Premium
Influence of sex and menstrual phase on the middle cerebral artery blood flow velocity responses to dynamic exercise in humans
Author(s) -
Hartwich Doreen,
Kim Areum,
Griffin Harry S,
Balanos George M,
Aldred Sarah,
Fadel Paul J,
Fisher James P
Publication year - 2011
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.25.1_supplement.1024.11
Subject(s) - middle cerebral artery , medicine , menstrual cycle , transcranial doppler , follicular phase , cerebral blood flow , cardiology , endocrinology , cerebral arteries , cerebral perfusion pressure , blood flow , hormone , ischemia
Emerging evidence suggests that resting cerebral blood flow is typically higher in women until menopause. However, it is presently unknown how sex and menstrual phase influence exercise‐induced increases in cerebral perfusion. Middle cerebral artery blood flow velocity (MCA V mean ; transcranial Doppler), heart rate (HR; ECG) and mean blood pressure (MBP; SunTech) were measured at rest and during leg cycling at 50% of HR reserve in young women (21±2 yr; n=8) and men (20±1yr; n=9). Women not taking oral contraceptives were tested during the early (EF, days 1–5) and late (LF, days 10–12) follicular phases of the menstrual cycle. Cerebral vascular conductance index (CVCi) was calculated (MCA V mean /MBP). At rest HR and MBP were similar between women at EF and LF, and men. However, MCA V mean was significantly higher in women compared to men (73±3 EF, 75±4 LF and 56±3 men, cm/s). Exercise‐induced increases in MBP were significantly lower in women (Δ+10±1 EF, Δ+10±2 LF) than men (Δ+17±2 mmHg), while increases in HR were similar between groups. The increase in MCA V mean during exercise was attenuated in women during LF phase (Δ+4±3 cm/s) compared with EF (Δ+10±3 cm/s) and men (Δ+16±5 cm/s). Resting CVCi was higher in men and unchanged from rest to exercise in all groups. These preliminary data suggest that exercise‐induced increases in cerebral perfusion are attenuated during LF phase of the menstrual cycle in women.