Elevation of liver enzymes within the normal limits and metabolic syndrome

Association between liver enzymes and metabolic syndrome: a study in Bangladeshi adults

BACKGROUND

This study aimed to investigate the association between serum liver enzymes and the presence of metabolic syndrome (MetS) among Bangladeshi adults.

RESEARCH DESIGN AND METHODS

A total of 602 participants (424 males and 178 females) were enrolled in this cross-sectional study. Serum levels of liver enzymes (ALT, AST, GGT and ALP) and other biochemical parameters were measured by standard colorimetric methods. The relationship between liver enzymes and MetS was assessed by multivariable logistic regression models.

RESULTS

Overall, the prevalence of MetS was 34.9% among the participants. Of the four liver enzymes, the mean levels of serum ALT and GGT were significantly higher among subjects with MetS than those without MetS (p < 0.01). When liver enzyme levels were categorized into normal and elevated ranges, MetS and its component's prevalence was higher in the elevated group except for ALP. Serum ALT and GGT showed a significant relationship with the maximum components of MetS. According to the logistic regression analysis, elevated levels of ALT and GGT were significantly associated with the prevalence of MetS (p < 0.01 and p < 0.001, respectively).

CONCLUSIONS

This study showed that elevated ALT and GGT levels were independently associated with MetS and its components.

Association between serum apolipoprotein B and atrial fibrillation: a case-control study

The relationship between apolipoprotein B (APOB) and atrial fibrillation (AF) is less well-known. We aimed to investigate the association between APOB and AF by gender. We conducted a case-control study including 1913 consecutive hospitalized patients to analyze the association between APOB and AF. 950 AF patients and 963 age-, sex-matched non-AF patients with sinus rhythm were evaluated. T-test, Mann-Whitney test, ANOVA, and Chi-square analysis were performed to analyze baseline data and intergroup comparisons. Pearson's correlation tests or Spearman correlation tests were performed to determine the interrelationships. Multiple regression analysis was performed to adjust for covariables. The receiver operator characteristic (ROC) curve was constructed to examine the performance of APOB. AF patients had lower APOB (P < 0.001) and an independent negative association between APOB and AF in both genders adjusting for confounding factors (OR 0.121, 95% CI 0.067-0.220, P < 0.001), regardless of statin use. APOB was positively correlated with total cholesterol (TC) (r = 0.529, p < 0.001), low-density lipoprotein cholesterol (LDL-C) (r = 0.545, p < 0.001), apolipoprotein A1 (APOA1) (r = 0.083, p < 0.001), and albumin (ALB) (r = 0.134, p < 0.001). ROC curve analysis showed that APOB level = 0.895 g/L was the most optimal cut-off value, the area under the ROC curve was 0.722. This study shows a protective association of APOB with AF in men and women. It implies APOB may be a potential biomarker for AF with a promising cut-off point of 0.895 g/L and may involve initiating and maintaining AF along with several metabolic factors.

Association between liver enzymes and metabolic syndrome: results of the enrollment phase of Tabari cohort

BACKGROUND

The association between liver enzymes and metabolic syndrome (MetS) has been evaluated in several studies with different results. The purpose of this study is to determine the association between the serum levels of these liver enzymes and MetS in Tabari cohort population.

METHOD

In this case-control study, data collected from the enrolment phase of the Tabari cohort population have been used. MetS was defined based on IDF (international diabetes federation) standards. Then, 476 patients with MetS (case group) and 476 age-sex matched controls were selected randomly.

RESULTS

Mean aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were higher in case group than control group (20.59 vs. 19.99 respectively, p = 0.339 and 24.64 vs. 20.16 respectively, p < 0.001). The chance of having MetS, high triglyceride, and fasting blood glucose (FBG) was significantly higher in people with ALT ≥ 40 (1.63, 2.35, and 2.02, respectively). The chance of having MetS in people with AST ≥ 40 was 1.45 times higher than that among those with normal AST level (p > 0.05).

CONCLUSION

This study showed that there is an association between liver enzymes and MetS as well as some of its components. Liver enzymes, especially ALT, can be used as an early indicator of MetS in the at risk population.

Association between Physical Activity and Non-Alcoholic Fatty Liver Disease in Adults with Metabolic Syndrome: The FLIPAN Study

Background: A lifestyle with regular PA (physical activity) and Mediterranean diet has benefits on NAFLD (non-alcoholic fatty liver disease) and MetS (metabolic syndrome). Objectives: To assess the association between physical activity and NAFLD in adults with MetS. Design: Cross-sectional study in 155 participants (40−60 years old) from Balearic Islands and Navarra (Spain) with diagnosis of NAFLD and MetS, and BMI (body mass index) between 27 and 40 Kg/m2. Methods: PA level was categorized into two groups according to weekly METs (metabolic equivalents of tasks). PA was assessed using a validated Minnesota questionnaire and accelerometers. MetS parameters were assessed by blood collection analysis and NAFLD by abdominal MRI (magnetic resonance imaging). Results: Participants with high PA showed more energy expenditure and expended more calories than ingested (−143.9 Kcal/day; p < 0.001). PA was a risk factor for AST (aspartate aminotransferase) (adjusted OR: 7.26; 95% CI: 1.79−29.40) and a protective factor for ALT (alanine aminotransferase) (adjusted OR: 0.24; 95% CI: 0.12−0.48), GGT (gamma-glutamyl transferase) (adjusted OR: 0.52; 95% CI: 0.29−0.94) and IFC-NMR (intrahepatic fat content by nuclear magnetic resonance) (adjusted OR: 0.26; 95% CI: 0.12−0.56) when sociodemographic confounders were considered. Conclusions: NAFLD patients with high PA showed more positive relationship on MetS parameters and liver profile (ALT, GGT, IFC-NMR) than subjects with low PA, but not for AST. Difference between calories ingested and expended influenced this relationship.

Index of Cardiac Age Index and Cardiometabolic Biomarkers in Adults with Metabolic Syndrome

Background: The presence of metabolic syndrome (MetS) seems to alter or accelerate the aging process of tissues or organs including the heart. We aim to investigate whether MetS are associated with an index of cardiac age calculated by parameters derived from 128-slice cardiac multidetector computed tomography (MDCT) and cardiometabolic biomarkers in adults. Materials and Methods: In this cross-sectional study, the data were collected from 135 subjects who underwent a comprehensive health checkup, including cardiac MDCT in adults (age ≥18 years). Cardiometabolic biomarkers and an index of cardiac age were measured. Results: Sixty-one (45.2%) had MetS and 44 subjects (32.6%) presented with moderate or severe coronary artery stenosis (CAS) on cardiac MDCT. MetS had positive correlations with several anthropometric variables, metabolic variables [triglyceride, gamma-glutamyl transpeptidase (GGT), homeostatic model assessment of insulin resistance (HOMA-IR)], and systolic blood pressure, cardiac parameters, an index of cardiac age and CAS, whereas had a negative correlation with high-density lipoprotein cholesterol. The diagnostic accuracy for MetS had similar area under the curve among the four variables (index of cardiac age, CAS, HOMA-IR, GGT). On age-adjusted multivariate analysis, only high index of cardiac age (≥55.0 years), and high HOMA-IR (≥1.22) were significantly and independently associated with MetS [odds ratio (OR) 2.48, 95% confidence interval (CI) 1.19-5.18, P = 0.016 and OR 3.41, 95% CI 1.65-7.06, P = 0.001, respectively]. Conclusion: Adults with MetS had higher index of cardiac age and higher HOMA-IR, compared with adults without MetS.

Circulating ALT Levels in Healthy Volunteers Over Life-Span: Assessing Aging Paradox and Nutritional Implications

Background: Two facts are generally recognized: (1) development of nonalcoholic fatty liver disease (NAFLD) is consistently linked to insulin resistance which has dietary implications and (2) circulating alanine aminotransferase (ALT) levels are reasonable markers predicting NAFLD status. In a recent cross-sectional study employing nondiabetic subjects, ALT values rose steadily within a normal range early in the life cycle but begin decreasing steadily around age 65 years.Objectives: Because of important nutritional implications, the association between ALT levels and aging in a significantly larger population of healthy volunteers was examined for corroborative purposes. A secondary goal was to gain further knowledge concerning mechanisms behind any age-related decline in ALT activity.Methods: Baseline data from over 10,000 physician-approved, nondiabetic subjects (age 21-84 years) of both genders who had volunteered for previous clinical investigations were assessed.Results: In this cross-sectional examination, the line of best fit (weighted) for average yearly circulating ALT levels displayed an upward surge from ages 21 to 64 years with a discernible steady downward decline around 65 years-mimicking earlier results. Examining linear lines of correlation in the younger and older age groups, the following calculations were determined: a significant positive slope for 21 to 64 years, r = 0.42, n = 44, p < 0.005, and a trending negative slope for 65 and beyond, r = -0.43, n = 20, p < 0.057. Using this same datum base, the correlations between age and fasting blood glucose (FBG) mimicked the ALT results by once more showing a similar upward rise in the younger and a steady decline the older group of volunteers.Conclusions: A paradoxical downward age-related (≥ 65 years) decline of circulating ALT coinciding with a comparable steady decrease in FBG levels was replicated in a larger population of volunteers. The close association of these two chemistries along with other findings suggest that altered glucose-insulin metabolism may participate via "survivor bias" in the ubiquitously found age-related decline of serum ALT-suggesting that nutritional measures could advance optimal health over the life-span.

The longitudinal increments of serum alanine aminotransferase increased the incidence risk of metabolic syndrome: A large cohort population in China

BACKGROUND

Although alanine aminotransferase (ALT) is well known to be associated with metabolic syndrome (MetS), prospective data on longitudinal increments in ALT activities and incident cases of MetS are limited. We analyzed the impact of longitudinal increments of ALT on MetS based on a health check-up population in China.

METHODS

A total of 4491 subjects free of MetS who completed at least two annual health examinations during March 2010 to April 2016 were enrolled in this cohort study. The MetS was defined according to the Joint Interim Statement criteria 2009. The RRs of incident MetS were estimated by using the Cox model and the Joint model in R software.

RESULTS

The cumulative incidence of MetS was 18.55% during the 7 years of follow-up. In the Cox model, the estimated RR of developing MetS was 1.751 (95% CI =1.532-2.000) for 1 unit augmented in LNALT-0 level. In the Joint model, the estimated RR of developing MetS was 3.626 (95% CI = 2.721-4.831) for 1 unit augmented in LNALT activity longitudinally.

CONCLUSIONS

The longitudinal increment of individuals' ALT activity over time increased the incidence risk of MetS and the effects generated by longitudinal increments of ALT on MetS was higher than that generated by baseline ALT.

Isolation and characterization of the Bacillus cereus BC7 strain, which is capable of zearalenone removal and intestinal flora modulation in mice

Zearalenone (ZEN) causes serious diseases in both animals and humans and thereby leads to substantial economic losses. The elimination of ZEN contamination from food and feed is an important concern worldwide. This study aimed to screen a bacterium that can efficiently detoxify ZEN both in vitro and in vivo. A bacterium (designated BC7) with high ZEN-removing capability was isolated from mouldy contaminated feeds and characterized as Bacillus cereus based on biochemical and 16S rRNA sequencing analyses. BC7 could remove 100% and 89.31% of 10 mg/L ZEN in Luria-Bertani (LB) medium and simulated gastric fluid (GSF), respectively, within 24 h at 37 °C. The effects of BC7 on ZEN detoxification and on the intestinal flora were further evaluated using four groups of mice that were intragastrically administered normal saline, BC7 culture (CFU = 3.45 × 10⁸/mL), ZEN (10 mg/kg BW) or BC7 culture (CFU = 3.45 × 10⁸/mL) + ZEN (10 mg/kg BW) for 2 weeks. ZEN showed distinct reproductive and hepatic toxicity, as characterized by increased weights of the uterus and liver, altered levels of oestradiol (E2) and luteinizing hormone (LH), increased secretion of the liver injury biomarkers alanine transaminase (ALT) and aspartate transaminase (AST), and abnormal histological phenotypes for the uterus, ovary and liver. However, BC7 could significantly reduce all the above-mentioned adverse effects caused by ZEN with no harmful effect on the reproductive system and liver in mice. Moreover, the addition of BC7 could efficiently renormalize the ZEN-induced perturbation of the gut microbiota and significantly increase the abundance of Lactobacillus to maintain the health of the intestinal flora in mice. In conclusion, Bacillus cereus BC7 could be used as a potential feed additive to efficiently remove ZEN in vitro or in vivo and to normalize the disordered gut microbiota in mice.

Examining the Relationship Between Nonalcoholic Fatty Liver Disease and the Metabolic Syndrome in Nondiabetic Subjects

OBJECTIVE

Nonalcoholic fatty liver disease (NAFLD) is considered by some to be the hepatic manifestation of the metabolic syndrome (MS). However, others believe NAFLD is a distinct entity that actually initiates MS. Whichever is true, a definite linkage exists between both is generally accepted based upon the frequency of common occurrence and realization that insulin resistance (IR) is and realization that. The objective is to better understand the relationship between NAFLD and MS. Specifically, is there any concrete evidence that development of NAFLD precedes MS or vice versa? Another goal was to better comprehend capabilities of circulating aminotransferases (aspartate aminotransferase [AST] and alanine aminotransferase [ALT]) and their ratio used commonly for diagnosis of NAFLD.

METHODS

Data from 288 participants with fasting blood glucose (FBG) levels below the diabetic level (<125 mg/dL) and AST and ALT values in the normal range (<40 U/L) were examined. Correlations between ALT and AST and their ratio as independent variables with a variety of metabolic parameter were evaluated and compared.

RESULTS

Like FBG, many significant positive correlations among glucose-insulin indices, body composition, blood pressure, dyslipidemias, and inflammation were discovered using ALT, and less so with AST, as the independent variable. In some cases, even stronger correlations in a negative direction with IR and MS were found with the ratio AST/ALT. Corroboration occurred when values in the lowest and highest quartiles of ALT and AST/ALT readings showed appropriate statistically significant differences.

CONCLUSIONS

The findings here suggest that both NAFLD and the MS very early in development have a common inciting mechanism(s)-most likely IR. Accordingly, the early concurrent temporal results are consistent with the concept that NAFLD is a hepatic manifestation of the IR associated with the MS. They do not exclude the possibility that once some liver functional adjustments take place, several aspects of the MS are bolstered further, perhaps via intensified heightening of IR.

Association between liver function and metabolic syndrome in Chinese men and women

Metabolic syndrome (MS) could be associated with liver function. Our study aimed to investigate the association between liver function and MS in a large cohort of Chinese men and women. We enrolled 32,768 ostensibly healthy participants. The associations between liver function and MS of both genders were analyzed separately after dividing total bilirubin (TBIL), gamma glutamyltransferase (GGT), alanine aminotransferase (ALT) into quartiles. Young males had significantly higher MS prevalence than females, yet after menopause, females had higher MS prevalence. We used TBIL, GGT and ALT quartiles as categorical variables in binary logistic regression models. Significantly decreased MS risks were demonstrated in TBIL quartiles 2 to 4 for males, and quartiles 3 to 4 for females. As to GGT and ALT, significantly increased MS risks were shown in high quartiles for both genders. Aging also resulted in significantly higher MS risks in both genders except for young females. This study displayed close associations between liver function and MS, which were influenced by gender and age. A high TBIL level had protective effect against MS, while high GGT and ALT levels were risk factors for MS. It is meaningful that liver function is used as clinical risk predictors for MS.

Serum alanine aminotransferase levels and all-cause mortality

BACKGROUND AND OBJECTIVES

Studies have examined the relationship between serum alanine aminotransferase (ALT) and mortality with inconsistent results. Our aims were to examine the association of normal range serum ALT with mortality, to explore a nonlinear relationship between ALT and mortality, and to investigate whether age modifies this relationship.

STUDY

We used the continuous National Health and Nutrition Examination Survey (NHANES) from 1999 to 2010. Vital status of the participants was obtained by probabilistic matching between NHANES and the National Death Index. Cox proportional models were used to examine the relationship with and without adjustment for age, sex, race, BMI, hypertension, diabetes, alcohol use, serum triglycerides, prescription drug use, and glomerular filtration rate, and accounting for the sampling methodology of NHANES. Nonlinear relationship was examined using spline (single knot at 17 U/l) regression. Interaction terms were used to examine effect modification by age.

RESULTS

Higher serum ALT was associated with lower all-cause mortality [adjusted hazard ratio (HR)/ALT increment=0.98, 95% confidence interval (CI)=0.97-0.99]; however, this relationship was nonlinear and present only until 17 U/l (adjusted HR/ALT increment=0.93, 95% CI=0.91-0.95) and not thereafter. Age modified the relationship between ALT and mortality; elderly patients (>64 years) had a 6% lower adjusted mortality risk than younger (<35 years) participants (HR/ALT increment=0.94, 95% CI=0.91-0.96; interaction P<0.001).

CONCLUSION

Increase in serum ALT within the normal range is initially associated with lower mortality, but has no effect after 17 U/l. The elderly show a significantly larger decrease in mortality with an increase in ALT than younger individuals. The mechanisms underlying this relationship need further exploration.

Indicators of fetal growth and adult liver enzymes: the Bogalusa Heart Study and the Cardiovascular Risk in Young Finns Study

Despite the interest in the relationship of fetal exposures to adult cardiovascular disease, few studies have examined indicators of adult fatty liver disease as an outcome. Previous results are inconsistent, and indicate possible variation by sex. Adult liver enzymes [γ-glutamyl transferase (GGT), alanine transaminase (ALT) and aspartase transaminase (AST)] were measured in two cohort studies: the Bogalusa Heart Study (BHS; n=1803) and the Cardiovascular Risk in Young Finns (YF; n=3571) study, which also had ultrasound measures of liver fat (n=2546). Predictors of dichotomized (clinical cut-offs) and continuous (within the reference range) liver enzymes included low birthweight (4000 g), small-for-gestational-age (birthweight 90th percentile), and preterm birth. Multiple logistic and linear regression were conducted, adjusted for medical, behavioral and socioeconomic indicators. Interactions with sex were also examined. In BHS, birth measures were not strongly associated with clinically high levels of liver enzymes, and within the reference range measures of reduced growth were associated with increased AST in women. In the YF study, at least one marker of reduced growth was associated with higher GGT, higher ALT and higher AST (in women). Probable fatty liver on ultrasound was associated with low birthweight (2.41, 1.42-4.09) and preterm birth (2.84, 1.70-4.76). These results suggest a link between birth parameters and adult fatty liver, but encourage consideration of population variation in these relationships.

Influence of Ethnicity on the Accuracy of Non-Invasive Scores Predicting Non-Alcoholic Fatty Liver Disease

OBJECTIVES

Presence of non-alcoholic fatty liver disease (NAFLD) can predict risks for diabetes, cardiovascular disease and advanced liver disease in the general population. We aimed to establish a non-invasive score for prediction of NAFLD in Han Chinese, the largest ethnic group in the world, and detect whether ethnicity influences the accuracy of such a score.

METHODS

Liver fat content (LFAT) was measured by quantitative ultrasound in 3548 subjects in the Shanghai Changfeng Community and a Chinese score was created using multivariate logistic regression analyses. This new score was internally validated in Chinese and externally in Finns. Its diagnostic performance was compared to the NAFLD liver fat score, fatty liver index (FLI) and hepatic steatosis index (HSI) developed in Finns, Italians and Koreans. We also analyzed how obesity related to LFAT measured by 1H-MRS in 79 Finns and 118 Chinese with type 2 diabetes (T2D).

RESULTS

The metabolic syndrome and T2D, fasting serum insulin, body mass index (BMI) and AST/ALT ratio were independent predictors of NAFLD in Chinese. The AUROC in the Chinese validation cohort was 0.76 (0.73-0.78) and in Finns 0.73 (0.68-0.78) (p<0.0001). 43%, 27%, 32% and 42% of Chinese had NAFLD when determined by the Chinese score, NAFLD liver fat score (p<0.001 vs. Chinese score), FLI (p<0.001) and HSI (NS). For any given BMI and waist circumference, the Chinese had a markedly higher LFAT than the Finns.

CONCLUSION

The predictors of NAFLD in Han Chinese are as in Europids but the Chinese have more LFAT for any given degree of obesity than Europids. Ethnicity needs to be considered when NAFLD is predicted using risk scores.

Liver enzymes and metabolic syndrome: a large-scale case-control study

Previous studies suggested that elevated liver enzymes could be used as potential novel biomarkers of Metabolic syndrome (MetS) and its clinical outcomes, although the results were inconsistent and the conclusions were underpowered. A case-control study with 6,268 MetS subjects and 6,330 frequency-matched healthy controls was conducted to systematically evaluated levels of four liver enzymes (ALT, AST, GGT and ALP), both in overall populations and in subjects with normal liver enzymes, with MetS risk using both quartiles and continuous unit of liver enzymes. We found significant associations were detected for all above analyses. Compared with quartile 1 (Q1), other quartiles have significant higher MetS risk, with ORs ranging from 1.15 to 18.15. The highest effected was detected for GGT, for which the OR value for the highest versus lowest quartile was 18.15 (95% CI: 15.7-20.9). Mutual adjustment proved the independence of the relations for all four liver enzymes. Sensitivity analyses didn’t materially changed the trend. To the best of our knowledge, this study should be the largest, which aimed at evaluating the association between liver enzymes measures and MetS risk. The results can better support that liver enzyme levels could be used as clinical predictors of MetS.

Reducing Liver Fat by Low Carbohydrate Caloric Restriction Targets Hepatic Glucose Production in Non-Diabetic Obese Adults with Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) impairs liver functions, the organ responsible for the regulation of endogenous glucose production and thus plays a key role in glycemic homeostasis. Therefore, interventions designed to normalize liver fat content are needed to improve glucose metabolism in patients affected by NAFLD such as obesity. Objective: this investigation is designed to determine the effects of caloric restriction on hepatic and peripheral glucose metabolism in obese humans with NAFLD. Methods: eight non-diabetic obese adults were restricted for daily energy intake (800 kcal) and low carbohydrate (<10%) for 8 weeks. Body compositions, liver fat and hepatic glucose production (HGP) and peripheral glucose disposal before and after the intervention were determined. Results: the caloric restriction reduced liver fat content by 2/3 (p = 0.004). Abdominal subcutaneous and visceral fat, body weight, BMI, waist circumference and fasting plasma triglyceride and free fatty acid concentrations all significantly decreased (p < 0.05). The suppression of post-load HGP was improved by 22% (p = 0.002) whereas glucose disposal was not affected (p = 0.3). Fasting glucose remained unchanged and the changes in the 2-hour plasma glucose and insulin concentration were modest and statistically insignificant (p > 0.05). Liver fat is the only independent variable highly correlated to HGP after the removal of confounders. Conclusion: NAFLD impairs HGP but not peripheral glucose disposal; low carbohydrate caloric restriction effectively lowers liver fat which appears to directly correct the HGP impairment.

Nonalcoholic fatty liver disease: a precursor of the metabolic syndrome

The conventional paradigm of nonalcoholic fatty liver disease representing the "hepatic manifestation of the metabolic syndrome" is outdated. We identified and summarized longitudinal studies that, supporting the association of nonalcoholic fatty liver disease with either type 2 diabetes mellitus or metabolic syndrome, suggest that nonalcoholic fatty liver disease precedes the development of both conditions. Online Medical databases were searched, relevant articles were identified, their references were further assessed and tabulated data were checked. Although several cross-sectional studies linked nonalcoholic fatty liver disease to either diabetes and other components of the metabolic syndrome, we focused on 28 longitudinal studies which provided evidence for nonalcoholic fatty liver disease as a risk factor for the future development of diabetes. Moreover, additional 19 longitudinal reported that nonalcoholic fatty liver disease precedes and is a risk factor for the future development of the metabolic syndrome. Finally, molecular and genetic studies are discussed supporting the view that aetiology of steatosis and lipid intra-hepatocytic compartmentation are a major determinant of whether fatty liver is/is not associated with insulin resistance and metabolic syndrome. Data support the novel paradigm of nonalcoholic fatty liver disease as a strong determinant for the development of the metabolic syndrome, which has potentially relevant clinical implications for diagnosing, preventing and treating metabolic syndrome.

γ-glutamyl transpeptidase in men and alanine aminotransferase in women are the most suitable parameters among liver function tests for the prediction of metabolic syndrome in nonviral hepatitis and nonfatty liver in the elderly

BACKGROUND/AIMS

Nonalchoholic fatty liver disease (NAFLD) has been reported as a hepatic manifestation of metabolic syndrome (MetS); it is common and accounts for 80% of the cases with abnormal liver function tests (LFTs). In addition, several studies have proved that there is a correlation between abnormal LFTs and MetS. Therefore, LFTs may represent the abnormal metabolic status of livers in the patients with MetS. To identify the early state of metabolic dysfunction, we investigate the value of LFTs for the future MetS development in the relatively healthy (non-NAFLD) elderly.

PATIENTS AND METHODS

A total of 16,912 subjects met the criteria for analysis. In the first stage of this study, subjects were enrolled in the cross-sectional study in order to find out the optimal cutoff value in different LFTs with higher chances to have MetS. In the second stage of the present study, subjects with MetS at baseline were excluded from the same study group, and a median 5.6-year longitudinal study was conducted on the rest of the group.

RESULTS

Among all LFTs, only aspartate aminotransferase in both genders and the α-fetal protein in women failed to show the significance in distinguishing subjects with MetS by the receiver operating characteristic curve. In the Kaplan-Meier plot, only γ-glutamyl transpeptidase (γ-GT) in men and the alanine aminotransferase (ALT) in women could be used to successfully separate subjects with higher risk of developing the MetS from those with lower risk. Finally, in the multivariant Cox regression model, similar results were identified. Still, the hazard ratio (HR) to have future MetS, γ-GT in men, and ALT in women showed significance (HR = 1.511 in men and 1.504 in women).

CONCLUSION

Among all the different LFTs, γ-GT (>16 U/L) in male and ALT (>21 U/L) in female were the best predictors for the development of MetS in healthy elderly. These two liver markers could be an ancillary test in predicting future MetS development/diagnosis. Elevation of the LFTs without underlying liver diseases should be treated as a warning sign of the possible MetS development in the elderly.

Elevated levels of alanine transaminase and triglycerides within normal limits are associated with fatty liver

In the present study, the threshold values of laboratory data for the diagnosis of non-alcoholic fatty liver disease (NAFLD) were investigated. The study enrolled patients who had undergone abdominal ultrasound (US) between April 2013 and August 2013, and for whom laboratory data were available on the same day. NAFLD was diagnosed following observations of a bright liver or hepatorenal echo contrast on the abdominal US scans. Patients were excluded from the study if they had liver diseases or had been prescribed prednisolone or methotrexate. Receiver operating characteristic curves, the Wilcoxon signed-rank test and Fisher's exact probability test were used for data analysis. In total, 80 NAFLD and 94 non-NAFLD patients were enrolled in the study. The threshold levels of alanine aminotransferase (ALT) and triglyceride (TG) for the diagnosis of NAFLD were 19.0 IU/l and 101 mg/dl, respectively. Patients were divided into two groups according to the levels of ALT and TG. Those with ALT levels of >19 IU/l and TG levels of >101 mg/dl were defined as the positive group, while the remaining patients were classified as the negative group. The specificity and positive predictive value using the combined threshold levels of ALT >19 IU/l and TG >101 mg/dl were 80.9 and 75.0%, respectively. Therefore, the results indicated that ALT levels of >19 IU/l or TG levels of >101 mg/dl were useful markers for the screening of NAFLD. However, NAFLD was more strongly suspected in patients with ALT levels of >19 IU/l and TG levels of >101 mg/dl.

Beneficial effects of an 8-week, very low carbohydrate diet intervention on obese subjects

Aim. To investigate the effects of weight loss during an 8-week very low carbohydrate diet (VLCD) on improvement of metabolic parameters, adipose distribution and body composition, and insulin resistance and sensitivity in Chinese obese subjects. Methods. Fifty-three healthy obese volunteers were given an 8-week VLCD. The outcomes were changes in anthropometry, body composition, metabolic profile, abdominal fat distribution, liver fat percent (LFP), and insulin resistance and sensitivity. Results. A total of 46 (86.8%) obese subjects completed the study. The VLCD caused a weight loss of −8.7 ± 0.6 kg (mean ± standard error (SE), P < 0.0001) combined with a significant improvement of metabolic profile. In both male and female, nonesterified fatty acid (NEFA) significantly decreased (−166.2 ± 47.6 μmol/L, P = 0.001) and β-hydroxybutyric acid (BHA) increased (0.15 ± 0.06 mmol/L, P = 0.004) after eight weeks of VLCD intervention. The significant reductions in subcutaneous fat area (SFA), visceral fat area (VFA), and LFP were −66.5 ± 7.9 cm², −35.3 ± 3.9 cm², and −16.4 ± 2.4%, respectively (all P values P < 0.0001). HOMA IR and HOMA β significantly decreased while whole body insulin sensitivity index (WBISI) increased (all P values P < 0.001). Conclusion. Eight weeks of VLCD was an effective intervention in obese subjects. These beneficial effects may be associated with enhanced hepatic and whole-body lipolysis and oxidation.

SGLT5 reabsorbs fructose in the kidney but its deficiency paradoxically exacerbates hepatic steatosis induced by fructose

Although excessive fructose intake is epidemiologically linked with dyslipidemia, obesity, and diabetes, the mechanisms regulating plasma fructose are not well known. Cells transfected with sodium/glucose cotransporter 5 (SGLT5), which is expressed exclusively in the kidney, transport fructose in vitro; however, the physiological role of this transporter in fructose metabolism remains unclear. To determine whether SGLT5 functions as a fructose transporter in vivo, we established a line of mice lacking the gene encoding SGLT5. Sodium-dependent fructose uptake disappeared in renal brush border membrane vesicles from SGLT5-deficient mice, and the increased urinary fructose in SGLT5-deficient mice indicated that SGLT5 was the major fructose reabsorption transporter in the kidney. From this, we hypothesized that urinary fructose excretion induced by SGLT5 deficiency would ameliorate fructose-induced hepatic steatosis. To test this hypothesis we compared SGLT5-deficient mice with wild-type mice under conditions of long-term fructose consumption. Paradoxically, however, fructose-induced hepatic steatosis was exacerbated in the SGLT5-deficient mice, and the massive urinary fructose excretion was accompanied by reduced levels of plasma triglycerides and epididymal fat but fasting hyperinsulinemia compared with fructose-fed wild-type mice. There was no difference in food consumption, water intake, or plasma fructose between the two types of mice. No compensatory effect by other transporters reportedly involved in fructose uptake in the liver and kidney were indicated at the mRNA level. These surprising findings indicated a previously unrecognized link through SGLT5 between renal fructose reabsorption and hepatic lipid metabolism.

Alanine aminotransferase is associated with an adverse nocturnal blood glucose profile in individuals with normal glucose regulation

OBJECTIVE

Although the association between alanine aminotransferase (ALT) levels and risk of type 2 diabetes is well-studied, the effects of slightly increased ALT levels within the normal range on the temporal normal glucose profile remains poorly understood.

METHODS

A total of 322 Chinese subjects without impaired glucose tolerance or previous diagnoses of diabetes were recruited for study from 10 hospitals in urban areas across China. All subjects wore a continuous glucose monitoring (CGM) system for three consecutive days. The diurnal (06∶00-20∶00) and nocturnal (20∶00-06∶00) mean blood glucose (MBG) levels were calculated. Subjects were stratified by ALT quartile level and correlation analyses were performed.

RESULTS

The median ALT level was 17 IU/L, and subjects with ALT ≥17 IU/L had higher nocturnal MBG level than those with ALT <17 IU/L (P<0.05). Nocturnal MBG was positively correlated with ALT levels (Pearson correlation analysis: r = 0.187, P = 0.001), and the correlation remained significant after correction for the homeostatic model assessment of insulin resistance index (HOMA-IR) (r = 0.105, P = 0.041). No correlations were found between diurnal MBG and ALT, and nocturnal or diurnal MBG and aspartate aminotransferase or gamma-glutamyltransferase (all, P>0.05). Multivariate stepwise regression analysis of elevated nocturnal MBG identified increased HOMA-IR, elevated ALT levels, and decreased homeostatic model assessment of ß-cell function as independent factors (all, P<0.05).

CONCLUSIONS

Mildly elevated ALT levels, within the normal range, are associated with unfavorable nocturnal glucose profiles in Chinese subjects with normal glucose regulation.

Relation of circulating liver transaminase concentrations to risk of new-onset atrial fibrillation

Heart failure, a strong risk factor for atrial fibrillation (AF), is often accompanied by elevated liver transaminases. The aim of this study was to test the hypothesis that elevated transaminases are associated with the risk for incident AF in the community. A total of 3,744 participants (mean age 65 ± 10 years, 56.8% women) from the Framingham Heart Study Original and Offspring cohorts, free of clinical heart failure, were studied. Cox proportional-hazards models adjusted for standard AF risk factors (age, gender, body mass index, systolic blood pressure, electrocardiographic PR interval, antihypertensive treatment, smoking, diabetes, valvular heart disease, and alcohol consumption) were examined to investigate associations between baseline serum transaminase levels (alanine transaminase and aspartate transaminase) and the incidence of AF over up to 10 years (29,099 person-years) of follow-up. During follow-up, 383 subjects developed AF. The 2 transaminases were significantly associated with greater risk for incident AF (hazard ratio expressed per SD of natural logarithmically transformed biomarker: alanine transaminase hazard ratio 1.19, 95% confidence interval 1.07 to 1.32, p = 0.002; aspartate transaminase hazard ratio 1.12, 95% confidence interval 1.01 to 1.24, p = 0.03). The associations between transaminases and AF remained consistent after the exclusion of participants with moderate to severe alcohol consumption. However, when added to known risk factors for AF, alanine transaminase and aspartate transaminase only subtly improved the prediction of AF. In conclusion, elevated transaminase concentrations are associated with increased AF incidence. The mechanisms by which higher mean transaminase concentrations are associated with incident AF remain to be determined.

Serological prevalence of hepatitis B virus and hepatitis C virus infection in the elderly population: Polish nationwide survey--PolSenior

BACKGROUND

The hepatitis B virus (HBV) and hepatitis C virus (HCV) infections may seriously affect survival rate. The median length of life in developed countries is increasing and the elderly may be considered as an epidemiologically distinct group due to higher whole-life risk of blood-borne viral infections.

AIM

To determine the seroprevalence of HBV and HCV infections in elderly individuals participating in a Polish nationwide survey - PolSenior.

METHODS

A total of 4979 individuals aged 65 years and older were asked about past or present viral hepatitis, and a blood test was carried out for HBsAg and anti-HCV antibodies in 3826 individuals. The respondents were divided into six age groups of equal size: 65-69, 70-74, 75-79, 80-84, 85-89, and 90+ years.

RESULTS

Past or present diagnosis of viral hepatitis was reported by 176 individuals (3.58%) and its prevalence was significantly most common in urban than in rural residents (4.02 vs. 2.92%; P=0.04). In multivariate analysis, only the job category was a significant variable (P=0.01) for the occurrence of viral hepatitis [most frequently in white-collar workers (3.56%) and least frequently in agricultural workers (1.47%)]. The overall prevalence of a positive HBsAg test was 1.12% (n=43) and that of an anti-HCV test was 2.93% (n=112). Only 12 anti-HCV-positive patients (10.7%) were aware of infection. Multivariate analyses did not indicate significant effects of age, sex, alcohol consumption, nutrition, marital or economic status, educational level, and site of residence on the incidence of HBV and HCV infections. HBsAg was associated with higher serum levels of aspartate aminotransferase, and anti-HCV with higher levels of aspartate aminotransferase and alanine aminotransferase.

CONCLUSIONS

In elderly individuals, the seroprevalence of HBsAg is lower and the seroprevalence of anti-HCV is considerably higher than that in the general Polish population. The former may have been because of increased mortality from HBV-related complications and the latter of increased whole-life risk of infection. Programs for screening of elderly individuals for occult HCV infection should be considered.