Aim: The commonly observed relationship between increased visceral adiposity and metabolic abnormalities may be partly mediated by a concomitant increase in liver fat content. We evaluated the independent association between the level of alanine aminotransferase (ALT) as a surrogate marker of the liver fat content and the incidence of metabolic abnormalities after adjusting for the amount of visceral adipose tissue (AT).
Methods: The subjects included 1,118 Japanese individuals (44% women) who underwent computed tomography to assess the amount of visceral AT on medical checkups. Cross-sectional associations between the serum ALT, visceral AT and metabolic risk factors were examined.
Results: The ALT level and visceral AT were found to show a significant correlation(r=0.41 in men and r=0.36 in women, p＜0.001). In a multivariable linear regression analysis, the ALT level and visceral AT were found to be independently associated with blood pressure in men and triglycerides and 2-hour post-challenge glucose in both genders(p＜0.01), whereas only visceral AT was found to be associated with HDL-cholesterol(p＜0.01). When the participants were classified into four subgroups based on the 75th percentiles of ALT and visceral AT, the low ALT/high-visceral AT group, but not the high-ALT/low-visceral AT group, had a significantly higher odds ratio for low HDL-cholesterol among both genders(p＜0.05) and for hypertriglyceridemia in men only(p＜0.05). Meanwhile, the high-ALT/low-visceral AT group, but ot the low-ALT/high-visceral AT group, had a significantly higher odds ratio for IGT among women(p＜0.05).
Conclusions: Although the ALT level and visceral AT were found to be independently associated with most metabolic risk factors, visceral AT had a dominant association with dyslipidemia in both genders, while the ALT level appeared to have a closer association with IGT in women.