Age-related changes on serum ggt activity and the assessment of ethanol intake

Gamma-glutamyl transferase and the risk of all-cause and disease-specific mortality in patients with diabetes: A nationwide cohort study

BACKGROUND

There exists a paucity of data regarding whether gamma-glutamyl transferase is associated with disease-specific mortality in patients with type 2 diabetes mellitus. This study aimed to investigate the association of serum gamma-glutamyl transferase levels with all-cause and disease-specific mortality in patients with diabetes mellitus using a Korean nationwide health-screening database.

METHODS

A total of 9 687 066 patients without viral hepatitis or liver cirrhosis who underwent health examination in 2009 were included. These patients were divided into four groups according to sex-specific quartiles of serum gamma-glutamyl transferase levels.

RESULTS

During a median follow-up period of 8.1 years, 222 242 deaths were identified. The all-cause mortality rate increased as the serum gamma-glutamyl transferase levels became higher (highest quartile vs lowest quartile: hazard ratio [HR], 1.57; 95% confidence interval [CI], 1.55-1.59; p for trend <.001). Similar trends were observed for cardiovascular disease (HR, 1.57; 95% CI, 1.53-1.62), ischemic heart disease (HR, 1.40; 95% CI, 1.33-1.48), and stroke (HR, 1.72; 95% CI, 1.60-1.85) in the highest quartile, as compared with the lowest quartile (p for trend <.001). As the gamma-glutamyl transferase quartiles became higher, mortality rates related to cancer (HR, 1.56; 95% CI, 1.52-1.60), liver disease (HR, 9.42; 95% CI, 8.81-10.07), respiratory disease (HR, 1.55; 95% CI, 1.49-1.62), and infectious disease (HR, 1.73; 95% CI, 1.59-1.87) also increased in the highest quartile, compared with the lowest quartile (p for trend <.001).

CONCLUSIONS

Serum gamma-glutamyl transferase levels may be useful for the risk assessment of all-cause and disease-specific mortality among patients with type 2 diabetes mellitus.

Hematological and Serum Biochemical Reference Intervals for Alphaxalone Sedated Common Marmosets (Callithrix jacchus)

Marmosets are routinely used in biomedical research, therefore there is an increasing need for updated reference intervals calculated using a large sample size, correct statistics, and considering different variables. Hematological and biochemical values from 472 healthy common marmosets sedated with alphaxalone were collected over a ten-year period (2013-2023). The variables assumed to have influenced the blood-based parameters were compared, i.e., sex, age, housing condition, pregnancy, and contraceptive use. Reference intervals were calculated based on observed percentiles without parametric assumptions, and with parametric assumptions following Box-Cox transformation. Juvenile marmosets showed increased ALP, phosphate, WBC, lymphocyte count, and basophil count and decreased levels of GGT and Fe compared to adults. Marmosets housed strictly indoors showed increased ALT and GGT levels and decreased levels of total bilirubin and neutrophil count compared to marmosets housed with outdoor access. Pregnant marmosets showed increased ALP, total bilirubin, neutrophil count, monocyte count, and basophil count, and decreased levels of AST, ALT, cholesterol, Fe, and lymphocyte count compared to non-pregnant marmosets. Etonogestrel contracepted marmosets showed decreased P-LCR compared to females who were not contracepted. Updated reference intervals will aid researchers and veterinarians in identifying physiological and pathological changes, as well as improve the reproducibility of research in this species.

Using urinary metabolomics to identify metabolic pathways linked to cardiac structural alterations in young adults: The African-PREDICT study

BACKGROUND AND AIMS

Risk factor exposure from young ages was shown to contribute to cardiovascular events - cardiac hypertrophy, which may be accompanied by an altered metabolism. To determine how early metabolic alterations associate with myocardial structural changes, we profiled urinary metabolites in young adults with cardiovascular disease (CVD) risk factor(s) and a control group without CVD risk factors.

METHODS AND RESULTS

We included healthy adults (N = 1202), aged 20-30 years, stratified based on risk factors, i.e., obesity, physical inactivity, elevated blood pressure (BP), hyperglycemia, dyslipidemia, low socio-economic status, smoking and excessive alcohol use - forming the CVD risk group (N = 1036) and the control group (N = 166). Relative wall thickness (RWT) and left ventricular mass index (LVMi) were measured using echocardiography. Targeted metabolomics data were obtained using a liquid chromatography-tandem mass spectrometry method. Clinic systolic BP, 24 h BP and RWT were higher in the CVD risk group compared to the control group (all P ≤ 0.031). Exclusively in the CVD risk group, RWT associated with creatine and dodecanoylcarnitine; while LVMi associated with glycine, serine, glutamine, threonine, alanine, citrulline, creatine, proline, pyroglutamic acid and glutamic acid (all P ≤ 0.040). Exclusively in the control group, LVMi associated with propionylcarnitine and butyrylcarnitine (all P ≤ 0.009).

CONCLUSION

In young adults without CVD, but with CVD risk factors, LVMi and RWT associated with metabolites linked energy metabolism (shifting from solely fatty acid oxidation to glycolysis, with impaired creatine kinase activity) and oxidative stress. Our findings support early onset metabolic changes accompanying cardiac structural alterations due to lifestyle and behavioural risk factors.

Markers of arterial stiffness and urinary metabolomics in young adults with early cardiovascular risk: the African-PREDICT study

INTRODUCTION

Increased exposure to risk factors in the young and healthy contributes to arterial changes, which may be accompanied by an altered metabolism.

OBJECTIVES

To increase our understanding of early metabolic alterations and how they associate with markers of arterial stiffness, we profiled urinary metabolites in young adults with cardiovascular disease (CVD) risk factor(s) and in a control group without CVD risk factors.

METHODS

We included healthy black and white women and men (N = 1202), aged 20-30 years with a detailed CVD risk factor profile, reflecting obesity, physical inactivity, smoking, excessive alcohol intake, masked hypertension, hyperglycemia, dyslipidemia and low socio-economic status, forming the CVD risk group (N = 1036) and the control group (N = 166). Markers of arterial stiffness, central systolic blood pressure (BP) and pulse wave velocity were measured. A targeted metabolomics approach was followed by measuring amino acids and acylcarnitines using a liquid chromatography-tandem mass spectrometry method.

RESULTS

In the CVD risk group, central systolic BP (adjusted for age, sex, ethnicity) was negatively associated with histidine, arginine, asparagine, serine, glutamine, dimethylglycine, threonine, GABA, proline, methionine, pyroglutamic acid, aspartic acid, glutamic acid, branched chain amino acids (BCAAs) and butyrylcarnitine (all P ≤ 0.048). In the same group, pulse wave velocity (adjusted for age, sex, ethnicity, mean arterial pressure) was negatively associated with histidine, lysine, threonine, 2-aminoadipic acid, BCAAs and aromatic amino acids (AAAs) (all P ≤ 0.044). In the control group, central systolic BP was negatively associated with pyroglutamic acid, glutamic acid and dodecanoylcarnitine (all P ≤ 0.033).

CONCLUSION

In a group with increased CVD risk, markers of arterial stiffness were negatively associated with metabolites related to AAA and BCAA as well as energy metabolism and oxidative stress. Our findings may suggest that metabolic adaptations may be at play in response to increased CVD risk to maintain cardiovascular integrity.

A urinary peptidomics approach for early stages of cardiovascular disease risk: The African-PREDICT study

Cardiovascular disease (CVD) affects individuals across the lifespan, with multiple cardiovascular (CV) risk factors increasingly present in young populations. The underlying mechanisms in early cardiovascular disease development are complex and still poorly understood. We therefore employed urinary proteomics as a novel approach to gain better insight into early CVD-related molecular pathways based on a CVD risk stratification approach. This study included 964 apparently healthy (no self-reported chronic illnesses, free from clinical symptoms of CVD) black and white men and women (aged 20-30 years old) from the African Prospective study on the Early Detection and Identification of Cardiovascular disease and Hypertension (African-PREDICT) study. Cardiovascular risk factors used for stratification included obesity, physical inactivity, tobacco use, high alcohol intake, hyperglycemia, dyslipidemia and hypertension. Participants were divided into low (0 risk factors), medium (1-2 risk factors) and high (≥3 risk factors) CV risk groups. We analyzed urinary peptidomics by capillary electrophoresis time-of-flight mass spectrometry. After adjusting for ethnicity, sex and age, 65 sequenced urinary peptides were differentially expressed between the CV risk groups (all q-values ≤ 0.01). These peptides included a lower abundance of collagen type I- and III-derived peptides in the high compared to the low CV risk group. With regard to noncollagen peptides, we found a lower abundance of alpha-1-antitrypsin fragments in the high compared to the low CV risk group (all q-values ≤ 0.01). Our findings indicate lower abundances of collagen types I and III in the high compared to the low CV risk group, suggesting potential early alterations in the CV extracellular matrix.

Gamma-glutamyl transferase and risk of all-cause and disease-specific mortality: a nationwide cohort study

Population-based data regarding the prognostic implication of gamma-glutamyl transferase (GGT) have been inconsistent. We examined the association of GGT with all-cause and disease-specific mortality. Using the Korean nationwide database, we included 9,687,066 subjects without viral hepatitis or cirrhosis who underwent a health examination in 2009. Subjects were classified into three groups by sex-specific tertile of serum GGT levels. The underlying causes of death were classified by 10th Revision of the International Classification of Diseases codes. During the median follow-up period of 8.3 years, 460,699 deaths were identified. All-cause mortality increased as serum GGT levels became higher (hazard ratio [HR], 95% confidence interval [CI] 1.05, 1.04-1.05 in the middle tertile, and 1.33, 1.32-1.34 in the high tertile) compared to the low tertile of serum GGT levels. Similar trends were observed for cardiovascular disease (CVD) (HR, 95% CI 1.07, 1.05-1.09 in the middle tertile, 1.29, 1.26-1.31 in the high tertile), cancer (HR, 95% CI 1.08, 1.07-1.10 in the middle tertile, 1.38, 1.36-1.39 in the high tertile), respiratory disease (HR, 95% CI 1.10, 1.08-1.13 in the middle tertile, 1.39, 1.35-1.43 in the high tertile), and liver disease mortality (HR, 95% CI 1.74, 1.66-1.83 in the middle tertile, 6.73, 6.46-7.01 in the high tertile). Regardless of smoking, alcohol consumption and history of previous CVD and cancer, a higher serum GGT levels were associated with a higher risk of mortality. Serum GGT levels may be useful for risk assessment of all-cause and disease-specific mortality in general population.

The health effects of low blood lead level in oxidative stress as a marker, serum gamma-glutamyl transpeptidase level, in male steelworkers

Background

This study aimed to investigate the association between lead exposure and serum gamma-glutamyl transpeptidase (γGT) levels as an oxidative stress marker in male steelworkers.

Methods

Data were collected during the annual health examination of workers in 2020. A total of 1,654 steelworkers were selected, and the variables for adjustment included the workers' general characteristics, lifestyle, and occupational characteristics. The association between the blood lead level (BLL) and serum γGT level was investigated by multiple linear and logistic regression analyses. The BLL and serum γGT values that were transformed into natural logarithms were used in multiple linear regression analysis, and the tertile of BLL was used in logistic regression analysis.

Results

The geometric mean of the participants' BLLs and serum γGT level was 1.36 μg/dL and 27.72 IU/L, respectively. Their BLLs differed depending on age, body mass index (BMI), smoking status, drinking status, shift work, and working period, while their serum γGT levels differed depending on age, BMI, smoking status, drinking status, physical activity, and working period. In multiple linear regression analysis, the difference in models 1, 2, and 3 was significant, obtaining 0.326, 0.176, and 0.172 (all: p < 0.001), respectively. In the multiple linear regression analysis stratified according to drinking status, BMI, and age, BLLs were positively associated with serum γGT levels. Regarding the logistic regression analysis, the odds ratio of the third BLL tertile in models 1, 2, and 3 (for having an elevated serum γGT level within the first tertile reference) was 2.74, 1.83, and 1.81, respectively.

Conclusions

BLL was positively associated with serum γGT levels in male steelworkers even at low lead concentrations (< 5 μg/dL).

Urinary metabolomics profiling by cardiovascular risk factors in young adults: the African Prospective study on Early Detection and Identification of Cardiovascular disease and Hypertension study

AIM

Risk factors contributes to a dysregulated metabolism and may ultimately increase the predisposition for cardiovascular disease (CVD) development. To increase our understanding of mechanistic pathways associated with CVD risk, we profiled the urinary metabolome according to individual and clusters of CVD risk factors in comparison with a control group without any risk factors.

METHODS AND RESULTS

Healthy black and white women and men ( N  = 1202), aged 20-30 years with a detailed CVD risk factor profile were included. CVD risk groups: obese, physical inactive, smoking, excessive alcohol intake, masked hypertensive, hyperglycaemic, dyslipidemic and low socioeconomic status. CVD risk clusters were based on the presence of 1, 2 and 3 or more risk factors. Liquid chromatography-tandem mass spectrometry was used to obtain urinary metabolomics data (amino acids and acylcarnities). Compared with the control group, higher levels of metabolites associated with aromatic and branched chain amino acid metabolism including phenylalanine, tyrosine and leucine/isoleucine were found in the obese, masked hypertensive, hyperglycaemic, low socioeconomic groups (all q  ≤ 0.032) and 3+ CVD risk cluster (all P  ≤ 0.034). Metabolites associated with the y-glutamyl cycle including glycine, histidine, serine, glutamine, methionine, cystine and pyroglutamic acid were found in the hyperglycaemic, low socioeconomic groups (all q  ≤ 0.050), 2 and 3+ CVD risk clusters (all P  ≤ 0.041). Metabolites associated with energetics including acetylcarnitine (lower levels), hexanoylcarnitine and decanoylcarnitine were found in the low socioeconomic group, 1 and 3+ CVD risk clusters ( q / P  ≤ 0.050) ( β -oxidation). In addition to the above-mentioned amino acids, alanine and threonine were found in the hyperglycaemic, low socioeconomic groups, 2 and 3+ CVD risk clusters (all q / P  ≤ 0.047) (glycolysis). Creatine in the obese, hyperglycaemic groups (all q  ≤ 0.049) and 3+ CVD risk cluster (all P  ≤ 0.041) (creatine pathway).

CONCLUSION

Exposure to CVD risk factors is associated with a dysregulated metabolism in the above-mentioned pathways that may precede the development of CVD.

Hematology and Plasma Chemistry Reference Values in Nursehound Shark (Scyliorhinus Stellaris) Maintained Under Human Care

Studies determining baseline hematological reference intervals (RI) in elasmobranchs are very limited. In this study, blood samples were collected from 94 clinically healthy Nursehound Shark (Scyliorhinus stellaris) maintained under human care. Median (RI) in major leukocyte types were similar to other Carcharhinid sharks as lymphocytes were the predominant leukocyte with 38.0 (28.2–53.5)%, followed by coarse eosinophilic granulocytes with 20.0 (12.2–31.7)%, fine eosinophilic granulocytes with 6.0 (1.2–12.8) %, monocytes with 2.0 (0.0–6.0)%, and neutrophils with 2.0 (0.0–6.0)%. Nursehound Shark produced granulated thrombocytes, which were classified as granulocytes and represented 28.5 (12.4–39.7)% of all leukocytes. Median (RI) manual red blood cell and white blood cell counts were 177.50 (132.50–210.00) x 109 cells/l and 8.26 (5.24–14.23) x 109 cells/l, respectively. Median (RI) plasma chemistry values showed alkaline phosphatase 7.7 (4.2–13.0) U/l, aspartate aminotransferase 7.6 (3.3–17.1) U/l, blood urea nitrogen 281.6 (261.2–305.0) mmol/l, calcium 3.97 (3.59–4.47) mmol/l, total cholesterol 2.04 (1.02–3.91) mmol/l, chloride 233.0 (215.2–259.0) mmol/l, iron 3.79 (1.74–6.93) μmol/l, glucose 0.87 (0.47–1.44 mmol/l), potassium 3.8 (2.9–4.6) mmol/l, sodium 243.0 (227.7–271.0) mmol/l, phosphorus 1.58 (1.13–2.10) mmol/l, total protein 24.0 (20.0–35.0) g/l, and triglycerides 0.97 (0.49–3.35) mmol/l. Creatine kinase, gamma glutamyl transferase, and lactate dehydrogenase levels were below the instrument reading range.

Increased concentration of serum gamma-glutamyl transferase in ischemic stroke patients

BACKGROUND:

Stroke is responsible for the largest proportion of neurological disorders causing a significant morbidity. Gamma-glutamyl transferase (GGT) enzyme has an active involvement in atherosclerosis through its role in oxidative and inflammatory mechanisms. Recent evidence suggests that serum GGT is related to the risk and prognosis of cerebrovascular diseases.

METHODS:

A total of 200 patients (100 with acute ischemic stroke and 100 without stroke) were recruited from various medical wards and medical intensive care unit. Categorical variables were compared between two groups using Chi-squared test and odds ratio (OR). Independent sample t-test was used to see to compare mean GGT level of stroke patients with control.

RESULTS:

There was no statistical difference with respect to distribution of age groups (χ² = 1.25, P = 0.741) and gender (χ² = 2.678, P = 0.1018) between cases and controls. Mean age of stroke patients (mean [M] = 61.7, standard deviation [SD] = 13.8) did not differ from controls (M = 62.2, SD = 13.6), P = 0.80. The odds of suffering from diabetes were significantly higher in stroke patients than cases (OR = 2.25, P = 0.005). Independent sample t-test found a significant difference in serum GGT level between cases (M = 57.47, SD = 11.8) and control (M = 41.72, SD = 7.5), P ≤ 0.0001.

CONCLUSIONS:

Serum GGT was significantly higher in stroke patients than age-sex-matched nonstroke patients. Association remained significant in stroke patients irrespective of age, gender, and other risk factors. Stroke patients with diabetes, hypertension, dyslipidemia, obesity, and smoking had higher level serum GGT level than those without these risk factors. Prospective cohort studies can further explore the potential of GGT as a predictor of acute ischemic stroke.

Indirect estimation of reference intervals using first or last results and results from patients without repeated measurements

Objectives

Indirect methods for the estimation of Reference Limits (RLs) use large data pools stored in modern laboratory information’s systems. To avoid correlation between observations repeated results from each patient should be excluded. Some data pools obtained are anonymized, and thereafter the data cannot be re-identified. The effect of the procedure of data selection on the estimations is not investigated yet.

Methods

We considered four parameters. Data sets were enclosed from two sources: a university hospital and a laboratory primarily reflecting a patient population from medical practitioners. Four algorithms were used for data selection, which generate first, last, all and non-repeated values. RLs were estimated through these data sets and compared.

Results

This study showed the broader reference range estimated by indirect methods if using the whole data set compared to first/last values or non-repeated values.

Conclusions

The use of all data without a filtering step results in a significant bias whereas the choice of first or last values has nearly no impact. The exclusion of repeated measurements results in narrower RLs. This influence confine the use of anonymous data sets where filtering is impossible for the estimation of RLs by indirect methods.

Determining the association between repeatedly elevated serum gamma-glutamyltransferase levels and risk of respiratory cancer: A nationwide population-based cohort study

Background

Although elevated serum gamma‐glutamyltransferase (GGT) is a known indicator of increased risk of several cancers, the clinical value of repeated measurements of GGT has not been determined. Therefore, we aimed to investigate whether repeatedly elevated serum GGT levels are associated with the risk of respiratory cancer incidence.

Methods

We included participants who had undergone the Korean Health screening four times during 2009–2012 and had previously undergone four consecutive examinations. Those who were diagnosed with respiratory cancer before the date of examination were excluded. The participants obtained one GGT point if their GGT levels were in the highest quartile (the quartile 4 group). We analyzed the association between GGT points and respiratory cancer incidence by Cox proportional hazard models.

Results

During mean follow‐up of 6.39 ± 1.2 years, 3,559,109 participants were enrolled. Of them, 8,944 (0.34%) men and 1,484 (0.14%) women were newly diagnosed with respiratory cancer. In multivariate analysis adjusted for confounding factors, male participants with 4 GGT points had a significantly higher hazards of developing respiratory cancer than those with 0 GGT points (hazard ratio [HR]: 1.39; 95% confidence interval [CI]: 1.31–1.48). Among female, participants with the highest points of GGT also had sixfold increased risk of developing laryngeal cancer. However, no significant association was observed between GGT points and lung cancer incidence among women (HR: 0.95; 95% CI: 0.81–1.11).

Conclusion

Repeatedly elevated serum levels of GGT were associated with a higher risk of respiratory cancer incidence, especially in men. This finding suggests that physicians can identify a person with a higher risk of respiratory cancer through a simple repeated measurement of GGT.

The association of alcohol with circulating total fibrinogen and plasma clot density is mediated by fibrinogen and FXIII genotypes

Background

Alcohol consumption is associated with haemostasis and so may influence cardiovascular conditions. It is unknown whether the association of alcohol with total and γ’ fibrinogen concentrations, as well as clot structure, are modulated by fibrinogen and factor (F) XIII single nucleotide polymorphisms (SNPs).

Methods

Total fibrinogen, γ’ fibrinogen and clot properties of 2010 healthy Africans residing in South Africa were measured in relation to alcohol intake as well as its markers – gamma-glutamyltransferase (GGT), percentage carbohydrate deficient transferrin (%CDT), aspartate aminotransferase (AST), and alanine aminotransferase (ALT). Fourteen fibrinogen and two SNPs in the FXIII gene were genotyped to determine their influence.

Results

Alcohol intake and its markers correlated negatively with fibrinogen and clot lysis time (CLT) as well as with most of the clot properties. Percentage γ’ fibrinogen correlated positively with AST and negatively with alcohol intake. We then stratified for alcohol intake and found inverse associations between γ’ fibrinogen and both %CDT and GGT–CDT in consumers, but the positive association with AST remained only in abstainers. Alcohol intake and its markers modulated the influence of fibrinogen SNPs on total fibrinogen concentrations and the fibrinogen SNPs as well as an FXIII SNP on clot density (all p < 0.004).

Conclusion/s

We show for the first time that some individuals harbour certain genotypes that, in combination with alcohol consumption, might predispose or protect them from haemostatic factors that might lead to the development of cardiovascular disease. Studies are needed to clarify the mechanisms related to the interplay between alcohol and the gene variants observed here.

Diagnostic thresholds and performance of noninvasive fibrosis scores are limited by age in patients with chronic hepatitis B

AIM

We aimed at investigating the effects of age on the predictive performances of noninvasive fibrosis scores for significant fibrosis in patients with chronic hepatitis B (CHB).

METHODS

A total of 496 CHB patients who underwent liver biopsy were stratified into four age groups: ≤30, 31 to 40, 41 to 50, and ≥51 years. Receiver operating characteristic curves were used to evaluate the diagnostic performance of aspartate aminotransferase to platelet ratio index (APRI), fibrosis score-4 (Fib-4) and γ-glutamyl transpeptidase to platelet ratio (GPR) in different age groups.

RESULTS

The extent of fibrosis significantly increased with age, and the percentage of significant fibrosis (≥F2) was 21.3%, 29.0%, 38.5%, and 46.1%, respectively. All three scores displayed a moderate accuracy to diagnose significant fibrosis in overall patients. However, for patients with age ≤30 years, APRI, Fib-4, and GPR performed poorly with the AUROC of 0.567, 0.627 and 0.596, respectively. Furthermore, using the established cut-off values-1.45 for Fib-4, the sensitivity for significant fibrosis increased with age, from 14.8%, 38.1%, 74.5% to 97.87% in above age groups, respectively. To improve the diagnostic accuracy for significant fibrosis, the proposed low and high cut-off points for Fib-4 were 0.41 and 1.15 in ≤30 years, 0.8 and 1.59 in 31 to 40 years, 1.17 and 1.94 in 41 to 50 years, 1.76 and 3.10 in ≥ 51 years, respectively.

CONCLUSIONS

Age may influence the diagnostic thresholds and performance of APRI, Fib-4, and GPR for significant fibrosis in patients with CHB. In particular, these scores performed poorly for identifying significant fibrosis in younger patients (≤30 years).

Biological variables influencing the estimation of reference limits

Reference limits (RLs) are required to evaluate laboratory results for medical decisions. The establishment of RL depends on the pre-analytical and the analytical conditions. Furthermore, biological characteristics of the sub-population chosen to provide the reference samples may influence the RL. The most important biological preconditions are gender, age, chronobiological influences, posture, regional and ethnic effects. The influence of these components varies and is often neglected. Therefore, a list of biological variables is collected from the literature and their influence on the estimation of RL is discussed. Biological preconditions must be specified if RL are reported as well for directly as for indirectly estimated RL. The influence of biological variables is especially important if RL established by direct methods are compared with those derived from indirect techniques. Even if these factors are not incorporated into the estimation of RL, their understanding can assist the interpretation of laboratory results of an individual.

Assessing alcohol intake & its dose-dependent effects on liver enzymes by 24-h recall and questionnaire using NHANES 2001-2010 data

BACKGROUND

Alcohol is a significant component of the diet with dose-dependent risks and benefits. High doses of alcohol damage the liver and early symptoms of liver disease include changes in routinely assessed liver enzymes. Less is known regarding the mechanisms responsible for the benefits of moderate alcohol consumption, including their effects on the liver. The objectives of this study were to examine alcohol's dose-dependent effects on markers of liver function (alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma glutamyl transferase (GGT), and bilirubin), as well as to compare the different methods of assessing alcohol intake using NHANES 2001-2010 adult data (N = 24,807).

METHODS

Three methods were used to estimate alcohol intake from all volunteers: 24-h recall; the National Cancer Institute (NCI) method of usual intake; and a specific alcohol intake questionnaire.

RESULTS

Mean alcohol intake by 24-h recall, NCI method and questionnaire was 41.0 ± 0.8 g/d, 10.9 ± 0.2 g/d and 11.0 ± 0.2 g/d, respectively. Alcohol consumers had significantly lower levels of ALP and higher levels of AST, GGT and bilirubin compared to non-consumers (P < 0.01) and activities of ALT, AST, and GGT increased and of ALP decreased as alcohol intake increased, regardless of intake assessment method used. The most sensitive measure of alcohol consumption was GGT.

CONCLUSIONS

Since alcohol had a graded linear effect on several liver enzymes, including at low and moderate doses, benefits as well as risks of alcohol intake may be related to liver function. Since the NCI method and alcohol questionnaire yielded very similar alcohol intake estimates, this study cross-validated these methods and demonstrated the robustness of the NCI method for estimating intake of irregularly consumed foods.

Impacts of common factors of life style on serum liver enzymes

AIM: To investigate the impacts of gender, age and factors of life style (alcohol, overweight, coffee and smoking) on serum liver enzymes.

METHODS: Serum alanine aminotransferase (ALT) and gamma-glutamyltransferase (GGT) were measured from 6269 apparently healthy individuals (2851 men, 3418 women, mean age 45 ± 12 years, range 25-74 years) in a national cross-sectional health survey. All subjects underwent detailed clinical examinations and interviews including the amount and pattern of alcohol use, coffee consumption and smoking habits.

RESULTS: In this population with a mean ± SD alcohol consumption of 65 ± 105 g/wk and body mass index (BMI) of 26.1 ± 4.3 kg/m², both ALT and GGT were significantly influenced by alcohol use (P < 0.001) and BMI (P < 0.001), whereas smoking increased only GGT (P < 0.001). A significant effect of age on ALT was seen in men (P < 0.001) whereas not in women. Significant two-factor interactions of alcohol use in men were observed with age (ALT: P < 0.01; GGT: P < 0.001) and BMI (GGT: P < 0.05). For ALT, a significant interaction also occurred between BMI and age (P < 0.005). In contrast, women showed significant interactions of alcohol use with BMI (GGT: P < 0.05), smoking (GGT: P < 0.001), and coffee consumption (GGT: P < 0.001).

CONCLUSION: Life-style associated changes in liver enzymes may reflect health risks, which should be considered in the definition of normal limits for liver enzymes.

Do mismatches between pre- and post-natal environments influence adult physiological functioning?

Purpose

Mismatches between pre- and post-natal environments have implications for disease in adulthood. However, less is known about how this mismatch can affect physiological systems more generally, especially at younger ages. We hypothesised that mismatches between pre- and post-natal environments, as measured by the measures of birthweight and adult leg length, would be associated with poorer biomarker levels across five key physiological systems in young adults.

Methods

Data were collected from 923, 36 year-old respondents from the West of Scotland Twenty-07 Study. The biomarkers were: systolic blood pressure (sBP); forced expiratory volume (FEV₁); glycated haemoglobin (HbA_1c); glomerular filtration rate (eGFR); and gamma-glutamyltransferase (GGT). These biomarkers were regressed against pre-natal conditions (birthweight), post-natal conditions (leg length) and the interaction between pre- and post-natal measures. Sex, childhood socioeconomic position and adult lifestyle characteristics were adjusted for as potential effect modifiers and confounders, respectively.

Results

There were no associations between birthweight and leg length and sBP, FEV₁, HbA_1c, or GGT. Higher birthweight and longer leg length were associated with better kidney function (eGFR). However, there was no evidence for mismatches between birthweight and leg length to be associated with worse sBP, FEV₁, HbA_1c, eGFR or GGT levels (P>0.05).

Conclusions

Our hypothesis that early signs of physiological damage would be present in young adults given mismatches in childhood environments, as measured by growth markers, was not proven. This lack of association could be because age 36 is too young to identify significant trends for future health, or the associations simply not being present.

Evaluation of the oxidative stress in chronic alcoholics

AIM

The present study was conducted to assess the activity of Gamma Glutamyl Transferase (GGT) and its association with oxidative stress in alcoholics.

METHOD

Sixty male alcoholics with a history of alcohol abuse for more than five years were the subjects of this study. Twenty healthy male volunteers who matched in age and the socio-economic status, served as the control subjects.

RESULTS

GGT, reduced glutathione (GSH, a key intra-cellular antioxidant) and malondialdehyde (MDA, a marker of the oxidative stress) were assayed in the plasma of the two groups, and the results were statistically analyzed. The activity of the plasma GGT, known as a marker of Alcoholic Liver Disease (ALD); was significantly higher in the alcoholics as compared to that in the healthy controls.

CONCLUSION

There was a significant positive correlation between the enzyme activity and the plasma levels of MDA and this indicated that there was an increased release of this enzyme with enhanced oxidative damage, due to the generation of oxygen free radicals in the study group. There was a significantly increased level of MDA and a decrease in the level of GSH in the alcoholics as compared to those in the controls. Significant negative correlations between GGT and GSH, and between MDA and GSH were observed. The present study demonstrates that alcoholics have a compromised antioxidant defense system.

Individual and joint impacts of ethanol use, BMI, age and gender on serum gamma-glutamyltransferase levels in healthy volunteers

Excessive ethanol consumption, obesity and increasing age may all lead to increased serum levels of gamma-glutamyltransferase (GGT) enzyme, which plays a key role in the metabolism of extracellular reduced glutathione. However, as yet, the interactions between the various modulators of GGT activities have remained poorly defined. We analyzed data from 15,617 apparently healthy individuals (7254 men and 8363 women, mean age 46 ± 13 years, range 25–74 years) who participated in a national cross-sectional health survey in Finland between 1997 and 2007. All subjects underwent detailed clinical examinations and interviews, including the amount of ethanol use and smoking habits. GGT levels were measured from all participants, and the individual and joint impacts of the different study variables on GGT levels were assessed. Significant individual effects were noted for ethanol use (p < 0.001), body mass index (BMI) (p < 0.001), age (p < 0.001) and smoking (p < 0.001). In men, significant two-factor interactions occurred between ethanol use and age (p < 0.020). Among those over 40 years of age, ethanol consumption was found to be a stronger determinant of increased GGT levels than in men below 40 years, whereas in the latter age group, BMI was found to predominate. In women, a significant two-factor interaction occurred between ethanol and BMI (p = 0.010), whereas it did not with ethanol use and age. The data underscores the role of ethanol consumption and age as major determinants of increased GGT levels in men, whereas in women, a relatively stronger impact was noted for ethanol intake and BMI. In light of the ability of GGT enzyme to modulate crucial redox-sensitive functions, the present findings also support the use of GGT as a biomarker of oxidative stress.

A search for novel markers of alcohol abuse using magnetic beads and MALDI-TOF/TOF mass spectrometry

Objective markers are required to assess excessive alcohol consumption, which can lead to a various medical and social problems. In this study, we carried out serum peptidome analyses using the ClinProt(™) system, which consists of magnetic beads and MALDI-TOF/TOF MS, to find novel biomarkers of alcohol abuse in 16 chronic alcoholic patients that were hospitalized for a rehabilitation program. A total of 22 peaks were found to be significantly altered during abstinence. Out of these 22 peaks, 3 peaks that had an m/z of 3000 or less and substantial peak intensities were subjected to MS/MS analysis followed by a MASCOT search. The 1466 Da and the 1616 Da peptides were upregulated on admission and were identified as fragments of fibrinopeptide A and phosphorylated fibrinopeptide A, respectively. On the other hand, the 2660 Da peptide, which was downregulated on admission and increased during abstinence, was identified as a fragment of the fibrinogen α C chain. These peaks were not detectable by the SELDI-TOF MS ProteinChip(®) system analysis. The alterations in these peaks induced by alcohol abuse were also seen in γ glutamyltransferase nonresponders. These protein fragments may be additional biomarkers for excessive alcohol drinking.

Effect of age and gender on the relationship between alcohol consumption and serum GGT: time to recalibrate goals for normal ranges

AIMS

While serum gamma-glutamyltransferase (GGT) enzyme activity is a well established biomarker of excessive alcohol consumption and liver dysfunction, recent studies have also implicated it as a predictor of morbidity due to extrahepatic causes. Therefore, further information on the associations between ethanol intake and GGT activities in apparently healthy individuals appears warranted.

METHODS

Data on alcohol consumption and serum GGT activities were collected from 18,899 individuals (8807 men, 10,092 women), mean age 48 years and range 25-74 years, who participated in a national cross-sectional health survey. Alcohol use was assessed by detailed questionnaires and the study population was subsequently divided into subgroups according to age and gender. Body mass index and smoking were used as covariates in all analyses.

RESULTS

In men over 40 years, a reported regular consumption of 8 standard ethanol doses ('dose' = 12 g ethanol) or more per week was found to lead to a significant elevation in serum GGT activities, whereas those below 40 showed first significant changes not until the reported ethanol intake exceeded 14 doses per week. For women, the corresponding threshold levels were four and seven standard ethanol doses, respectively.

CONCLUSION

The data pertaining to the present population sample indicate that rather low levels of reported regular ethanol consumption lead to elevated levels of GGT and that age over 40 markedly enhances the impact of alcohol consumption on GGT activity. The present findings should form the basis for defining safe levels of ethanol consumption and in recalibrating goals for normal limits in the clinical use of GGT measurements.

Alcohol, metabolic risk and elevated serum gamma-glutamyl transferase (GGT) in Indigenous Australians

BACKGROUND

The interaction between overweight/obesity and alcohol intake on liver enzyme concentrations have been demonstrated. No studies have yet examined the interaction between metabolic syndrome or multiple metabolic risk factors and alcohol intake on liver enzymes. The aim of this study was to examine if alcohol consumption modifies the effect of metabolic risk on elevated serum GGT in Indigenous Australians.

METHODS

Data were from N = 2609 Indigenous Australians who participated in a health screening program in rural far north Queensland in 1999-2000 (44.5% response rate). The individual and interactive effects of metabolic risk and alcohol drinking on elevated serum GGT concentrations (>or=50 U/L) were analyzed using logistic regression.

RESULTS

Overall, 26% of the population had GGT>or=50 U/L. Elevated GGT was associated with alcohol drinking (moderate drinking: OR 2.3 [95%CI 1.6 - 3.2]; risky drinking: OR 6.0 [4.4 - 8.2]), and with abdominal obesity (OR 3.7 [2.5 - 5.6]), adverse metabolic risk cluster profile (OR 3.4 [2.6 - 4.3]) and metabolic syndrome (OR 2.7 [2.1 - 3.5]) after adjustment for age, sex, ethnicity, smoking, physical activity and BMI. The associations of obesity and metabolic syndrome with elevated GGT were similar across alcohol drinking strata, but the association of an adverse metabolic risk cluster profile with elevated GGT was larger in risky drinkers (OR 4.9 [3.7 - 6.7]) than in moderate drinkers (OR 2.8 [1.6 - 4.9]) and abstainers (OR 1.6 [0.9 - 2.8]).

CONCLUSIONS

In this Indigenous population, an adverse metabolic profile conferred three times the risk of elevated GGT in risky drinkers compared with abstainers, independent of sex and ethnicity. Community interventions need to target both determinants of the population's metabolic status and alcohol consumption to reduce the risk of elevated GGT.

The effect of long-term danazol prophylaxis on liver function in hereditary angioedema-a longitudinal study

BACKGROUND

Danazol is a drug most widely used for the prophylaxis of hereditary angioedema resulting from the deficiency of the C1-inhibitor. Potential hepatotoxic or liver tumor-inducing side effects of long-term danazol prophylaxis have been investigated during the follow-up of hereditary angioedema patients.

METHODS

Characteristic parameters of liver function (including bilirubin, GOT, GPT, gammaGT, total protein, ALP, LDH), as well as findings of viral serology screens and abdominal ultrasonography-determined during years 0 and 5 of follow-up of patient groups taking/not taking danazol-have been reviewed and analyzed comparatively.

RESULTS

From a population of 126 hereditary angioedema patients, 46 subjects taking danazol and another 46 not taking danazol fulfilled the inclusion criteria. Longitudinal follow-up did not reveal any clinically relevant difference between the liver function parameters determined in years 0 and 5 in the two groups. Abdominal ultrasound did not detect neoplastic or other potentially treatment-related alterations of the liver parenchyma. There were no discontinuations of treatment during the study.

CONCLUSIONS

Our results clearly suggest that, administered at the lowest effective dose, danazol does not induce liver injury in hereditary angioedema patients.

Statistical analysis of the associations between polymorphisms within aldehyde dehydrogenase 2 (ALDH2), and quantitative and qualitative traits extracted from a large-scale database of Japanese single-nucleotide polymorphisms (SNPs)

A scan of 4,190 single-nucleotide polymorphisms (SNPs) in 199 different genes using 38 different quantitative traits to search for associations between genotypes and phenotypes detected an association between the genotypes at rs671 of ALDH2 and gamma-glutamyltranspeptidase (gamma-GTP) levels. We examined the associations between five factors such as gender, age, rs671 genotype, alcohol-drinking habit, and serum gamma-GTP level and found that all pairs were associated except for the pair of rs671 genotype and gender and rs671 genotype and age. We further analyzed the data by both multiple regression and subgroup analyses and found that the associations between rs671 genotype and alcohol-drinking habit, alcohol-drinking habit and gamma-GTP level, gender and gamma-GTP, and age and gamma-GTP were independent of other factors. Conversely, the association between rs671 genotype and gamma-GTP level was dependent on alcohol-drinking habit. Associations between genetic and environmental factors will become a focus of medical and biological studies. Our study has shown that (1) a large sample size combined with a replication study is necessary to overcome the multiple-comparison problem, and (2) subgroup analysis along with logistic and linear multiple regression analysis may be useful to dissect a complicated relationship.

Obesity and the clinical use of serum GGT activity as a marker of heavy drinking

OBJECTIVE

Gamma-glutamyl transferase (GGT) is a widely used clinical marker of alcohol abuse. However, although obesity may also elevate serum GGT activities, the effects of overweight on the interpretation of GGT testing have remained poorly defined.

MATERIAL AND METHODS

GGT activities from 1147 moderate drinkers and 449 abstainers who were classified according to body mass index (BMI) were compared with those of 208 heavy drinkers admitted for detoxification.

RESULTS

GGT upper normal limits, defined based on normal weight abstainers (men 53 U/L; women 45 U/L) were lower than those based on moderate drinkers (men 68 U/L; women 50 U/L). The relative increases in GGT activities in male moderate drinkers with overweight (54%) or obesity (125%) exceeded the corresponding changes found in women (25% and 75%, respectively). The BMI-dependent variation on the sensitivity of GGT for correctly classifying heavy drinkers ranged from 29% to 67%. The rates of false-positive values in the subgroups from low to high BMI varied from 0% to 27%, respectively.

CONCLUSIONS

The data indicate that the diagnostic value of serum GGT testing could be improved by using reference data derived from databases of abstainers with normal weight or BMI-based categorization of reference ranges.

Combined metadoxine and garlic oil treatment efficaciously abrogates alcoholic steatosis and CYP2E1 induction in rat liver with restoration of AMPK activity

Alcoholic steatosis is the earliest and most common response to heavy alcohol intake, and may precede more severe forms of liver injury. Accumulation of fat, largely triglyceride, in hepatocytes results from the inhibition of fatty acid oxidation and excessive oxidative stress involving CYP2E1. This study evaluated the therapeutic effects of metadoxine, garlic oil or their combination on alcoholic steatosis. Feeding rats an alcohol-containing diet for 4 weeks elicited an increase in hepatic triglyceride content and induced CYP2E1. The concurrent administration of metadoxine and garlic oil (MG) to rats during the last week of the diet feeding efficaciously abrogated both fat accumulation and CYP2E1 induction as compared to the individual treatment at higher doses. Histopathology confirmed the ability of MG combination to inhibit lipid accumulation. Blood biochemistry verified improvement of liver function in rats treated with MG. Alcohol administration resulted in a decrease in AMP-activated protein kinase-alpha (AMPKalpha) phosphorylation, which was restored by MG treatments. Recovery of AMPK activity by MG was supported by an increase in acetyl-CoA carboxylase phosphorylation. Hepatic fatty acid synthase (FAS) expression was markedly decreased after alcohol consumption, which correlated with a decrease in AMPK activity and a commensurate increase in lipid content. Combined MG treatments caused restoration of the FAS level. These results demonstrate that the combination of MG effectively treats alcoholic steatosis with CYP2E1 inhibition, which may be associated with the recovery of AMPK activity, promising that the combination therapy may constitute an advance in the development of clinical candidates for alcoholic steatosis.

Biomarkers in alcoholism

Alcoholism ranks as one of the main current threats to the health and safety of people in most Western countries. Therefore, a high priority should be given to aims at reducing its prevalence through more effective diagnosis and early intervention. The need for objective methods for revealing alcohol abuse in its early phase has also been widely acknowledged. It is postulated here that the diagnosis of alcohol use disorders could be markedly improved by a more systematic use of specific questionnaires and laboratory tests, including blood ethanol, serum gamma-glutamyltransferase (GGT), carbohydrate-deficient transferrin (CDT), and mean corpuscular volume of erythrocytes (MCV). Recent research has provided new insights into the relationships between ethanol intake, biomarkers, and factors affecting their diagnostic validation, including gender, age, and the effects of moderate drinking and obesity. It appears that the concept of reference intervals for several ethanol-sensitive parameters in laboratory medicine needs to be revisited. CDT is currently the most specific marker of alcohol abuse, and when combined with GGT using a mathematically formulated equation a high sensitivity is reached without loss of assay specificity. Possible new biomarkers include minor ethanol metabolites (protein-acetaldehyde condensates and associated autoimmune responses, ethylglucuronide, and phosphatidylethanolamine), 5-hydroxytryptophol, and genetic markers although so far their routine applications have been limited.