Elevated Levels Within the Normal Limits of Liver Enzymes in Patients With Atrial Fibrillation

  • Spyros Tsikrikas
  • Konstantinos Letsas
  • Panagiotis Korantzopoulos
  • Charalampos Charalampous
  • Charalampos Ntavelas
  • George Bakosis
  • Charalampos Kavvouras
  • Dimitrios Asvestas
  • Antonios Sideris
Keywords: atrial fibrillation, γ-glutamyltransferase, alanine transaminase, inflammation, oxidative stress.


Background. Emerging evidence suggests that a strong link exists between certain liver enzymes such as γ-glutamyltransferase (γ-GT) and alanine transaminase (ALT) and cardiovascular diseases independently of alcohol intake. Elevated levels of γ-GT and ALT within normal values are considered as markers of inflammation and oxidative stress independent of the metabolic syndrome.

Objective. This pilot observational study was conducted to evaluate serum levels of γ-GT and ALT within normal values in different atrial fibrillation (AF) populations.

Methods. Consecutive patients with AF and healthy control subjects were screened. Clinical and echocardiographic characteristics were carefully recorded. In each participant, serum levels of γ-GT and ALT along with conventional inflammatory markers were determined. The final study population consisted of 81 patients with paroxysmal AF, 45 patients with persistent AF, and 39 control subjects.

Results. Serum γ-GT levels within normal values were significantly elevated in patients with paroxysmal (30.40±12.34 U/L) and persistent AF (38.38±18.11 U/L) in relation to control population (24.03±11.73 U/L) (p<0.001). Of note, γ-GT concentration was significantly higher in patients with persistent AF compared to those with paroxysmal AF (p: 0.010). Serum ALT levels were significantly higher in patients with paroxysmal (27.51±10.23 U/L) and persistent AF (28.73±9.34 U/L) compared to controls (20.26±9.34 U/L) (p<0.001). In multinomial logistic regression analysis, the relative risk ratio of developing paroxysmal AF per 1 U/L increase in ALT was 1.08 (CI: 1.02-1.14, p: 0.011). The relative risk ratio of having persistent AF per 1 U/L increase in γ-GT was 1.06 (CI: 1.01-1.12, p: 0.013).

Conclusions. This study shows an association between increased levels within normal reference intervals of liver enzymes such as γ-GT and ALT and AF. Serum γ-GT levels may be related to AF burden. Larger studies are needed to examine this potential association.