Author(s): HENLEY-MARTIN, S., BRADE, C., COLLIS, J., NAYLOR, L., SPENCE, A., Institution: CURTIN UNIVERSITY, Country: AUSTRALIA, Abstract-ID: 1024

INTRODUCTION:
Menopause is a critical phase in female reproductive ageing and is characterised by a rapid decline in oestrogen. Due to its cardioprotective effects, cardiac health is particularly affected. Exercise exerts protective effects on cardiovascular health to mitigate the age-related decline, preserving function and maximal aerobic capacity. While studies in men offer insight, female-specific responses regarding the impact of exercise on cardiac function in post-menopausal (PM) women is limited. This study assessed cardiac geometry and function in early PM women who identified as athletes (AT) compared to recreationally active healthy controls (CO).
METHODS:
Twenty women (age 56.9±3.9 y), classified as Stage +1c using the STRAW staging system (4.5±2.2 y post-final menstrual period) participated. Cyclists/triathletes (AT, n=10) and CO (n=10) were matched for age and hormone replacement therapy use (pooled n=8). Resting transthoracic echocardiography was used to assess diastolic function (medial e’ cm/s; lateral e’ cm/s; E/e’ ratio; indexed left atrial volume LA ESVi mL.m-2), stroke volume (SV mL), ejection fraction (EF %). Left ventricular mass (LVMi g/kg) and end-diastolic volume (EDVi mL/kg) were both indexed to lean mass (kg) while speckle-tracking echocardiography assessed LV global longitudinal strain (GLS%). Resting heart rate (HR bpm), resting mean arterial pressure (MAP, mmHg), peak oxygen consumption (VO2peak mL.kg.min-1), DXA-derived body composition (lean mass kg; body fat %) and physical activity (PA mins/wk) were also assessed. Student’s t-test was used to assess significance between groups (p<.05).
RESULTS:
VO2peak (41.7±5.4 v 33.2±3.3 mL.kg.min-1 p<.001) and PA (1000.0±202.3 v 200.0±77.6 mins/wk p<.001) were significantly higher in AT compared to CO, while resting HR (47±5 v 55±6 BPM p<.005) and MAP (82±8 v 92±9 mmHg p<.05) were significantly lower in AT. Lean mass did not differ between groups (45.2±3.8 v 48.8±5.0 kg p=0.085) but body fat % was significantly lower in AT compared to CO (27.4±2.4 v 32.1±4.3% p<.05). No significant difference was found for cardiac geometry (LVMi 3.1±0.4 v 3.0±0.4 g/kg p=0.512; EDVi 2.2±0.3 v 1.9±0.3 mL/kg p=0.077), systolic (SV 65.4±8.9 v 63.3±11.1 mL p=0.639; EF 66.9±7.1 v 67.0±4.2% p=0.951) or diastolic function (medial e’ 7.7±2.1 v 7.2±1.7cm/s p=0.600; lateral e’ 11.0±2.5 v 10.5±2.3cm/s p=0.629; E/e’ 9.0±2.6 v 9.5±1.9 p=0.620; LA ESVi 36.6±9.6 v 35.3±11.5mL/m2 p=0.790). No significant difference was observed for GLS (-23.0±1.3 v -22.0±1.8% p=0.177).
CONCLUSION:
Despite significantly lower resting HR, lower MAP and improved VO2peak in PM athletes, we observed no cardiac geometrical or functional differences between PM athletes and recreationally active controls, when studied at rest. The greater aerobic capacity in PM athletes may therefore be due to improved cardiac functional reserve as well as peripherally-mediated mechanisms such as enhanced oxygen extraction efficiency and thus warrants further investigation.