Serum γ-glutamyltransferase: independent predictor of risk of diabetes, hypertension, metabolic syndrome, and coronary disease

Association of GGT and hs-CRP with hypertension across different glycemic states in Saudi adults: A cross-sectional study

Introduction

Atherosclerosis, hypertension, and diabetes (DM) is preceded by inflammation and endothelial dysfunction. Early detection of these risk factors is expected to improve prognosis. We aimed to examine the association between gamma-glutamyl transferase (GGT) and highly sensitive C-reactive protein (hs-CRP) with hypertension (HTN) in the presence and absence of dysglycaemia among Saudi adults not previously diagnosed with DM.Methods: adults were recruited randomly from public healthcare centres in Jeddah. Demographic information, blood pressure, and anthropometric measurements were taken. Fasting blood samples were drawn to measure glucose, glycated haemoglobin, lipid profile, hs-CRP, and GGT. Blood was drawn again following a 1-h oral glucose tolerance test, and plasma glucose was measured.

Results

Mean GGT and hs-CRP were higher in people with HTN and dysglycaemia than those without both (P < 0.001). In people with HTN, those with intermediate hyperglycaemia (pre-DM) had significantly higher means of GGT and hs-CRP compared with those without (P < 0.001 and 0.013, respectively). In people with pre-DM, those with HTN had significantly higher means of GGT than those without (P = 0.008), but the increase in mean hs-CRP was not statistically significant. Mean GGT was higher in people with DM compared to means of those with pre-DM and HTN (P = 0.04).

Conclusion

An association between higher serum levels of hs-CRP and GGT and dysglycaemia exists, especially in hypertensive people. Monitoring both biomarkers in dysglycaemic people, especially if they have elevated blood pressure, is recommended to initiate therapeutic interventions.

Association Between a New Model of Insulin Sensitivity and Hypertension in Patients With Type 2 Diabetes: A Cross-Sectional Study

Type 2 diabetes (T2D) and hypertension often coexist, and insulin resistance (IR) plays an important role in their pathological progression. An increasing number of studies have focused on the relationship between different IR indices and hypertension. A natural log transformation of the glucose disposal rate (loge GDR) has been proposed as a new model for insulin sensitivity in patients with T2D. The study aimed to explore the relationship between loge GDR and hypertension in T2D patients. This cross-sectional study included 1544 Chinese T2D patients. Clinical and biochemical characteristics were collected. The loge GDR was calculated based on triglycerides, urinary albumin to creatinine ratio, gamma-glutamyl transferase, and body mass index. Patients were categorized into hypertension and nonhypertension groups stratified by gender. Among both females and males, compared with the nonhypertension group, the level of loge GDR was significantly decreased in the hypertension group (both p < 0.001). As the loge GDR increased, the levels of systolic and diastolic blood pressure, and the prevalence of hypertension were obviously increased (all p < 0.001). Univariate analysis displayed that loge GDR was negatively related to hypertension (correlation coefficient: -0.243, p < 0.001 in females; correlation coefficient: -0.181, p < 0.001 in males). Furthermore, the logistic regression analysis showed that loge GDR was independently associated with hypertension (OR: 0.456; 95% CI: 0.224-0.927 in females; OR: 0.544; 95% CI: 0.314-0.941 in males). This study revealed that loge GDR was closely related to hypertension, which might help monitor and manage hypertension in T2D patients.

Development and validation of a predictive model for metabolic syndrome in a large cohort of people living with HIV

BACKGROUND

The global prevalence of metabolic syndrome (MetS) in people living with HIV (PLWH) is on the rise in the post era of antiretroviral therapy (ART). Nevertheless, there are no validated predictive models available for assessing the risk of MetS in this specific population.

METHODS

This study included PLWH who participated in annual follow-ups at Southern Medical University Nanfang Hospital from September 2022 to November 2023. Participants enrolled in this study were divided into the training set and validation set based on the follow-up duration. We employed both multivariate logistic regression and lasso regression to develop three distinct prediction models. Subsequently, the optimal model was determined through comprehensive analyses, including receiver operating characteristic (ROC) curve analysis, calibration curve, and decision curve analysis (DCA). Ultimately, we generated a nomogram for the optimal model and analyzed the correlation between the model score and the components of MetS.

RESULTS

A total of 1017 participants were included in this study, with 814 in the training set and 203 in the validation set. The ultimate prediction model of MetS risk in PLWH incorporated five factors: age, CD8 + T cell counts, controlled attenuation parameter (CAP), gamma-glutamyl transferase (γ-GT) and lactate dehydrogenase (LDH). The area under the ROC curve (AUC) of the model in the training set and validation set was 0.849 and 0.834, respectively. Furthermore, we revealed a significant correlation between the model score and the MetS components. Additionally, the model score revealed significant group differences in MetS and related metabolic disorders.

CONCLUSIONS

This study established a potential model for predicting MetS in PLWH.

A Prediction Model of Preeclampsia in Hyperglycemia Pregnancy

Purpose

To investigate the risk factors associated with preeclampsia in hyperglycemic pregnancies and develop a predictive model based on routine pregnancy care.

Patients and Methods

The retrospective collection of clinical data was performed on 951 pregnant women with hyperglycemia, including those diagnosed with diabetes in pregnancy (DIP) and gestational diabetes mellitus (GDM), who delivered after 34 weeks of gestation at the Maternal and Child Health Hospital Affiliated to Anhui Medical University between January 2017 and December 2019. Observation indicators included liver and kidney function factors testing at 24-29+6 weeks gestation, maternal age, and basal blood pressure. The indicators were screened univariately, and the "rms" package in R language was applied to explore the factors associated with PE in HIP pregnancy by stepwise regression. Multivariable logistic regression analysis was used to develop the prediction model. Based on the above results, a nomogram was constructed to predict the risk of PE occurrence in pregnant women with HIP. Then, the model was evaluated from three aspects: discrimination, calibration, and clinical utility. The internal validation was performed using the bootstrap procedure.

Results

Multivariate logistic regression analysis showed that cystatin C, uric acid, glutamyl aminotransferase, blood urea nitrogen, and basal systolic blood pressure as predictors of PE in pregnancy with HIP. The predictive model yielded an area under curve (AUC) value of 0.8031 (95% CI: 0.7383-0.8679), with an optimal threshold of 0.0805, at which point the sensitivity was 0.8307 and specificity of 0.6604. Hosmer-Lemeshow test values were P = 0.3736, Brier score value was 0.0461. After 1000 Bootstrap re-samplings for internal validation, the AUC was 0.7886, the Brier score was 0.0478 and the predicted probability of the calibration curve was similar to the actual probability. A nomogram was constructed based on the above to visualize the model.

Conclusion

This study developed a model for predicting PE in pregnant women with HIP, achieving high predictive performance of PE risk through the information of routine pregnancy care.

Validation of the Framingham Diabetes Risk Model Using Community-Based KoGES Data

BACKGROUND

An 8-year prediction of the Framingham Diabetes Risk Model (FDRM) was proposed, but the predictor has a gap with current clinical standards. Therefore, we evaluated the validity of the original FDRM in Korean population data, developed a modified FDRM by redefining the predictors based on current knowledge, and evaluated the internal and external validity.

METHODS

Using data from a community-based cohort in Korea (n = 5,409), we calculated the probability of diabetes through FDRM, and developed a modified FDRM based on modified definitions of hypertension (HTN) and diabetes. We also added clinical features related to diabetes to the predictive model. Model performance was evaluated and compared by area under the curve (AUC).

RESULTS

During the 8-year follow-up, the cumulative incidence of diabetes was 8.5%. The modified FDRM consisted of age, obesity, HTN, hypo-high-density lipoprotein cholesterol, elevated triglyceride, fasting glucose, and hemoglobin A1c. The expanded clinical model added γ-glutamyl transpeptidase to the modified FDRM. The FDRM showed an estimated AUC of 0.71, and the model's performance improved to an AUC of 0.82 after applying the redefined predictor. Adding clinical features (AUC = 0.83) to the modified FDRM further improved in discrimination, but this was not maintained in the validation data set. External validation was evaluated on population-based cohort data and both modified models performed well, with AUC above 0.82.

CONCLUSION

The performance of FDRM in the Korean population was found to be acceptable for predicting diabetes, but it was improved when corrected with redefined predictors. The validity of the modified model needs to be further evaluated.

Serum γ-glutamyltransferase level and incidence risk of metabolic syndrome in community dwelling adults: longitudinal findings over 12 years

PURPOSE

Although a recent meta-analysis demonstrated a positive association between serum γ-glutamyltransferase (GGT) and metabolic syndrome (MetS), sex differences in the relationship between GGT levels and MetS risk were not fully considered. We prospectively examined the relationship between serum GGT levels and incidence risk of MetS.

METHODS

Data were collected from the Korean Genome and Epidemiology Study (KoGES) enrolled in 2001-2002. Among 10,030 total participants, 5960 adults (3130 men and 2830 women) aged 40-69 without MetS were included and divided according to sex-specific quartiles of baseline serum GGT levels and followed up biennially until 2014. The hazard ratios (HRs) with 95% confidence intervals (CIs) for incident MetS were prospectively analyzed using multiple Cox proportional hazards regression analysis models.

RESULTS

Among 5960 participants, 1215 males (38.8%) and 1263 females (44.6%) developed MetS during 12-year follow up. Higher quartiles of GGT showed significantly higher cumulative incidence of MetS in both sexes (log-rank test P < 0.001). The HRs (95% CIs) for incident type 2 diabetes for the highest quartile versus referent lowest quartile for serum GGT levels were 3.01 (2.35-3.76) for men and 1.83 (1.30-2.57) for women after adjusting for age, smoking status, daily alcohol intake (g/day), regular exercise, family history of diabetes, and log-transformed LDL-cholesterol, creatinine, and aminotransferase levels.

CONCLUSION

In conclusion, high levels of GGT were found to be associated with increased risk of Mets in both men and women and the positive associations were stronger in men than in women.

Useful Biomarkers of Metabolic Syndrome

The Special Issue call for papers on "Metabolic syndrome and its association with biomarkers" was proposed to present research on various markers for pathophysiology and the early detection of metabolic syndrome (MetS) [...].

Machine learning integration of multimodal data identifies key features of blood pressure regulation

BACKGROUND

Association studies have identified several biomarkers for blood pressure and hypertension, but a thorough understanding of their mutual dependencies is lacking. By integrating two different high-throughput datasets, biochemical and dietary data, we aim to understand the multifactorial contributors of blood pressure (BP).

METHODS

We included 4,863 participants from TwinsUK with concurrent BP, metabolomics, genomics, biochemical measures, and dietary data. We used 5-fold cross-validation with the machine learning XGBoost algorithm to identify features of importance in context of one another in TwinsUK (80% training, 20% test). The features tested in TwinsUK were then probed using the same algorithm in an independent dataset of 2,807 individuals from the Qatari Biobank (QBB).

FINDINGS

Our model explained 39·2% [4·5%, MAE:11·32 mmHg (95%CI, +/- 0·65)] of the variance in systolic BP (SBP) in TwinsUK. Of the top 50 features, the most influential non-demographic variables were dihomo-linolenate, cis-4-decenoyl carnitine, lactate, chloride, urate, and creatinine along with dietary intakes of total, trans and saturated fat. We also highlight the incremental value of each included dimension. Furthermore, we replicated our model in the QBB [SBP variance explained = 45·2% (13·39%)] cohort and 30 of the top 50 features overlapped between cohorts.

INTERPRETATION

We show that an integrated analysis of omics, biochemical and dietary data improves our understanding of their in-between relationships and expands the range of potential biomarkers for blood pressure. Our results point to potentially key biological pathways to be prioritised for mechanistic studies.

FUNDING

Chronic Disease Research Foundation, Medical Research Council, Wellcome Trust, Qatar Foundation.

Gamma glutamyl transferases in association with cardiovascular risk scores in non-diabetic hypertensive Cameroonians: preliminary data from HYRICCA study

Objective

The usefulness of gamma glutamyl transferase (GGT) as biomarker of cardiovascular risk (CVR) remains unexplored in sub-Saharan Africans. To evaluate their relevance on CVR assessment in non-diabetic hypertensive Cameroonians. This was a prospective cross-sectional study on non-diabetic hypertensive adults aged 57.7 ± 10 years (62% female), without evidence of acute or chronic liver disease, in which we assessed GGT levels and correlates it with validated CVR biomarkers, CVR scores (WHO risk score, Framingham 2008, ASCVD 2013, EuroSCORE 2003, and Reynolds score), and plasma atherogenic index (PAI).

Results

We found a positive but weak association between GGT and PAI on linear regression [0.004 (0.001; 0.007); p = 0.021], which was dependent of triglycerides levels (r = 0.17; p = 0.03). We did not find a significant association between GGT levels and the results of the CVR scores studied; Although being related to atherogenic risk, as reported in literature in non-sub-Saharan Africans, GGTs would be of little value for CVR assessment in our population.

Gut microbiome is associated with metabolic syndrome accompanied by elevated gamma-glutamyl transpeptidase in men

It is predicted that by 2035, metabolic syndrome (MS) will be found in nearly more than half of our adult population, seriously affecting the health of our body. MS is usually accompanied by the occurrence of abnormal liver enzymes, such as elevated gamma-glutamyl transpeptidase (GGT). More and more studies have shown that the gut microbiota is involved in MS; however, the correlation between gut microbiota and MS with elevated GGT has not been studied comprehensively. Especially, there are few reports about its role in the physical examination of the population of men with MS and elevated GGT. By using the whole-genome shotgun sequencing technology, we conducted a genome-wide association study of the gut microbiome in 66 participants diagnosed as having MS accompanied by high levels of GGT (case group) and 66 participants with only MS and normal GGT level (control group). We found that the number of gut microbial species was reduced in participants in the case group compared to that of the control group. The overall microbial composition between the two groups is of significant difference. The gut microbiota in the case group is characterized by increased levels of "harmful bacteria" such as Megamonas hypermegale, Megamonas funiformis, Megamonas unclassified, Klebsiella pneumoniae, and Fusobacterium mortiferum and decreased levels of "beneficial bacteria" such as Faecalibacterium prausnitzii, Eubacterium eligens, Bifidobacterium longum, Bifidobacterium pseudocatenulatum, Bacteroides dorei, and Alistipes putredinis. Moreover, the pathways of POLYAMSYN-PWY, ARG+POLYAMINE-SYN, PWY-6305, and GOLPDLCAT-PWY were also increased in the case group, which may play a role in the elevation of GGT by producing amine, polyamine, putrescine, and endogenous alcohol. Taken together, there are apparent changes in the composition of the gut microbiome in men with MS and abnormal GGT levels, and it is high time to discover specific gut microbiome as a potential therapeutic target in that population. More in-depth studies of relevant mechanism could offer some new methods for the treatment of MS with elevated GGT.

Can Gamma-glutamyl Transferase Predict Unhealthy Metabolic Phenotypes Among Healthcare Workers in Azar Cohort Study?

Background: Although various studies have assessed the correlation between gamma-glutamyl transferase (GGT) and cardiometabolic risk factors in obesity, no research has differentiated among metabolically-healthy obese (MHO) and metabolically unhealthy obese (MUHO), metabolically-healthy lean (MHL), and metabolically-unhealthy lean (MUHL). Objectives: Accordingly, this study evaluated the correlation between GGT and cardiometabolic phenotypes among healthcare workers. Methods: In this study, there were anthropometric measurements as well as the measurements of fasting blood sugar (FBS), GGT, cholesterol, triglyceride (TG), high lipoprotein density (HDL), and blood pressure in 1458 healthcare workers enrolled in the Azar Cohort Study. Metabolic syndrome (MetS) was defined according to the National Cholesterol Education Program Adult Treatment Panel III (ATP III). Accordingly, the participants were divided into four cardiometabolic phenotypes. Results: In this cross-sectional study, there was a significant difference in the prevalence of cardiometabolic phenotypes regarding the GGT tertiles (P ≤ 0.001). The highest prevalence of MHO was observed in the third GGT tertile. The mean waist circumference, TG, FBS, HDL, and systolic and diastolic blood pressure levels increased in the MHO, MUHO, and MHL groups in a dose dependent manner with an increase in the GGT tertiles (P < 0.05). In comparing the highest and lowest GGT tertile, the risk of MHO and MUHO increased by 2.84 (95%CI 2.01 - 4.01) and 9.12 (95%CI 5.54 - 15), respectively. However, the correlation between the GGT tertile and MUHL did not reveal a similar trend. The ROC curve shows the cutoff value of 18.5 U/L for GGT, which allowed us to distinguish between the MUHO and MHO individuals. Conclusions: The findings revealed that GGT can indicate the risk of MetS as such, it can be used to detect at-risk MHO individuals and administer proper interventions.

Liver-function parameters are associated with incident hypertension in a large Taiwanese population follow-up study

Previous studies demonstrated inconsistent results regarding the association between liver function and hypertension. In addition, large cohort follow-up studies are lacking. Therefore, this longitudinal study aimed to investigate the association between liver function and incident hypertension using data from the Taiwan Biobank (TWB). We evaluated liver biomarkers, including aspartate aminotransferase (AST), alanine aminotransferase (ALT), albumin, alpha-fetoprotein (AFP), total bilirubin, and gamma-glutamyl transferase (GGT) in this study. A total of 21,293 participants without hypertension at baseline were analyzed. During the mean 3.9-year follow-up, 3002 participants developed hypertension (defined as incident hypertension). Multivariable analysis revealed that high AST (odds ratio [OR], 1.004; 95% confidence interval [CI], 1.001-1.007; p = 0.014), high ALT (OR, 1.004; 95% CI, 1.002-1.006; p < 0.001), high albumin (OR, 1.897; 95% CI, 1.573-2.286; p < 0.001), and high GGT (OR, 1.004; 95% CI, 1.003-1.005; p < 0.001) were significantly associated with incident hypertension in all study participants. In subgroup analysis of the participants with an ALT level ≤2 times the normal limit (80 u/l) (n = 20,983), multivariable analysis demonstrated that high ALT (OR, 1.009; 95% CI, 1.005-1.012; p < 0.001) and high GGT (OR, 1.005; 95% CI, 1.003-1.006; p < 0.001) were significantly associated with incident hypertension. In conclusion, we found that elevated AST, ALT, albumin, and GGT were associated with incident hypertension in a large Taiwanese cohort. A greater understanding of potential risk factors for hypertension may help to reduce the burden of hypertension in this Taiwanese population.

Cumulative Exposure to High γ-Glutamyl Transferase Level and Risk of Diabetes: A Nationwide Population-Based Study

BACKGROUND

Elevated γ-glutamyl transferase (γ-GTP) level is associated with metabolic syndrome, impaired glucose tolerance, and insulin resistance, which are risk factors for type 2 diabetes. We aimed to investigate the association of cumulative exposure to high γ-GTP level with risk of diabetes.

METHODS

Using nationally representative data from the Korean National Health Insurance system, 346,206 people who were free of diabetes and who underwent 5 consecutive health examinations from 2005 to 2009 were followed to the end of 2018. High γ-GTP level was defined as those in the highest quartile, and the number of exposures to high γ-GTP level ranged from 0 to 5. Hazard ratio (HR) and 95% confidence interval (CI) for diabetes were analyzed using the multivariable Cox proportional-hazards model.

RESULTS

The mean follow-up duration was 9.2±1.0 years, during which 15,183 (4.4%) patients developed diabetes. There was a linear increase in the incidence rate and the risk of diabetes with cumulative exposure to high γ-GTP level. After adjusting for possible confounders, the HR of diabetes in subjects with five consecutive high γ-GTP levels were 2.60 (95% CI, 2.47 to 2.73) in men and 3.05 (95% CI, 2.73 to 3.41) in women compared with those who never had a high γ-GTP level. Similar results were observed in various subgroup and sensitivity analyses.

CONCLUSION

There was a linear relationship between cumulative exposure to high γ-GTP level and risk of diabetes. Monitoring and lowering γ-GTP level should be considered for prevention of diabetes in the general population.

Big and Free Fractions of Gamma-Glutamyltransferase: New Diagnostic Biomarkers for Malignant Mesothelioma?

Malignant pleural mesothelioma (MPM) is a cancer mainly caused by asbestos fiber inhalation, characterized by an extremely long latency and poor prognosis. Recently, researchers have focused on testing the diagnostic ability of several biomarkers. Gamma-Glutamyltransferase (GGT) has been demonstrated to be the sum of several GGT sub-fractions activity, classified based on their molecular weight in big-GGT, medium-GGT, small-GGT, and free-GGT. This work aims to evaluate whether specific GGT fractional enzymatic activity patterns could be helpful in MPM diagnosis. We analyzed blood samples from 175 workers previously exposed to asbestos, 157 non-exposed healthy subjects, and 37 MPM patients through a molecular exclusion chromatographic method. We found a specific profile of GGT fractions activity, significantly associated with MPM, resulting in an increase in b-, m- activity, along with an evident, yet not significant, decrease in f-activity. Receiver-operating characteristic (ROC) analysis showed that the best Area Under Curve (AUC) value resulted from the combined index b/f (0.679, 95% CI: 0.582–0.777). Combining the b-/f-GGT activity with the levels of serum mesothelin-related protein (SMRP; another promising MPM biomarker) improved the diagnostic accuracy, increasing the AUC value to 0.875 (95% CI: 0.807–0.943, p = <0.0001). Since MPM has a specific pattern of GGT enzymatic activity, we could hypothesize that GGT fractions play different specific biochemical roles. The improvement in the diagnostic power given by the combination of these two biomarkers confirms that the strategy of biomarkers combination might be a better approach for MPM diagnosis.

Association between FTO (rs17817449) genetic variant, gamma-glutamyl transferase, and hypertension in Slovak midlife women

OBJECTIVES

This cross-sectional study investigates associations between the FTO rs 17817449 genetic variant, liver enzymes, and hypertension in Slovak midlife women.

METHODS

We assessed 576 Slovak women aged 39 to 65 years. The women were interviewed and examined during their medical examination at local Health Centers and then divided into subgroups according to their blood pressure status; 255 women with hypertension and 321 normotensive. The FTO genetic variant was detected by polymerase chain reaction-restriction fragment length polymorphism. Resultant data was analyzed by linear regression analysis and general linear models to adjust for risk factors associated with gamma-glutamyl transferase levels (GGT), including waist to hip ratio (WHR) and uric acid (UA).

RESULTS

A significant association between the FTO variant and GGT levels was observed in the hypertensive group after control for confounding covariates, including WHR and UA (p = .004). The predicted GGT level for GT/TT hypertensive carriers is 0.158 μkat/L higher than for GG carriers. Moreover, the two-way analysis of covariance revealed significant interaction between FTO effects and hypertension on logGGT levels (p = .042). Finally, hypertensive women with the T-allele had the highest estimated marginal mean value of logGGT at -0.39 μkat/L while the GG-genotype in both hypertensive and normotensive women had the lowest value at -0.54 μkat/L.

CONCLUSIONS

This study suggests that the FTO (rs17817449) variant is associated with higher serum GGT levels in hypertensive midlife women.

Increased Uric Acid, Gamma-Glutamyl Transpeptidase and Alkaline Phosphatase in Early-Pregnancy Associated With the Development of Gestational Hypertension and Preeclampsia

Background: Previous studies have reported that biomarkers of liver injury and renal dysfunction were associated with hypertensive disorders of pregnancy (HDP). However, the associations of these biomarkers in early pregnancy with the risk of HDP and longitudinal blood pressure pattern during pregnancy were rarely investigated in prospective cohort studies. Methods: A total of 1,041 pregnant women were enrolled in this prospective cohort study. BP was assessed in four stages throughout pregnancy. The following biomarkers were measured at early pregnancy before 18 weeks gestation: lactate dehydrogenase (LDH), aspartate aminotransferase to alanine aminotransferase ratio (AST/ALT), gamma-glutamyl transpeptidase (GGT), alkaline phosphatase (ALP), uric acid (UA), and estimated glomerular filtration rate (eGFR). Linear mixed-effects and logistic regression models were used to examine the associations of these biomarkers with longitudinal BP pattern during pregnancy and HDP incidence, respectively. Results: In unadjusted models, higher serum UA, GGT, ALP, and LDH levels, as well as lower eGFR and AST/ALT, were associated with higher BP levels during pregnancy and an increased risk of HDP. After adjustment for maternal age, pre-pregnancy BMI and other potential confounders, UA, GGT, ALP, and LDH remained positively associated with both BP and HDP. However, eGFR and AST/ALT were not associated with HDP after adjusting for potential confounders. When including all 6 biomarkers simultaneously in multivariable analyses, increased UA, GGT, and ALP significantly associated with gestational hypertension and preeclampsia. Conclusion: This study suggests that increased UA, GGT, and ALP in early-pregnancy are independent risk factors of gestational hypertension and preeclampsia.

Blood multiomics reveal insights into population clusters with low prevalence of diabetes, dyslipidemia and hypertension

Diabetes, dyslipidemia and hypertension are important metabolic diseases that impose a great burden on many populations worldwide. However, certain population strata have reduced prevalence for all three diseases, but the underlying mechanisms are poorly understood. We sought to identify the phenotypic, genomic and metabolomic characteristics of the low-prevalence population to gain insights into possible innate non-susceptibility against metabolic diseases. We performed k-means cluster analysis of 16,792 subjects using anthropometric and clinical biochemistry data collected by the Taiwan Biobank. Nuclear magnetic resonance spectra-based metabolome analysis was carried out for 217 subjects with normal body mass index, good exercise habits and healthy lifestyles. We found that the gene APOA5 was significantly associated with reduced prevalence of disease, and lesser associations included the genes HIF1A, LIMA1, LPL, MLXIPL, and TRPC4. Blood plasma of subjects belonging to the low disease prevalence cluster exhibited lowered levels of the GlycA inflammation marker, very low-density lipoprotein and low-density lipoprotein cholesterol, triglycerides, valine and leucine compared to controls. Literature mining revealed that these genes and metabolites are biochemically linked, with the linkage between lipoprotein metabolism and inflammation being particularly prominent. The combination of phenomic, genomic and metabolomic analysis may also be applied towards the study of metabolic disease prevalence in other populations.

The Dose-Response Relationship between Gamma-Glutamyl Transferase and Risk of Diabetes Mellitus Using Publicly Available Data: A Longitudinal Study in Japan

PURPOSE

The purpose of this study was to examine the association between baseline serum gamma-glutamyl transferase (GGT) and incident diabetes mellitus and to explore their dose-response relationship in a cohort of Japanese adults. Patients and Methods. Data were drawn from the NAGALA (NAfld in the Gifu Area, Longitudinal Analysis) study between 2004 and 2015, including hierarchical information on participants ≥18 years of age without diabetes mellitus, preexisting diabetes mellitus, heavy alcohol drinking, or other liver diseases (e.g., hepatitis B/C). The final analytic sample included 15464 participants, 373 of who were diagnosed as diabetes mellitus with a maximum 13-year follow-up. The risk of incident diabetes mellitus according to baseline serum GGT was estimated using multivariable Cox proportional hazards models and a two-piecewise linear regression model was developed to find out the threshold effect.

RESULTS

Being in the highest quintile versus the lowest quintile of GGT levels was associated with an almost twofold increased risk of incident diabetes mellitus (hazard ratio 1.83 (95% CI 1.06, 3.15)), independent of age, gender, smoking status, alcohol intake, BMI, SBP, triglycerides, fatty liver, ALT, AST, and fasting plasma glucose. Further analysis revealed a positive curvilinear association between GGT and incident diabetes mellitus, with a saturation effect predicted at 24 IU/L. When serum GGT level was less than 24 IU/L, the risk of developing diabetes mellitus increased significantly with an increase in serum GGT levels (HR 1.04 (1.02, 1.07), P=0.0017). Besides, the association was more significant in nonsmoking participants than ex- or current-smokers (P=0.0017). Besides, the association was more significant in nonsmoking participants than ex- or current-smokers (P for interaction = 0.0378).

CONCLUSION

Serum GGT level was a significant predictor of subsequent risk of diabetes mellitus, which increased by 4% for every 1 IU/L increase in GGT when GGT was less than 24 IU/L.

Biomarkers and their relative contributions to identifying coronary artery stenosis based on coronary computed tomography angiography in asymptomatic adults

BACKGROUND

Coronary computed tomography angiography (CCTA) has emerged as an important, non-invasive imaging modality for the assessment of coronary vascular disease. However, CCTA as a screening tool still has issues with radiation exposure and cost in asymptomatic adults. In this study, we investigated the relationship between cardio-metabolic biomarkers and coronary artery stenosis on CCTA in asymptomatic, apparently healthy adults.

METHODS

Data for this cross-sectional study were obtained from 306 subjects who underwent a comprehensive medical check-up including CCTA. A 128-slice CT device was used to detect earlier stages of coronary stenosis, which was defined as > 25% luminal reduction in the most severe stenosis in the calcified segments of the coronary arteries.

RESULTS

On multivariate analysis, after adjustment for age, only γ-glutamyl transferase (GGT) was significantly and independently associated with CCTA stenosis (OR 1.006, 95% CI 1.001-1.011, P = .026). In a subgroup analysis of 103 subjects with brachial-ankle pulse wave velocity (baPWV) data, baPWV was significantly associated with CCTA stenosis (OR 1.005; 95% CI 1.003-1.008, P < .001).

CONCLUSIONS

GGT and baPWV were associated independently with the presence of CCTA stenosis in apparently healthy adults. Further research is needed to re-confirm on these findings.

Association between Gamma-Glutamyl Transferase and Coronary Atherosclerotic Plaque Vulnerability: An Optical Coherence Tomography Study

Background

Gamma-glutamyl transferase (GGT) has been detected in coronary plaques. However, the association between serum GGT levels and coronary atherosclerotic plaque vulnerability in patients with coronary artery disease (CAD) as detected by optical coherence tomography (OCT) has not been investigated.

Methods

We performed a retrospective study of consecutively enrolled CAD patients undergoing preintervention OCT examination during coronary angiography. Plaque vulnerability was defined as the presence of ruptured plaques or thin-cap fibroatheroma (TCFA) upon OCT. The association between serum GGT levels and coronary plaque vulnerability was evaluated using multivariate logistic regression analysis.

Results

A total of 142 patients were included in our analysis. OCT examination detected ruptured plaques in 16 patients, nonruptured plaques with TCFA in 17 patients, and nonruptured plaques and non-TCFA in 109 patients. Univariate analyses showed that gender, diabetes, Apolipoprotein A1 (ApoA1) and high-density lipoprotein cholesterol (HDL-c), and diagnosis of acute coronary syndrome (ACS) were associated with plaque vulnerability (P all < 0.05). Patients grouped according to serum GGT tertiles did not differ statistically in baseline characteristics or OCT findings. Results of multivariate logistic analyses showed that diabetes and diagnosis of ACS were associated with plaque rupture and TCFA (P < 0.05).

Conclusions

GGT serum levels were not associated with OCT detected coronary vulnerability in our cohort of CAD patient.

The Association Between Metabolic Syndrome and Serum Concentrations of Micronutrients, Inflammation, and Oxidative Stress Outside of the Clinical Reference Ranges: A Cross-Sectional Study

BACKGROUND

Clinical reference ranges are often used to assess nutritional status, but whether having lower or higher than the current clinical reference range for micronutrients, inflammation, and oxidative stress is related to metabolic syndrome (MetS) is not known. Our objectives are to estimate the odds of having MetS outside of established clinical references, and to identify any effect modifications by sex have for these relationships.

METHODS

Data from the 2005 to 2006 National Health and Nutrition Examination Survey were used (≥20 years; N = 2049) with MetS defined utilizing the harmonized criteria from the Joint Interim Statement. The odds of having MetS in individuals with lower or higher than the clinical reference range for the serum concentrations of micronutrient antioxidants, inflammation, and oxidative stress were estimated following adjustments for age, sex, ethnicity, education, income, smoking, alcohol intake, recreational physical activity, and BMI.

RESULTS

Having lower than the clinical reference range for carotenoids and vitamin C [odds ratios (95% confidence interval): 1.37 (1.05-1.78) and 1.39 (1.01-1.90), respectively] was associated with significantly greater odds of MetS. By contrast, having higher than the clinical reference range for vitamins A and E, uric acid, and γ-glutamyl transferase (GGT) [2.10 (1.50-2.92), 2.36 (1.78-3.13), 2.65 (1.54-4.57), and 2.08 (1.61-2.69), respectively] was associated with higher odds of MetS, whereas higher levels of vitamins B12 were protective [0.64 (0.42-0.98]. Sex moderated these relationships for carotenoids, vitamin A, C, E, uric acid, C-reactive protein, and GGT.

CONCLUSIONS

Lower carotenoids and vitamin C and higher vitamins A and E, uric acid, and oxidative stress were associated with a greater likelihood of MetS, whereas higher vitamin B12 was protective. Further research is necessary to replicate these findings in a prospective setting to confirm the importance of the overall and sex-specific findings.

Serum gamma-glutamyl transferase is a predictor of mortality in patients with acute myocardial infarction

Gamma-glutamyl transferase (GGT) is involved in the pathogenesis of atherosclerosis and has been associated with adverse cardiovascular outcomes in patients with ischemic heart disease. However, the association between GGT and long-term mortality has not been studied in patients with acute myocardial infarction (AMI).A total of 2239 AMI patients for whom serum GGT values were available and who underwent percutaneous coronary intervention (PCI) were enrolled in the COREA-AMI (CardiOvascular Risk and idEntificAtion of potential high-risk population in Korean patients with AMI) registry. Patients with acute liver injury were excluded. Patients were classified into 2 groups according to normal (n = 1983) or elevated (n = 256) levels of serum GGT. The primary clinical outcome was all-cause mortality. The secondary outcome was cardiac death and recurrent non-fatal myocardial infarction (MI).The median follow-up period was 3.7 years, and both groups had similar characteristics. Patients with elevated GGT had significantly higher all-cause mortality compared to patients with normal GGT (21.9% vs. 14.4%, P = .001). The multivariate Cox proportional hazards model showed that elevated serum GGT level was independently correlated with mortality (hazard ratio 2.12[1.44-3.11]; P < .001). Although elevated serum GGT was independently associated with long-term mortality after 30 days after PCI, there was no association within 30 days after PCI. Elevated GGT was also associated with death of cardiac causes with statistical significance. In the subgroup analysis, stronger associations were observed in the young and female patients and in patients who had ST-segment elevation MI and preserved left ventricular ejection fraction at the first echocardiography after the indexed PCI.Elevated serum GGT is an independent predictor of long-term mortality in AMI patients.

The nonalcoholic fatty liver disease (NAFLD) fibrosis score, cardiovascular risk stratification and a strategy for secondary prevention with ezetimibe

OBJECTIVE

The nonalcoholic fatty liver disease fibrosis score (NFS) is comprised of unique metabolic risk indicators that may accurately predict residual cardiovascular (CV) risk in patients with established coronary disease and metabolic dysfunction.

METHODS

We applied the NFS prospectively to 14,819 post-ACS patients randomized to ezetimibe/simvastatin (E/S) or placebo/simvastatin (P/S), in the IMPROVE-IT trial, using validated NFS cutoffs. The primary endpoint included CV death, myocardial infarction, unstable angina, revascularization or stroke. Outcomes were compared between NFS categories and treatment arms using frequency of events, KM rates and adjusted Cox proportional hazard models. The ability of the NFS to predict recurrent CV events was independently validated in 5395 placebo-treated patients enrolled in the SOLID-TIMI 52 trial.

RESULTS

Among 14,819 patients enrolled in IMPROVE-IT, 14.2% (N = 2106) were high-risk (NFS > 0.67). The high-risk group had a 30% increased risk of recurrent major CV events, compared to the low-risk NFS group (HR 1.30 [1.19-1.43]; p < 0.001). Among high-risk patients, ezetimibe/simvastatin conferred a 3.7% absolute reduction in risk of recurrent CV events, compared to placebo/simvastatin (HR 0.85 [0.74-0.98]), translating to a number-needed-to-treat of 27. Similar benefit was not found in the low-risk group (HR ezetimibe/simvastatin vs. placebo/simvastatin, 1.01 [0.91-1.12]; p-interaction = 0.053). The relationship between NFS category and recurrent CV events was independently validated in patients enrolled in SOLID-TIMI 52 (HR for NFS > 0.67 vs. NFS < -1.455 = 1.55 [1.32-1.81]; p < 0.001).

CONCLUSION

Stratification of cardiovascular risk by NFS identifies an independent population of patients who are at highest risk of recurrent events, and most likely to benefit from dual lipid-lowering therapy. Clinical trials.gov: NCT00202878.

Body mass index, abdominal adiposity, weight gain and risk of developing hypertension: a systematic review and dose-response meta-analysis of more than 2.3 million participants

OBJECTIVE

This study aimed to test the association between anthropometric measures and risk of developing hypertension.

METHODS

We did a systematic search using PubMed and Scopus, from inception up to January 2017. Prospective cohort studies reporting the risk estimates of hypertension for three or more quantitative categories of indices of general and abdominal adiposity were included. Summary relative risks were calculated using random-effects models.

RESULTS

Fifty-seven prospective cohort studies were included. Summary relative risks were 1.49 (95% confidence interval [CI]: 1.41, 1.58; I2  = 97.4%, n = 50) for a five-unit increment in body mass index, 1.27 (95%CI: 1.15, 1.39; I2  = 95.0%, n = 14) for a 10-cm increment in waist circumference, 1.16 (95%CI: 1.09, 1.23; I2  = 77.8%, n = 5) for weight gain equal to a one-unit increment in BMI, and 1.37 (95%CI: 1.24, 1.51; I2  = 76.4%, n = 8) and 1.74 (95%CI: 1.35, 2.13; I2  = 58.9%, n = 4) for a 0.1-unit increment in waist-to-hip ratio and waist-to-height ratio, respectively. The risk of hypertension increased continuously with increasing all anthropometric measures, and also along with weight gain.

CONCLUSION

Being as lean as possible within the normal body mass index range may be the best suggestion in relation to primary prevention of hypertension.

The associations between serum biomarkers and stenosis of the coronary arteries

Serum biochemical indices reflect dynamic physiological and pathophysiological processes within the body, the associations between these markers and the number of stenotic coronary arteries have been rarely studied. 627 healthy controls and 1,049 coronary heart disease (CHD) patients were sequentially recruited in our hospital. The association patterns between serum biochemical markers and the numbers of stenotic coronary arteries were evaluated in a cross-sectional manner. Upon binary multiple logistic regression analysis, the risk factor patterns differed by gender. Age, high-density lipoprotein cholesterol (HDL) and homocysteine (HCY) were common risk factors for CHD in both males and females. Upon ordinal multiple logistic regression analysis, age, low-density lipoprotein cholesterol (LDL) and lipoprotein (Lp) (a) increased, and HDL decreased, as the number of stenotic coronary arteries increased in male patients. Age and Lp(a) were positively associated with the number of stenotic coronary arteries and total bilirubin (TBil) was negatively associated with the number of stenotic coronary arteries in female patients. Age and Lp(a) were common risk factors positively associated with the number of stenotic coronary arteries in both male and female patients. HDL and LDL were male-specific risk factors and TBil was a female-specific risk factor for an increasing number of stenotic coronary arteries. In conclusion, serum biomarker levels correlated with the number of stenotic coronary arteries and showed gender different patterns.

Relationship between serum gamma-glutamyltransferase activity and cardiometabolic risk factors in metabolic syndrome

Objectives

The objective of this study was to examine the associations of serum gamma-glutamyltransferase (GGT) levels with the metabolic syndrome (MetS) and its components in Saudi adults.

Methods

The study comprised 400 participants (70 men and 330 women), aged between 40 and 88 years, randomly selected from the medicine clinics at the King Abdulaziz University Hospital in Jeddah, Saudi Arabia, in a cross-sectional study design. A standardized questionnaire was used to determine demographics variables, general health, lifestyle habits, and medical history. Anthropometric and biochemical variables measurements were taken for all study participants. MetS was defined according to the American Heart Association/National Heart, Lung, and Blood Institute report, by the presence of abdominal obesity.

Results

Higher means for triglycerides and insulin resistance indices (P < 0.0001) was found among those in the second, third, and fourth GGT quartiles as compared with their counterparts in the first quartile. McAuley index (β = -0.239, P < 0.0001, 95% confidence interval: -4.1--1.5) was shown to be a major determinant of circulating GGT in a multivariate analysis.

Conclusion

Elevated serum GGT could be a cardiometabolic risk factor either as a mediator of low-grade systemic inflammation and as a mediator of oxidative stress through mediation of extracellular glutathione transport into cells of organ systems.

Gamma-glutamyltransferase activity as a surrogate biomarker of metabolic health status in young nondiabetic obese women

Aim: We investigated the association of gamma-glutamyltransferase (GGT) activity with atherogenic risk factors and metabolic health status in young nondiabetic obese women. Methods & results: In 140 obese women GGT activity was independently associated with BMI, triglyceride to high-density cholesterol ratio and homeostasis model assessment. Metabolically healthy but obese women had significantly lower GGT activity, associated with a normal insulin sensitivity, favorable lipid profile and apolipoprotein B to apolipoprotein AI ratio. GGT activity showed good diagnostic accuracy to distinguish between metabolically healthy but obese and obese women at risk (77.8% sensitivity and 60% specificity). GGT activity >17 U/l can predict atherogenic risk and insulin resistance. Conclusion: GGT activity may serve as a potential surrogate biomarker of atherogenic risk and metabolic health status.

Fasting glycemia and glycated hemoglobin categories: Relationship to serum lipoprotein(a) level and disparity in 2 geographic regional groups of Turkey

OBJECTIVE

The goal of the present study was to determine covariates of serum lipoprotein (Lp) (a) within fasting glucose and glycated hemoglobin (HbA1c) categories, and to detect features that were different among covariates based on residence in Marmara and Central Anatolia (Marm-CA) regions or remaining 5 geographic regions of Turkey.

METHODS

Data of randomly-selected group of 1167 men and women (mean age 61 years) who participated in biennial surveys of 2013 and 2015 were cross-sectionally analyzed in 6 categories.

RESULTS

In multiple linear regression analysis of nondiabetic women, homeostatic model assessment (HOMA) index score was inversely associated with Lp(a) (ß coefficient 0.49; p=0.001); this was not true for men. In the whole sample, Lp(a) was significantly positively associated with female sex and with serum creatinine, and inversely in each sex with HOMA index (ß coefficient 0.63; p<0.001). Linear models within separate categories showed significant associations of Lp(a) only in individuals with no evidence of diabetes other than HbA1c >6.5%: in women, positive association with total cholesterol and inverse relationship with creatinine were found, and in men, positive association with apolipoprotein (apo) B was determined. Similar age, diastolic blood pressure, fasting glucose, triglyceride, uric acid, and C-reactive protein values were obtained from participants of 2 regional groups. Residents of the Marm-CA region who were nondiabetic exhibited significantly (by 23%) lower serum Lp(a) among individuals with HbA1c ≥5.7%, significantly higher HOMA index score, concentrations of apoB, and low-density lipoprotein cholesterol.

CONCLUSION

Hallmark of prediabetic and diabetic glycemia/HbA1c categories seems to be an independent inverse association between Lp(a) protein (yet not of apoB) and HOMA score, this being primarily so in residents of Marm-CA region.

Change in Serum Bilirubin Level as a Predictor of Incident Metabolic Syndrome

Aim

Serum bilirubin level was negatively associated with the prevalence of metabolic syndrome (MetS) in previous cross-sectional studies. However, bilirubin variance preceding the development of MetS has yet to be investigated. We aimed to determine the effect of change in bilirubin concentration on the risk of incident MetS in healthy Korean adults.

Methods

We conducted a retrospective longitudinal study of subjects who had undergone at least four yearly health check-ups between 2006 and 2012. Of 24,185 total individuals who received annual check-ups, 11,613 non-MetS participants with a baseline bilirubin level not exceeding 34.2 μmol/l were enrolled. We evaluated the association between percent change in bilirubin and risk of incident MetS.

Results

During 55,407 person-years of follow-up, 2,439 cases of incident MetS developed (21.0%). Baseline serum bilirubin level clearly showed no association with the development of MetS in men but an independent significant inverse association in women which attenuated (hence may be mediated) by elevated homeostatic model assessment index 2 for insulin resistance (HOMA2-IR). However, increased risk for incident MetS was observed in higher percent change in bilirubin quartiles, with hazard ratios of 2.415 (95% CI 2.094–2.785) in men and 2.156 (95% CI 1.738–2.675) in women in the fourth quartile, compared to the lowest quartile, after adjusting for age, smoking status, medication history, alanine aminotransferase, uric acid, estimated glomerular filtration rate, fasting glucose, baseline diabetes mellitus prevalence, systolic blood pressure, waist circumference, and body mass index. The hazard ratios per one standard deviation increase in percent change in bilirubin as a continuous variable were 1.277 (95% CI 1.229–1.326) in men and 1.366 (95% CI 1.288–1.447) in women.

Conclusions

Increases in serum bilirubin concentration were positively associated with a higher risk of incident MetS. Serum bilirubin increment might be a sensitive marker for the development of MetS.

Effects of the Dietary Detoxification Program on Serum γ-glutamyltransferase, Anthropometric Data and Metabolic Biomarkers in Adults

Background

Persistent Organic Pollutants (POPs) are well-known environmental contaminants which are associated with chronic diseases. As foods are the major sources of human exposure to toxic pollutants, we developed an integrated dietary and education program to eliminate the chemical toxin throughout the human body. The present study evaluated effects of the dietary detoxification program on serum γ-glutamyltransferase (GGT), anthropometric data and metabolic biomarkers in adults.

Methods

Single-armed, pre-post study was conducted from June 2013 to June 2015 at a health examination center and a public health center in Seoul, Korea. Sixty eight subjects (mean age of 52.4 years) were recruited. Subjects participated 20 hours’ dietary education sessions. On-line coaching with SNS was performed to enhance participants’ proper protocol compliance. Physical and laboratory examinations were assessed at week 0 and 3.

Results

Changes of the serum GGT were correlated with reductions of the body fat percentage (r = .379, p = .001), body fat mass (r = .435, p = .000) and fasting blood glucose (r = .423, p = .000). Serum GGT, weight, body fat percentage, body fat mass, waist circumference, LDL-cholesterol, HDL-cholesterol, triglyceride, total cholesterol, and blood pressure of all participants were reduced with statistical significance in 3 weeks. In metabolic syndrome group, total cholesterol (p = .049), fasting blood glucose (p = .002), and systolic blood pressure (p = .001) were significantly reduced comparison to non-metabolic syndrome group.

Conclusion

This dietary detoxification program might decrease serum GGT which indicated the overall toxic burden in the body. Anthropometric data and metabolic biomarkers were improved. The integrated dietary and education detoxification program seemed to be a protective intervention for elimination of toxicants from the body.

Nonalcoholic fatty liver disease is associated with an almost twofold increased risk of incident type 2 diabetes and metabolic syndrome. Evidence from a systematic review and meta-analysis

BACKGROUND AND AIM

The magnitude of the risk of incident type 2 diabetes (T2D) and metabolic syndrome (MetS) among patients with nonalcoholic fatty liver disease (NAFLD) is poorly known. We gauged the risk of developing T2D and MetS in patients with NAFLD diagnosed by either serum liver enzymes (aminotransferases or gamma-glutamyltransferase [GGT]) or ultrasonography.

METHODS

Pertinent prospective studies were identified through extensive electronic database research, and studies fulfilling enrolment criteria were included in the meta-analysis.

RESULTS

Overall, in a pooled population of 117020 patients (from 20 studies), who were followed-up for a median period of 5 years (range: 3-14.7 years), NAFLD was associated with an increased risk of incident T2D with a pooled relative risk of 1.97 (95% confidence interval [CI], 1.80-2.15) for alanine aminotransferase, 1.58 (95% CI, 1.43-1.74) for aspartate aminotransferase, 1.86 (95% CI, 1.71-2.03) for GGT (last vs first quartile or quintile), and 1.86 (95% CI, 1.76-1.95) for ultrasonography, respectively. Overall, in a pooled population of 81411 patients (from eight studies) who were followed-up for a median period of 4.5 years (range: 3-11 years), NAFLD was associated with an increased risk of incident MetS with a pooled relative risk of 1.80 (95% CI, 1.72-1.89) for alanine aminotransferase (last vs first quartile or quintile), 1.98 (95% CI, 1.89-2.07) for GGT, and 3.22 (95% CI, 3.05-3.41) for ultrasonography, respectively.

CONCLUSIONS

Nonalcoholic fatty liver disease, as diagnosed by either liver enzymes or ultrasonography, significantly increases the risk of incident T2D and MetS over a median 5-year follow-up.

Low Serum Lysosomal Acid Lipase Activity Correlates with Advanced Liver Disease

Fatty liver has become the most common liver disorder and is recognized as a major health burden in the Western world. The causes for disease progression are not fully elucidated but lysosomal impairment is suggested. Here we evaluate a possible role for lysosomal acid lipase (LAL) activity in liver disease. To study LAL levels in patients with microvesicular, idiopathic cirrhosis and nonalcoholic fatty liver disease (NAFLD). Medical records of patients with microvesicular steatosis, cryptogenic cirrhosis and NAFLD, diagnosed on the basis of liver biopsies, were included in the study. Measured serum LAL activity was correlated to clinical, laboratory, imaging and pathological data. No patient exhibited LAL activity compatible with genetic LAL deficiency. However, serum LAL activity inversely predicted liver disease severity. A LAL level of 0.5 was the most sensitive for detecting both histologic and noninvasive markers for disease severity, including lower white blood cell count and calcium, and elevated γ-glutamyltransferase, creatinine, glucose, glycated hemoglobin, uric acid and coagulation function. Serum LAL activity <0.5 indicates severe liver injury in patients with fatty liver and cirrhosis. Further studies should define the direct role of LAL in liver disease severity and consider the possibility of replacement therapy.

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.

Gender differences in the association of hypertension with gamma-glutamyltransferase and alanine aminotransferase levels in Chinese adults in Qingdao, China

The aim of the study was to study the associations of hypertension with gamma-glutamyltransferase (GGT) and alanine aminotransferase (ALT) levels. Data of 3575 men and 5504 women were analyzed. Multivariate logistic regression analysis was performed to estimate the odds ratio (OR) for hypertension with GGT and ALT. Compared with the lowest quartile, the multivariate adjusted ORs for hypertension were 0.97 (0.79, 1.19) in men and 0.88 (0.74, 1.04) in women for ALT and 2.29 (1.68, 3.14) and 1.52 (1.27, 1.83) for GGT in the highest quartile group. The ORs for hypertension in the low waist circumference category were 2.61 (1.56, 4.36) in men and 1.41 (0.94, 2.12) in women and in the high waist circumference category 4.01 (2.21, 7.29) and 2.26 (1.54, 3.32) for GGT. The elevated GGT, but not ALT, was associated with the presence of the hypertension in men and women. The association is stronger in obese men and women than in their lean counterparts.

Identification of reciprocal causality between non-alcoholic fatty liver disease and metabolic syndrome by a simplified Bayesian network in a Chinese population

OBJECTIVES

It remains unclear whether non-alcoholic fatty liver disease (NAFLD) is a cause or a consequence of metabolic syndrome (MetS). We proposed a simplified Bayesian network (BN) and attempted to confirm their reciprocal causality.

SETTING

Bidirectional longitudinal cohorts (subcohorts A and B) were designed and followed up from 2005 to 2011 based on a large-scale health check-up in a Chinese population.

PARTICIPANTS

Subcohort A (from NAFLD to MetS, n=8426) included the participants with or without NAFLD at baseline to follow-up the incidence of MetS, while subcohort B (from MetS to NAFLD, n=16,110) included the participants with or without MetS at baseline to follow-up the incidence of NAFLD.

RESULTS

Incidence densities were 2.47 and 17.39 per 100 person-years in subcohorts A and B, respectively. Generalised estimating equation analyses demonstrated that NAFLD was a potential causal factor for MetS (relative risk, RR, 95% CI 5.23, 3.50 to 7.81), while MetS was also a factor for NAFLD (2.55, 2.23 to 2.92). A BN with 5 simplification strategies was used for the reciprocal causal inference. The BN's causal inference illustrated that the total effect of NAFLD on MetS (attributable risks, AR%) was 2.49%, while it was 19.92% for MetS on NAFLD. The total effect of NAFLD on MetS components was different, with dyslipidemia having the greatest (AR%, 10.15%), followed by obesity (7.63%), diabetes (3.90%) and hypertension (3.51%). Similar patterns were inferred for MetS components on NAFLD, with obesity having the greatest (16.37%) effect, followed by diabetes (10.85%), dyslipidemia (10.74%) and hypertension (7.36%). Furthermore, the most important causal pathway from NAFLD to MetS was that NAFLD led to elevated GGT, then to MetS components, while the dominant causal pathway from MetS to NAFLD began with dyslipidaemia.

CONCLUSIONS

The findings suggest a reciprocal causality between NAFLD and MetS, and the effect of MetS on NAFLD is significantly greater than that of NAFLD on MetS.

What does serum γ-glutamyltransferase tell us as a cardiometabolic risk marker?

γ-glutamyltransferase plays a key role in the synthesis and metabolism of extracellular glutathione, a major antioxidant in several defence mechanisms in the body. γ-glutamyltransferase is affected by environmental and genetic factors, and is raised when there is depletion of glutathione. Hence, it is a marker of oxidative stress. There is robust evidence that γ-glutamyltransferase even when values are within the reference interval is associated with increased cardiovascular and all-cause mortality in both sexes, in normal subjects and subjects with coronary artery disease, in the middle-aged and the elderly after adjusting for confounding factors. γ-glutamyltransferase even within the reference interval is associated with future presentation of type 2 diabetes, and the longitudinal increase in γ-glutamyltransferase activity is associated with increased risk of type 2 diabetes and cardiovascular mortality. γ-glutamyltransferase is associated with cardiovascular risk factors and metabolic syndrome. It has a prognostic value after a previous acute myocardial infarction and may be an indicator of adverse outcome in acute coronary syndromes and other chronic cardiac disorders. There is limited data about γ-glutamyltransferase and any association with peripheral arterial disease and also whether knowing γ-glutamyltransferase activity improves cardiovascular risk prediction beyond conventional risk factors. γ-glutamyltransferase is present in atherosclerotic lesions in the coronary and carotid arteries, and has a prooxidant role leading to the production of reactive oxygen species and atherosclerosis. Current reference intervals for γ-glutamyltransferase are inappropriate and need to be addressed. Some laboratories still use non- International Federation of Clinical Chemistry methods for estimation of γ-glutamyltransferase which are associated with lower results. Such laboratories should review their method and consider changing to the International Federation of Clinical Chemistry method.

Increased liver markers are associated with higher risk of type 2 diabetes

AIM: To investigate the association between liver markers and the risk of type 2 diabetes (T2DM) and impaired fasting glucose (IFG).

METHODS: A total of 8863 participants (3408 men and 5455 women) over 30 years of age were analyzed from the fifth Korean National Health and Nutrition Examination Survey (2010-2011). The associations of serum liver markers such as aspartate aminotransferase (AST), alanine aminotransferase (ALT), AST/ALT, and gamma-glutamyltransferase (GGT) with T2DM and IFG were analyzed using logistic regression models. Participants were divided into sex-specific quartiles on the basis of liver markers.

RESULTS: The prevalence of T2DM and IFG were 11.3% and 18.3%. Increasing quartiles of ALT and GGT were positively and AST/ALT were negatively correlated with T2DM and IFG. Analysis of the liver marker combinations showed that if any two or more markers were in the highest risk quartile, the risks of both T2DM and IFG increased significantly. The risk was greatest when the highest ALT and GGT and lowest AST/ALT quartile were combined, with the risk of T2DM at 3.21 (95%CI: 1.829-5.622, P < 0.001) in men and 4.60 (95%CI: 3.217-6.582, P < 0.001) in women. Men and women with the highest AST and ALT and lowest AST/ALT quartile had a 1.99 and 2.40 times increased risk of IFG.

CONCLUSION: Higher levels of GGT and ALT and lower AST/ALT within the physiological range are independent, additive risk factors of T2DM and IFG.

A novel hypothesis for atherosclerosis as a cholesterol sulfate deficiency syndrome

BACKGROUND

Despite a vast literature, atherosclerosis and the associated ischemia/reperfusion injuries remain today in many ways a mystery. Why do atheromatous plaques make and store a supply of cholesterol and sulfate within the major arteries supplying the heart? Why are treatment programs aimed to suppress certain myocardial infarction risk factors, such as elevated serum homocysteine and inflammation, generally counterproductive?

METHODS

Our methods are based on an extensive search of the literature in atherosclerotic cardiovascular disease as well as in the area of the unique properties of water, the role of biosulfates in the vascular wall, and the role of electromagnetic fields in vascular flow. Our investigation reveals a novel pathology linked to atherosclerosis that better explains the observed facts than the currently held popular view.

RESULTS

We propose a novel theory that atherosclerosis can best be explained as being due to cholesterol sulfate deficiency. Furthermore, atheromatous plaques replenish the supply of cholesterol and sulfate to the microvasculature, by exploiting the inflammatory agent superoxide to derive sulfate from homocysteine and other sulfur sources. We argue that the sulfate anions attached to the glycosaminoglycans in the glycocalyx are essential in maintaining the structured water that is crucial for vascular endothelial health and erythrocyte mobility through capillaries. Sulfate depletion leads to cholesterol accumulation in atheromas, because its transport through water-based media depends on sulfurylation. We show that streaming potential induces nitric oxide (NO) release, and NO derivatives break down the extracellular matrix, redistributing sulfate to the microvasculature. We argue that low (less negative) zeta potential due to insufficient sulfate anions leads to hypertension and thrombosis, because these responses can increase streaming potential and induce nitric-oxide mediated vascular relaxation, promoting oxygen delivery. Our hypothesis is a parsimonious explanation of multiple features of atherosclerotic cardiovascular disease.

CONCLUSIONS

If our interpretation is correct, then it would have a significant impact on how atherosclerosis is treated. We recommend a high intake of sulfur-containing foods as well as an avoidance of exposure to toxicants that may impair sulfate synthesis.

Interactive effects of a common γ-glutamyltransferase 1 variant and low high-density lipoprotein-cholesterol on diabetic macro- and micro-angiopathy

BACKGROUND

We investigated the clinical relevance of a common variant, rs4820599, in the γ-glutamyltransferase (GGT)1 gene, associated with the serum GGT level, in Japanese type 2 diabetes mellitus (T2DM) subjects.

METHODS

We conducted a retrospective longitudinal study (4.9 ± 2.5 years) including 352 T2DM patients (T2DM subjects) and a cross-sectional study including 796 health screening program participants (general subjects). A real-time TaqMan allelic discrimination assay was used to identify the genotypes. Risk factors for a high brachial-ankle pulse wave velocity (baPWV) (≥1750 cm/sec) or diabetic retinopathy (DR) were determined using a generalized estimating equations approach, receiver operating characteristic (ROC) analysis or Cox proportional hazards model, etc.

RESULTS

The frequency of the GGT1 G allele was 20.8% in the T2DM subjects, and no associations were found between the GGT1 genotype and risk of T2DM. The mean log GGT values in the T2DM and general subjects were significantly higher among G allele carriers than non-carriers. The G allele and a low HDL-C level were identified to be risk factors for a high baPWV in the T2DM subjects [odds ratio (OR) 1.80, P = 0.008; OR 1.71, P = 0.03; respectively), and a significant interactive effect between these factors was found on the risk of a high baPWV and DR. The HDL-C level at baseline was a significant predictor of a high baPWV only in G allele carriers according to the ROC analysis. This result regarding baPWV in the T2DM subjects was replicated in the general population. Meanwhile, the GGT1 genotype was not associated with the risk of DR, although it affected the principal factors involved in the risk of DR, and a low HDL-C level was also found to be a risk factor for DR only in G allele carriers.

CONCLUSIONS

We herein describe for the first time the significant interactive effects of the GGT1 G allele and a low HDL-C level on a high baPWV and DR. These findings may encourage future clinical trials comparing the efficacy of agents increasing the HDL-C levels among the GGT1 genotypes. However, well-designed studies in larger cohorts are needed to confirm our results.

Liver function parameters in hip fracture patients: relations to age, adipokines, comorbidities and outcomes

AIM

To asses liver markers in older patients with hip fracture (HF) in relation to age, comorbidities, metabolic characteristics and short-term outcomes.

METHODS

In 294 patients with HF (mean age 82.0±7.9 years, 72.1% women) serum alanine aminotransferase (ALT), gammaglutamyltransferase (GGT), alkaline phosphatase (ALP), albumin, bilirubin, 25(OH)vitaminD, PTH, calcium, phosphate, magnesium, adiponectin, leptin, resistin, thyroid function and cardiac troponin I were measured.

RESULTS

Elevated ALT, GGT, ALP or bilirubin levels on admission were observed in 1.7%-9.9% of patients. With age GGT, ALT and leptin decrease, while PTH and adiponectin concentrations increase. Higher GGT (>30 U/L, median level) was associated with coronary artery disease (CAD), diabetes mellitus (DM), and alcohol overuse; lower ALT (≤20 U/L, median level) with dementia; total bilirubin>20 μmol/L with CAD and alcohol overuse; and albumin>33 g/L with CAD. Multivariate adjusted regression analyses revealed ALT, ALP, adiponectin, alcohol overuse and DM as independent and significant determinants of GGT (as continuous or categorical variable); GGT for each other liver marker; and PTH for adiponectin. The risk of prolonged hospital stay (>20 days) was about two times higher in patients with GGT>30 U/L or adiponectin>17.14 ng/L (median level) and 4.7 times higher if both conditions coexisted. The risk of in-hospital death was 3 times higher if albumin was <33 g/L.

CONCLUSIONS

In older HF patients liver markers even within the normal range are associated with age-related disorders and outcomes. Adiponectin (but not 25(OH)vitaminD, PTH, leptin or resistin) is an independent contributor to higher GGT. Serum GGT and albumin predict prolonged hospital stay and in-hospital death, respectively. A unifying hypothesis of the findings presented.

Gamma glutamyl transferase activity is independently associated with oxidative stress rather than SYNTAX score

BACKGROUND

Gamma glutamyl transferase (GGT) is involved in the pathophysiologic process of coronary atherosclerosis. GGT activity plays a role in the catabolism of glutathione which is known as one of the major antioxidants. However, there is a lack of research on direct examination of relevance between serum GGT activity with systemic oxidative stress.

OBJECTIVES

We aimed to investigate the relationship between GGT activity with systemic oxidative stress markers and the extent and complexity of coronary artery disease (CAD) assessed with SYNTAX score in stable CAD.

METHODS

Measurements were obtained from 359 patients with stable CAD (Mean age = 57.7 ± 10.1 years). The patients were divided into two groups according to the median GGT level (GGT < median group < 22 and GGT > median group ≥ 22). Angiography was performed and SYNTAX score was calculated in all patients. Oxidative stress markers (total oxidant status [TOS], total antioxidant capacity [TAC] and oxidative stress index [OSI]) were measured in all patients.

RESULTS

While SYNTAX score and oxidative stress markers such as TOS and OSI have been increased, TAC was decreased in GGT > median group compared with GGT < median group (p < 0.05, for all). GGT activity was independently associated with diabetes (β = 0.106, p = 0.015) and OSI (β = 0.556, p < 0.001) in multiple linear regression analysis. However, the independent association between GGT activity and SYNTAX score was not found in present study (β = 0.063, p = 0.238).

CONCLUSION

In stable CAD, increased GGT activity within the normal range is associated with increased oxidative stress rather than increased extent and complexity of CAD.

Association between long working hours and serum gamma-glutamyltransferase levels in female workers: data from the fifth Korean National Health and Nutrition Examination Survey (2010-2011)

Objectives

The present study investigated the association between long working hours and serum gamma-glutamyltransferase (GGT) levels, a factor influencing the incidence of cardiovascular disease.

Methods

Data from the fifth Korean National Health and Nutrition Examination Survey (2010–2011) were used to analyze 1,809 women. Subjects were divided into three groups based on the number of weekly working hours: ≤29, 30–51, and ≥52 hours per week. Complex samples logistic regression was performed after adjusting for general and occupational factors to determine the association between long working hours and high serum GGT levels.

Results

The prevalence of high serum GGT levels in groups with ≤29, 30–51, and ≥52 working hours per week was 22.0%, 16.9%, and 26.6%, respectively. Even after adjusting for general and occupational factors, those working 30–51 hours per week had the lowest prevalence of high serum GGT levels. Compared to those working 30–51 hours per week, the odds ratios (OR) of having high serum GGT levels in the groups with ≥52 and ≤29 working hours per week were 1.56 (95% confidence interval [CI], 1.10–2.23) and 1.53 (95% CI, 1.05–2.24), respectively.

Conclusions

Long working hours were significantly associated with high serum GGT levels in Korean women.

Association of gamma-glutamyltransferase with non-alcoholic fatty liver disease and other related diseases

Gamma-glutamyltransferase (GGT) activity is a sensitive marker of liver dysfunction. It is commonly used to evaluate liver diseases such as viral hepatitis or alcoholic hepatitis. Several studies have shown the association between GGT levels and risk of non-alcoholic fatty liver disease, insulin resistance, metabolic syndrome and cardiovascular disease. This paper will review recent advances in understanding the association of GGT with these diseases.

Lack of association between serum gamma-glutamyltransferase and carotid atherosclerosis: the Namwon Study

OBJECTIVES

There is little evidence for an association between gamma-glutamyltransferase (GGT) and carotid atherosclerosis, an independent predictor of cardiovascular disease. We examined the association between serum GGT and carotid atherosclerotic parameters, including carotid intima-media thickness (IMT) and plaques, in a large general population.

METHODS

The study population consisted of community-dwelling adults who participated in the baseline survey of the Namwon Study. A total of 9120 subjects aged 45-74 years were included in the analyses. High-resolution B-mode ultrasound was used to measure carotid IMT and to evaluate the presence of carotid plaques. A mean carotid IMT of ≥1.0 mm was classified as 'high carotid IMT'.

RESULTS

Serum GGT levels were classified into quartiles. In a fully adjusted model, we found no linear trend between GGT quartile and mean carotid IMT (P for trend = 0.167). Compared with the first quartile (the reference category), the odds ratios (ORs) and 95% confidence intervals (CIs) for high carotid IMT were 0.89 (0.68-1.16), 1.10 (0.84-1.43), and 0.97 (0.71-1.33) for the second, third, and fourth quartiles (P for trend = 0.754), respectively. The ORs (95% CIs) for carotid plaques were 0.89 (0.77-1.02), 0.95 (0.82-1.10), and 0.94 (0.79-1.11) for the second, third, and fourth quartiles, respectively, in the fully adjusted model (P for trend = 0.644).

CONCLUSIONS

No significant association of GGT concentration with carotid IMT or plaques was found in this large cross-sectional study. Further longitudinal studies are needed to confirm our findings.

Omentin changes following bariatric surgery and predictive links with biomarkers for risk of cardiovascular disease

BACKGROUND

Although no receptor has yet been identified, changes in circulating levels of the adipokine designated as Omentin have been demonstrated in obesity and related comorbidities such as cardiovascular disease, insulin resistance, metabolic syndrome and chronic inflammation.

METHODS

Changes in Omentin levels at 1 and 5 days and 6 and 12 months in response to biliopancreatic diversion with duodenal switch bariatric surgery were evaluated, specifically to investigate if changes preceded gain of insulin sensitivity.

RESULTS

Pre-operative plasma Omentin was not different between men (n = 18) vs women (n = 48), or diabetic status but correlated with body mass index (BMI). Altogether, Omentin increased as early as 24-h post-surgery, with changes maintained up to 1-year. Fifty-nine percent of subjects increased Omentin >10% by 24-H following surgery (OmentinINC p < 0.0001), while 18% of subjects decreased (OmentinDEC p < 0.0001), with changes maintained throughout one-year. These two groups had comparable age, sex distribution, diabetes, BMI, waist circumference and fat mass, however OmentinDEC had elevated levels of cardiovascular risk markers; homocysteine (p = 0.019), NT-proBNP (p = 0.006) and total bilirubin (p = 0.0001) while red blood cell (RBC) count was lower (p = 0.0005) over the one-year period. Omentin levels at 1-DAY also correlated with immune parameters (white blood cell count, % neutrophil, % monocytes, % lymphocytes).

CONCLUSION

OmentinDEC at 1 day following surgery may be a marker of cardiovascular "at-risk" group before weight loss or insulin sensitivity restoration.

Different associations between obesity and impaired fasting glucose depending on serum gamma-glutamyltransferase levels within normal range: a cross-sectional study

BACKGROUND

Despite the consistent relationship between serum γ-glutamyltransferase (GGT) and type 2 diabetes (T2D), one unsolved issue is the role of serum GGT in the well-known association between obesity and T2D. This study was performed to investigate whether the association between body mass index (BMI) and impaired fasting glucose (IFG) differed depending on serum GGT levels within the normal range.

METHODS

Study subjects were 2,424 men and 3,652 women aged ≥ 40, participating in the Fifth Korean National Health and Nutrition Examination Survey. Serum GGT levels within the normal range were classified into gender-specific tertiles.

RESULTS

Among men and women belonging to the lowest tertile of serum GGT, BMI showed statistically non-significant weak associations with the risk of IFG. However, among persons in the highest tertile of serum GGT, the risk of IFG was 3 - 4 times higher among persons with BMI ≥ 25 kg/m2 than those with BMI < 23 kg/m2 (Pinteraction = 0.032 in men and 0.059 in women).

CONCLUSIONS

The well-known strong association between BMI and IFG was observed mainly among persons with elevation of serum GGT to certain physiological levels, suggesting a critical role of serum GGT in the pathogenesis of IFG. This finding has an important clinical implication because serum GGT can be used to detect high-risk obese persons.