Influence of gender and family history of hypertension on autonomic control of heart rate, diastolic function and brain natriuretic peptide.

Abstract

To verify in a unitary view whether autonomic control of heart rate and cardiac structure and function are modified early in offspring of hypertensive families. We selected 87 age- and sex-matched young normotensive subjects with (n = 45) and without (n = 42) a family history of hypertension who underwent evaluations of arterial pressure, time-domain parameters of autonomic heart rate control (24-h ECG monitoring), spectral baroreflex sensitivity, left ventricular geometry and function (echo-Doppler) and plasma brain natriuretic peptide levels (BNP). The group with a family history of hypertension significantly differed from their counterparts for systolic pressure (119 +/- 11 versus 114 +/- 9 mmHg, P< 0.05), heart rate (RR interval, 766 +/- 64 versus 810 +/- 93 ms, P< 0.05), heart rate variability [the standard deviation of normal RR intervals (SDNN), 147 +/- 29 versus 171 +/- 33 ms, P < 0.051, diastolic function (isovolumetric relaxation time, 65 +/- 9 versus 60 +/- 8 ms, P< 0.05) and BNP (23 +/- 13 versus 37 +/- 10 pg/ml, P< 0.05). Baroreflex sensitivity values did not differ between the two groups. When gender was considered, all the above-mentioned measures, as well as baroreflex sensitivity, were significantly different between males with and without a family history of hypertension but not between females, except for BNP, which was lower in males and females with a history of hypertension (males, 24 +/- 11 versus 38 +/- 8 pg/ml, P< 0.01; females 21 +/- 14 versus 36 +/- 13 pg/ml, P < 0.05). Male, but not female, hypertensive offspring have modified diastolic function and autonomic control of heart rate; BNP is the only parameter able to characterize hypertensive offspring independently from the influence of gender. This provides the hypothesis that the impaired production of this hormone could play a primary role in the pre-hypertensive state.