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.
The strongest correlations were noted between HOMA-IR and waist circumference (WC) in the MS group (r=0.57) as well as between HOMA-IR and alanine aminotransferase (ALT, r=0.57) or aspartate aminotransferase (r=0.56) in the controls, with a statistical significance of p<0.001.
Finally, serum GPI-PLD levels were strongly and independently associated with serum alanine transaminase (R = 0.37, P = 0.0006) and triglyceride (R = 0.34, P = 0.001) levels in male subjects with metabolic syndrome.
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.
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.
Upon adjusted multivariable analysis of serial ALT values, ALT was significantly higher (mean 12%; <i>P</i> = 0.02) among those with MS at baseline and even higher (mean 19%; <i>P</i> = 0.003) among those with persistent MS compared with those with persistent absence of MS. MS was not associated with serial APRI on follow-up.
However, after adjusting for covariates (age, residential area, income, dyslipidemia medication, education, current smoking, regular exercise, alcohol consumption, body mass index, years after menopause, aspartate aminotransferase, alanine aminotransferase, and white and red blood cell counts), longer reproductive years were associated with a lower prevalence of MetS (OR 0.751, 95% CI 0.745-0.747).
Lean MetS subjects were older, had more diabetes, and had higher metabolic component levels, but lower alanine transaminase and aspartate transaminase-platelet ratio index levels compared with obese MetS subjects.
In women, with increasing the quartiles of ALT within normal limits, the percent of participants with metabolic syndrome also increased significantly (P<sub>trend</sub>=0.04).
Our study confirmed a positive association between components of metabolic syndrome and elevated serum alanine aminotransferase in a Korean population.
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.
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.
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).