Linked Life Data

15778279

Source:http://linkedlifedata.com/resource/pubmed/id/15778279

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2005-7-14
pubmed:abstractText
Women have decreased orthostatic tolerance compared with men, and anecdotal evidence suggests women are more susceptible to orthostatic intolerance in warm environments. Because estrogen and progesterone affect numerous physiological variables that may alter orthostatic tolerance, the purpose of our study was to compare orthostatic tolerance across the menstrual cycle phases in women during combined orthostatic and heat stress and to compare these data with those of men. Eight normally menstruating women and eight males (22 +/- 4.0 and 23 +/- 3.5 yr, respectively) completed the protocol. Women were studied during their early follicular (EF), ovulatory (OV), and midluteal (ML) phases. Men were studied twice within 2-4 wk. Heart rate, cardiac output, blood pressure, core temperature (T(c)), and cutaneous vascular conductance (CVC) were measured during three head-up tilt tests, consisting of two tilts in the thermoneutral condition and one tilt after a 0.5 degrees C rise in T(c). There was no difference in orthostatic tolerance across the menstrual cycle phases, despite higher CVC in the ML phase after heating (EF, 42.3 +/- 4.8; OV, 40.1 +/- 3.7; ML, 57.5 +/- 4.5; P < 0.05). Orthostatic tolerance in the heat was greater in men than women (P < 0.05). These data suggest that although many physiological variables associated with blood pressure regulation fluctuate during the menstrual cycle, orthostatic tolerance in the heat remains unchanged. Additionally, our data support a clear sex difference in orthostatic tolerance and extend upon previous data to show that the sex difference in the heat is not attributable to fluctuating hormone profiles during the menstrual cycle.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0363-6135
pubmed:author
pubmed:issnType
Print
pubmed:volume
289
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
H631-42
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Menstrual cycle and sex affect hemodynamic responses to combined orthostatic and heat stress.
pubmed:affiliation
Department of Human Physiology, University of Oregon, 1240 Univ. of Oregon, Eugene, OR 97403, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't