Arterial stiffness, blood pressure progression and penile vascular disease in males with erectile dysfunction: a closer look at microcirculatory damage

Abstract

Abstract Background Elevated aortic stiffness may be associated with microvascular remodelling and damage, which may be an important causal contributor to incident cardiovascular disease. Recent evidence supports the independent of age and blood pressure (BP) level predictive value of severe penile arterial insufficiency for adverse cardiovascular events. Purpose Aim of the study is to examine in men with erectile dysfunction the association of increased aortic stiffness with penile vascular damage by taking into account BP level. Methods We measured carotid-femoral pulse wave velocity (PWV) and assessed microvascular (penile vascular damage) changes in four age-matched groups without a history of diabetes and cardiovascular disease; Normal BP (n=137), high-normal BP (n=94), stage I hypertension (n=82) and stage II and III hypertension (n=76). Microvascular damage was examined by measuring penile peak systolic velocity (PSV) with a dynamic penile color Doppler ultrasonography after intracavernous injection of prostaglandin E1. Lower PSV values indicate severe penile vascular disease. Results Carotid-femoral PWV increased and PSV decreased across BP groups (all P<0.001). In regression analysis increased systolic BP (b= -0.185, P<0.01) and PWV (b= -0.170, P<0.05) are significant determinants of low penile PSV after controlling for age, body mass index, cholesterol and smoking. We dichotomized carotid-femoral PWV taking into account the mean value in the whole study population. Figure shows the differences in PSV across the BP groups considering the cut-off PWV value of 8.5m/s (high vs low PWV). Individuals with higher PWV had lower penile PSV in normal BP (P<0.01) and in high normal BP group (P=0.02) after adjusting for age and systolic BP. On the contrary, hypertensive patients already have significant structural damage in the penile arteries and high PWV does not further reduce penile blood flow. Interestingly, figure shows the comparable PSV measurements between individuals with high-normal BP level who had high PWV and patients in stage 1 hypertension group denoting significantly impaired microvascular damage in males with high-normal BP and increased aortic stiffness. The high normal BP group has significantly lower PSV compared to normal BP group independently of PWV value. Conclusion Increased aortic stiffness may promote penile microvascular remodelling and damage in men without increased BP level. Additionally, in men with high-normal BP higher arterial stiffness is associated with comparable penile microvascular damage of men with arterial hypertension. Because aortic stiffening may be preventable, further clinical research on earlier preventive measures that focus on aortic stiffness and microvascular remodelling within individuals with erectile dysfunction who have normal BP is warranted.Aortic stiffness, BP level and PSV