Objective: To evaluate the effect of risk factors for coronary artery disease (CAD) on urokinase receptor (uPAR) expression on monocytes.
Methods: A total of 106 patients were enrolled and divided into five risk-factor groups: sixteen with hypertension, twenty-four with dyslipidemia, eighteen with hypertension + obesity, eighteen with dyslipidemia + obesity and thirty with hypertension + dyslipidemia + obesity. Seventeen healthy volunteers were recruited as control group. Monocyte expression of uPAR and mean fluorescence intensity index (MFI Index) of uPAR were measured by flow cytometer (FACSCalibur).
Results: No difference in monocyte uPAR expression was detected between hypertension and control group [(4.9 +/- 12.5)% vs. (7.7 +/- 10.3)%, P=0.74]. However, the uPAR expression was raised to (23.7 +/- 22.5)% in hyperlipidemia group, a 3.9- and a 2.1-fold increase compared with those in hypertension (P<0.01) and control group (P<0.05), respectively. When combined with obesity, uPAR expression was elevated further to (32.9 +/- 30.8)% in hypertension + obesity group, (37.4 +/- 31.4)% in dyslipidemia + obesity group and (23.8 +/- 20.5)% in hypertension + dyslipidemia + obesity group, all having statistical significance compared with control group or hypertension group (P<0.01). The results were the same when corrected by age, BMI and hs-CRP. uPAR MFI Index was increased from 0.78 +/- 0.86 in control group to 1.91 +/- 1.97 and 3.33 +/- 2.52 in dyslipidemia group and hypertension + obesity group, respectively, P<0.05. Linear regression analysis revealed a significant correlation between uPAR expression and FBG concentration in dyslipidemia group, r=0.72, P=0.04.
Conclusions: uPAR expression was elevated on monocytes in patients with risk factors for CAD. Dyslipidemia and obesity may contribute to the increase of uPAR expression.