The association between the metabolic syndrome and alanine amino transferase is mediated by insulin resistance via related metabolic intermediates (the Cohort on Diabetes and Atherosclerosis Maastricht [CODAM] study)

Serum amyloid A and metabolic disease: evidence for a critical role in chronic inflammatory conditions

Serum amyloid A (SAA) subtypes 1-3 are well-described acute phase reactants that are elevated in acute inflammatory conditions such as infection, tissue injury, and trauma, while SAA4 is constitutively expressed. SAA subtypes also have been implicated as playing roles in chronic metabolic diseases including obesity, diabetes, and cardiovascular disease, and possibly in autoimmune diseases such as systemic lupus erythematosis, rheumatoid arthritis, and inflammatory bowel disease. Distinctions between the expression kinetics of SAA in acute inflammatory responses and chronic disease states suggest the potential for differentiating SAA functions. Although circulating SAA levels can rise up to 1,000-fold during an acute inflammatory event, elevations are more modest (∼5-fold) in chronic metabolic conditions. The majority of acute-phase SAA derives from the liver, while in chronic inflammatory conditions SAA also derives from adipose tissue, the intestine, and elsewhere. In this review, roles for SAA subtypes in chronic metabolic disease states are contrasted to current knowledge about acute phase SAA. Investigations show distinct differences between SAA expression and function in human and animal models of metabolic disease, as well as sexual dimorphism of SAA subtype responses.

Individual and combined relationship of serum uric acid and alanine aminotransferase on metabolic syndrome in adults in Qingdao, China

BACKGROUND AND AIMS

Associations of alanine aminotransferase (ALT) and serum uric acid (SUA) with metabolic syndrome (MetS) remain controversial. We aimed to explore individual and combined effects of ALT and SUA on MetS in community residents.

METHODS AND RESULTS

A population-based cross-sectional survey involving randomly selected Chinese adults aged 35-74 years was conducted in 2009 in Qingdao, China, and 4642 participants were included in the current study. Based on a combination of SUA and ALT levels in the tertile, subjects were grouped into Group 1-9. The individual and combined relations of SUA and ALT to MetS were analyzed by logistic regression models. The prevalence of MetS was 28.50% in males and 22.30% in females. ALT and SUA were independently associated with MetS and ORs (95% CIs) were 1.55 (1.42-1.70) and 1.92 (1.72-2.14), respectively, after adjusting for potential confounders. With the elevation of ALT and SUA levels, the risk of developing MetS increased. Compared to Group 1, ORs (95% CIs) of combined ALT and SUA for MetS were 2.21 (1.70-2.88), 4.02 (3.10-5.21), 2.19 (1.62-2.97), 2.53 (1.91-3.34), 4.69 (3.60-6.12), 1.76 (1.17-2.64), 3.65 (2.63-5.06) and 7.15 (5.41-9.46) in Group 2-9, respectively.

CONCLUSIONS

ALT and SUA were both related to MetS independently. Combined elevation of ALT and SUA levels could increase the risk of MetS and its components than an elevation in SUA and ALT alone. Therefore, measures should be taken to lower SUA and ALT levels to reduce the risk of having MetS.

Phenome-Wide Association Analysis Reveals Novel Links Between Genetically Determined Levels of Liver Enzymes and Disease Phenotypes

Serum liver enzymes (alanine aminotransferase [ALT], aspartate aminotransferase [AST], λ-glutamyl transferase [GGT] and alkaline phosphatase [ALP]) are the leading biomarkers to measure liver injury, and they have been reported to be associated with several intrahepatic and extrahepatic diseases in observational studies. We conducted a phenome-wide association study (PheWAS) to identify disease phenotypes associated with genetically predicted liver enzymes based on the UK Biobank cohort. Univariable and multivariable Mendelian randomization (MR) analyses were performed to obtain the causal estimates of associations that detected in PheWAS. Our PheWAS identified 40 out of 1,376 pairs (16, 17, three and four pairs for ALT, AST, GGT and ALP, respectively) of genotype-phenotype associations reaching statistical significance at the 5% false discovery rate threshold. A total of 34 links were further validated in Mendelian randomization analyses. Most of the disease phenotypes that associated with genetically determined ALT level were liver-related, including primary liver cancer and alcoholic liver damage. The disease outcomes associated with genetically determined AST involved a wide range of phenotypic categories including endocrine/metabolic diseases, digestive diseases, and neurological disorder. Genetically predicted GGT level was associated with the risk of other chronic non-alcoholic liver disease, abnormal results of function study of liver, and cholelithiasis. Genetically determined ALP level was associated with pulmonary heart disease, phlebitis and thrombophlebitis of lower extremities, and hypercholesterolemia. Our findings reveal novel links between liver enzymes and disease phenotypes providing insights into the full understanding of the biological roles of liver enzymes.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43657-021-00033-y.

Associations between sex hormones and metabolic-associated fatty liver disease in a middle-aged and elderly community

Metabolic-associated fatty liver disease (MAFLD) was proposed by an international expert consensus to replace non-alcoholic fatty liver disease (NAFLD) in 2020. Previous studies have shown that sex hormones are strongly linked to NAFLD development. This study aims to explore whether sex hormones are associated with MAFLD and liver fat content (LFC) in a middle-aged and elderly community. The study included 732 subjects aged 50-80 years enrolled from communities. MAFLD was diagnosed using the 2020 International Expert Consensus. LFC was calculated using parameters from abdominal ultrasound images. Serum estradiol (E2), total testosterone (TT), sex hormone-binding globulin (SHBG), FSH, and LH were measured by chemiluminescent microparticle immunoassay. MAFLD was diagnosed in 107/304 (35.2%) men and 154/428 (35.2%) women. After adjustments for confounding factors, logistic regression analysis showed that SHBG was negatively correlated with MAFLD in men (OR, 0.95 [0.93-0.97], p < 0.001). In women, SHBG and FSH were negatively correlated with MAFLD (OR, 0.95 [0.94-0.97], p < 0.001; OR, 0.97 [0.96-0.98], p < 0.001). Multivariate linear regression analysis showed that SHBG was a negative factor for LFC in both men (standardized β = -0.188, p < 0.001) and women (standardized β = -0.184, p < 0.001). FSH was a negative factor for LFC in women (standardized β = -0.082, p = 0.046). SHBG was negatively correlated with MAFLD in middle-aged and elderly men and women. Moreover, FSH was negatively correlated, and bioactive testosterone was positively correlated with MAFLD in women. These findings suggest a relationship between sex hormones and MAFLD.

Coagulation and Endothelial Dysfunction Associated with NAFLD: Current Status and Therapeutic Implications

Non-alcoholic fatty liver disease (NAFLD) is closely related to insulin resistance, type 2 diabetes mellitus and obesity. It is considered a multisystem disease and there is a strong association with cardiovascular disease and arterial hypertension, which interfere with changes in the coagulation system. Coagulation disorders are common in patients with hepatic impairment and are dependent on the degree of liver damage. Through a review of the literature, we consider and discuss possible disorders in the coagulation cascade and fibrinolysis, endothelial dysfunction and platelet abnormalities in patients with NAFLD.

Metabolically Healthy and Unhealthy Obese Phenotypes among Arabs and South Asians: Prevalence and Relationship with Cardiometabolic Indicators

Obesity is a public health crisis in Kuwait. However, not all obese individuals are metabolically unhealthy (MuHO) given the link between obesity and future cardiovascular events. We assessed the prevalence of the metabolically healthy obese (MHO) phenotype and its relationship with high sensitivity C-reactive protein (hs-CRP), serum alanine aminotransferase (ALT), and insulin resistance (HOMA-IR) in Arab and South Asian ethnic groups in Kuwait. The national cross-sectional survey of diabetes and obesity in Kuwait adults aged 18-60 years were analysed. The harmonised definition of metabolic syndrome was used to classify metabolic health. Multinomial logistic regression analysis was used to model the relationship between the MHO and MuHO phenotypes and hs-CRP, ALT and HOMA-IR levels. Overall, the prevalence of MHO for body mass index (BMI)- and waist circumference (WC)-defined obesity was 30.8% and 56.0%, respectively; it was greater in women (60.4% and 61.8%, respectively) than men (39.6% and 38.2%, respectively). Prevalence rates were also lower for South Asians than for Arabs. The MHO phenotype had hs-CRP values above 3 µg/mL for each age group category. Men compared to women, and South Asians compared to Arabs had a lower relative risk for the MHO group relative to the MuHO group. This study shows there is high prevalence of MHO in Kuwait.

Role of Leptin in Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD), which affects about a quarter of the global population, poses a substantial health and economic burden in all countries, yet there is no approved pharmacotherapy to treat this entity, nor well-established strategies for its diagnosis. Its prevalence has been rapidly driven by increased physical inactivity, in addition to excessive calorie intake compared to energy expenditure, affecting both adults and children. The increase in the number of cases, together with the higher morbimortality that this disease entails with respect to the general population, makes NAFLD a serious public health problem. Closely related to the development of this disease, there is a hormone derived from adipocytes, leptin, which is involved in energy homeostasis and lipid metabolism. Numerous studies have verified the relationship between persistent hyperleptinemia and the development of steatosis, fibrinogenesis and liver carcinogenesis. Therefore, further studies of the role of leptin in the NAFLD spectrum could represent an advance in the management of this set of diseases.

Scoring system for gallbladder polyps based on the cross-sectional area and patient characteristics

BACKGROUND

Current management guidelines for gallbladder polyps (GBPs) focus on a diameter more than 1 cm as an indication for cholecystectomy. Since most GBPs are not malignant, unnecessary cholecystectomies can lead to unnecessary complications and costs. We developed a score to identify true polyps focusing on their cross-sectional area (CSA).

METHODS

We retrospectively analyzed the demographic, clinical, laboratory, and sonographic characteristics of 522 patients with GBPs who had undergone cholecystectomy at our hospital between January 2010 and July 2020 (reference group). We used univariate analysis to compare these parameters between 88 true polyps and 434 pseudopolyps and multivariate logistic regression analysis to identify parameters to include in our scoring model. Receiver operating characteristics and area under the curve were used to identify cut-off values. The model was tested on a validation group of 98 patients.

RESULTS

In the multivariate analysis, a CSA >123 mm², positive blood flow signal, age >55.5 years, alanine aminotransferase (ALT) levels > 50 U/L, and an ALT/aspartate aminotransferase ratio > 0.77 were significantly associated with true polyps (odds ratio 6.528, 2.377, 2.617, 2.445, and -0.372, respectively). A prediction model based on cut-off values was used to distinguish a low-risk and high-risk GBP group; true polyps accounted for 6.54% and 58.72%, respectively (p < 0.001). In the low-risk and high-risk validation groups, true polyps comprised 12.35% and 82.35%, respectively (p < 0.001).

CONCLUSIONS

Our scoring system shows high accuracy and specificity in identifying true polyps and helps determine the need for surgical resection.

The Association between Metabolic Syndrome and Elevated Alanine Aminotransferase Levels in an Indigenous Population in Northern Taiwan: A Community-Based and Cross-Sectional Study

Our study aims to determine the prevalence of metabolic syndrome (MetS) among the Northern Taiwanese indigenous population and to explore the relationship between MetS and liver enzyme, especially serum alanine transaminase (ALT). This is an observational and cross-sectional study that was conducted in remote villages of an indigenous community in Northern Taiwan between 2010 and 2015. MetS was defined based on the revised NCEP/ATPIII criteria from Taiwan Health Promotion Administration. A total of 454 participants were included in the analysis. There were 277 people with MetS and 177 people without. The prevalence of MetS was 61.01%. The average age was 49.50 years. People with MetS had a significantly higher liver enzyme (ALT) level than those without MetS. In addition, the study showed that participants with higher ALT had a tendency towards a higher prevalence of MetS (76.7% vs. 57.3%, p = 0.001). The adjusted odds ratio (OR) of ALT levels >36 U/L for MetS was 2.79 (95% CI = 1.24–6.27, p = 0.01). The area under the ROC curve (AUC) of the ALT level was 0.63 (95% CI = 0.58–0.68, p < 0.001), which showed that the ALT level was positively associated with MetS. The overall prevalence of MetS was 61.01% in the highland indigenous population in Northern Taiwan; this study indicated that higher serum ALT levels were associated with an increased risk of MetS.

RNA-sequencing analysis of the effect of luteolin on methamphetamine-induced hepatotoxicity in rats: a preliminary study

In this study, RNA-sequencing (RNA-seq) was utilized to investigate the effects of luteolin on hepatotoxicity caused by methamphetamine (METH). The rats in METH group were administrated with METH (15 mg/kg, two times per day) via intraperitoneal (i.p.) injections for four consecutive days. The rats in luteolin + METH group were firstly administrated with luteolin (100 mg/kg, once a day) by oral gavage for 3 days before METH treatment. Lueolin attenuated the hepatotoxicity induced by METH via histopathological and biochemical analysis. The results of RNA-seq showed that luteolin could regulate 497 differentially expressed genes (DEGs), and the selected DEGs were mainly enriched in eight pathways, according to KEGG analysis. Furthermore, qRT-PCR was utilized to verify the results of RNA-seq. Six genes were selected as follows: liver enriched antimicrobial peptide 2 (Leap2), fatty acid synthase (Fasn), fatty acid binding protein 5 (Fabp5), patatin like phospholipase domain containing 3 (Pnpla3), myelin basic protein (Mbp) and calmodulin 3 (Calm3). Though because of the design flaws, the luteolin group has not been included, this study demonstrated that luteolin might exert hepato-protective effects from METH via modulation of oxidative phosphorylation, cytochrome P450 and certain signaling pathways.

Alanine Aminotransferase and Body Composition in Obese Men and Women

There is a known relationship between serum alanine aminotransferase (ALT) and obesity in humans, but the mechanism(s) are not clarified. This study investigated the associations between serum ALT and body composition in an overweight and obese population. The results are based on data from a previous randomized controlled trial treating obesity with vitamin D₃. A sample of 448 overweight and obese individuals underwent dual-energy X-ray absorptiometry (DEXA) and measured serum ALT along with supplementary blood samples at study baseline. Body fat mass and lean mass indexes were calculated by dividing total body fat/lean weight (kg) by body height squared (kg/m²). ALT correlated with body mass index (BMI) in men but not women (r = 0.33, P < 0.0001 vs. r = 0.06, P = 0.29). In men, serum ALT correlated positively with fat mass index (r = 0.23, P = 0.004) and lean mass index (r = 0.32, P < 0.0001). In women, ALT correlated with lean mass index (r = 0.13, P = 0.031) but not fat mass index (r = 0.003, P = 0.96). In a multivariate model adjusted for age and fat mass index, a 1-unit increase in lean mass index associated with a 0.37 U/L higher ALT in the male subgroup (95% CI 0.024 to 0.040, P < 0.0001). In conclusion, serum ALT was associated with body fat mass index in men and with lean mass index in men and women in an overweight and obese population. The findings also demonstrate a gender difference in the role of fat.

High dietary glycemic load is associated with higher concentrations of urinary advanced glycation endproducts: the Cohort on Diabetes and Atherosclerosis Maastricht (CODAM) Study

BACKGROUND

Advanced glycation endproducts (AGEs) and their precursors (dicarbonyls) are associated with the progression of diseases such as diabetes and cardiovascular disease. Plasma concentrations of dicarbonyls methylglyoxal (MGO), glyoxal (GO), and 3-deoxyglucosone (3-DG) are increased after an oral glucose load indicating that consumption of diets high in carbohydrates may induce the endogenous formation of dicarbonyls and AGEs.

OBJECTIVE

To examine the associations of dietary glycemic index (GI) and glycemic load (GL) with concentrations of dicarbonyls and AGEs in plasma and urine.

METHODS

Cross-sectional analyses were performed in a human observational cohort [Cohort on Diabetes and Atherosclerosis Maastricht (CODAM), n = 494, 59 ± 7 y, 25% type 2 diabetes]. GI and GL were derived from FFQs. Dicarbonyls and AGEs were measured in the fasting state by ultra-performance liquid chromatography-tandem MS. MGO, GO, and 3-DG and protein-bound Nε-(carboxymethyl)lysine (CML), Nε-(1-carboxyethyl)lysine (CEL), and pentosidine were measured in plasma. Free forms of CML, CEL, and Nδ-(5-hydro-5-methyl-4-imidazolon-2-yl)-ornithine (MG-H1) were measured in both plasma and urine. Multiple linear regression was performed with dicarbonyls and AGEs as dependent variables, and dietary GI or GL as main independent variables (all standardized). Models were adjusted for health and lifestyle factors, dietary factors, and reciprocally for GI and GL. As this was an explorative study, we did not adjust for multiple testing.

RESULTS

GI was not associated with any of the dicarbonyls or AGEs. GL was positively associated with free urinary MG-H1 (β = 0.34; 95% CI: 0.12, 0.55). Furthermore, GL was positively associated with free plasma MG-H1 and free urinary CML (β = 0.23; 95% CI: 0.02, 0.43; and β = 0.28; 95% CI: 0.06, 0.50), but these associations were not independent of dietary AGE intake.

CONCLUSIONS

A habitual diet higher in GL is associated with higher concentrations of free urinary MG-H1. This urinary AGE is most likely a reflection of AGE accumulation and degradation in tissues, where they may be involved in tissue dysfunction.

Association of sex hormone-binding globulin with nonalcoholic fatty liver disease in Chinese adults

Background

Sex hormone-binding globulin (SHBG), a glycoprotein synthesized by hepatocytes, has been linked to insulin resistance and hepatic lipid metabolism and is suggested to be associated with nonalcoholic fatty liver disease (NAFLD). This study aimed to investigate the association of SHBG with NAFLD in Chinese adults.

Methods

We conducted a community-based, cross-sectional study in China involving 2912 participants aged 40–75 years old. All participants underwent detection for hepatic fat infiltration by ultrasound in addition to providing complete medical history and undergoing physical and blood biochemical examinations. The association of serum SHBG with the presence of NAFLD was reported by adjusted odds ratio after applying logistic regression models. To further explore the relationship between SHBG and NAFLD, mRNA expression of SHBG and hepatocyte nuclear factor 4-α (HNF4α), as well as intrahepatic triglycerides, were determined from the liver tissues of 32 subjects with different degrees of steatosis.

Results

Serum SHBG levels in patients with NAFLD (median, 43.8 nmol/L; interquartile range, 33.4–56.8 nmol/L) were significantly lower than those in non-NAFLD subjects (median, 63.4 nmol/L; interquartile range, 47.6–83.1 nmol/L). Serum SHBG levels were inversely correlated with WHR, trunk fat percentage, glucose, HOMA-IR, TG, UA and DHEAS, and were positively correlated with HDL-C levels (all p <  0.001). Logistic regression analysis indicated that serum SHBG levels were negatively associated with the presence of NAFLD in all subjects, as well as the subgroups stratified by sex, BMI and HOMA-IR (all p <  0.05). In human liver tissues, SHBG and HNF4α mRNA expression decreased along with the elevated grade of hepatic steatosis. Both SHBG and HNF4α mRNA expression levels were negatively correlated with intrahepatic triglycerides.

Conclusions

These results demonstrate that SHBG levels were negatively associated with the presence of NAFLD in middle-aged and elderly Chinese adults.

Electronic supplementary material

The online version of this article (10.1186/s12986-018-0313-8) contains supplementary material, which is available to authorized users.

Correlation between normal range of serum alanine aminotransferase level and metabolic syndrome: A community-based study

Serum alanine aminotransferase (ALT) is a biomarker of hepatocyte damage. However, the relationship between normal range of serum ALT level and metabolic syndrome (MetS) has not been completely understood. This study aimed to investigate the correlation between normal range of serum ALT level and MetS.A total of 2453 participants from the Beijing Community Pre-Diabetes study were enrolled. Multiple linear regression analysis was performed to calculate the regression coefficient. Normal serum ALT levels were divided into quartiles. Logistic regression model was used to compare the relative risk of MetS, and the receiver operating characteristic (ROC) curve to calculate the optimal ALT boundary value for predicting MetS.The frequency of MetS increased with the ALT level within the normal range. Compared with the first group, the risk of MetS was greater in the other quartiles of ALT level in males, the difference was significant for the fourth group. For females, the risk of MetS increased with ALT level within the normal range as well, with all differences showing statistical significance. The optimal ALT boundary value of the ROC curve for males and females was 24.5 and 14.5 U/L, respectively.ALT was related to metabolic factors and used as one of the indicators to assess the morbidity risk of metabolic diseases.

The Transplantation of ω3 PUFA-Altered Gut Microbiota of fat-1 Mice to Wild-Type Littermates Prevents Obesity and Associated Metabolic Disorders

Altering the gut microbiome may be beneficial to the host and recently arose as a promising strategy to manage obesity. Here, we investigated the relative contribution of ω3 polyunsaturated fatty acid (PUFA)-mediated alterations in the microbiota to metabolic parameter changes in mice. Four groups were compared: male fat-1 transgenic mice (with constitutive production of ω3 PUFAs) and male wild-type (WT) littermates fed an obesogenic (high fat/high sucrose [HFHS]) or a control diet. Unlike WT mice, HFHS-fed fat-1 mice were protected against obesity, glucose intolerance, and hepatic steatosis. Unlike WT mice, fat-1 mice maintained a normal barrier function, resulting in a significantly lower metabolic endotoxemia. The fat-1 mice displayed greater phylogenic diversity in the cecum, and fecal microbiota transplantation from fat-1 to WT mice was able to reverse weight gain and to normalize glucose tolerance and intestinal permeability. We concluded that the ω3 PUFA-mediated alteration of gut microbiota contributed to the prevention of metabolic syndrome in fat-1 mice. It occurred independently of changes in the PUFA content of host tissues and may represent a promising strategy to prevent metabolic disease and preserve a lean phenotype.

Sex-specific reference intervals of hematologic and biochemical analytes in Sprague-Dawley rats using the nonparametric rank percentile method

BACKGROUND

Hematologic and biochemical analytes of Sprague-Dawley rats are commonly used to determine effects that were induced by treatment and to evaluate organ dysfunction in toxicological safety assessments, but reference intervals have not been well established for these analytes. Reference intervals as presently defined for these analytes in Sprague-Dawley rats have not used internationally recommended statistical method nor stratified by sex. Thus, we aimed to establish sex-specific reference intervals for hematologic and biochemical parameters in Sprague-Dawley rats according to Clinical and Laboratory Standards Institute C28-A3 and American Society for Veterinary Clinical Pathology guideline.

METHODS

Hematology and biochemistry blood samples were collected from 500 healthy Sprague-Dawley rats (250 males and 250 females) in the control groups. We measured 24 hematologic analytes with the Sysmex XT-2100i analyzer, 9 biochemical analytes with the Olympus AU400 analyzer. We then determined statistically relevant sex partitions and calculated reference intervals, including corresponding 90% confidence intervals, using nonparametric rank percentile method.

RESULTS

We observed that most hematologic and biochemical analytes of Sprague-Dawley rats were significantly influenced by sex. Males had higher hemoglobin, hematocrit, red blood cell count, red cell distribution width, mean corpuscular volume, mean corpuscular hemoglobin, white blood cell count, neutrophils, lymphocytes, monocytes, percentage of neutrophils, percentage of monocytes, alanine aminotransferase, aspartate aminotransferase, and triglycerides compared to females. Females had higher mean corpuscular hemoglobin concentration, plateletcrit, platelet count, eosinophils, percentage of lymphocytes, percentage of eosinophils, creatinine, glucose, total cholesterol and urea compared to males. Sex partition was required for most hematologic and biochemical analytes in Sprague-Dawley rats. We established sex-specific reference intervals, including corresponding 90% confidence intervals, for Sprague-Dawley rats.

CONCLUSIONS

Understanding the significant discrepancies in hematologic and biochemical analytes between male and female Sprague-Dawley rats provides important insight into physiological effects in test rats. Establishment of locally sex-specific reference intervals allows a more precise evaluation of animal quality and experimental results of Sprague-Dawley rats in our toxicology safety assessment.

Systemic Perturbations of Key Metabolites in Type 2 Diabetic Rats Treated by Polyphenol Extracts from Litchi chinensis Seeds

Our previous research obtained Litchi chinensis Sonn. seeds extract (LSE) which showed hypoglycaemic effects on type 2 diabetes (T2D) rats. In order to understand the detailed pathogenesis of diabetes intervened by LSE, the metabonomics strategy was used. As a result, LSE decreased the insulin resistance index and the levels of glucose in urine through elevating the mRNA level of insulin, while decreasing the expression of glucagon to enhance the function of the pancreas. Meanwhile, LSE regulated the glucose and fatty acid metabolisms via increasing the expression of glucose transporter (Glu) 2, Glu4, insulin receptor (IR), and IR substrate-2 (IRS2). LSE effectively restored the impairment of the IRS2/PI3K/Akt/mTOR insulin signaling in the livers. All in all, LSE played a pivotal role in the treatment of T2D through regulation of broad-spectrum metabolic changes and inhibition of the glycogenesis, proteolysis, and lipogenesis in T2D rats.

High serum alanine aminotransferase is associated with the risk of colorectal adenoma in Korean men

BACKGROUND AND AIM

An elevated alanine aminotransferase (ALT) is frequently observed in subjects with metabolic syndrome, which is associated with the risk of colorectal adenoma (CRA). However, the relationship between ALT and CRA remains unclear. Therefore, we aimed to investigate whether high serum ALT is associated with the risk of CRA in a metabolically healthy population.

METHODS

We conducted this cross-sectional study in 27,717 asymptomatic Korean adults who underwent a health checkup. Subjects were categorized as adenoma-free, hyperplastic polyp, low-risk adenoma, or high-risk adenoma. High-risk adenoma was defined as three or more adenomas, any adenoma ≥ 10 mm, or adenoma with high-grade dysplasia or villous features.

RESULTS

Among all participants, 10.3% and 1.5% of cases were categorized as low-risk and high-risk adenoma, respectively. In multivariate analyses adjusting for age, sex, body mass index, smoking habits, alcohol intake, regular exercise, aspirin and analgesics use, family history of colon cancer, education level, fatty liver, high-sensitivity C reactive protein, homeostasis model assessment of insulin resistance, total cholesterol, and triglyceride, an increase in ALT was positively associated with the prevalence of low-risk and high-risk adenoma (P for trend = 0.029 and 0.027, respectively). The highest quartile group of ALT level showed a significantly increased prevalence in low-risk (odds ratio, 1.17) and high-risk adenoma (odds ratio, 1.48) groups compared with the lowest quartile group. This phenomenon persisted in the subgroup analysis in men, but not in women.

CONCLUSIONS

In the asymptomatic healthy population, high serum ALT is significantly associated with the risk of CRA.

Hepatic, lipid and genetic factors associated with obesity: crosstalk with alcohol dependence?

OBJECTIVES

Alcohol dependence represents a leading cause of mortality and morbidity. Understanding the variables that contribute to this diagnosis and its severity is critical. An overlap between factors that may predispose people to become obese and those that may increase the risk of alcohol dependence may exist. However, data in the literature are not conclusive. Therefore, this study aimed to identify the association between alcohol dependence and obesity-related factors, including biochemical and genetic factors.

METHODS

In a case-control study with 829 participants, factors involved with metabolism and obesity were assessed, including biochemical lipid and liver markers, and the fat mass and obesity-associated (FTO) single nucleotide polymorphism (SNP) rs8050136.

RESULTS

Increased triglycerides, having one or two minor A alleles for rs8050136 and being a smoker were associated with increased risk of alcohol dependence, while increased low-density lipoprotein cholesterol was associated with decreased risk. In addition, having abnormal gamma-glutamyl transferase and being female were factors associated with an increased severity of alcohol dependence.

CONCLUSIONS

Our preliminary findings suggest a link between alcohol dependence and obesity-related biochemical and genetic factors. Future studies are needed to better understand if these factors may play a predictive role and/or may act as biomarkers for treatment response.

Discriminatory ability of simple OGTT-based beta cell function indices for prediction of prediabetes and type 2 diabetes: the CODAM study

AIMS/HYPOTHESIS

The hyperglycaemic clamp technique and the frequently sampled IVGTT are unsuitable techniques to assess beta cell function (BCF) in large cohorts. Therefore, the aim of this study was to evaluate the discriminatory ability of simple OGTT-based BCF indices for prediction of prediabetes (meaning impaired fasting glucose and/or impaired glucose tolerance) and type 2 diabetes.

METHODS

Glucose metabolism status was assessed by 2 h 75 g OGTT at baseline (n = 476, mean age 59.2 years, 38.7% women) and after 7 years of follow-up (n = 416) in the Cohort on Diabetes and Atherosclerosis Maastricht (CODAM) study (1999-2009). Baseline plasma glucose, insulin and C-peptide values during OGTTs were used to calculate 21 simple indices of BCF. Disposition indices (BCF index × Matsuda index), to compensate for the prevailing level of insulin resistance, were calculated for the BCF indices with the best discriminatory abilities. The discriminatory ability of the BCF indices was estimated by the area under the receiver operating characteristics curve (ROC AUC) with an outcome of incident prediabetes (n = 73) or type 2 diabetes (n = 60 and n = 18 cases, respectively, in individuals who were non-diabetic or had normal glucose metabolism at baseline).

RESULTS

For incident prediabetes (n = 73), all ROC AUCs were less than 70%, whereas for incident type 2 diabetes, I₃₀/I₀, CP₃₀/CP₀, ΔI₃₀/ΔG₃₀, ΔCP₃₀/ΔG₃₀ (where I, CP and G are the plasma concentrations of insulin, C-peptide and glucose, respectively, at the times indicated), and corrected insulin response at 30 min had ROC AUCs over 70%. In at-baseline non-diabetic individuals, disposition indices ΔI₃₀/ΔG₃₀, ΔCP₃₀/ΔG₃₀ and corrected insulin response at 30 min had ROC AUCs of over 80% for incident type 2 diabetes. Moreover, these BCF disposition indices had significantly better discriminatory abilities for incident type 2 diabetes than the Matsuda index alone.

CONCLUSIONS/INTERPRETATION

BCF indices reflecting early-phase insulin secretion have the best ability to discriminate individuals who will develop prediabetes and type 2 diabetes. Of these, ΔCP₃₀/ΔG₃₀, often referred to as the C-peptidogenic index, performed consistently well.

Liver Enzymes and Risk of Ischemic Heart Disease and Type 2 Diabetes Mellitus: A Mendelian Randomization Study

We used Mendelian randomization to estimate the causal effects of the liver enzymes, alanine aminotransferase (ALT), alkaline phosphatase (ALP) and gamma glutamyltransferase (GGT), on diabetes and cardiovascular disease, using genetic variants predicting these liver enzymes at genome wide significance applied to extensively genotyped case-control studies of diabetes (DIAGRAM) and coronary artery disease (CAD)/myocardial infarction (MI) (CARDIoGRAMplusC4D 1000 Genomes). Genetically higher ALT was associated with higher risk of diabetes, odds ratio (OR) 2.99 per 100% change in concentration (95% confidence interval (CI) 1.62 to 5.52) but ALP OR 0.92 (95% CI 0.71 to 1.19) and GGT OR 0.88 (95% CI 0.75 to 1.04) were not. Genetically predicted ALT, ALP and GGT were not clearly associated with CAD/MI (ALT OR 0.74, 95% CI 0.54 to 1.01, ALP OR 0.86, 95% CI 0.64 to 1.16 and GGT OR 1.08, 95% CI 0.97 to 1.19). We confirm observations of ALT increasing the risk of diabetes, but cannot exclude the possibility that higher ALT may protect against CAD/MI. We also cannot exclude the possibility that GGT increases the risk of CAD/MI and reduces the risk of diabetes. Informative explanations for these potentially contradictory associations should be sought.

Do symbiotic and Vitamin E supplementation have favorite effects in nonalcoholic fatty liver disease? A randomized, double-blind, placebo-controlled trial

Background:

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the world. Oral administration of symbiotic and Vitamin E has been proposed as an effective treatment in NAFLD patients. This study was carried out to assess the effects of symbiotic and/or Vitamin E supplementation on liver enzymes, leptin, lipid profile, and some parameters of insulin resistance (IR) in NAFLD patients.

Materials and Methods:

We randomly assigned sixty NAFLD adult patients to receive (1) symbiotic twice daily + Vitamin E-like placebo capsule; (2) 400 IU/d Vitamin E + symbiotic-like placebo; (3) symbiotic twice daily + 400 IU/d Vitamin E; and (4) symbiotic-like placebo + Vitamin E-like placebo for 8 weeks.

Results:

Symbiotic plus Vitamin E supplementation led to a significant decrease in concentrations of liver transaminase (P ≤ 0.05). Mean difference of apolipoprotein A-1 was more significant in symbiotic group compared to control. However, mean difference of apolipoprotein B100/A-1 was only significant in symbiotic group compared to control. At the end of the study, significant differences in total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) were seen between the symbiotic plus Vitamin E and control groups (P < 0.001). Furthermore, intake of symbiotic plus Vitamin E supplements led to a significant decrease in concentrations of triglycerides (TG) after the intervention. Significant differences in leptin, fasting blood sugar (FBS), and insulin levels were seen between the symbiotic plus Vitamin E and control groups at the end of the study (P < 0.001). In contrast, symbiotic and/or Vitamin E supplementation did not affect high-density lipoprotein cholesterol and homeostasis model assessment for IR levels.

Conclusion:

In our study, symbiotic plus Vitamin E supplementation was the most effective treatment in lowering liver enzymes, leptin, FBS, insulin, TG, TC, and LDL-C among NAFLD patients.

Adipokines in nonalcoholic fatty liver disease

Since the discovery of adipose tissue as a higly active endocrine tissue, adipokines, peptides produced by adipose tissue and exerting autocrine, paracrine and endocrine function, have gained increasing interest in various obesity-related diseases, including nonalcoholic fatty liver disease (NAFLD). Data regarding the association between NAFLD and circulating leptin and adiponectin levels are generally well documented: leptin levels increase, whereas adiponectin levels decrease, by increasing the severity of NAFLD. Data regarding other adipokines in histologically confirmed NAFLD populations are inconclusive (e.g., resistin, visfatin, retinol-binding protein-4, chemerin) or limited (e.g., adipsin, obestatin, omentin, vaspin etc.). This review summarizes evidence on the association between adipokines and NAFLD. The first part of the review provides general consideration on the interplay between adipokines and NAFLD, and the second part provides evidence on specific adipokines possibly involved in NAFLD pathogenesis. A thorough insight into the pathophysiologic mechanisms linking adipokines with NAFLD may result in the design of studies investigating the combined adipokine use as noninvasive diagnostic markers of NAFLD and new clinical trials targeting the treatment of NAFLD.

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.

Leptin in nonalcoholic fatty liver disease: a narrative review

Leptin, the first described adipokine, interplays with hepatic metabolism. The aim of this review was to summarize available data on the association between leptin and nonalcoholic fatty liver disease (NAFLD). Leptin has a potential dual action on NAFLD experimental models, exerting a possible anti-steatotic, but also a proinflammatory and profibrogenic action. Observational clinical studies have shown higher or similar leptin levels between simple steatosis and nonalcoholic steatohepatitis (NASH) compared with controls. Interventional studies showed that circulating leptin diminishes together with body mass index after successful weight loss following lifestyle modifications or bariatric surgery. Studies providing evidence for the effect of other medications on leptin levels in NAFLD populations are limited and of low power. Data from small studies claim that recombinant leptin administration had a possibly beneficial effect on steatosis, but not fibrosis, in NAFLD patients with hypoleptinemia. Although the aforementioned dual leptin action has not yet been validated in humans, leptin administration in NAFLD patients with normoleptinemia or hyperleptinemia is discouraged. Further well-controlled studies in cautiously selected populations are needed to elucidate whether leptin has any prognostic and therapeutic role in NAFLD patients.

Fatty liver and serum cholinesterase are independently correlated with HbA1c levels: cross-sectional analysis of 5384 people

OBJECTIVES

To examine the association between glycosylated haemoglobin (HbA1c) and fatty liver markers.

METHODS

This cross-sectional analysis stratified subjects into quintiles based on HbA1c. Fatty liver using ultrasonography scores (FLUS) were assigned as follows: 2 points, moderate or severe fatty liver; 1 point, mild fatty liver; and 0 points, normal liver. Subjects with viral hepatitis, alcohol intake >175 g/week or receiving hypoglycaemic treatment were excluded.

RESULTS

The study included 5384 subjects. Serum cholinesterase (ChE) and FLUS showed a significant graded increase with increasing HbA1c. In linear regression analysis stratified by body mass index (BMI) and age, ChE and FLUS were significantly associated with lower (1 + 2) and higher (3 + 4 + 5) HbA1c quintiles, respectively, independent of BMI and age.

CONCLUSIONS

The findings show that both ChE and FLUS are significantly correlated with HbA1c, independent of BMI and age.

Irisin in patients with nonalcoholic fatty liver disease

OBJECTIVE

Irisin is a recently discovered myokine proposed to increase thermogenesis-related energy expenditure and improve metabolism. We aimed to comparatively evaluate serum irisin levels in patients with biopsy-proven nonalcoholic fatty liver disease (NAFLD) vs. controls and study their association with disease severity.

METHODS

Fifteen and 16 consecutively enrolled patients with biopsy-proven nonalcoholic simple steatosis (NAFL) and steatohepatitis (NASH), respectively, and 24 lean and 28 obese controls without NAFLD were recruited. Irisin, established adipokines and biochemical tests were measured.

RESULTS

Serum irisin levels were statistically different in obese controls (33.7±2.7 ng/mL; p<0.001) and patients with NAFL (30.5±1.5 ng/mL; p<0.001) and NASH (35.8±1.9 ng/mL; p=0.001) compared with lean controls (47.7±2.0 ng/mL), but were similar among patients with NAFL, NASH and obese controls. This difference remained significant after adjustment for body mass index (or waist circumference), gender, age, insulin resistance (assessed by HOMA-IR or QUICKI), exercise and time since blood collection. Serum leptin and adiponectin, but not irisin, levels were independently from BMI correlated with insulin resistance and cardiometabolic factors. Serum irisin tended to be higher in patients with (36.7±2.4 ng/mL) than without (30.8±1.2 ng/mL; p=0.02) portal inflammation and independently associated with the latter; these data need to be confirmed by future studies.

CONCLUSIONS

Serum irisin levels differ between lean controls and obese controls or NAFLD patients. Despite similar circulating irisin levels between NAFL and NASH groups, irisin may be independently and positively associated with the presence of portal inflammation. Future clinical and mechanistic studies are needed to confirm and extend these data.

Early detection of liver steatosis by magnetic resonance imaging in rats infused with glucose and intralipid solutions and correlation to insulin levels

OBJECTIVE

Magnetic resonance (MR) techniques allow noninvasive fat quantification. We aimed to investigate the accuracy of MR imaging (MRI), MR spectroscopy (MRS) and histological techniques to detect early-onset liver steatosis in three rat phenotypes assigned to an experimental glucolipotoxic model or a control group.

MATERIALS AND METHODS

This study was approved by the institutional committee for the protection of animals. Thirty-two rats (13 young Wistar, 6 old Wistar and 13 diabetic Goto-Kakizaki rats) fed a standard diet were assigned to a 72h intravenous infusion of glucose and Intralipid fat emulsion or a saline infusion. Plasma insulin levels were measured. Steatosis was quantified in ex vivo livers with gradient-recalled multi-echo MRI, MRS and histology as fat fractions (FF).

RESULTS

A significant correlation was found between multi-echo MRI-FF and MRS-FF (r=0.81, p<0.01) and a weaker correlation was found between histology and MRS-FF (r=0.60, p<0.01). MRS and MRI accurately distinguished young Wistar and Goto-Kakizaki rats receiving the glucose+Intralipid infusion from those receiving the saline control whereas histology did not. Significant correlations were found between MRI or MRS and insulin plasma level (r=0.63, p<0.01; r=0.57, p<0.01), and between MRI or MRS and C-peptide concentration (r=0.54, p<0.01; r=0.44, p<0.02).

CONCLUSIONS

Multi-echo MRI and MRS may be more sensitive to measure early-onset liver steatosis than histology in an experimental glucolipotoxic rat model.

Metabolism of plasma cholesterol and lipoprotein parameters are related to a higher degree of insulin sensitivity in high HDL-C healthy normal weight subjects

Background

We have searched if plasma high density lipoprotein-cholesterol (HDL-C) concentration interferes simultaneously with whole-body cholesterol metabolism and insulin sensitivity in normal weight healthy adult subjects.

Methods

We have measured the activities of several plasma components that are critically influenced by insulin and that control lipoprotein metabolism in subjects with low and high HDL-C concentrations. These parameters included cholesteryl ester transfer protein (CETP), phospholipid transfer protein (PLTP), lecithin cholesterol acyl transferase (LCAT), post-heparin lipoprotein lipase (LPL), hepatic lipase (HL), pre-beta-₁HDL, and plasma sterol markers of cholesterol synthesis and intestinal absorption.

Results

In the high-HDL-C group, we found lower plasma concentrations of triglycerides, alanine aminotransferase, insulin, HOMA-IR index, activities of LCAT and HL compared with the low HDL-C group; additionally, we found higher activity of LPL and pre-beta-₁HDL concentration in the high-HDL-C group. There were no differences in the plasma CETP and PLTP activities.

Conclusions

These findings indicate that in healthy hyperalphalipoproteinemia subjects, several parameters that control the metabolism of plasma cholesterol and lipoproteins are related to a higher degree of insulin sensitivity.

Insulin-related biomarkers to predict the risk of metabolic syndrome

BACKGROUND

The predictive ability of insulin resistance or insulin sensitivity, in combination with traditional cardiovascular risk factors for metabolic syndrome (MetS), has not yet been clearly evaluated in Japanese male subjects.

OBJECTIVES

A one-year follow-up study was conducted to determine the ability of the insulin-related biomarkers to predict the risk of MetS development.

PATIENTS AND METHODS

A total of 2642 male workers of a Japanese company free from MetS at the baseline were monitored. The homeostasis model assessment for insulin resistance (HOMA-IR), and quantitative insulin sensitivity check index (QUICKI) were selected as the insulin-related markers.

RESULTS

The incidence of metabolic syndrome after one year was 8.8%. A multiple logistic regression analysis identified regular physical activity, age (≥ 45 years old), serum uric acid (≥ 7 mg/dL), serum alanine aminotransferase (≥ 45 IU/L), serum C-reactive protein (≥ 0.1 mg/L) and HOMA-IR (≥ 2.5) as significant risk factors for the development of MetS, with odds ratios (95% confidence intervals) of 0.68 (0.50 - 0.92), 2.0 (1.5 - 2.6), 2.2 (1.6 - 3.0), 1.5 (1.02 - 2.2), 1.4 (1.01 - 2.0), and 2.3 (1.6 - 3.3), respectively. When QUICKI was used instead of HOMA-IR, age (≥ 45 years old), serum uric acid (≥ 7 mg/dL), serum gamma-glutamyl transferase (≥ 50 IU/L), and QUICKI (≤ 0.33) were identified as significant contributors to the risk of MetS, with odds ratios (95% confidence intervals) of 0.68 (0.51 - 0.93), 2.0 (1.5 - 2.6), 2.2 (1.6 - 3.0), 1.4 (1.01 - 2.0), and 2.5 (1.7 - 3.6), respectively.

CONCLUSIONS

The mathematical meaning of the two insulin-related biomarkers examined was the same, and the odds ratios of the two biomarkers were almost the same after adjustments for other independent variables.

Activated complement factor 3 is associated with liver fat and liver enzymes: the CODAM study

BACKGROUND

The complement system may be involved in the pathogenesis of alcoholic and nonalcoholic liver disease, although studies in humans are scarce. For this reason, we investigated whether circulating levels of activated complement factor 3 (C3a) were associated with hepatic steatosis and hepatocellular damage.

MATERIALS AND METHODS

Plasma C3a, aspartate aminotransferase (AST), alanine aminotransferase (ALT) and gamma-glutamyl transferase (GGT) were determined in 523 individuals (61% men, age 59 ± 7 years). Liver enzymes (LEs) were standardized and compiled into a LE score. Liver fat content was estimated using a predictive equation that has recently been validated with magnetic resonance spectrometry. Cross-sectional associations between C3a and liver fat or LE s were investigated with multiple linear regression analyses, stratified in no-to-moderate vs. heavy alcohol consumers (men: > 30 g/day; women: > 20 g/day).

RESULTS

C3a was associated with liver fat percentage both in the no-to-moderate (β = 0.223; 95%CI 0.036; 0.409) and in the heavy alcohol consumers (β = 0.632; 95%CI 0.259-1.004; P-interaction = 0.047). C3a was also associated with the LE score in heavy alcohol consumers (β = 0.917; 95%CI 0.443-1.392), but not in no-to-moderate alcohol consumers (β = 0.042; 95%CI -0.198 to 0.281; P-interaction = 0.001).

CONCLUSIONS

C3a levels, as a marker of complement activation, were associated with liver fat content and hepatocellular injury, at least in subjects who consume considerable amounts of alcohol daily.

Effect and the probable mechanisms of silibinin in regulating insulin resistance in the liver of rats with non-alcoholic fatty liver

Our previous study has shown that reduced insulin resistance (IR) was one of the possible mechanisms for the therapeutic effect of silibinin on non-alcoholic fatty liver disease (NAFLD) in rats. In the present study, we investigated the pathways of silibinin in regulating hepatic glucose production and IR amelioration. Forty-five 4- to 6-week-old male Sprague Dawley rats were divided into a control group, an HFD group (high-fat diet for 6 weeks) and an HFD + silibinin group (high-fat diet + 0.5 mg kg^-1·day^-1 silibinin, starting at the beginning of the protocol). Both subcutaneous and visceral fat was measured. Homeostasis model assessment-IR index (HOMA-IR), intraperitoneal glucose tolerance test and insulin tolerance test (ITT) were performed. The expression of adipose triglyceride lipase (ATGL) and of genes associated with hepatic gluconeogenesis was evaluated. Silibinin intervention significantly protected liver function, down-regulated serum fat, and improved IR, as shown by decreased HOMA-IR and increased ITT slope. Silibinin markedly prevented visceral obesity by reducing visceral fat, enhanced lipolysis by up-regulating ATGL expression and inhibited gluconeogenesis by down-regulating associated genes such as Forkhead box O1, phosphoenolpyruvate carboxykinase and glucose-6-phosphatase. Silibinin was effective in ameliorating IR in NAFLD rats. Reduction of visceral obesity, enhancement of lipolysis and inhibition of gluconeogenesis might be the underlying mechanisms.

Combined effects of hepatitis B virus infection and elevated alanine aminotransferase levels on dyslipidemia

OBJECTIVE

Although elevated alanine aminotransferase (ALT) levels are associated with lipid profiles, most studies do not consider the role of hepatitis B virus (HBV) infection. This study investigated the combined effects of HBV infection and elevated ALT levels on the lipid profiles of Taiwanese adults.

MATERIALS/METHODS

A total of 7695 subjects were enrolled after an annual health examination. Dyslipidemia was defined as serum total cholesterol≥200 mg/dL, serum triglyceride≥150 mg/dL, high-density lipoprotein cholesterol<40 mg/dL in men or <50 mg/dL in women, or low-density lipoprotein cholesterol≥130 mg/dL. Multiple logistic regression analysis was performed to assess the associations between dyslipidemia, HBV infection, and elevated ALT levels.

RESULTS

Hepatitis B surface antigen positivity (HBV[+]) and elevated ALT levels (ALT[+], ≥50 U/L) were observed in 13.5% and 12.2% of the subjects, respectively. Multiple logistic analysis revealed that the HBV(+) group had a significantly lower odds ratios (ORs) for hypercholesterolemia (OR, 0.8), hypertriglyceridemia (OR, 0.7), and high low-density lipoprotein cholesterol levels (OR, 0.8); whereas, the subjects with elevated ALT levels had significantly higher ORs for all of the dyslipidemia criteria. The interaction between HBV(+) and ALT(+) had a significantly lower OR for hypertriglyceridemia (OR, 0.7). The subjects with HBV infections had a significantly lower OR for hypertriglyceridemia regardless of the ALT levels.

CONCLUSIONS

HBV infection and elevated ALT levels have opposite effects on dyslipidemia, whereas their combined effects result in a significantly lower OR for hypertriglyceridemia.

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.

Obesity-independent association of human adenovirus Ad37 seropositivity with nonalcoholic fatty liver disease

OBJECTIVE

Adenoviruses Ad36 and Ad37 increase adiposity in animals and are associated with obesity in humans; effects on the liver have been reported. The association of Adenovirus Ad36 seropositivity (Ad36+) with obesity but not with the severity of nonalcoholic fatty liver disease (NAFLD) has been previously shown. We investigate whether nondiabetic Ad37+ patients show a different prevalence of NAFLD and ultrasound Bright Liver score.

PATIENTS

A total of 268 adult nondiabetic patients (146 men, 122 women) were included after lifestyle counseling including a personalized Mediterranean diet, increase in physical activity, and smoking withdrawal. After an Ad37+/Ad36+ assay, overweight obesity, insulin resistance, C-reactive protein, and bright liver prevalence and severity were compared according to Ad37+.

RESULTS

Sixty-five of 268 patients were Ad37+ and 82/268 patients were both Ad37 seronegative (Ad37-) and Ad36-. The prevalence of obesity, defined as body mass index≥30, was not significantly different in Ad37+ (11/65; 16.9%) vs. Ad37- (15/82; 18.2%) patients; Bright Liver was present in 22/65 (33.8%) Ad37+ patients vs. 13/82 (15.8%) Ad37- patients (P<0.019). By odds ratio (OR), a consistent risk for NAFLD was associated with Ad37+, greater insulin resistance, and C-reactive protein. By a predictive multiple linear regression model, 40.0% of variance toward NAFLD and 50.4% toward the severity of Bright Liver score was explained significantly and independently by Ad37+ and by body mass index.

CONCLUSIONS

Ad37+ status in nondiabetic patients on an appropriate diet is significantly associated with NAFLD; because fatty liver improves even without weight loss by a "healthy" diet, and not only by lower food caloric intake, Ad37+ may be an adjunctive hallmark of an unfavorable clinical-metabolic profile, if not a causative factor of NAFLD.

Relationship between several markers and presence of metabolic syndrome or components of the metabolic syndrome in Japanese workers

BACKGROUND

The reported associations between metabolic syndrome (MetS) and systemic vascular inflammation/insulin resistance prompted the author to determine the predictive ability of markers for MetS in the occupational field.

METHODS

The study was performed in 3460 working men aged 30 to 64 years. The author measured the serum levels of high-sensitivity C-reactive protein and insulin as potential key biomarkers of MetS.

RESULTS

Multivariate analysis revealed significant associations between the presence of MetS and the log-transformed value of serum insulin and log-transformed value of serum C-reactive protein, with odds ratios of 29.4 (95% confidence interval, 18.0 to 48.2; P < 0.001) and 1.87 (95% confidence interval, 1.47 to 2.38; P < 0.001) of these two markers, respectively, for the presence of MetS.

CONCLUSION

Elevated serum levels of insulin were found to be strongly associated with MetS in this cross-sectional study.