.

Implication of liver enzymes on incident cardiovascular diseases and mortality: A nationwide population-based cohort study

Although liver enzymes, such as γ-glutamyltransferase (GGT), alanine aminotransferase (ALT), and aspartate aminotransferase (AST), have recently been suggested as risk factors for cardiovascular diseases (CVD), impact on mortality after myocardial infarction (MI) or ischemic stroke (IS) was not previously examined. Using a population-based, nationwide cohort database, we explored the implication of GGT and aminotransferases on the development of CVD and all-cause mortality during a median 9.1 years of follow-up. Among 16,624,006 Korean adults, both GGT and aminotransferases exhibited a positive relationship with MI, IS, and mortality in a multivariate adjusted model. ALT and AST showed U-shaped associations with mortality, whereas GGT showed a positive linear relationship with mortality. The risk of 1-year mortality after MI or IS was significantly higher in the highest quartile of GGT compared to the lowest quartile (HR, 1.46; 95% CI, 1.40-1.52). The implication of GGT on MI, IS, and mortality persisted regardless of traditional cardiovascular risk parameters. This study demonstrated the unique pattern of association of ALT, AST, and GGT with the development of CVD and all-cause mortality in the Korean population. In particular, GGT showed the most robust linear relationship with mortality before and after cardiovascular events independent of risk factors.

Gamma-glutamyl transferase and cardiovascular disease

Gamma-glutamyl transferase (GGT) is an enzyme located on the external surface of cellular membranes. GGT contributes in maintaining the physiological concentrations of cytoplasmic glutathione and cellular defense against oxidative stress via cleavage of extracellular glutathione and increased availability of amino acids for its intracellular synthesis. Increased GGT activity is a marker of antioxidant inadequacy and increased oxidative stress. Ample evidence suggests that elevated GGT activity is associated with increased risk of cardiovascular disease (CVD) such as coronary heart disease (CHD), stroke, arterial hypertension, heart failure, cardiac arrhythmias and all-cause and CVD-related mortality. The evidence is weaker for an association between elevated GGT activity and acute ischemic events and myocardial infarction. The risk for CVD or CVD-related mortality mediated by GGT may be explained by the close correlation of GGT with conventional CVD risk factors and various comorbidities, particularly non-alcoholic fatty liver disease, alcohol consumption, oxidative stress, metabolic syndrome, insulin resistance and systemic inflammation. The finding of GGT activity in atherosclerotic plaques and correlation of intra-plaque GGT activity with histological indexes of plaque instability may suggest a participation of GGT in the pathophysiology of CVD, particularly atherosclerosis. However, whether GGT has a direct role in the pathophysiology of CVD or it is an epiphenomenon of coexisting CVD risk factors or comorbidities remains unknown and Hill's criteria of causality relationship between GGT and CVD are not fulfilled. The exploration whether GGT provides prognostic information on top of the information provided by known cardiovascular risk factors regarding the CVD or CVD-related outcome and exploration of molecular mechanisms of GGT involvement in the pathophysiology of CVD and eventual use of interventions to reduce circulating GGT activity remain a duty of future studies.

Rationale, Design, and Methodological Aspects of the BUDAPEST-GLOBAL Study (Burden of Atherosclerotic Plaques Study in Twins-Genetic Loci and the Burden of Atherosclerotic Lesions)

The heritability of coronary atherosclerotic plaque burden, coronary geometry, and phenotypes associated with increased cardiometabolic risk are largely unknown. The primary aim of the Burden of Atherosclerotic Plaques Study in Twins-Genetic Loci and the Burden of Atherosclerotic Lesions (BUDAPEST-GLOBAL) study is to evaluate the influence of genetic and environmental factors on the burden of coronary artery disease. By design this is a prospective, single-center, classical twin study. In total, 202 twins (61 monozygotic pairs, 40 dizygotic same-sex pairs) were enrolled from the Hungarian Twin Registry database. All twins underwent non-contrast-enhanced computed tomography (CT) for the detection and quantification of coronary artery calcium and for the measurement of epicardial fat volumes. In addition, a single non-contrast-enhanced image slice was acquired at the level of L3-L4 to assess abdominal fat distribution. Coronary CT angiography was used for the detection and quantification of plaque, stenosis, and overall coronary artery disease burden. For the primary analysis, we will assess the presence and volume of atherosclerotic plaques. Furthermore, the 3-dimensional coronary geometry will be assessed based on the coronary CT angiography datasets. Additional phenotypic analyses will include per-patient epicardial and abdominal fat quantity measurements. Measurements obtained from monozygotic and dizygotic twin pairs will be compared to evaluate the genetic or environmental effects of the given phenotype. The BUDAPEST-GLOBAL study provides a unique framework to shed some light on the genetic and environmental influences of cardiometabolic disorders.

Gamma-Glutamyltransferase: A Predictive Biomarker of Cellular Antioxidant Inadequacy and Disease Risk

Gamma-glutamyltransferase (GGT) is a well-established serum marker for alcohol-related liver disease. However, GGT's predictive utility applies well beyond liver disease: elevated GGT is linked to increased risk to a multitude of diseases and conditions, including cardiovascular disease, diabetes, metabolic syndrome (MetS), and all-cause mortality. The literature from multiple population groups worldwide consistently shows strong predictive power for GGT, even across different gender and ethnic categories. Here, we examine the relationship of GGT to other serum markers such as serum ferritin (SF) levels, and we suggest a link to exposure to environmental and endogenous toxins, resulting in oxidative and nitrosative stress. We observe a general upward trend in population levels of GGT over time, particularly in the US and Korea. Since the late 1970s, both GGT and incident MetS and its related disorders have risen in virtual lockstep. GGT is an early predictive marker for atherosclerosis, heart failure, arterial stiffness and plaque, gestational diabetes, and various liver diseases, including viral hepatitis, other infectious diseases, and several life-threatening cancers. We review literature both from the medical sciences and from life insurance industries demonstrating that serum GGT is a superior marker for future disease risk, when compared against multiple other known mortality risk factors.

Screening for suspected coronary heart disease in patients, using integrated serum biochemical indices

Background

Many serum biochemical indices have been found to be associated with coronary heart disease (CHD); however, few studies have evaluated the value on screening CHD of the integrated serum biochemical indices.

Methods

In this study, 627 healthy controls and 1049 patients with CHD were recruited to develop CHD screening models for males and females using unconditional logistic regression. The performance of the screening models was evaluated by areas under the receiver operating characteristic (ROC) curves (AUCs), and externally validated in another population comprised of 190 healthy controls and 246 patients with CHD.

Results

Backward stepwise variable selection showed that increasing age, total cholesterol (TC), logarithm-transformed homocysteine (lnHCY), logarithm-transformed γ-glutamyl transpeptidase (lnGGT), and decreasing uric acid, logarithm-transformed triglyceride, apolipoprotein A (apoA) and apolipoprotein B (apoB), increased the detection of CHD in males. In comparison, increasing age, TC, lnHCY, lnGGT and high-density lipoprotein cholesterol versus low-density lipoprotein cholesterol, and decreasing apoA, apoB, logarithm transformed lipoprotein (A) and logarithm transformed total bilirubin, increased the detection of CHD in females. The AUCs for the screening models for males and females were 0.958 (95% CI 0.946 to 0.969) and 0.986 (95% CI 0.977 to 0.994), respectively. The performance of the screening models was further evaluated in external validation samples, the AUCs for males and females were 0.907 and 0.992, respectively.

Conclusions

Our study suggests that integrated serum biochemical indices may be used to screen for suspected CHD in participants.

Association between serum vitamin D levels and subclinical coronary atherosclerosis and plaque burden/composition in young adult population

Evidence suggests that low 25-OH vitamin D 25(OH)D concentrations may increase the risk of several cardiovascular diseases such as hypertension, peripheral vascular disease, diabetes mellitus, obesity, myocardial infarction, heart failure and cardiovascular mortality. Recent studies suggested a possible relationship between vitamin D deficiency and increased carotid intima-media wall thickness and vascular calcification. We hypothesized that low 25(OH)D may be associated with coronary atherosclerosis and coronary plaque burden and composition, and investigated the relationship between serum vitamin D levels and coronary atherosclerosis, plaque burden or structure, in young adult patients by using dual-source 128x2 slice coronary computed tomography angiography (CCTA). We included 98 patients with coronary atherosclerosis and 110, age and gender matched, subjects with normal findings on CCTA examinations. Patients with subclinical atherosclerosis had significantly higher serum total cholesterol, triglycerides, hs-CRP, uric acid, HbA1c and creatinine levels and lower serum 25(OH)D levels in comparison with controls. There was no significant correlation between 25(OH)D and plaque morphology. There was also a positive relationship between 25(OH)D and plaque burden of coronary atherosclerosis. In multivariate analysis, coronary atherosclerosis was associated high hs-CRP (adjusted OR: 2.832), uric acid (adjusted OR: 3.671) and low 25(OH)D (adjusted OR: 0.689). Low levels of 25(OH)D were associated with coronary atherosclerosis and plaque burden, but there was no significant correlation between 25(OH)D and plaque morphology.