Effects of obesity smoking and hypertension on plasma endothelin

ABSTRACT

Endothelins belong to a family of vasoactive peptides implicated in several disorders of the microvasculature. Endothelin-1 is a potent vasoconstrictive peptide with divers physiologic actions and has been considered to be involved in pathogenesis of hypertension. Several investigators had reported multiple vascular complications related to the high circulatory level of endothelin-[1]. The study comprised 80 male subjects allocated in 4 study groups Group 1 contained 20 normal men. Group 11 contained 20 obese men. Group 111 contained 20 hypertensive men. Group IV contained 20 smokers. All of study participants were assigned for estimation of plasma levels of endothelin-1 .insulin and blood lipid profile. The obtained results showed a significantly higher fasting plasma ET-[1] levels in all study groups compared to the control. furthermore, there was a significant increase of fasting plasma insulin levels in all study groups, except the smokers, hypertensive as compared to the control levels. The mean value of serum cholesterol and LDL was significantly increased in obese group as compared to controls, but did not differ significantly in hypertensive and smokers compared to controls. The mean value of serum TGS was significantly increased in all study group compared to controls, On the other hand, serum HDL was significantly decreased in all study groups compared with controls. Analysis of the obtained results showed the presence of a positive significant correation between fasting plasma ET-[1] and the mean BMI of obese subjects. Furthermore, fasting plasma ET-[1] showed a positive significant correlation with fasting plasma of insulin in all study groups except the smokers, such correlation suggested a synergistic or additive effect of both peptides in the pathogenesis of obesity, hypertension. Moreover, there was a positive significant correlation between fasting plasma level of ET-[1] with cholesterol, TGs and LDL and a negative significant correlation with serum levels of HDL in all study group. These results signify the presence of a relationship between dyslipidemia occuring in obese, hypertensive and smokers and these peptides. This relation may be causal or concomitant Conclusion, Increased fasting plasma levels of ET-[1] increases the risk of occurrence of cardiovascular complications in either obese, hypertensive, or smoker subjects. The concomitant increase of fasting plasma insulin levels leads to a more pronounced damaging effect and despite being a causal or result, the concomitant dyslipidemia will sign a danger signal for these high risk subjects of being at an increased risk of cardiovascular complications