Methods: The study included 25 patients (22 males 3 females; mean age 56±3 years; range 42 to 67 years) in whom radial artery was used for elective coronary artery bypass grafting. Data from 10 patients with histopathological evidence for atherosclerosis of the radial artery (group 1) were prospectively compared with those of 15 patients without atherosclerosis (group 2). Risk factors for atherosclerosis including age, gender, the presence of hypertension, diabetes mellitus, obesity, smoking, and peripheral artery disease were recorded. Detailed blood lipid profile (triglyceride, cholesterol, and lipoprotein analyses), C-reactive protein, and antioxidant enzyme levels (catalase, glutathione peroxidase, and superoxide dismutase), and urine 6-sulphatoxymelatonin levels were determined.

Results: In group 1, histopathological examination of the radial artery wall revealed atherosclerotic changes of grade 1 in four patients, grade 2 in three patients, grade 3 in two patients, and grade 4 in one patient. Serum levels of triglyceride, total cholesterol, HDL-cholesterol, LDL-cholesterol, VLDL-cholesterol, lipoprotein (a), and C-reactive protein were similar in both groups (p>0.05). Serum apoprotein A and apoprotein B levels were significantly higher in group 1 (p<0.05). Although patients in group 1 had increased antioxidant enzyme levels in the radial artery wall and decreased urine 6-sulphatoxymelatonin levels, these did not reach significance (p>0.05).

Conclusion: Our results suggest that, although not statistically significant, higher oxidative stress and decreased melatonin levels may play a role in radial artery atherosclerosis.