The primary aim of this study was to test penile endothelial microvascular function in patients with treated arterial hypertension, compared to an age-matched group of normotensive subjects using laser speckle contrast imaging (LSCI). Additionally, we tested the acute penile microvascular effects induced by the oral administration of the phosphodiesterase type 5 inhibitor sildenafil citrate (SIL).Design and method:
Endothelium-dependent penile microvascular reactivity of hypertensive patients (aged 58.8 ± 6.6 years, n = 34) and age-matched healthy volunteers (n = 33) was evaluated at rest and 60 minutes following oral administration of SIL (100 mg). LSCI was coupled with the cutaneous iontophoresis of acetylcholine (ACh) using increasing anodal currents. The measurements of skin blood flow (arbitrary perfusion units, APU) were divided by values of mean arterial pressure to give the cutaneous vascular conductance (CVC) in APU/mmHg.Results:
Office systolic arterial pressure was 122.6 ± 8.8 and 136.7 ± 13.8 mmHg for control and hypertensive subjects, respectively (P < 0.0001); diastolic arterial pressure was 79.3 ± 6.6 and 86.7 ± 7.6 mmHg for control and hypertensive subjects, respectively (P < 0.0001). The basal values of skin microvascular flow (APU) in the penis before (P = 0.5808) and after SIL (P = 0.4256) were similar in the control and hypertensive subjects. Penile baseline microvascular flow was significantly increased after SIL in control (P = 0.0006) and also in hypertensive (P = 0.0038) subjects, compared to basal values before SIL. The basal values of CVC in the penis before (P = 0.0590) and after (P = 0.0857) SIL in the control and hypertensive participants were not significantly different. The peak values of CVC during iontophoresis of ACh in the penis before SIL were of 0.62 (0.44–0.91) and 0.50 (0.33–0.79) APU/mmHg in the control and hypertensive participants, respectively (P = 0.2052). After administration of SIL, the peak values of CVC during iontophoresis of ACh in the penis were of 0.88 (0.66–1.12) and 0.69 (0.56–0.84) APU/mmHg in the control and hypertensive participants, respectively (P = 0.0427).Conclusions:
Penile endothelium-dependent microvascular function was similar in hypertensive patients and healthy controls. Nevertheless, the response to the acute administration of SIL was higher in the controls than in hypertensive patients.