Changes in Lp-PLA₂ Are Associated With Elevated Alanine Aminotransferase Levels: A Nested Case-Control Study in a Three-Year Prospective Cohort

Background/Aim: Elevation in liver enzymes and hepatic fat may indicate a higher susceptibility to cardiovascular disease (CVD). This research sought to find anthropometric/biochemical variables significantly related to the alanine aminotransferase (ALT) increase in healthy populations. Methods: Nine hundred healthy subjects were included in a 3-year prospective cohort study. The initial screening revealed that 538 were found to be nondiabetic (fasting glucose < 126 mg/dL) and had normal ALT levels. Among them, 79 individuals with slightly elevated ALT levels after three years were assigned to the elevated ALT group. Of the remaining 459 participants, 241 subjects matched to the increased ALT group were the control group. Results: After three years of follow-up, individuals with elevated ALT showed notably higher aspartate aminotransferase (AST), ALT, gamma-glutamyltransferase (γ-GT), high sensitivity C-reactive protein (hs-CRP), lipoprotein-associated phospholipase A₂ (Lp-PLA₂ ) activity, oxidised low-density lipoprotein (ox-LDL), urinary 8-epi-prostaglandin F_2α (8-epi-PGF_2α ) levels and brachial-ankle pulse wave velocity (ba-PWV) in comparison to the control group. Changes (Δ) in ALT showed a positive correlation with Δ AST, Δ gamma-GT, Δ hs-CRP, Δ Lp-PLA₂ activity, Δ ox-LDL, Δ urinary 8-epi-PGF_2α and Δ ba-PWV. Furthermore, a direct positive link was observed between the Δ Lp-PLA₂ activity and Δ AST, Δ ox-LDL and Δ ba-PWV. Conclusion: Increased Lp-PLA₂ activity and other CVD risk indicators were observed to have a pronounced association with elevated ALT levels. This mild ALT elevation could potentially contribute to chronic low-grade inflammation.