Document Detail


Hormonal responses in elders experiencing pre-syncopal symptoms during head-up tilt before and after exercise training.
MedLine Citation:
PMID:  7583804     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: Hormonal responses of elderly individuals experiencing pre-syncopal symptoms during head-up tilt testing (HUT) were compared with responses of nonsymptomatic subjects both before (T1) and after (T2) 6 months of endurance training. METHODS: Based on responses to HUT at T1, 35 men and women (ages 61-79 years) were placed into symptomatic and nonsymptomatic groups for analysis. Symptomatic subjects (n = 5) experienced lightheadedness, nausea, sweating, or syncope during T1 HUT but completed 15 minutes of HUT at T2. Training consisted of treadmill walking or stairclimbing 3 x/wk, 30-45 min/day, at 75-85% of maximal heart rate reserve. Adrenocorticotropic hormone (ACTH), vasopressin, aldosterone, norepinephrine, epinephrine, hemoglobin, and hematocrit were measured during supine rest prior to HUT, and either at the end of the 15-minute HUT or at symptom onset. Plasma volume (PV) was measured at supine rest; tilt-induced changes in PV were calculated from changes in hemoglobin and hematocrit. RESULTS: During T1 HUT, symptomatic subjects had greater increases in vasopressin and a greater rate of PV loss (p < .05). Increases in ACTH and aldosterone were greater in symptomatic subjects at T1 and T2, while increases in norepinephrine were greater at T2 (p < .05). Reductions in tilt-induced vasopressin concentration and a decreased rate of PV loss were seen at T2 in symptomatic subjects. CONCLUSIONS: T1 results from symptomatic subjects are consistent with greater stimulation of volume-sensitive receptors induced by a greater rate of fall in PV. Exercise training resulted in increased tilt tolerance for symptomatic subjects associated with reductions in vasopressin concentration and rate of PV loss during tilt.
Authors:
J F Carroll; C E Wood; M L Pollock; J E Graves; V A Convertino; D T Lowenthal
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Publication Detail:
Type:  Comparative Study; Journal Article    
Journal Detail:
Title:  The journals of gerontology. Series A, Biological sciences and medical sciences     Volume:  50     ISSN:  1079-5006     ISO Abbreviation:  J. Gerontol. A Biol. Sci. Med. Sci.     Publication Date:  1995 Nov 
Date Detail:
Created Date:  1995-12-21     Completed Date:  1995-12-21     Revised Date:  2010-03-24    
Medline Journal Info:
Nlm Unique ID:  9502837     Medline TA:  J Gerontol A Biol Sci Med Sci     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  M324-9     Citation Subset:  AIM; IM; S    
Affiliation:
Center for Exercise Science, College of Medicine, University of Florida, Gainesville, USA.
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MeSH Terms
Descriptor/Qualifier:
Aged
Aged, 80 and over
Aging / blood*
Blood Volume
Dizziness / blood
Exercise / physiology*
Female
Hormones / blood*
Humans
Male
Middle Aged
Nausea / blood
Physical Education and Training
Physical Endurance / physiology
Sweating
Syncope / blood*
Tilt-Table Test*
Chemical
Reg. No./Substance:
0/Hormones

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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