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Oral Contraceptives Attenuate Metaboreflex in Young Women
Author(s) -
AsirvathamJeyaraj Ninitha,
Chantigian Daniel,
KellerRoss Manda L.
Publication year - 2018
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2018.32.1_supplement.725.2
Subject(s) - medicine , heart rate , blood pressure , mean arterial pressure , estrogen , endocrinology , cardiology
Background Skeletal muscle afferent feedback (group III/IV) increases mean arterial pressure (MAP) and heart rate (HR) during exercise. Evidence suggests that oral contraceptive (OC) use can increase resting blood pressure. The influence of OC on MAP and HR when activating group III/IV afferents is unclear. Objective To determine if women taking OCs have greater cardiovascular responses to activating group III/IV afferents and if phases of menstrual cycle influence this response. Methods Twelve women (means ± SD; 24±2 yrs, 7 taking OCs) attended two identical experimental visits, once during early follicular (low estrogen, days 1–4, LE) and once during ovulation (high estrogen, days 10–14, HE). Visits included 1) 3 min of rest and 3 min of passive knee flexion (HUMAC Norm, CSMI, Stoughton, MA) to activate the mechanoreflex and 2) steady state cycling (5 min) with bilateral post exercise circulatory occlusion (PECO) (2 min) of the vastus lateralis to activate the metaboreflex. Continuous noninvasive blood pressure (Nexfin, Edward Lifesciences, Irvine, CA) and a 3 lead ECG (AD Instruments, Coloroado Springs, CO) measured MAP and HR, respectively. Results Resting MAP was similar in women taking OC (90±4 mmHg) vs. no OC (87±8 mmHg, p=0.24). Mechanoreceptor activation did not increase MAP (OC: 90±6 mmHg and no OC: 88±8 mmHg) or HR (OC: 64±7 bpm and no OC: 67±12 bpm, p<0.05) in either group. MAP and HR were similar in women during both LE and HE phases with mechanoreflex activation (p>0.05). Metaboreflex activation increased MAP in women not taking OCs (steady state 95±23 mmHg vs. PECO 105±24 mmHg). On the other hand, MAP decreased with metaboreceptor activation in women taking OCs (steady state 94±12 mmHg vs. PECO 89±16 mmHg, p=0.032). Resting HR was greater in women not taking OCs (136±11 bpm) vs. OCs (107±32 bpm, p<0.05). HR declined with metaboreflex activation in both OC and no OC group irrespective of LE and HE phase (p<0.05). Conclusions Although mechanoreflex activation did not influence MAP for either group of women, women taking OCs had an attenuated MAP with metaboreflex activation. This is in contrast to evidence suggesting that OCs can increase MAP at rest and may indicate that during exercise OC use can be beneficial in lowering blood pressure in women. Support or Funding Information No funding to disclose. This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .