A comparison of associations of alanine aminotransferase and gamma-glutamyltransferase with fasting glucose, fasting insulin, and glycated hemoglobin in women with and without diabetes

Combined effect of serum carcinoembryonic antigen and hepatic steatosis on new-onset ischemic heart disease among middle-aged and older Korean adults: a cohort study

Background

Carcinoembryonic antigen (CEA) is a commonly used tumor marker in cancer screening. However, it has also been associated with metabolic alterations. Hepatic steatosis, the accumulation of fat in liver cells, is associated with various cardiovascular risk factors. This study investigated the risk of ischemic heart disease (IHD) in individuals with elevated CEA levels, hepatic steatosis, and their co-occurrence.

Methods

The study cohort comprised 5,580 Korean adults who underwent health examinations between November 2006 and June 2010. Data regarding baseline CEA levels, hepatic steatosis status, and development of IHD were collected. Hepatic steatosis was defined as more than two findings: deep attenuation, vascular blurring, and increased liver echogenicity on abdominal ultrasound. Participants were divided into four groups based on their CEA and hepatic steatosis status: no hepatic steatosis and low CEA (group 1), no hepatic steatosis and elevated CEA (group 2), low CEA and hepatic steatosis (group 3), and elevated CEA and hepatic steatosis (group 4).

Results

A total of 226 (4.1%) participants developed IHD during the follow-up period. Participants with elevated CEA levels and hepatic steatosis (group 4) had the highest cumulative incidence of IHD in comparison to other groups (p < 0.001). The combined effect of elevated CEA levels and hepatic steatosis showed significantly greater area under the receiver operating characteristic curve than hepatic steatosis alone (p < 0.001). Furthermore, participants with elevated CEA and hepatic steatosis (group 4) had higher risk of developing IHD compared to those with low CEA and no hepatic steatosis (group 1) (hazard ratio: 1.63, 95% confidence interval: 1.04-2.55, p = 0.034).

Conclusion

Co-occurrence of elevated CEA levels and hepatic steatosis increases the risk of IHD. Comprehensive risk assessment is crucial to guide interventions and improve cardiovascular health in individuals with both the conditions.

Liver enzymes, alcohol consumption and the risk of diabetes: the Suita study

AIM

We aimed to investigate the combined impact of liver enzymes and alcohol consumption on the diabetes risk.

METHODS

Data on 5972 non-diabetic participants aged 30-79 years from the Suita study were analyzed. Diabetes incidence was surveyed every 2 years. Current daily alcohol consumption was defined as light drinking (< 23.0 g ethanol/day in men and < 11.5 g in women), moderate drinking (23.0-45.9 g and 11.5-22.9 g), and heavy drinking (≥ 46.0 g and ≥ 23.0 g). The nondrinkers category included both never-drinkers and former drinkers.

RESULTS

During the median follow-up of 13 years, 597 incident diabetes cases were diagnosed. Higher levels of γ-glutamyltransferase (GGT), alanine aminotransferase (GPT), and aspartate aminotransferase (GOT) were associated with an increased diabetes risk, and current light drinkers had a lower risk of diabetes than nondrinkers. No sex differences were observed in these associations. Compared to nondrinkers having the lowest quartiles of liver enzymes, nondrinkers and current moderate/heavy drinkers having the highest quartiles had an increased risk of diabetes. However, no association was observed for current light drinkers having the highest quartiles of liver enzymes; the multivariable hazard ratios (95% CIs) in current light drinkers with the highest quartile of liver enzymes were 1.27 (0.68-2.37) for GGT, 1.05 (0.59-1.89) for GPT, and 0.76 (0.40-1.47) for GOT, respectively.

CONCLUSION

High liver enzymes were associated with an increased diabetes risk. No increased diabetes risk was observed in current light drinkers, even in these who had high levels of liver enzymes.

Near-infrared (NIR) fluorescence-emitting small organic molecules for cancer imaging and therapy

We discuss recent advances made in the development of NIR fluorescence-emitting small organic molecules for tumor imaging and therapy.

Review on the recent progress in the development of fluorescent probes targeting enzymes

Enzymes are very important for biological processes in a living being, performing similar or multiple tasks in and out of cells, tissues and other organisms at a particular location. The abnormal activity of particular enzyme usually caused serious diseases such as Alzheimer's disease, Parkinson's disease, cancers, diabetes, cardiovascular diseases, arthritis etc. Hence, nondestructive and real-time visualization for certain enzyme is very important for understanding the biological issues, as well as the drug administration and drug metabolism. Fluorescent cellular probe-based enzyme detectionin vitroandin vivohas become broad interest for human disease diagnostics and therapeutics. This review highlights the recent findings and designs of highly sensitive and selective fluorescent cellular probes targeting enzymes for quantitative analysis and bioimaging.

Joint Effect of Hepatic Steatosis and Alanine Aminotransferase Within the Normal Range on Incident Ischemic Heart Disease: A Prospective Study in Koreans

Purpose

Hepatic steatosis has been associated with some cardiovascular risks. Increased alanine aminotransferase (ALT) was suggested to be linked to endothelial dysfunction. We prospectively investigated the joint effect of hepatic steatosis and elevated ALT within the normal range on incident ischemic heart disease (IHD) risk as an extrahepatic complication.

Patients and Methods

We assessed 16,541 participants without diabetes using data from a health risk assessment study (HERAS) and Korean Health Insurance Review and Assessment (HIRA) data. We defined elevated ALT within the normal range as 30-40 IU/L in men and 23-40 IU/L in women, according to previous Korean epidemiological data. We prospectively assessed hazard ratios (HRs) with 95% confidence intervals (CIs) for IHD using multivariate Cox proportional hazards regression models over a 50-month period after the baseline survey.

Results

During the follow-up period, 368 (2.2%) participants developed IHD. Compared to the group with no hepatic steatosis and controlled ALT, the HRs for IHD were 1.68 (95% CI, 1.16-2.42) in the group with hepatic steatosis and elevated ALT after adjusting for confounding variables.

Conclusion

Hepatic steatosis and elevated ALT levels within the normal range may jointly affect the development of IHD among nondiabetic adults. This indicates that lifestyle advice and vascular health management should be recommended among individuals with hepatic steatosis and elevated ALT, even if it falls within the normal range.

Elevated Alanine Aminotransferase in Early Pregnancy and Subsequent Development of Gestational Diabetes and Preeclampsia

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is now considered as a hepatic manifestation of metabolic syndrome and elevated alanine aminotransferase (ALT) is commonly related to NAFLD in the absence of viral hepatitis or alcohol abuse. Previous studies have indicated that elevated ALT is associated with diabetes or metabolic syndrome in adults, but the clinical significance of ALT or NAFLD in pregnancy has not been well determined. The objective of this study was to determine the association between elevated ALT in early pregnancy and the development of gestational diabetes or preeclampsia in late pregnancy.

METHODS

In this retrospective cohort study, pregnant women who met the following inclusion criteria were included: 1) singleton pregnancy; 2) ALT levels were measured in antenatal outpatient clinic at 4-20 weeks of gestation; 3) patients were screened for gestational diabetes and delivered in Cheil General Hospital and Women's Healthcare Center. Cases with viral hepatitis or other liver diseases were excluded. The early ALT levels were divided into two groups (normal ALT [≤ 95th percentile] and elevated ALT [> 95th percentile]), and the frequency of gestational diabetes and preeclampsia was compared between the two groups of cases. Gestational diabetes was screened and diagnosed by two-step procedure (50 g oral glucose challenge test and 75 g glucose challenge test with World Health Organization [WHO] criteria).

RESULTS

A total of 2,322 women met the inclusion criteria. Cases with elevated early ALT levels (> 95th percentile) had a higher risk of subsequent gestational diabetes and preeclampsia (gestational diabetes by WHO criteria, 2.1% in normal ALT vs. 6.5% in elevated ALT, P < 0.01; preeclampsia, 1.0% in normal ALT vs. 4.1% in elevated ALT, P < 0.05). This relationship between elevated ALT and increased risk of gestational diabetes/preeclampsia remained significant after adjustment for maternal age and pre-pregnancy body mass index.

CONCLUSION

Elevated unexplained ALT in early pregnancy is associated with the risk of subsequent development of gestational diabetes and preeclampsia in late pregnancy.

A "Double-Locked" and enzyme-activated molecular probe for accurate bioimaging and hepatopathy differentiation

Molecular probes activated by a single enzyme have been extensively used in bioimaging and disease diagnosis; however, imaging and identification in an accurate manner remains a challenge for such probes. Here, based on the specificity of enzyme recognition, we engineered a "double-locked" and enzyme-activated molecular probe (NML) for accurate bioimaging and hepatopathy differentiation. Triggered by the successive reactions with leucine aminopeptidase (LAP, first "key") and monoamine oxidase (MAO, second "key"), the emissive fluorophore (NF) was released. NML can be activated only in the presence of both LAP and MAO and can be silenced when either enzyme is inhibited. Benefiting from the "double-locked" strategy, NML showed higher accuracy for imaging of drug-induced liver injury (DILI) than the "single-locked" probe. With serum testing, NML showed significant differences in mouse models of both CCl₄-induced liver cirrhosis and DILI. Significantly, NML can be applied to accurately distinguish serum samples from clinical patients with different hepatopathies. Our smart molecular probe may hold great potential for hepatopathy diagnosis and clinical transformation.

A novel triarylboron based ratiometric fluorescent probe for in vivo targeting and specific imaging of cancer cells expressing abnormal concentration of GGT

Abnormal expression of γ-glutamyltranspeptidase (GGT) in living organisms is closely associated with tumorigenesis. However, few reported fluorescence probes can specifically respond to abnormal concentration of GGT. Here, by functionalizing triarylboron moiety with three GGT-specific substrate (GSH) units, a novel fluorescence probe, TAB-3-GSH, was developed for detecting GGT. The results showed that TAB-3-GSH selectively responds to abnormally high levels of GGT (100-1000 U/L) rather than to normal GGT levels (<100 U/L) with ratiometric readout, since the amide linkage can be further hydrolyzed under high GGT levels. TAB-3-GSH was also capable of differentiating GGT-overexpressing ovarian cancer cells from normal cells, because of an improvement in the probe's cell membrane permeability upon reaction with GGT. Moreover, the probe could achieve selective imaging of SKOV-3 tumor site in xenograft mice model. Thus, TAB-3-GSH is a promising probe for tumor targeting in vivo.

Comparison between Roche Integra 400 plus and Abbott Architect ci8200 in Alanine aminotransferase assay

Background

The aim of this work is to present the results of a comparative study between the ALT assay on Integra 400 plus Roche Diagnostic versus Architect ci8200 of Abbott Diagnostic.

Methods

A total of 200 patients hospitalized in the various departments of the university hospital Mohammed VI of Oujda were prospectively tested on two systems: Abbott Architect ci8200 and Roche Integra 400 plus. Both analyzers use the spectrophotometric technique by coupling the transamination reaction to the oxidation-reduction reaction at NAD. The agreement of the results between the different techniques was evaluated using the Bland-Altman difference diagram and the Passing-Bablok and Deming regression line.

Results

There was a high concordance between the two assays: the equation of the Passing-Bablok line is YArchitect ​= ​−0,5625 ​+ ​0,9917 XIntegra with a correlation coefficient r² = 0.999. The Bland-Altman diagram shows that the mean bias between the two methods is of the order of 1.1 IU/L and the difference between the ALT measurements by Architect and Integra is in the range of −1.4 to 3.6.

Conclusion

Our study shows a high correlation of the ALT assay results between the architect ci8200 and Integra 400 plus.

A novel mitochondrial-targeting near-infrared fluorescent probe for imaging γ-glutamyl transpeptidase activity in living cells

γ-Glutamyl transpeptidase (GGT) plays an essential role in regulating cellular glutathione and cysteine homeostasis, and its abnormal elevation is associated with different diseases including cancers. Here a novel mitochondrial-targeting near-infrared fluorescent probe was designed for GGT by conjugating glutamate acid to a newly synthesized amine hemicyanine fluorophore. The fluorescent probe was initially non-emissive due to the formation of an amide bond which destroyed the electronic-donating ability of the amine moiety and disrupted the push-pull structure. GGT-mediated cleavage of the γ-glutamyl bond regenerated the initial fluorophore with distinct intramolecular charge transfer (ICT) and activated the fluorescence signal. The fluorescent probe displayed a linear relationship to the concentration of GGT in the range of 1.0-90 U L-1, with an estimated limit of detection (LOD) of 0.4 U L-1. Its ability to target and image mitochondrial GGT activity was demonstrated in living cells with high specificity and fast response. We believe our near-infrared fluorescent probe could have great potential in imaging mitochondrial GGT activity and elucidating GGT-associated pathological consequences in living cells and even small animal models.

Ideal cardiovascular health associated with fatty liver: Results from a multi-ethnic survey

BACKGROUND AND AIMS

Little is known about the role of liver enzymes as predictors of non-liver-related morbidity and mortality. The ideal cardiovascular health (CVH) score proposed by the American Heart Association (AHA) can be used to predict mortality and morbidity. We investigated the association of the CVH score with liver enzymes and the risk of non-alcoholic fatty liver disease (NAFLD) among US adults.

METHODS

By using the National Health and Nutrition Examination Survey database (cross-sectional), the CVH score was calculated as meeting ideal levels of the following components: 4 behaviors (smoking, body mass index, physical activity and diet adherence) and 3 factors (total cholesterol, blood pressure and fasting glucose).

RESULTS

Individuals with a higher CVH score ("better CVH") had a more favorable profile of liver biomarkers. Adjusted (for age, gender, race, poverty to income ratio, education, marital status and alcohol intake) linear regression indicated significant and negative associations between liver biomarkers and CVH score: (β = -0.069, p < 0.001) for alanine aminotransferase, (β = -0.095, p < 0.001), aspartate aminotransferase, (β = -0.067, p < 0.001), alkaline phosphatase and (β = -0.125, p < 0.001) and fatty liver index. In the logistic regression, with the same confounders, individuals with a higher CVH score had 12% less likelihood of NAFLD compared with those with a lower score. Furthermore, each CVH metric separately was inversely linked to the risk of NAFLD.

CONCLUSIONS

For the first time among US adults, our findings shed light on the role CVH on liver biomarkers.

Targeted Delivery of a γ-Glutamyl Transpeptidase Activatable Near-Infrared-Fluorescent Probe for Selective Cancer Imaging

The noninvasive and specific detection of cancer cells in living subjects has been essential for the success of cancer diagnoses and treatments. Herein, we report a strategy of combining an α_vβ₃-integrin-receptor-targetable ligand, c-RGD, with the γ-glutamyl transpeptidase (GGT)-recognizable substrate, γ-glutamate (γ-Glu), to develop a tumor-targeting and GGT-activatable near-infrared (NIR)-fluorescent probe for the noninvasive imaging of tumors in living mice. We demonstrated that the probe's fluorescence was off initially, but when the γ-Glu in the probe was specifically cleaved by GGT, the fluorescent product was released and could be selectively taken up by U87MG-tumor cells via α_vβ₃-receptor-mediated endocytosis. Remarkably, enhanced intracellular NIR fluorescence distributed mainly in the lysosomes was observed in the tumor cells only, showing that the probe was capable of differentiating the tumor cells from the GGT-positive, α_vβ₃-deficient normal cells. Moreover, the probe also showed a high selectivity for the real-time and noninvasive detection of GGT activity in xenograft U87MG tumors following iv administration. This study reveals the advantage of using a combination of receptor-mediated cell uptake and molecular-target-triggered activation to design molecular probes for improved cancer imaging, which could facilitate effective cancer diagnoses.

Dual-channel near-infrared fluorescent probe for real-time tracking of endogenous γ-glutamyl transpeptidase activity

We developed a curcuminoid difluoroboron-based fluorescent probe for tracking endogenous GGT activity with dual-channel light-up near-infrared (NIR) imaging.

Ideal cardiovascular health predicts lower risk of abnormal liver enzymes levels in the Chilean National Health Survey (2009-2010)

High levels of gamma glutamyltransferase (gamma-GT) and alanine aminotransferase (ALT), as well as fatty liver index (FLI) has been associated with higher cardiovascular disease risk factors in adults. The aim of this study was to examine the relationship between gamma-GT, ALT, and fatty liver index FLI levels across a gradient number of ideal cardiovascular health metrics in a representative sample of adults from the Chilean National Health Survey 2009-2010. Data from 1,023 men and 1,449 women (≥ 15 years) from the Chilean Health Survey 2009-2010 were analyzed. Ideal cardiovascular health was defined as meeting ideal levels of the following components: four behaviours (smoking, body mass index, physical activity and diet adherence) and three factors (total cholesterol, blood pressure and fasting glucose). Adults were grouped into three categories according to their number of ideal cardiovascular health metrics: ideal (5-7 metrics), intermediate (3-4 metrics), and poor (0-2 metrics). Blood levels of gamma-GT and ALT were measured and the FLI was calculated. A higher number of ideal cardiovascular health index metric was associated with lower gamma-GT, ALT and FLI (p from trend analysis <0.001). Also, adults meeting at least 3-4 metrics were predicted less likely to have prevalence of abnormal levels of gamma-GT and FLI (p<0.001) compared to adults who met only 0-2 metrics. These findings reinforce the usefulness of the ideal cardiovascular health metrics proposed by the American Heart Association as a tool to identify target subjects and promote cardiovascular health in South-American adults.

Elevated Liver Enzymes and Mortality in Older Individuals: A Prospective Cohort Study

AIM OF THE STUDY

The aim of the study was to determine the excess risk of all-cause and cardiovascular mortality in older people with elevated liver enzymes [alanine transaminase (ALT) and gamma glutamyltransferase (GGT)].

METHODS

We utilized data from a large, prospective, population based study of 2061 people aged 50 to 99 years with linkage to a National Death Registry. Participants were categorized as having elevated liver enzymes using standard thresholds (for males, GGT>51 and ALT>40 IU/L, and GGT>33 and ALT>31 IU/L for females). Adjusted Cox proportional hazards models assessed the association of elevated liver enzymes and mortality with long duration follow-up.

RESULTS

Over a median follow-up of 10 years (20,145 person years), 701 people died, including 203 (34%) from cardiovascular disease. Cox regression models adjusted for sex, age, smoking, and alcohol intake indicated that people with elevated liver enzymes had an increased risk of all-cause mortality that was modified by age (test for interaction P=0.01). Age-stratified analyses demonstrated no increased risk at younger ages [age 59 y and below; hazard ratio (HR): 0.46; 95% confidence interval, 0.06-3.49], but increased risk with age; age 60 to 69, HR: 1.05 (0.53-2.07), age 70 to 79 years, HR: 1.54 (0.81 to 2.93), and age 80 years and above, HR: 3.53 (1.55 to 8.04). Similarly, the risk of cardiovascular mortality with elevated liver enzymes was also modified by, and increased with age (test for interaction P=0.02); age 70 to 79, HR: 3.15 (1.37 to 7.23), age 80 years and above, HR: 6.86 (2.44 to 19.30).

CONCLUSIONS

In community-dwelling elderly persons, an elevation in both ALT and GGT are associated with an excess risk of all-cause and cardiovascular mortality which increases with age.

High Liver Enzyme Concentrations are Associated with Higher Glycemia, but not with Glycemic Variability, in Individuals without Diabetes Mellitus

BACKGROUND

Elevated concentrations of liver enzymes have been associated with an increased risk of developing type 2 diabetes mellitus. However, it remains unclear to which specific aspects of diurnal glucose metabolism these associate most. We aimed to investigate the associations between liver enzyme concentrations and 24 h-glucose trajectories in individuals without diabetes mellitus from three independent cohorts.

METHODS

This cross-sectional study included 436 participants without diabetes mellitus from the Active and Healthy Aging Study, the Switchbox Study, and the Growing Old Together Study. Fasting blood samples were drawn to measure gamma-glutamyltransferase (GGT), alanine transaminase, and aspartate transaminase. Measures of glycemia (e.g., nocturnal and diurnal mean glucose levels) and glycemic variability (e.g., mean amplitude of glucose excursions) were derived from continuous glucose monitoring. Analyses were performed separately for the three cohorts; derived estimates were additionally meta-analyzed.

RESULTS

After meta-analyses of the three cohorts, elevated liver enzyme concentrations, and specifically elevated GGT concentrations, were associated with higher glycemia. More specific, participants in the highest GGT tertile (GGT ≥37.9 U/L) had a 0.39 mmol/L (95% confidence interval: 0.23, 0.56) higher mean nocturnal glucose (3:00 to 6:00 a.m.) and a 0.23 mmol/L (0.10, 0.36) higher diurnal glucose (6:00 to 0:00 a.m.) than participants in the lowest GGT tertile (GGT <21.23 U/L). However, elevated liver enzyme concentrations were not associated with a higher glycemic variability.

CONCLUSION

Though elevated liver enzyme concentrations did not associate with higher glycemic variability in participants without diabetes mellitus, specifically, elevated GGT concentrations associated with higher glycemia.

Prevalence of elevated alanine transaminase in Australia and its relationship to metabolic risk factors: A cross-sectional study of 9,447 people

BACKGROUND AND AIM

Elevated alanine transaminase (ALT) is a strong predictor of metabolic syndrome, but there are few data from the Australian population. We aimed to determine the prevalence of elevated ALT and association with metabolic risk factors.

METHODS

In this cross-sectional study including adult participants (N = 9,447) from a nationwide, population-based survey, we assessed the prevalence of elevated ALT [defined as ≥ 40 IU/L (men) and ≥ 30 IU/L (women) as baseline, and ALT as ≥ 30 IU/L (men) and ≥ 19 IU/L (women) as lower threshold], distribution of metabolic risk factors, and independent predictors of elevated ALT in logistic regression models. Analyses were weighted to the population with population weights.

RESULTS

Elevated ALT levels were found in 11.2% of the Australian population. People with elevated ALT were younger (43 vs 46 yrs) with more truncal adiposity (100 vs 91 cm), higher pro-atherogenic lipids and glucose and exercised less (120 vs 160 min per week, P < 0.05 for all analyses). Regression analyses indicated that younger age, male sex, diabetes, triglycerides, apolipoprotein B, and waist circumference were independent predictors of elevated ALT. The population attributable fraction of elevated ALT due to truncal obesity was estimated at 47%.

CONCLUSION

These data demonstrate a high prevalence of elevated ALT in the general population that is closely associated with metabolic risk factors. Individuals with elevated ALT should be evaluated for co-existent metabolic disorders.

An efficient two-photon fluorescent probe for measuring γ-glutamyltranspeptidase activity during the oxidative stress process in tumor cells and tissues

We have developed a novel TP excited fluorescent probe for GGT detection and bioimaging in an oxidative stress model in living cells and tissues.

ACG Clinical Guideline: Evaluation of Abnormal Liver Chemistries

Clinicians are required to assess abnormal liver chemistries on a daily basis. The most common liver chemistries ordered are serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase and bilirubin. These tests should be termed liver chemistries or liver tests. Hepatocellular injury is defined as disproportionate elevation of AST and ALT levels compared with alkaline phosphatase levels. Cholestatic injury is defined as disproportionate elevation of alkaline phosphatase level as compared with AST and ALT levels. The majority of bilirubin circulates as unconjugated bilirubin and an elevated conjugated bilirubin implies hepatocellular disease or cholestasis. Multiple studies have demonstrated that the presence of an elevated ALT has been associated with increased liver-related mortality. A true healthy normal ALT level ranges from 29 to 33 IU/l for males, 19 to 25 IU/l for females and levels above this should be assessed. The degree of elevation of ALT and or AST in the clinical setting helps guide the evaluation. The evaluation of hepatocellular injury includes testing for viral hepatitis A, B, and C, assessment for nonalcoholic fatty liver disease and alcoholic liver disease, screening for hereditary hemochromatosis, autoimmune hepatitis, Wilson's disease, and alpha-1 antitrypsin deficiency. In addition, a history of prescribed and over-the-counter medicines should be sought. For the evaluation of an alkaline phosphatase elevation determined to be of hepatic origin, testing for primary biliary cholangitis and primary sclerosing cholangitis should be undertaken. Total bilirubin elevation can occur in either cholestatic or hepatocellular diseases. Elevated total serum bilirubin levels should be fractionated to direct and indirect bilirubin fractions and an elevated serum conjugated bilirubin implies hepatocellular disease or biliary obstruction in most settings. A liver biopsy may be considered when serologic testing and imaging fails to elucidate a diagnosis, to stage a condition, or when multiple diagnoses are possible.

Sex influenced association of directly measured insulin sensitivity and serum transaminase levels: Why alanine aminotransferase only predicts cardiovascular risk in men?

Background

Non alcoholic fatty liver disease (NAFLD) is an independent cardiovascular (CV) risk factor which is closely associated with insulin resistance measured by both direct or indirect methods. Gender specific findings in the relationship between alanine aminotransferase (ALT) and CV disease, the prevalence of NAFLD and type 2 diabetes (T2DM) have been published recently.

The aim of the present study was to explore the gender aspects of the association between insulin sensitivity, liver markers and other metabolic biomarkers in order to elucidate the background behind the sex influenced difference in both NAFLD, T2DM and their association with CV risk.

Patients and methods

158 female (47 normal and 111 impaired glucose intolerant) and 148 male (74 normal and 74 impaired glucose tolerant) subjects were included (mean age: 46.5 ± 8.31 vs. 41.6 ± 11.3, average Hba1c < 6.1 %, i.e. prediabetic population, drug naive at the time of the study). Subjects underwent a hyperinsulinemic normoglycemic clamp to determine muscle glucose uptake (M₃), besides liver function tests and other fasting metabolic and anthropometric parameters were determined.

Results

Significant bivariate correlations were found between clamp measured M₃ and all three liver enzymes (ALT, aspartate aminotransferase and gamma-glutamyl transferase) in both sexes. When data were adjusted for possible metabolic confounding factors correlations ceased in the male population but stayed significant in the female group. Feature selection analysis showed that ALT is an important attribute for M₃ in the female but not in male group (mean Z: 3.85 vs. 0.107). Multiple regression analysis confirmed that BMI (p < 0.0001) and ALT (p = 0.00991) significantly and independently predicted clamp measured muscle glucose uptake in women (R² = 0.5259), while in men serum fasting insulin (p = 0.0210) and leptin levels (p = 0.0294) but none of the liver enzymes were confirmed as significant independent predictors of M₃ (R² = 0.4989).

Conclusion

There is a gender specific association between insulin sensitivity, metabolic risk factors and liver transaminase levels. This might explain the sex difference in the predictive role of ALT elevation for CV disease. Moreover, ALT may be used as a simple diagnostic tool to identify insulin resistant subjects only in the female population according to our results.

Glycated Hemoglobin is a Better Predictor than Fasting Glucose for Cardiometabolic Risk in Non-diabetic Korean Women

This study aimed to investigate if glycated hemoglobin (Hgb_A1C) as compared to fasting blood glucose is better for reflecting cardiometabolic risk in non-diabetic Korean women. Fasting glucose, Hgb_A1C and lipid profiles were measured in non-diabetic women without disease (n = 91). The relationships of fasting glucose or Hgb_A1C with anthropometric parameters, lipid profiles, and liver and kidney functions were analyzed. Both fasting glucose and Hgb_A1C were negatively correlated with HDL-cholesterol (r = -0.287, p = 0.006; r = -0.261, p = 0.012), and positively correlated with age (r = 0.202, p = 0.008; r = 0.221, p = 0.035), waist circumference (r = 0.296, p = 0.005; r = 0.304, p = 0.004), diastolic blood pressure (DBP) (r = 0.206, p = 0.050; r = 0.225, p = 0.032), aspartate transaminase (AST) (r = 0.237, p = 0.024; r = 0.368, p < 0.0001), alanine transaminase (ALT) (r = 0.296, p = 0.004; r = 0.356, p = 0.001), lipid profiles including triglyceride (r = 0.372, p < 0.001; r = 0.208, p = 0.008), LDL-cholesterol (r = 0.315, p = 0.002; r = 0.373, p < 0.0001) and total cholesterol (r = 0.310, p = 0.003; r = 0.284, p = 0.006). When adjusted for age and body mass index, significant relationships of DBP (r = 0.190, p = 0.049), AST (r = 0.262, p = 0.018), ALT (r = 0.277, p = 0.012), and HDL-cholesterol (r = -0.202, p = 0.049) with Hgb_A1C were still retained, but those with fasting glucose disappeared. In addition, the adjusted relationships of LDL-cholesterol and total cholesterol with Hgb_A1C were much greater than those with fasting glucose. These results suggest that glycated hemoglobin may be a better predictor than fasting glucose for cardiometabolic risk in non-diabetic Korean women.

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.

Surrogate index for insulin sensitivity composed of factors not using glucose and insulin in Japanese patients with diabetes

INTRODUCTION

  The aim of the present study is to propose a novel index of insulin sensitivity instead of homeostasis model assessment of insulin resistance (HOMA-IR), which has a fundamental limitation of validity when applied to subjects with lower insulin secretions or high fasting plasma glucose (FPG) levels.

MATERIALS AND METHODS

  A total of 25 apparently healthy subjects and 24 patients with type 2 diabetes participated in the study. We assessed relationships of glucose infusion rate (GIR), obtained by using the euglycemic hyperinsulinemic glucose clamp technique, with other measurements of metabolic and anthropometric parameters.

RESULTS

  In multiple regression analysis, a model including log-transformed (log) triglyceride/log high-density lipoprotein cholesterol and waist circumference as predictive variables showed the strongest contribution rate to explain GIR as an outcome variable (R (2) = 0.710). The validity of estimated GIR (EGIR) calculated from the regression equation composed of these factors was further tested in another group of patients including type 1, type 2 and pancreatic diabetes in whom HOMA-IR could not be used as a result of either high FPG or low fasting insulin level, or both. Even in those patients, EGIR showed a good positive relationship with measured GIR (r = 0.681, P < 0.0001).

CONCLUSIONS

  The proposed index without HOMA-IR can adequately show insulin sensitivity in Japanese diabetic patients, even in cases with the limitation of HOMA-IR application. (J Diabetes Invest, doi: 10.1111/j.2040-1124.2010.00076.x, 2010).

A new strategy for early diagnosis of type 2 diabetes by standard-free, label-free LC-MS/MS quantification of glycated peptides

The early diagnosis of diabetes, one of the top three chronic incurable diseases, is becoming increasingly important. Here, we investigated the applicability of an (18)O-labeling technique for the development of a standard-free, label-free liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the early diagnosis of type 2 diabetes mellitus (T2DM). Rather than attempting to identify quantitative differences in proteins as biomarkers, glycation of the highest abundance protein in human plasma, human serum albumin (HSA), was monitored through quantitative analysis of HSA characteristic peptides using the (18)O-labeling technique. Eight glucose-sensitive peptides and one glucose-insensitive peptide were discovered. The glucose-insensitive peptide served as the internal standard, and a standard-free, label-free LC-MS/MS method was developed. This method was then used to select putative biomarkers for T2DM in a clinical trial with 389 human plasma samples. As a result, three of the eight glucose-sensitive peptides (FKDLGEENFK, LDELRDEGK, and KVPQVSTPTLVEVSR) were selected and could be used as potential biomarkers for the early diagnosis of T2DM.

Oral probiotic microcapsule formulation ameliorates non-alcoholic fatty liver disease in Bio F1B Golden Syrian hamsters

The beneficial effect of a microencapsulated feruloyl esterase producing Lactobacillus fermentum ATCC 11976 formulation for use in non-alcoholic fatty liver disease (NAFLD) was investigated. For which Bio F1B Golden Syrian hamsters were fed a methionine deficient/choline devoid diet to induce non-alcoholic fatty liver disease. Results, for the first time, show significant clinical benefits in experimental animals. Examination of lipids show that concentrations of hepatic free cholesterol, esterified cholesterol, triglycerides and phospholipids were significantly lowered in treated animals. In addition, serum total cholesterol, triglycerides, uric acid and insulin resistance were found to decrease in treated animals. Liver histology evaluations showed reduced fat deposits. Western blot analysis shows significant differences in expression levels of key liver enzymes in treated animals. In conclusion, these findings suggest the excellent potential of using an oral probiotic formulation to ameliorate NAFLD.

Association of Alanine Aminotransferase Levels (ALT) with the Hepatic Insulin Resistance Index (HIRI): a cross-sectional study

BACKGROUND

The association between serum alanine aminotransferase (ALT) levels and hepatic insulin resistance (IR) has been evaluated with the hyperinsulinemic-euglycemic clamp. However, there is no information about the association of ALT with the Hepatic Insulin Resistance Index (HIRI). The aim of this study was to evaluate the association between serum ALT levels and HIRI in subjects with differing degrees of impaired glucose metabolism.

METHODS

This cross-sectional study included subjects that had an indication for testing for type 2 diabetes mellitus (T2DM) with an oral glucose tolerance test (OGTT). Clinical and biochemical evaluations were carried out including serum ALT level quantification. HIRI was calculated for each participant. Correlation analyses and lineal regression models were used to evaluate the association between ALT levels and HIRI.

RESULTS

A total of 324 subjects (37.6% male) were included. The mean age was 40.4 ± 14.3 years and the mean body mass index (BMI) was 32.0 ± 7.3 kg/m2. Individuals were divided into 1 of 5 groups: without metabolic abnormalities (n = 113, 34.8%); with the metabolic syndrome (MetS, n = 179, 55.2%), impaired fasting glucose (IFG, n = 85, 26.2%); impaired glucose tolerance (IGT, n = 91, 28.0%), and T2DM (n = 23, 7.0%). The ALT (p < 0.001) and HOMA2-IR (p < 0.001) values progressively increased with HIRI quartiles, while ISI-Matsuda (p < 0.001) progressively decreased. After adjustment for sex, age, and BMI, we identified a significant correlation between HIRI and ALT in persons with the MetS (r = 0.22, p = 0.003), IFG (r = 0.33, p < 0.001), IGT (r = 0.37, p < 0.001), and T2DM (r = 0.72, p < 0.001). Lineal regression analysis adjusting for age, HDL-C, TG and waist circumference (WC) showed an independent association between ALT and HIRI in subjects with the MetS (beta = 0.07, p = 0.01), IFG (beta = 0.10, p = 0.02), IGT (beta = 0.09, p = 0.007), and T2DM (beta = 0.31, p = 0.003). This association was not identified in subjects without metabolic abnormalities.

CONCLUSIONS

ALT levels are independently associated with HIRI in subjects with the MetS, IFG, IGT, and T2DM. The ALT value in these subjects may be an indirect parameter to evaluate hepatic IR.

Accuracy of b-GGT fraction for the diagnosis of non-alcoholic fatty liver disease

BACKGROUND

Serum gamma-glutamyltransferase (GGT) activity is a sensitive but non-specific marker of non-alcoholic fatty liver disease (NAFLD). Recently, four GGT fractions (big-, medium-, small-, free-GGT) were described in humans.

AIM

We aimed to investigate whether a specific GGT fraction pattern is associated with NAFLD.

METHODS

Gamma-glutamyltransferase fractions were determined in patients with NAFLD (n = 90), and compared with those in control subjects (n = 70), and chronic hepatitis C (CHC, n = 45) age and gender matched.

RESULTS

Total GGT was elevated in NAFLD as compared to controls (median, 25°-75° percentile: 39.4, 20.0-82.0 U/L vs. 18.4, 13.2-24.9 U/L respectively, P < 0.001). All fractions were higher in NAFLD than in controls (P < 0.001). The b-GGT showed the highest diagnostic accuracy for NAFLD diagnosis [area under ROC curve (ROC-AUC): 0.85; cut-off 2.6 U/L, sensitivity 74%, specificity 81%]. Also subjects with CHC showed increased GGT (41.5, 21.9-84.5 U/L, P < 0.001 vs. controls, P = n.s. vs. NAFLD), as well as m-, s-, and f-GGT, while b-GGT did not show any significant increase (P = n.s. vs. HS, P < 0.001 vs. NAFLD). In subjects with CHC, s-GGT showed the best diagnostic value (ROC-AUC: 0.853; cut-off 14.1 U/L, sensitivity 73%, specificity 90%). Serum GGT did not show any value in the differential diagnosis between NAFLD and CHC (ROC-AUC 0.507, P = n.s.), while b-GGT/s-GGT ratio showed the highest diagnostic accuracy for distinguishing NAFLD and CHC (ROC-AUC: 0.93; cut-off value 0.16, sensitivity 82%, specificity 90%).

CONCLUSIONS

b-GGT increases in NAFLD, but not in CHC. GGT fraction analysis might help in improving the sensitivity and specificity of the diagnosis of NAFLD and other liver dysfunctions.

Elevated serum γ-glutamyltransferase predicts the development of impaired glucose metabolism in middle-aged and elderly Chinese

The aim of this article is to prospectively investigate the association of the liver enzyme γ-glutamyltransferase (GGT) with the development of diabetes and impaired glucose regulation (IGR) in a Chinese population. Seven hundred and sixty normoglycaemic subjects aged 40 years or older randomly selected from an urban community of Shanghai received a baseline investigation in May 2005. The participants were invited to receive a standard 75-g oral glucose tolerance test (OGTT) in November 2008. Incident diabetes and IGR were determined according to the 1999 WHO criteria. Serum GGT levels were significantly associated with incident diabetes or combined diabetes and IGR prospectively. After extensive adjustment, the diabetes risk was significantly increased with incrementing serum GGT quartiles (P value for trend = 0.0027). As compared with the lowest quartile of GGT, the highest quartile had an adjusted hazard ratio of 1.30 (95% CI 1.03-1.65) for developing combined diabetes and IGR. Furthermore, a high serum GGT level at baseline was independently associated with an increase in the index of homeostasis model assessment of insulin resistance (HOMA-IR) at follow-up. Serum GGT concentration, even within its normal range, is a risk marker for developing impaired glucose metabolism in middle-aged and elderly Chinese.

Association between markers of fatty liver disease and impaired glucose regulation in men and women from the general population: the KORA-F4-study

OBJECTIVE

To investigate whether the elevated liver enzymes gamma-glutamyltransferase (GGT), glutamate-pyruvate transaminase (GPT), glutamate-oxalacetate transaminase (GOT) and alkaline phosphatase (AP) and non-alcoholic fatty liver disease (NAFLD) respectively are independently associated with pre-diabetic states, namely impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) or known and newly diagnosed diabetes (NDD), in men and women from the general German population.

METHODS

The study was based on 3009 subjects (1556 females, 1453 males) aged 32 to 81 years who participated in the KORA-F4-Study in 2006/2008 in Augsburg, Southern Germany. All non-diabetic participants underwent an oral glucose tolerance test to assess disturbances in glucose metabolism. NAFLD was estimated by liver enzyme concentrations and the Bedogni Fatty Liver Index (FLI).

RESULTS

229 participants (7.6%) reported known diabetes, 106 had NDD (3.5%), 107 (3.6%) had IFG, 309 (10.3%) had IGT, 69 (2.3%) were affected with both metabolic disorders (IFG/IGT) and 74 (2.5%) could not be classified. GGT and GPT were significantly elevated in persons with pre-diabetes and diabetes (GGT in diabetic persons OR = 1.76, [1.47-2.09], in IFG OR = 1.79 [1.50-2.13], GPT in diabetic persons OR = 1.51, [1.30-1.74], in NDD OR = 1.77 [1.52-2.06]), GOT and AP only inconsistently in some pre-diabetes groups. The effects were sharpened in models using an increase of two or three out of three enzymes as an estimate of fatty liver and especially in models using the FLI. Overall frequency of NAFLD applying the index was 39.8% (women: 27.3% and men: 53.2%). In participants with fatty liver disease, the OR for NDD adjusted for sex and age was 8.48 [5.13-14.00], 6.70 [3.74-12.01] for combined IFG and IGT and 4.78 [3.47-6.59] for known diabetes respectively.

CONCLUSIONS

Elevated GGT and GPT-values as well as estimates of fatty liver disease are significantly associated with pre-diabetes and diabetes and thus very useful first indicators of a disturbed glucose metabolism.

Pretreatment prediction of response to peginterferon plus ribavirin therapy in genotype 1 chronic hepatitis C using data mining analysis

BACKGROUND

This study aimed to develop a model for the pre-treatment prediction of sustained virological response (SVR) to peg-interferon plus ribavirin therapy in chronic hepatitis C.

METHODS

Data from 800 genotype 1b chronic hepatitis C patients with high viral load (>100,000 IU/ml) treated by peg-interferon plus ribavirin at 6 hospitals in Japan were randomly assigned to a model building (n = 506) or an internal validation (n = 294). Data from 524 patients treated at 29 hospitals in Japan were used for an external validation. Factors predictive of SVR were explored using data mining analysis.

RESULTS

Age (<50 years), alpha-fetoprotein (AFP) (<8 ng/mL), platelet count (≥ 120 × 10(9)/l), gamma-glutamyltransferase (GGT) (<40 IU/l), and male gender were used to build the decision tree model, which divided patients into 7 subgroups with variable rates of SVR ranging from 22 to 77%. The reproducibility of the model was confirmed by the internal and external validation (r (2) = 0.92 and 0.93, respectively). When reconstructed into 3 groups, the rate of SVR was 75% for the high probability group, 44% for the intermediate probability group and 23% for the low probability group. Poor adherence to drugs lowered the rate of SVR in the low probability group, but not in the high probability group.

CONCLUSIONS

A decision tree model that includes age, gender, AFP, platelet counts, and GGT is useful for predicting the probability of response to therapy with peg-interferon plus ribavirin and has the potential to support clinical decisions regarding the selection of patients for therapy.

Use of a Mendelian randomization approach to assess the causal relation of gamma-Glutamyltransferase with blood pressure and serum insulin levels

Elevated levels of γ-glutamyltransferase (GGT) have been associated with elevated blood pressure (BP) and diabetes. However, the causality of these relations has not been addressed. The authors performed a cross-sectional analysis (2003-2006) among 4,360 participants from the population-based Cohorte Lausannoise (CoLaus) Study (Lausanne, Switzerland). The rs2017869 variant of the γ-glutamyltransferase 1 (GGT1) gene, which explained 1.6% of the variance in GGT levels, was used as an instrument for Mendelian randomization (MR). Sex-specific GGT quartiles were strongly associated with both systolic and diastolic BP (all P's < 0.0001). After multivariable adjustment, these relations were attenuated but remained significant. Using MR, the authors observed no positive association of GGT with BP (systolic: β -5.68, 95% confidence interval (CI): -11.51, 0.16 (P = 0.06); diastolic: β = -2.24, 95% CI: -5.98, 1.49 (P = 0.24)). The association of GGT with insulin was also attenuated after multivariable adjustment but persisted in the fully adjusted model (β = 0.07, 95% CI: 0.04, 0.09; P < 0.0001). Using MR, the authors also observed a positive association of GGT with insulin (β = 0.19, 95% CI: 0.01, 0.37; P = 0.04). In conclusion, the authors found evidence for a direct causal relation of GGT with fasting insulin but not with BP.

Insulin resistance is independently associated with liver aminotransferases in diabetic patients without ultrasound signs of nonalcoholic fatty liver disease

BACKGROUND

It has been shown that elevated levels of alanine and aspartate aminotransferases (ALT and AST) are associated with insulin resistance and type 2 diabetes mellitus; however, the pattern of this association in diabetic patients with negative or mild steatosis is not well understood. The aim of this study was to assess the association between elevated liver enzymes and insulin resistance in diabetic subjects without ultrasound signs of nonalcoholic fatty liver disease (NAFLD) (i.e., with less than 30% steatosis).

METHODS

In a cross-sectional study, a total of 670 diabetic subjects without established causes of liver injury were included. Patients with evidence of NAFLD in ultrasonography were not included. Fasting blood samples were obtained and plasma glucose, insulin, glycosylated hemoglobin (HbA1c), C-peptide, alkaline phosphatase, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lipid profile were measured. Three indices of insulin sensitivity/insensitivity: Homeostasis model assessment of insulin resistance (HOMA-IR), quantitative insulin sensitivity check index (QUICKI), and McAuley were also calculated.

RESULTS

Elevated ALT was significantly (p < 0.001) correlated with fasting insulin, C-peptide, HOMA-IR, QUICKI, McAuley, and waist circumference. The same correlations were also observed for AST, which in all cases were weaker than ALT. Multivariate regression analysis showed that, among the above-mentioned variables, only HOMA-IR and fasting insulin were independently correlated with both ALT and AST. This correlation was independent of body mass index (BMI) or waist circumference.

CONCLUSION

In type 2 diabetes, in the absence of a detectable steatosis by ultrasonography, ALT and AST are associated with hyperinsulinemia and insulin resistance, independent of obesity. This finding possibly indicates that in diabetes a mild stage of steatosis is sufficient to mediate the association between insulin resistance and aminotransferases.

Relationship of hepatic steatosis and alanine aminotransferase with coronary calcification

BACKGROUND

It has been observed that hepatic steatosis is related to an increased risk of cardiovascular disease (CVD). Alanine aminotransferase (ALT), an indicator of the severity of hepatic steatosis is also associated with CVD. This study focused on the relationship between hepatic steatosis and ALT with coronary calcification.

METHODS

We performed a cross-sectional study to examine the association between hepatic steatosis and serum ALT with coronary calcification in 1218 subjects (772 men, 446 women; ages 30-75 years). We evaluated hepatic steatosis and ALT as categorical variables, and constructed four groups (reference group; only with hepatic steatosis; only with ALT >30 U/L; with both hepatic steatosis and ALT >30 U/L), which did not overlap. Multi-detected row computed tomography (MDCT) was used to measure coronary calcium score.

RESULTS

The adjusted ORs (95% CIs) for coronary calcification in the four groups were 1.00 (reference), 1.24 (0.68-2.26), 1.82 (0.78-4.23), and 2.12 (1.08-4.20) after adjusting for confounding variables. In addition, an increase in serum ALT activity of 10 U/L was associated with an increased risk of coronary atherosclerosis.

CONCLUSIONS

In summary, patients with both hepatic steatosis and increases in ALT are associated with coronary calcification as a marker of coronary atherosclerosis determined by MDCT. This finding suggested that subjects with both hepatic steatosis and increased ALT should be considered for further evaluation of coronary atherosclerosis.

Low hemoglobin A1c and risk of all-cause mortality among US adults without diabetes

BACKGROUND

Among individuals without diabetes, elevated hemoglobin A1c (HbA1c) has been associated with increased morbidity and mortality, but the literature is sparse regarding the prognostic importance of low HbA1c.

METHODS AND RESULTS

National Health and Nutrition Examination Survey III (NHANES III) participants, 20 years and older, were followed up to 12 years (median follow-up, 8.8 years) for all-cause mortality. Cox proportional hazards regression was used to calculate hazard ratios (HR) and 95% confidence intervals (CI) for the association between HbA1c levels and all-cause mortality for 14 099 participants without diabetes. There were 1825 deaths during the follow-up period. Participants with a low HbA1c (<4.0%) had the highest levels of mean red blood cell volume, ferritin, and liver enzymes and the lowest levels of mean total cholesterol and diastolic blood pressure compared with their counterparts with HbA1c levels between 4.0% and 6.4%. An HbA1c <4.0% versus 5.0% to 5.4% was associated with an increased risk of all-cause mortality (HR, 3.73; 95% CI, 1.45 to 9.63) after adjustment for age, race-ethnicity, and sex. This association was attenuated but remained statistically significant after further multivariable adjustment for lifestyle, cardiovascular factors, metabolic factors, red blood cell indices, iron storage indices, and liver function indices (HR, 2.90; 95% CI, 1.25 to 6.76).

CONCLUSIONS

In this nationally representative cohort, low HbA1c was associated with increased all-cause mortality among US adults without diabetes. Additional research is needed to confirm these results and identify potential mechanisms that may be underlying this association.

A predictive model of response to peginterferon ribavirin in chronic hepatitis C using classification and regression tree analysis

AIM

Early disappearance of serum hepatitis C virus (HCV) RNA is the prerequisite for achieving sustained virological response (SVR) in peg-interferon (PEG-IFN) plus ribavirin (RBV) therapy for chronic hepatitis C. This study aimed to develop a decision tree model for the pre-treatment prediction of response.

METHODS

Genotype 1b chronic hepatitis C treated with PEG-IFN alpha-2b and RBV were studied. Predictive factors of rapid or complete early virological response (RVR/cEVR) were explored in 400 consecutive patients using a recursive partitioning analysis, referred to as classification and regression tree (CART) and validated.

RESULTS

CART analysis identified hepatic steatosis (<30%) as the first predictor of response followed by low-density-lipoprotein cholesterol (LDL-C) (>/=100 mg/dL), age (<50 and <60 years), blood sugar (<120 mg/dL), and gamma-glutamyltransferase (GGT) (<40 IU/L) and built decision tree model. The model consisted of seven groups with variable response rates from low (15%) to high (77%). The reproducibility of the model was confirmed by the independent validation group (r(2) = 0.987). When reconstructed into three groups, the rate of RVR/cEVR was 16% for low probability group, 46% for intermediate probability group and 75% for high probability group.

CONCLUSIONS

A decision tree model that includes hepatic steatosis, LDL-C, age, blood sugar, and GGT may be useful for the prediction of response before PEG-IFN plus RBV therapy, and has the potential to support clinical decisions in selecting patients for therapy and may provide a rationale for treating metabolic factors to improve the efficacy of antiviral therapy.

Serum gamma-glutamyltransferase levels are related to insulin sensitivity and secretion in subjects with abnormal glucose regulation

BACKGROUND

To test the association between gamma-glutamyltransferase level and glucose regulation.

METHODS

We performed a cross-sectional analysis of 500 subjects [199 men/301 women, age 47 +/- 11 years, body mass index (BMI) 28.6 +/- 5.5 kg/m(2)] referred to Diabetes Clinics because of potential risk of type 2 diabetes mellitus (T2DM).

RESULTS

The prevalence of all glucose intolerance categories was higher in the top quartile of gamma-glutamyltransferase than in the first. Subjects with normal glucose tolerance showed lower gamma-glutamyltransferase levels compared with those with impaired glucose tolerance (IGT), impaired fasting glucose (IFG)+ IGT and T2DM (ANOVA, p < 0.0001), but not those with IFG. Homeostasis model assessment-insulin resistance (HOMA-IR) increased with increasing levels of gamma-glutamyltransferase, while the insulinogenic index/HOMA-IR ratio decreased. In an age- and sex-adjusted analysis, the top gamma-glutamyltransferase quartile was independently associated with IFG + IGT [odds ratio (OR) 2.41; 95% confidence interval (CI): 1.13-5.15] and T2DM (OR 2.77; 95% CI: 1.47-5.22). After further adjustment for BMI, alcohol intake, family history of diabetes, cigarette smoking and physical activity, the top quartile of gamma-glutamyltransferase remained an independent predictor of IFG + IGT (OR 2.62; 95% CI: 1.13-6.07) and T2DM (OR 2.39; 95% CI: 1.20-4.76). Only when transaminases and HOMA-IR have been added to the model, the top quartile of gamma-glutamyltransferase resulted no more independently associated to IFG + IGT or T2DM.

CONCLUSIONS

Gamma-glutamyltransferase is closely related to insulin resistance, reduced beta-cell function and deterioration of glucose tolerance.

The metabolic syndrome and nonalcoholic fatty liver disease in children

PURPOSE OF REVIEW

Nonalcoholic fatty liver disease (NAFLD) is increasingly prevalent in pediatric-age individuals, in parallel with increasing obesity, and can lead to liver inflammation, fibrosis, and even cirrhosis. NAFLD appears tightly linked with features of the metabolic syndrome (MetS). This review aims to reconsider the clinical presentation, laboratory and pathologic assessment, and treatment of NAFLD, with a focus on its relationship with the MetS.

RECENT FINDINGS

NAFLD occurs with a high prevalence and severity in obese, insulin-resistant adolescents, especially Hispanic males. Pediatric NAFLD may improve with lifestyle therapy and agents that improve insulin sensitivity. In youth, NAFLD appears tightly correlated with components of the MetS, especially visceral fat, which appears to predict fibrosis as well as liver fat. In addition, noninvasive techniques such as transient elastography may help provide data on fibrosis in youth with NAFLD and avoid biopsy.

SUMMARY

The close association between NAFLD and the MetS supports screening for other comorbidities associated with the MetS. Further research is urgently required to best identify effective therapies to prevent and treat NAFLD, but its close association with MetS argues for a focus on strategies designed to improve insulin resistance and components of the MetS.

Elevation of serum aminotransferase activity increases risk of carotid atherosclerosis in patients with non-alcoholic fatty liver disease

BACKGROUND AND AIM

Patients with non-alcoholic fatty liver disease (NAFLD) have an increased risk of atherosclerosis and alanine aminotransferase (ALT) is associated with insulin resistance independently of metabolic factors. The aim of the present study was to investigate whether NAFLD patients with ALT elevation had a higher risk of carotid atherosclerosis.

METHODS

A total of 190 individuals were enrolled from the health management center. Among them, 20 subjects were excluded due to the presence of hepatitis B surface antigen (HbsAg), anti-hepatitis C virus (HCV) and cardiovascular disease. NAFLD was diagnosed by ultrasound examination. Carotid ultrasonography was used to measure maximal intima-media thickness (IMT) of the common carotid artery (CCA) and IMT (mean) > 1.0 mm was defined as the presence of carotid atherosclerosis.

RESULTS

NAFLD patients with ALT elevation had increased risk of carotid atherosclerosis than those with normal ALT by Fisher's exact test (P < 0.05). Multivariate analyses showed that serum ALT levels were positively associated with carotid atherosclerosis after adjustment for age, sex, number of metabolic syndrome components or status of metabolic syndrome (OR, 1.44; 95% CI 1.09-1.89; OR, 1.45; 95% CI 1.11-1.91). In addition, the higher the serum ALT levels with every 10 IU/L increment, the greater the risk of carotid atherosclerosis.

CONCLUSIONS

Serum ALT levels are positively associated with the risk of carotid atherosclerosis in patients with NAFLD, suggesting that serum ALT levels could serve as a surrogate marker of cardiovascular risk in this special clinical setting.

Serum gamma-glutamyl transferase activity predicts future development of metabolic syndrome defined by 2 different criteria

BACKGROUND

Recent studies suggest the role of liver enzymes, such as serum gamma-glutamyl transferase (GGT) and alanine aminotransferase (ALT) as the predictor for future development of metabolic syndrome (MetS), diabetes and cardiovascular disease in epidemiologic studies. We hypothesized that serum concentrations of GGT and ALT are associated with the development of MetS, according to newly recommended criteria from International Diabetes Federation (IDF) and American Heart Association/National Heart, Lung, and Blood Institute (AHA/NHLBI) definition in Koreans.

METHODS

A total of 15,250 males (mean 38 y) and 6280 females (mean 41 y) who visited the Health Promotion Center at Kangbuk Samsung Hospital for medical check-up in 2002, were followed-up after 4 y. We analyzed the development of MetS in their follow-up data in 2006.

RESULTS

When the subjects were divided into quartiles by the baseline GGT levels, the odds ratio for the MetS defined by both criteria across the quartile groups increased as the quartile groups increased in both gender groups. This association remained significant even after adjustment for confounding factors, such as, age, alcohol intake, smoking status, physical activity, ALT, fasting insulin and HOMA-IR. Serum ALT concentration also showed significantly positive correlation with development of MetS defined by the two criteria even after adjustment for age and GGT in both gender groups. In addition, risk for the individual MetS components increased as the baseline GGT concentrations increased, except low high-density lipoprotein cholesterol (HDL-C) in female group. In receiver operating characteristic (ROC) curves, the area under the curves (AUC) of GGT and ALT to predict future MetS by both criteria was larger than the AUCs of blood pressure, fasting glucose and HDL-C.

CONCLUSIONS

In this large prospective study in Koreans, high baseline GGT and ALT concentrations predicted future development of MetS defined by IDF and AHA/NHLBI criteria after 4 y of follow-up.

Elevated serum alanine aminotransferase and gamma-glutamyltransferase and mortality in the United States population

BACKGROUND & AIMS

Elevated serum alanine aminotransferase (ALT) and gamma-glutamyltransferase (GGT) activities are markers of liver injury, but may also be associated with other diseases and death. In a prospective, national, population-based sample, we examined whether elevated ALT and GGT were associated with increased risk of all-cause and disease-specific mortality.

METHODS

Death certificate-based 12-year mortality was analyzed among 14,950 adult participants in the third US National Health and Nutrition Examination Survey, 1988-1994, who were negative for markers of viral hepatitis B and C. Abnormal ALT was defined as >30 U/L in men or >19 U/L in women, and abnormal GGT as >51 U/L in men or >33 U/L in women.

RESULTS

Cumulative mortality was 13.9% from all causes, including 4.2% from cardiovascular disease, 4.2% from neoplasms, 0.44% from diabetes, and 0.13% from liver disease. In multivariate-adjusted analyses, elevated ALT was not associated with all-cause mortality (hazard ratio [HR], 1.2; 95% confidence interval [CI], 0.88-1.6). ALT elevation was associated with deaths from liver disease (HR, 8.2; 95% CI, 2.1-31.9), but not from cardiovascular disease (HR, 0.90; 95% CI, 0.56-1.4), neoplasms (HR, 1.0; 95% CI, 0.65-1.5), or diabetes (HR, 2.4; 95% CI, 0.65-9.1). All-cause mortality increased with elevated GGT (HR, 1.5; 95% CI, 1.2-1.8), as did mortality from liver disease (HR, 13.0; 95% CI, 2.4-71.5), neoplasms (HR, 1.5; 95% CI, 1.01-2.2), and diabetes (HR, 3.3; 95% CI, 1.4-7.6), but not from cardiovascular disease (HR, 1.3; 95% CI, 0.80-2.0).

CONCLUSIONS

In the US population, elevated GGT was associated with mortality from all causes, liver disease, cancer, and diabetes, while ALT was associated only with liver disease mortality.

Nonalcoholic fatty liver disease in asymptomatic Brazilian adolescents

AIM

To evaluate the prevalence and clinical characteristics of Nonalcoholic fatty liver disease (NAFLD) among asymptomatic Brazilian adolescents.

METHODS

Transversal observational study included asymptomatic adolescents with central obesity from private and public schools in Salvador-Bahia, northeastern Brazil. The children answered a questionnaire that included age, gender, race, and medical history, and were submitted to a complete physical exam and abdominal ultrasound. Biochemical exams included: ALT, AST, GGT, C reactive protein (CRP), fasting glucose, insulin, cholesterol and triglycerides. Criteria for NAFLD included: the presence of steatosis in ultrasound and/or high level of ALT, negative or occasional historic of intake of alcohol (<or= 140 g/wk), negative investigation for hepatitis A, B, C, auto-immune hepatitis, Wilson disease and hemochromatosis.

RESULTS

From October, 2005 to October, 2006, the study included 1801 subjects between 11 and 18 years of age and a mean age of 13.7+/-2.0 years. One hundred ninety-nine had central obesity. The prevalence of NAFLD was 2.3%, most of whom were male and white. Insulin resistance (IR) was observed in 22.9% of them and had positive correlations with ALT and GGT (P<0.05). Elevated CRP was observed in 6.9% of the cases; however, it was not associated with WC, IR or liver enzymes.

CONCLUSION

The prevalence of NAFLD in Brazilian adolescents was low. The ethnicity may have influence this frequency in the population studied, which had a large proportion of African descendents.

[Alcohol, steatohepatitis, insulin resistance and hepatitis C]

Patients with chronic hepatitis C have frequently other morbidities, either because they are frequent in the general population (metabolic syndrome) and/or because the route of contamination (chronic alcohol consumption succeeding to drug abuse). These co-morbidities have a harmfull impact on fibrosis progression during the natural history of HCV infection and reduce the efficacy of antiviral treatments. Thus, it is crucial to diagnose early and treat these different diseases which may be combined. They are the metabolic syndrome and/or chronic alcohol consumption resulting in insuline resistance, infection by the human immune deficiency virus or by the hepatitis B virus as well as chronic tobacco use or excessive consumption of cannabis. An optimal is based on a multidisciplinary approach to reduce fibrosis progression and improve the efficiency of antiviral therapies. However, the hepatologist has to come back to a global care, which is mandatory at the individual level as well as for the public health.

Liver enzymes compared with alcohol consumption in predicting the risk of type 2 diabetes: the Kansai Healthcare Study

OBJECTIVE

It has been reported that moderate alcohol consumption decreased the risk of type 2 diabetes but that elevated liver enzymes increased it. The comparative importance of alcohol consumption and liver enzymes as predictors of type 2 diabetes remains unconfirmed.

RESEARCH DESIGN AND METHODS

The participants included 8,576 Japanese men, aged 40-55 years, without type 2 diabetes at entry. Type 2 diabetes was diagnosed if a fasting plasma glucose level was >or=126 mg/dl or if participants were taking oral hypoglycemic medications or insulin.

RESULTS

During the 4-year follow-up period, we confirmed 878 cases. In multivariate models, moderate daily alcohol consumption (16.4-42.6 g ethanol/day) decreased the risk of type 2 diabetes, and higher levels of gamma-glutamyltransferase (GGT) and alanine aminotransferase (ALT) increased the risk. In joint analyses of alcohol consumption and liver enzymes, moderate drinkers with the lowest tertile of GGT had the lowest risk of type 2 diabetes. Compared with them, nondrinkers with the highest GGT had the highest risk of type 2 diabetes (odds ratio 3.18 [95% CI 1.75-5.76]). At every level of GGT, moderate or heavy alcohol drinkers (>or=42.7 g ethanol/day) had a lower risk of type 2 diabetes than nondrinkers. The relationship of ALT and daily alcohol consumption with the risk of type 2 diabetes was almost the same as that of GGT.

CONCLUSIONS

GGT, ALT, and daily alcohol consumption were independently associated with the risk of type 2 diabetes. Nondrinkers with the highest GGT or ALT had a high risk of type 2 diabetes.

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.