Family history of hypertension was associated with lower baroreflex sensitivity (e.g., 8.1 vs 15.4 ms/mmHg in hypertensives via amyl nitrite), acting as the strongest unique predictor.
Observational (n=64)
Does a family history of hypertension affect baroreflex sensitivity in normotensive and hypertensive individuals?
Impairment in baroreflex sensitivity in hypertension is partly genetically determined and may be an important hereditary component in the pathogenesis of essential hypertension.
BACKGROUND: Abnormalities in baroreflex control of heart rate may be important in the pathogenesis of essential hypertension. METHODS AND RESULTS: To investigate the influence of heredity on baroreflex function, we measured baroreflex sensitivity in 40 untreated patients with essential hypertension grouped by the presence (FH+) or absence (FH-) of a family history of hypertension and in 24 normotensive counterparts. Baroreflex sensitivity was assessed by both high-pressure (phenylephrine bolus) and low-pressure (amyl nitrite inhalation) stimuli. Subject groups were matched for age, blood pressure, body weight, and race. Baroreflex sensitivity (in milliseconds per millimeter of mercury) assessed by amyl nitrite inhalation was 24.3 +/- 2.8 in FH- normotensives, 12.3 +/- 1.7 in FH+ normotensives, 15.4 +/- 3.3 in FH- hypertensives, and 8.1 +/- 1.2 in FH+ hypertensives. Baroreflex sensitivity assessed by phenylephrine bolus was 28.8 +/- 5.6 in FH- normotensives, 19.3 +/- 2.8 in FH+ normotensives, 19.1 +/- 2.0 in FH- hypertensives, and 13.6 +/- 1.3 in FH+ hypertensives. Two-factor analysis of variance showed significant effects on baroreflex sensitivity for blood pressure status (normotensive versus hypertensive) and for family history of hypertension. After control line (controlling) for the effects of several variables, including age, mean arterial pressure, body weight, and race through multiple linear regression analysis, the effect of family history of hypertension on baroreflex sensitivity was still highly significant. Indeed, of all variables investigated, family history of hypertension was the strongest unique baroreflex sensitivity predictor. CONCLUSIONS: These data suggest that the impairment in baroreflex sensitivity in hypertension is in part genetically determined and may be an important hereditary component in the pathogenesis of essential hypertension.
Parmer et al. (Sat,) conducted a observational in Essential hypertension (n=64). Family history of hypertension vs. No family history of hypertension was evaluated on Baroreflex sensitivity. Family history of hypertension was associated with lower baroreflex sensitivity (e.g., 8.1 vs 15.4 ms/mmHg in hypertensives via amyl nitrite), acting as the strongest unique predictor.