Severity of metabolic syndrome is greater among nonalcoholic adults with elevated ALT and advanced fibrosis

Causal relationship analysis between 35 blood/urine metabolites and gastroesophageal reflux disease: A Mendelian randomization combined meta-analysis study

Gastroesophageal reflux disease (GERD) is a common condition worldwide. Despite numerous studies on GERD, the causal relationships between blood/urine metabolites and GERD remain unclear. This study aims to explore the causal relationships between GERD and 35 blood/urine metabolites. In this study, we conducted Mendelian randomization (MR) analyses for 35 blood/urine metabolites with GERD phenotypes from the FinnGen R10 and UKB databases separately. We then performed a meta-analysis of the inverse variance weighted results from the 2 MR analyses and applied multiple corrections to the significant P values from the meta-analysis. Finally, we conducted reverse causality validation for the corrected positive blood/urine metabolite phenotypes with GERD. After conducting MR analysis combined with meta-analysis and performing multiple corrections, we found significant positive causal associations between only 3 blood/urine metabolites and GERD, with no significant reverse associations. Among them, 2 are risk factors for the occurrence of GERD: alanine aminotransferase levels (odds ratio (OR) = 1.120, 95% confidence interval (CI) = 1.064-1.180, P = .0005) and urate levels (OR = 1.095, 95% CI = 1.044-1.147, P = .005). Additionally, sex hormone-binding globulin levels are protective against GERD (OR = 0.928, 95% CI = 0.896-0.961, P = .0009). Elevated levels of the metabolites alanine aminotransferase and urate are associated with an increased risk of GERD, identifying them as risk factors for the condition. In contrast, higher levels of SHBG are linked to a decreased risk of GERD, indicating that SHBG is a protective factor against the disease.

Changes in alanine aminotransferase and body composition and metabolic factors among individuals receiving medical health checkups

AIM

To examine the relationship between changes in alanine aminotransferase (ALT) and those in body composition and metabolic factors in participants receiving medical health checkups (4350 men [mean age 52.5 years] and 5398 women [mean age 50.5 years]) METHODS: We divided the participants into four types based on their ALT value at baseline and 1 year: A, ALT ≤30 (baseline) and ≤30 (1 year); B, ALT ≥31 (baseline) and ≤30 (1 year); C, ALT ≤30 (baseline) and ≥31 (1 year); and D, ALT ≥31 (baseline) and ≥31 (1 year). The change in each body composition-related parameter (waist circumference, fat mass, fat-free mass, fat mass to fat-free mass ratio, etc.) after 1-year was defined as Δ.

RESULTS

The mean changes in waist circumference (cm) in the four types (A, B, C, and D) were -0.33, -1.54, 0.66, and -0.29 (overall p < 0.0001) in men, and -0.19, -0.90, 0.30, and 0.090 (overall p < 0.0001) in women. The mean changes in fat mass (kg) in the four types were -0.027, -0.86, 0.62, and 0.092 (overall p < 0.0001) in men, and 0.0067, -0.48, 0.39, and 0.063 (overall p < 0.0001) in women. The mean changes in fat-free mass (kg) in the four types were -0.028, -0.55, 0.42, and -0.034 (overall p < 0.0001) in men, and -0.0091, -0.34, 0.12, and -0.045 (overall p = 0.0012) in women. The mean changes in fat mass to fat-free mass ratio in the four types were -0.00042, -0.0120, 0.00837, and 0.00171 (overall p < 0.0001) in men, and -0.00013, -0.00817, 0.00730, and 0.00628 (overall p < 0.0001) in women.

CONCLUSION

A decrease in ALT to ≤30 IU/L may be associated with improved body composition balance, but caution should be exercised for the decrease in muscle mass.

Lower alanine aminotransferase levels are associated with increased all-cause and cardiovascular mortality in nonalcoholic fatty liver patients

BACKGROUND

Serum alanine aminotransferase (ALT) levels are often considered a marker to evaluate liver disease and its severity.

AIM

To investigate the association between ALT levels and all-cause and cause-specific mortality in patients with nonalcoholic fatty liver disease (NAFLD).

METHODS

The Third National Health and Nutrition Examination Survey (NHANES-III) from 1988 to 1994 and NHANES-III-related mortality data from 2019 onward were used to obtain the necessary data for the study. NAFLD was defined as hepatic steatosis, as diagnosed by ultrasound, with no other liver diseases. ALT levels were categorized into four groups according to the different recommended upper limits of normal (ULN) in men and women: < 0.5 ULN, 0.5-1 ULN, 1-2 ULN, and ≥ 2 ULN. The hazard ratios for all-cause mortality and cause-specific mortality were analyzed using the Cox proportional hazard model.

RESULTS

Multivariate logistic regression analysis demonstrated that the odds ratio of NAFLD correlated positively with increased serum ALT levels. In patients with NAFLD, all-cause mortality and cardiovascular mortality were the highest when ALT was < 0.5 ULN, yet cancer-related mortality was the highest when ALT was ≥ 2 ULN. The same results could be found in both men and women. Univariate analysis showed that severe NAFLD with normal ALT levels had the highest all-cause and cause-specific mortality, but the difference was not statistically significant after adjustment for age and multivariate factors.

CONCLUSION

The risk of NAFLD was positively correlated with ALT level, but all-cause and cardiovascular mortality were the highest when ALT was < 0.5 ULN. Regardless of the severity of NAFLD, normal or lower ALT levels were associated with higher mortality than elevated ALT levels. Clinicians should be aware that high ALT levels indicate liver injury, but low ALT levels are associated with a higher risk of death.

Prevalence and metabolic determinants of abnormal alanine aminotransferase: A cross-sectional study of Iranian adults, 2018-2022

BACKGROUND

Alanine aminotransferase (ALT) is an enzyme whose activity became the principal biomarker for liver disease. In the current study, we aimed to determine the prevalence of abnormal ALT, as a surrogate of nonalcoholic fatty liver disease (NAFLD) and its associated determinants using different criteria among Tehranian subjects between 2018 and 2022.

METHODS

This is a cross-sectional study on 5676 Tehranian individuals aged 20-70 years. The weighted prevalence of abnormal ALT was calculated using both the National Health and Nutrition Examination Survey in the United States (US-NHANCE; ALT ≥30 U/L for females and ≥40 U/L for males) and the American College of Gastroenterology (ACG) guideline (ALT >25 U/L for females, and >33 U/L for males) thresholds. Moreover, uni/multivariable logistic regression analysis was performed to find the determinants of abnormal ALT.

RESULTS

The weighted prevalence of abnormal ALT was 12.8% (7.6% females and 18% males) and 22.5% (17.7% females and 27.3% males) based on US-NHANCE and ACG criteria, respectively. Our results showed every decade increase in age decreased the risk of abnormal ALT by 32%. We also found that generally male gender, being overweight/obese, central adiposity, TG ≥6.9 mmol/L, non-HDL-C ≥3.37 mmol/L, lipid-lowering medications, pre-diabetes/T2DM were associated with abnormal ALT using different cutoff points. Moreover, among men resting tachycardia (≥90 beats per min), hypertension, and females past-smoker were also found as other determinants of abnormal ALT.

CONCLUSION

High prevalence of abnormal ALT among non-elderly Iranian adults, especially among men, necessitates immediate multifaceted strategies by policymakers to prevent potential complications caused by NAFLD.

Adipose Tissue Insulin Resistance Predicts the Severity of Liver Fibrosis in Patients with Type 2 Diabetes and NAFLD

CONTEXT

While T2D is a risk factor for liver fibrosis in NAFLD, the specific contribution of insulin resistance (IR) relative to other factors is unknown.

OBJECTIVE

Assess the impact on liver fibrosis in NAFLD of adipose tissue (Adipo-IR) and liver (HOMA-IR) IR in people with T2D and NAFLD.

DESIGN

Participants were screened by elastography in the outpatient clinics for hepatic steatosis and fibrosis, including routine metabolites, cytokeratin-18 (marker of hepatocyte apoptosis/steatohepatitis), and HOMA-IR/Adipo-IR.

SETTING

University ambulatory care practice.

PARTICIPANTS

483 participants with T2D.

INTERVENTION

Screening for steatosis and fibrosis with elastography.

MAIN OUTCOME MEASURES

Liver steatosis (CAP) and fibrosis (LSM) and measurements of IR (Adipo-IR, HOMA-IR) and fibrosis (cytokeratin-18).

RESULTS

Clinically significant liver fibrosis (stage F ≥ 2= LSM ≥8.0 kPa) was found in 11%, having more features of the metabolic syndrome, lower adiponectin, and higher AST, ALT, liver fat and cytokeratin-18 (p < 0.05-0.01). In multivariable analysis including just clinical variables (model 1), obesity (BMI) had the strongest association with fibrosis (OR: 2.56, CI:1.87-3.50; p < 0.01). When metabolic measurements and cytokeratin-18 were included (model 2), only BMI, AST and liver fat remained significant. When fibrosis stage was adjusted for BMI, AST, and steatosis (model 3), only adipo-IR remained strongly associated with fibrosis (OR: 1.51, CI:1.05-2.16; p = 0.03), but not BMI, hepatic IR or steatosis.

CONCLUSIONS

These findings pinpoint to the central role of dysfunctional, insulin-resistant adipose tissue to advanced fibrosis in T2D, beyond simply BMI or steatosis. The clinical implication is that targeting adipose tissue should be the priority of treatment in NAFLD.

Associations of body shape index (ABSI) and hip index with liver, metabolic, and inflammatory biomarkers in the UK Biobank cohort

Associations of liver, metabolic, and inflammatory biomarkers in blood with body shape are unclear, because waist circumference (WC) and hip circumference (HC) are dependent on overall body size, resulting in bias. We have used the allometric "a body shape index" (ABSI = WC_(mm)[Formula: see text]Weight_(kg)^-2/3[Formula: see text]Height_(m)^5/6) and hip index (HI_women = HC_(cm)[Formula: see text]Weight_(kg)^-0.482[Formula: see text]Height_(cm)^0.310, HI_men = HC_(cm)[Formula: see text]Weight_(kg)^-2/5[Formula: see text]Height_(cm)^1/5), which are independent of body mass index (BMI) by design, in multivariable linear regression models for 121,879 UK Biobank men and 135,559 women. Glucose, glycated haemoglobin (HbA1c), triglycerides, low-density-lipoprotein cholesterol, apolipoprotein-B, alanine aminotransferase (ALT), gamma-glutamyltransferase, and lymphocytes were associated positively with BMI and ABSI but inversely with HI. High-density-lipoprotein cholesterol and apolipoprotein-A1 were associated inversely with BMI and ABSI but positively with HI. Lipid-related biomarkers and ALT were associated only with HI in obese men. C-reactive protein, neutrophils, monocytes, and alkaline phosphatase were associated positively, while bilirubin was associated inversely, with BMI and ABSI but not with HI. Associations were consistent within the clinical reference ranges but were lost or changed direction for low or high biomarker levels. Our study confirms associations with waist and hip size, independent of BMI, for metabolic biomarkers but only with waist size for inflammatory biomarkers, suggesting different contribution of the mechanistic pathways related to body shape.