The following known risk factors for liver disease/cancer were evaluated: elevated aminotransferase levels (elevated alanine aminotransferase was defined as > 40 IU/L for males and females; elevated aspartate aminotransferase was defined as > 40 IU/L for males and females), infection with hepatitis B or hepatitis C, metabolic syndrome, high total cholesterol, diabetes, obesity, abdominal obesity, and heavy alcohol use.
The restricted cubic spline models revealed a positive non-linear dose-response relationship between ALT levels and the risk of MS in women (p for nonlinearity was 0.0327), but a positive linear dose-response relationship in men (p for nonlinearity was 0.0659).
Although V-type MS and WC is a common significant predictor of an increased prevalence of FL with ALT elevation in both males and females with MS, gender, lifestyle-related factors, and MS type in individuals with MS should be considered for the development of FL with ALT elevation.
Some studies have proposed that serum ALT levels, even those within the conventional normal range, are associated with metabolic syndrome and fatty liver.
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.
There were highly significant correlations with variables associated with the metabolic syndrome: plasma triglyceride, HDL- and LDL-cholesterol, apolipoprotein B and E, urate, and insulin concentrations; gamma-glutamyltransferase and aspartate and alanine aminotransferase activities; body mass index; and blood pressure.
In variable (age, body surface area, total cholesterol, alanine aminotransferase, gamma-glutamyl transferase, smoking, alcohol intake and exercise) adjusted multiple linear regression analysis, Q4 (the highest quartile of AAD) was significantly associated with MS compared with Q1 (OR 4.52, 95% CI 1.67 to 9.87).
Compared with non-MetS without fatty liver, hazard ratios (HR) for incident diabetes after adjusting for age, body mass index, smoking status, exercise habit, alcohol consumption, family history of diabetes logarithm of alanine aminotransferase and fasting plasma glucose, were as follow: 2.35 (95 % CI 1.91-2.89, p<0.001) in non-MetS with fatty liver, 1.70 (95% CI 1.30-2.20, p<0.001) in MetS without fatty liver, and 2.33 (95% CI 1.85-2.94, p<0.001) in MetS with fatty liver.
Plasma FA composition was also investigated in the Metabolic Syndrome in Men (METSIM) Study (n=769), in which serum alanine aminotransferase (ALT) was used as a marker of liver disease.
Our findings suggest that the relationship between metabolic abnormalities and elevated ALT may differ by sex, possibly due to the MetS more prevalent in young adult men than in women.
The secondary outcomes included alanine aminotransferase (ALT), aspartate aminotransferase (AST), C-reactive protein (CRP) and components of metabolic syndrome.
There were 441 (7.7%) and 377 (20.6%) cases with metabolic syndrome in the normal and fatty liver groups, respectively, with significant difference (P=0.001), and the subgroup of 385 cases with fatty liver and elevated ALT had higher prevalence (28.8%) of metabolic syndrome.
Pleiotropy (a common set of genes affecting two traits) detected between SBP and waist circumference, SBP and glucose, HDL and waist circumference, ALT and waist circumference, and TG and ALT may underlie the clustering of the components of the metabolic syndrome.
Similarly, high ALT was also associated with increased risk for MetS in a multivariate model (OR: 1.81, 95% CI: 1.20-2.71), especially among those with 2nd & 3rd tertiles of T-BiL.
An elevated alanine aminotransferase (ALT) is frequently observed in subjects with metabolic syndrome, which is associated with the risk of colorectal adenoma (CRA).