Evaluation of serum levels of oxidized low density lipoprotein autoantibodies (olab)‎ and soluble urokinase plasminogen activator receptor (supar)‎ as possible risk factors in essential hypertension

الملخص EN

Background The exact pathophysiologic mechanisms underlying the development of essential hypertension are still unknown, but several theories have been implicated. The presence of a subclinical atherosclerotic process that associates hypertension has gained a reputation in recent years.

Several factors contribute in the atherogenic process, where immunological factors, atherothrombotic events, oxidative stress, and the chronic low grade inflammation play a big role. Aim: the study aimed at evaluation of serum levels of oxidized Low Density Lipoprotein (LDL) autoantibodies (OLAB), soluble urokinase plasminogen activator receptor (SUPAR), C-reactive protein (CRP), and thiobarbituric acid reactive substances (TBARs) in essential hypertensive patients. Methods: Fifty subjects were included in this work, divided into thirty essential hypertensive patients, and Twenty apparently healthy volunteers of the same age, Sex, and socioeconomic status as a control group. Methods: Full clinical examination, standard 12 leads ECG, and ultrasonography assessment of the common carotid artery intima media thickness (CIMT) were done to all the subjects.

Laboratory investigations were done to both groups, and included the determination of routine biochemical parameters, as well as the estimation of serum levels of OLAB, SUPAR, and CRP.

Plasma TBARs level was also determined. Results : the mean sera and plasma values of OLAB, SUPAR, CRP, and TBARs were significantly higher in the patient group compared to the corresponding control group (p = 0.005, 0.001, 0.000 and 0.000 respectively).

Furthermore, correlation studies in the patient group revealed that OLAB was inversely related to both total cholesterol and its Low Density Lipoprotein fraction, whereas plasma TBARs level positively correlated with total serum cholesterol and its LDL fraction.

In addition, the CIMT correlated positively with serum triglycerides and negatively with serum High Density Lipoprotein cholesterol. Conclusion : the present work supports the hypothesis of the existence of a subclinical atherosclerotic process underlying essential hypertension.

The significantly elevated OLAB titer suggests a possible role in trying to clear oxidized LDL from the circulation, whereas the significantly elevated SUPAR level reflects a decrease in the fibrin lytic capacity as well as an enhanced collagenase expression that contribute to the instability of the athermanous lesion.

Moreover, the significantly increased levels of CRP and TBARs reflect the aggressiveness of the subclinical atherosclerotic process present in essential hypertension.