Gamma-glutamyl transpeptidase as an indicator for subclinical cardiovascular disease in patients with psoriatic arthritis

Abstract
Background
Gamma-glutamyl transpeptidase (GGT) is an important molecule produced by hepatocytes that has been noticed as a prooxidative enzyme. GGT has been found to be included in the inflammation process and oxidative damage in multiple diseases in human. Psoriatic arthritis (PsA) is an inflammatory disorder leading to high mortality and morbidity due to cardiovascular events. However, GGT role in PsA remains unclear. The aim of this study is to determine the association of GGT with PsA activity and atherosclerosis in PsA patients. Also, to investigate if GGT can serve as an indicator of subclinical atherosclerosis in PsA patients.

Results
This study was performed on 30 PsA patients and 30 matched healthy subjects. All patients underwent detailed history taking and clinical assessment. Disease activity in PsA (DAPSA) score was used to assess disease activity in PsA patients. GGT level in serum was quantified by utilizing enzyme-linked immunosorbent assay and correlated with carotid intima media thickness (CIMT) and PsA disease activity. Patients’ mean age and disease duration was 43.37 ± 7.65 years (30–55 years) and 7.97 ± 4.214 years (2–15 years) respectively. Levels of GGT in serum were significantly increased in patients compared to GGT serum levels in controls (p < 0.001). Serum GGT levels showed significant positive correlation with DAPSA score, LDL, cholesterol triglycerides, and right and left CIMT (r = 0.913, 0.587, 0.779, 0.803, 0.736, 0.728 and p < 0.001 respectively) and significant negative correlation with HDL (r = − 0.681 and p < 0.001). However, GGT serum levels and PsA disease duration did not show significant correlation.

Conclusion
Serum GGT was associated with high disease activity, high lipid profile, and large CIMT in PsA patients. GGT might be an indicator of subclinical atherosclerosis and increased disease activity in patients with PsA.