Serum alanine aminotransferase activity is age- and sex-depended but independently predicted by body mass index in both sexes. The Tromsø study

Abstract

Background High and low levels of serum alanine aminotransferase (ALT) are associated with cardiovascular diseases (CVD) especially in elderly but the roles of sex and age are unexplained. This study investigated sex- and age-related variation of serum ALT and associations between ALT and CVD risk factors in men and women in a Caucasian population. Methods This study used cross-sectional data from Tromsø 6 in 2555 men (mean age 60.4 years) and 2858 women (mean age 60.0 years). Associations were assessed by variance analysis and multivariable logistic regression of odds to have abnormal ALT. Results Abnormal ALT was detected in 113 (4.4%) men and 188 (6.6%) women. ALT correlated negatively with age in men (r = -0.231, p < 0.001) and positively in women (r = 0.124, p < 0.001). A linear inversed association between age and ALT in men and a non-linear inversed U-trend in women with maximum level between 60–64 years were found. Age was independently associated with ALT in men only [OR 1.05 (95% CI 1.04, 1.07), p < 0.001] and body mass index (BMI) was independently associated with ALT in both sexes. Conclusion The relationship between age and ALT was opposite directed in men compared to women, and linearly and independently in men only. Neither BMI as the strongest associated CVD risk factor in both sexes nor other risk components could explain this. Separate sex-analyses should be used in studies investigating the role of ALT as a disease marker.