Low ALT blood levels predict long-term all-cause mortality among adults. A historical prospective cohort study

Increased blood levels of alanine amino transferase (ALT, also known as SGPT; serum glutamic pyruvic transaminase) serve as a marker of liver injury by various mechanisms. Less is known about the clinical implications associated with low-normal ALT levels. Previous studies showed low ALT levels to be associated with poor long-term outcomes among elderlies, serving as a biomarker for increased incidence of frailty and subsequent risk of mortality. However, it has not been determined yet whether low-normal ALT values might be predictive of frailty and mortality in younger, middle-aged adults.

We conducted a historical prospective cohort analysis.

A total of 23,506 adults with ALT levels within the normal range, at the mean age of 48 ± 11 years, participating in an annual screening program for preventive medicine, were followed-up for a median period of 8.5 years during which 638 died. Low-normal ALT values (serum ALT activity <17IU/L) were found to be predictive for increased risk of all-cause mortality (HR=1.6; 95% CI 1.34-1.92; p<0.001). Statistically significant correlation was demonstrated even after applying a multifactorial model correction for age, gender, eGFR, low albumin, arterial hypertension, diabetes mellitus and ischemic heart disease.

We suggest that low-normal ALT values may serve as an independent predictive marker for increased long-term mortality in middle-aged adults.