Adenosine plasma level correlates with homocysteine and uric acid concentrations in patients with coronary artery disease

The role of hyperhomocysteinemia in coronary artery disease (CAD) patients remains unclear. The present study evaluated the relationship between homocysteine (HCys), adenosine plasma concentration (APC), plasma uric acid, and CAD severity evaluated using the SYNTAX score. We also evaluated in vitro the influence of adenosine on HCys production by hepatoma cultured cells (HuH7). Seventy-eight patients (mean age +/- SD: 66.3 +/- 11.3; mean SYNTAX score: 19.9 +/- 12.3) and 30 healthy subjects (mean age: 61 +/- 13) were included. We incubated HuH7 cells with increasing concentrations of adenosine and addressed the effect on HCys level in cell culture supernatant. Patients vs. controls had higher APC (0.82 +/- 0.5 mu mol/L vs 0.53 +/- 0.14 mu mol/L; p < 0.01), HCys (15 +/- 7.6 mu mol/L vs 6.8 +/- 3 mu mol/L, p < 0.0001), and uric acid (242.6 +/- 97 vs 202 +/- 59, p < 0.05) levels. APC was correlated with HCys and uric acid concentrations in patients (Pearson's R = 0.65 and 0.52; p < 0.0001, respectively). The SYNTAX score was correlated with HCys concentration. Adenosine induced a time- and dose-dependent increase in HCys in cell culture. Our data suggest that high APC is associated with HCys and uric acid concentrations in CAD patients. Whether the increased APC participates in atherosclerosis or, conversely, is part of a protective regulation process needs further investigations.