Baroreflex sensitivity and heredity in essential hypertension.

Abstract

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.

Brain nitric oxide production by a proline-rich decapeptide from Bothrops jararaca venom improves baroreflex sensitivity of spontaneously hypertensive rats

“…35 Xing-Sheng et al 31 concluded from human genetic studies that polymorphism of the eNOS gene results in reduced eNOS activity, indicating a depressant effect of eNOS-generated NO on baroreflex sensitivity. Based on the observation that Bj-PRO-10c induced production of NO in neuronal cells from postnatal whole-SHR-brain cell culture, we analyzed the gene expression levels of ASS, eNOS and nNOS, which are known to be involved in NO synthesis.…”

Genetic influences on baroreflex sensitivity during rest and mental stress

“…Most evidence suggests that BRS is partly influenced by genetic factors [4], and indeed previously identified polymorphisms seem to explain part of the variance in BRS [30,31]. However, until now only one study reported on the heritability of BRS, in that case obtained from 5-min measurements during a rest condition [5].…”

“…However, there is a poor understanding of the determinants of spontaneous BRS. Impaired BRS in hypertensive patients has been suggested to be in part genetically determined [4]. The relative contribution of genetic influences to individual variation in BRS can be estimated in a twin design.…”

Renal kallikrein excretion: role of ethnicity, gender, environment, and genetic risk of hypertension

“…16,24 We have previously shown hypertension family history to influence such potentially pathogenic traits as baroreceptor slope 24 or the cardiac response to alpha 2 -adrenergic blockade. 16 Such early phenotypic responses, occurring in at-risk subjects even before the onset of hypertension, may qualify as more informative 'intermediate phenotypes' 1,2,16 in the genetic analysis of this complex trait.…”