Higher systemic vascular resistance in individuals with a family history of hypertension.

Objective: To compare blood pressure (BP) and cardiovascular function between individuals with and without a family history of hypertension in a first-degree relative.

Methods: The haemodynamics of participants with (n = 437) and without (n = 274) a family history of hypertension were recorded using continuous tonometric pulse wave analysis and whole-body impedance cardiography during passive head-up tilt.

Results: The group with a family history of hypertension had a higher percentage of antihypertensive medication users (15.6 vs. 8%, P = 0.003) and higher office BP (143/91 vs. 140/87 mmHg, P < 0.05) than the group without hypertensive first-degree relatives. The proportion of men (51.9 vs. 55.1%) and the mean age (48.2 vs. 48.1 years) were similar in both groups. During head-up tilt, participants with a family history of hypertension consistently had 5/4 mmHg (systolic/diastolic) higher radial and aortic BP (P < 0.001 for all comparisons), a shorter aortic reflection time (-2.4 ms, P = 0.017), and a higher systemic vascular resistance (SVR) index (180 dyn s/cm5 m2, P < 0.001) than participants without hypertensive first-degree relatives. Central forward wave amplitude, pulse pressure, augmentation pressure, augmentation index, heart rate, cardiac output, and pulse wave velocity did not differ between the study groups. All haemodynamic variables changed significantly in response to head-up tilt with no differences between the two study groups.

Conclusion: Participants with a family history of hypertension were characterized by elevated central and peripheral BP probably due to higher SVR, whereas the stiffness of large arteries was not higher. These findings highlight the role of SVR in the pathogenesis of primary hypertension.