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Association of cardiac baroreflex sensitivity with blood pressure transients: influence of sex and menopausal status.

Barnes JN, Matzek LJ, Charkoudian N, Joyner MJ, Curry TB, Hart EC - Front Physiol (2012)

Bottom Line: The magnitude of decrease in blood pressure (BP) during a vasoactive drug bolus may be associated with the calculated baroreflex sensitivity (BRS).However, there was no relationship between the decrease in BP and sympathetic BRS.The fact that these relationships do not exist in young women suggest that the female sex hormones influence baroreflex responses.

View Article: PubMed Central - PubMed

Affiliation: Human Integrative Physiology Laboratory, Department of Anesthesiology, Mayo Clinic, Rochester MN, USA.

ABSTRACT
The magnitude of decrease in blood pressure (BP) during a vasoactive drug bolus may be associated with the calculated baroreflex sensitivity (BRS). The purpose of the present study was to evaluate whether sympathetic and/or cardiac BRS relates to the extent of change in BP and whether this was altered by sex hormones. Fifty-one young women (27 ± 1 years), 14 older women (58 ± 1 years), and 36 young men (27 ± 1 years) were studied. Heart rate, BP, and muscle sympathetic nerve activity (MSNA) were monitored. Sympathetic BRS was analyzed using the slope of the MSNA-diastolic blood pressure (DBP) relationship and cardiac BRS was analyzed using the R-R interval-systolic blood pressure (SBP) relationship. Young women and men had similar mean arterial pressures (MAP, 91 ± 1 vs. 90 ± 1 mmHg), cardiac BRS (19 ± 1 vs. 21 ± 2 ms/mmHg), and sympathetic BRS (-6 ± 1 vs. -7 ± 1 AU/beat/mmHg), respectively. Older women had higher MAP (104 ± 4 mmHg, p < 0.05) and lower cardiac BRS (7 ± 1 ms/mmHg, p < 0.05), but similar sympathetic BRS (-8 ± 1 AU/beat/mmHg). There was no association between BP transients with either cardiac or sympathetic BRS in young women. In the older women, the drop in SBP, DBP, and MAP were associated with cardiac BRS (r = 0.60, r = 0.59, and r = 0.70, respectively; p < 0.05), but not sympathetic BRS. The decrease in SBP was positively related to cardiac BRS in young men (r = 0.41; p < 0.05). However, there was no relationship between the decrease in BP and sympathetic BRS. This indicates that older women and young men with low cardiac BRS have larger transients in BP during nitroprusside. This suggests a more prominent role for cardiac (as opposed to sympathetic) BRS in responding to acute BP changes in young men and older women. The fact that these relationships do not exist in young women suggest that the female sex hormones influence baroreflex responses.

No MeSH data available.


Related in: MedlinePlus

Linear regression analysis of the correlation between the magnitude of decrease in SBP and cardiac BRS (left panel) and the magnitude of decrease in MAP during the decreasing pressure transients and cardiac BRS (right panel) in young women, young men, and older women. Slopes for young men and older women for decreasing SBP and cardiac BRS was 0.72 and 0.12 respectively. The slope for the decrease in MAP and cardiac BRS in the older women was 0.30.
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Figure 1: Linear regression analysis of the correlation between the magnitude of decrease in SBP and cardiac BRS (left panel) and the magnitude of decrease in MAP during the decreasing pressure transients and cardiac BRS (right panel) in young women, young men, and older women. Slopes for young men and older women for decreasing SBP and cardiac BRS was 0.72 and 0.12 respectively. The slope for the decrease in MAP and cardiac BRS in the older women was 0.30.

Mentions: The cardiac BRS was positively associated with the decrease in SBP (Figure 1) in young men (r = 0.41, slope = 0.72, p < 0.05) and older women (Figure 1; r = 0.60, slope = 0.12, p < 0.05). However, there was no significant relationship in young women (Figure 1). The cardiac BRS was also positively correlated with DBP and MAP in older women (r = 0.59, p = 0.05; r = 0.70, p = 0.01, respectively), but not with the change in PP (r = 0.43, p = 0.12). Cardiac BRS was not significantly associated with the decrease in DBP, MAP, or PP in young women (r = 0.09, p = 0.58; r = 0.12, p = 0.45; r = −0.17, p = 0.29 respectively) or young men (r = 0.18, p = 0.31; r = 0.18, p = 0.32; r = 0.28, p = 0.11 respectively).


Association of cardiac baroreflex sensitivity with blood pressure transients: influence of sex and menopausal status.

Barnes JN, Matzek LJ, Charkoudian N, Joyner MJ, Curry TB, Hart EC - Front Physiol (2012)

Linear regression analysis of the correlation between the magnitude of decrease in SBP and cardiac BRS (left panel) and the magnitude of decrease in MAP during the decreasing pressure transients and cardiac BRS (right panel) in young women, young men, and older women. Slopes for young men and older women for decreasing SBP and cardiac BRS was 0.72 and 0.12 respectively. The slope for the decrease in MAP and cardiac BRS in the older women was 0.30.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3369369&req=5

Figure 1: Linear regression analysis of the correlation between the magnitude of decrease in SBP and cardiac BRS (left panel) and the magnitude of decrease in MAP during the decreasing pressure transients and cardiac BRS (right panel) in young women, young men, and older women. Slopes for young men and older women for decreasing SBP and cardiac BRS was 0.72 and 0.12 respectively. The slope for the decrease in MAP and cardiac BRS in the older women was 0.30.
Mentions: The cardiac BRS was positively associated with the decrease in SBP (Figure 1) in young men (r = 0.41, slope = 0.72, p < 0.05) and older women (Figure 1; r = 0.60, slope = 0.12, p < 0.05). However, there was no significant relationship in young women (Figure 1). The cardiac BRS was also positively correlated with DBP and MAP in older women (r = 0.59, p = 0.05; r = 0.70, p = 0.01, respectively), but not with the change in PP (r = 0.43, p = 0.12). Cardiac BRS was not significantly associated with the decrease in DBP, MAP, or PP in young women (r = 0.09, p = 0.58; r = 0.12, p = 0.45; r = −0.17, p = 0.29 respectively) or young men (r = 0.18, p = 0.31; r = 0.18, p = 0.32; r = 0.28, p = 0.11 respectively).

Bottom Line: The magnitude of decrease in blood pressure (BP) during a vasoactive drug bolus may be associated with the calculated baroreflex sensitivity (BRS).However, there was no relationship between the decrease in BP and sympathetic BRS.The fact that these relationships do not exist in young women suggest that the female sex hormones influence baroreflex responses.

View Article: PubMed Central - PubMed

Affiliation: Human Integrative Physiology Laboratory, Department of Anesthesiology, Mayo Clinic, Rochester MN, USA.

ABSTRACT
The magnitude of decrease in blood pressure (BP) during a vasoactive drug bolus may be associated with the calculated baroreflex sensitivity (BRS). The purpose of the present study was to evaluate whether sympathetic and/or cardiac BRS relates to the extent of change in BP and whether this was altered by sex hormones. Fifty-one young women (27 ± 1 years), 14 older women (58 ± 1 years), and 36 young men (27 ± 1 years) were studied. Heart rate, BP, and muscle sympathetic nerve activity (MSNA) were monitored. Sympathetic BRS was analyzed using the slope of the MSNA-diastolic blood pressure (DBP) relationship and cardiac BRS was analyzed using the R-R interval-systolic blood pressure (SBP) relationship. Young women and men had similar mean arterial pressures (MAP, 91 ± 1 vs. 90 ± 1 mmHg), cardiac BRS (19 ± 1 vs. 21 ± 2 ms/mmHg), and sympathetic BRS (-6 ± 1 vs. -7 ± 1 AU/beat/mmHg), respectively. Older women had higher MAP (104 ± 4 mmHg, p < 0.05) and lower cardiac BRS (7 ± 1 ms/mmHg, p < 0.05), but similar sympathetic BRS (-8 ± 1 AU/beat/mmHg). There was no association between BP transients with either cardiac or sympathetic BRS in young women. In the older women, the drop in SBP, DBP, and MAP were associated with cardiac BRS (r = 0.60, r = 0.59, and r = 0.70, respectively; p < 0.05), but not sympathetic BRS. The decrease in SBP was positively related to cardiac BRS in young men (r = 0.41; p < 0.05). However, there was no relationship between the decrease in BP and sympathetic BRS. This indicates that older women and young men with low cardiac BRS have larger transients in BP during nitroprusside. This suggests a more prominent role for cardiac (as opposed to sympathetic) BRS in responding to acute BP changes in young men and older women. The fact that these relationships do not exist in young women suggest that the female sex hormones influence baroreflex responses.

No MeSH data available.


Related in: MedlinePlus