Poster Esformes

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[4] RESULTS The decreases in blood pressures that follow a single bout of exercise (post exercise hypotension: PEH) are well documented in both hypertensive and normotensive individuals (Coats et al., 1989; Reuckert et al., 1996), and indeed resting blood pressure is often normalized following acute exercise in hypertensives (Arakawa, 1993). Although the magnitude of PEH seems to be unaffected by gender, the impact of menstrual cycle phase upon gender comparisons has been ignored. We studied 8 females (age: 20±0.3 yr) during the early follicular (EF), late follicular (LF) and mid-luteal (ML) phases of the menstrual cycle, and 8 males (age: 21±0.7 yr) on 2 separate occasions (M 1 and M 2 ). Cycle phase was determined via urinary assessment of LH. Central and peripheral haemodynamics were recorded via echocardiography and venous occlusion plethysmography (Fig. 1), at rest and for 45 min following 30 min of cycle ergometry at 80% of the lactate threshold. This is the first study to examine the influence of menstrual cycle phase upon gender differences in PEH. We demonstrated that gender affects the magnitude and haemodynamic mechanisms regulating PEH. Immediately post-exercise, females demonstrated a greater reliance in stroke volume, whilst males relied on a greater left ventricular end systolic volume and HR in order to maintain post-exercise CO in the presence of peripheral vasodilation. Systemic vascular resistance was non- significantly lower in males than females probably as a result of a greater body size. Furthermore, menstrual cycle phase appears to influence the pattern of PEH such that pressures are lower in those phases concurrent with low reproductive hormone concentrations. Enhanced buffering of peripheral vasodilation in the LF and ML phases meant that gender differences in MAP and DBP were evident in the EF phase of the cycle. This study was supported by the School of Sport and Exercise Sciences of the University of Leeds. The aim of the present study was to examine central and peripheral haemodynamics regulating PEH following moderate- intensity exercise in moderately active males and females. The impact of menstrual cycle phase upon potential gender differences was examined by investigating females in three phases of their cycle. [1] INTRODUCTION INFLUENCE OF MENSTRUAL CYCLE PHASE UPON GENDER DIFFERENCES IN POST EXERCISE HYPOTENSION Joseph I. Esformes, Katherine Bird, Jennifer Cornes, Frances Norman, Andrew Roberts, Joanna Sigley, Karen M. Birch. School of Sport & Exercise Sciences, University of Leeds, Leeds, United Kingdom. [2] AIMS [3] METHODS [7] REFERENCES [5] SUMMARY [6] CONCLUSION Both males and females in this study demonstrated a classic pattern of post-exercise recovery in all blood pressure variables. However, cardiovascular recovery from exercise appears to differ between males and females and this difference is further influenced by menstrual cycle phase. Haemodynamics at rest did not differ between males and females or between the testing phases (P > 0.05; Table 1). Significant PEH was observed in all subjects (P < 0.05) with the magnitude of the nadir in all blood pressure variables being significantly greater (P < 0.05) in females compared to males; 10±1 vs 4±1, 9±1 vs 5±1, 8±1 vs 4±1 for systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP), respectively. Blood pressure responses did not differ between tests in males, whilst females demonstrated a lower DBP and MAP (Fig. 2) throughout recovery in the EF phase compared to the LF and ML phases (P <0.05). This variation resulted in a phase-by-gender interaction with DBP and MAP demonstrating a different pattern of recovery in females compared to males in the EF phase only (P < 0.05). SBP displayed a gender-by-time interaction, indicating a different temporal pattern of recovery in each gender (Table 1; P< 0.05). Mean values for central and peripheral haemodynamics reported for both males and females are displayed over time in Table 1. Cardiac output (CO; Fig. 3) and heart rate (HR) displayed gender-by-time interactions (P < 0.05). Both values were significantly greater than rest at 5 min recovery, but this increase was larger in males than in females (P < 0.05: CO, 31±0.7% vs 15±6.8 %; HR, 26±0.3 % vs 3±3.2 %). Fig. 1 Venous occlusion plethysmography in the lower limb and echocardiographic measurements obtained from the left parasternal long axis view of the heart. Central haemodynamic indices were unaffected by menstrual cycle phase, whilst calf blood flow and systemic vascular resistance were unaffected by either menstrual phase or gender (P > 0.05). Fig. 2 Mean arterial pressure (MAP) recorded at baseline (0 on the time axis) and throughout the recovery period. * P < 0.05 versus 0. Table 1. Post-exercise cardiovascular data Fig. 3 Cardiac output (CO) recorded at baseline (0 on the time axis) and throughout the recovery period. * P < 0.05 versus 0; ** P < 0.05 versus 5 min. AMERICAN COLLEGE OF SPORTS MEDICINE ∙ 52ND ANNUAL MEETING ∙NASHVILLE ∙TENNESSEE ∙ JUNE 1 – 4, 2005 Arakawa, K (1993). J Hypertens. 11, 223-229. Coats, AJS et al. (1989). J Physiol. 413, 289-298. Rueckert PA et al. (1996). Med Sci Sports Exerc. 28, 24-32.

Transcript of Poster Esformes

Page 1: Poster Esformes

[4] RESULTS

The decreases in blood pressures that follow a single bout of exercise (post exercise hypotension: PEH) are well documented in both hypertensive and normotensive individuals (Coats et al., 1989; Reuckert et al., 1996), and indeed resting blood pressure is often normalized following acute exercise in hypertensives (Arakawa, 1993). Although the magnitude of PEH seems to be unaffected by gender, the impact of menstrual cycle phase upon gender comparisons has been ignored.

We studied 8 females (age: 20±0.3 yr) during the early follicular (EF), late follicular (LF) and mid-luteal (ML) phases of the menstrual cycle, and 8 males (age: 21±0.7 yr) on 2 separate occasions (M1 and M2). Cycle phase was determined via urinary assessment of LH. Central and peripheral haemodynamics were recorded via echocardiography and venous occlusion plethysmography (Fig. 1), at rest and for 45 min following 30 min of cycle ergometry at 80% of the lactate threshold.

This is the first study to examine the influence of menstrual cycle phase upon gender differences in PEH. We demonstrated that gender affects the magnitude and haemodynamic mechanisms regulating PEH. Immediately post-exercise, females demonstrated a greater reliance in stroke volume, whilst males relied on a greater left ventricular end systolic volume and HR in order to maintain post-exercise CO in the presence of peripheral vasodilation. Systemic vascular resistance was non-significantly lower in males than females probably as a result of a greater body size. Furthermore, menstrual cycle phase appears to influence the pattern of PEH such that pressures are lower in those phases concurrent with low reproductive hormone concentrations. Enhanced buffering of peripheral vasodilation in the LF and ML phases meant that gender differences in MAP and DBP were evident in the EF phase of the cycle.

This study was supported by the School of Sport and Exercise Sciences of the University of Leeds.

The aim of the present study was to examine central and peripheral haemodynamics regulating PEH following moderate-intensity exercise in moderately active males and females. The impact of menstrual cycle phase upon potential gender differences was examined by investigating females in three phases of their cycle.

[1] INTRODUCTION

INFLUENCE OF MENSTRUAL CYCLE PHASE UPON GENDER DIFFERENCES IN POST EXERCISE HYPOTENSIONJoseph I. Esformes, Katherine Bird, Jennifer Cornes, Frances Norman, Andrew Roberts, Joanna Sigley, Karen M. Birch.

School of Sport & Exercise Sciences, University of Leeds, Leeds, United Kingdom.

[2] AIMS

[3] METHODS

[7] REFERENCES

[5] SUMMARY

[6] CONCLUSION

Both males and females in this study demonstrated a classic pattern of post-exercise recovery in all blood pressure variables. However, cardiovascular recovery from exercise appears to differ between males and females and this difference is further influenced by menstrual cycle phase.

Haemodynamics at rest did not differ between males and females or between the testing phases (P > 0.05; Table 1). Significant PEH was observed in all subjects (P < 0.05) with the magnitude of the nadir in all blood pressure variables being significantly greater (P < 0.05) in females compared to males; 10±1 vs 4±1, 9±1 vs 5±1, 8±1 vs 4±1 for systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP), respectively. Blood pressure responses did not differ between tests in males, whilst females demonstrated a lower DBP and MAP (Fig. 2) throughout recovery in the EF phase compared to the LF and ML phases (P <0.05). This variation resulted in a phase-by-gender interaction with DBP and MAP demonstrating a different pattern of recovery in females compared to males in the EF phase only (P < 0.05).

SBP displayed a gender-by-time interaction, indicating a different temporal pattern of recovery in each gender (Table 1; P< 0.05). Mean values for central and peripheral haemodynamics reported for both males and females are displayed over time in Table 1. Cardiac output (CO; Fig. 3) and heart rate (HR) displayed gender-by-time interactions (P < 0.05). Both values were significantly greater than rest at 5 min recovery, but this increase was larger in males than in females (P < 0.05: CO, 31±0.7% vs 15±6.8 %; HR, 26±0.3 % vs 3±3.2 %).

Fig. 1 Venous occlusion plethysmography in the lower limb and echocardiographic measurements obtained from the left parasternal long axis view of the heart.

Central haemodynamic indices were unaffected by menstrual cycle phase, whilst calf blood flow and systemic vascular resistance were unaffected by either menstrual phase or gender (P > 0.05).

Fig. 2 Mean arterial pressure (MAP) recorded at baseline (0 on the time axis) and throughout the recovery period. * P < 0.05 versus 0.

Table 1. Post-exercise cardiovascular data

Fig. 3 Cardiac output (CO) recorded at baseline (0 on the time axis) and throughout the recovery period. * P < 0.05 versus 0; ** P < 0.05 versus 5 min.

AMERICAN COLLEGE OF SPORTS MEDICINE ∙ 52ND ANNUAL MEETING ∙NASHVILLE ∙TENNESSEE ∙ JUNE 1 – 4, 2005

Arakawa, K (1993). J Hypertens. 11, 223-229.Coats, AJS et al. (1989). J Physiol. 413, 289-298.Rueckert PA et al. (1996). Med Sci Sports Exerc. 28, 24-32.