Studies have examined the relationship between serum alanine aminotransferase (ALT) and mortality with inconsistent results.
Dr Erica Karaphillis and colleagues examined the association of normal range serum ALT with mortality, to explore a nonlinear relationship between ALT and mortality, and to investigate whether age modifies this relationship.
The researchers used the continuous National Health and Nutrition Examination Survey (NHANES) from 1999 to 2010.
Vital status of the participants was obtained by probabilistic matching between NHANES and the National Death Index.
The team used Cox proportional models to examine the relationship with and without adjustment for age, sex, race, BMI, hypertension, diabetes, alcohol use, serum triglycerides, prescription drug use, and glomerular filtration rate, and accounting for the sampling methodology of NHANES.
|Elderly patients had a 6% lower adjusted mortality risk than younger participants|
|European Journal of Gastroenterology & Hepatology|
The research team found that higher serum ALT was associated with lower all-cause mortality.
However, this relationship was nonlinear and present only until 17 U/l, and not thereafter.
The team noted that age modified the relationship between ALT and mortality.
Elderly patients had a 6% lower adjusted mortality risk than younger participants.
Dr Karaphillis' team comments, "Increase in serum ALT within the normal range is initially associated with lower mortality, but has no effect after 17 U/l."
"The elderly show a significantly larger decrease in mortality with an increase in ALT than younger individuals."
"The mechanisms underlying this relationship need further exploration."