Relationships between alanine aminotransferase (ALT), visceral adipose tissue (AT) and metabolic risk factors in a middle-aged Japanese population.

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.