Vascular and baroreceptor abnormalities in young males with a family history of hypertension

Vascular and baroreceptor abnormalities in 44 young males, mean age 21 years, comprising of offspring with (FH⁺; n = 22) and without (FH⁻; n = 22) hypertensive parents, were investigated. Peak forearm blood flow (FBF), which was defined as the highest blood flow obtained following reactive hyperaemia, was assessed using strain gauge plethysmography following 5 min of ischemia. Cardiopulmonary baroreceptor sensitivity was assessed using lower body negative pressure for 5 min at −20 mmHg and was determined by calculating change of stroke volume and forearm vascular resistance (FVR) to lower body negative pressure. Carotid baroreceptor sensitivity was assessed using neck suction at −20, −40, −60, and −80 mmHg and was calculated by dividing RR interval by systolic blood pressure. Augmentation index, a measure of wave reflection, was assessed using applanation tonometry and was calculated as the ratio of augmented pressure and pulse pressure. Peak FBF of FH⁺ was 19% lower than the FH⁻ (p = 0.02). Also FH⁺ had 17% higher peak FVR compared to FH⁻ (p = 0.04). However, there were no significant differences between groups for cardiopulmonary, carotid baroreceptor sensitivity, and augmentation index. These results suggest that peripheral vascular dysfunction appears earlier than abnormal baroreceptor sensitivity in young males with a family history of hypertension.