|
|
| Author |
Message |
A1CR
Site Admin
Joined: 18 Jan 2006
Posts: 559
|
 Posted: Tue Mar 07, 2006 5:13 am Post subject: High Altitude and CRON |
 |
|
First, keep in mind that alterations may occur in CRONies at higher altitudes. So are CRONies better off at sea-level than at higher elevations?
| Quote: |
| High-altitude anorexia leads to a hormonal response pattern modulated by both hypoxia and caloric restriction (CR). The purpose of this study was to compare altitude-induced neuroendocrine changes with or without energy imbalance and to explore how energy sufficiency alters the endocrine acclimatization process. Twenty-six, normal-weight, young men were studied for three weeks. One group (HYPO, n = 9) stayed at sea level and consumed 40% fewer calories than required to maintain body weight (BW). Two other groups were deployed to 4300m (Pikes Peak, CO) where one group (ADQ, n = 7) was adequately fed to maintain BW and the other (DEF, n=10) had calories restricted as above. HYPO experienced a typical CR induced reduction in many hormones such as insulin, testosterone, and leptin. At altitude, fasting glucose, insulin, and epinephrine exhibited a muted rise in DEF compared to ADQ. Free T4, TSH, and norepinephrine showed similar patterns between the two altitude groups. Morning cortisol initially rose higher in DEF than ADQ at 4300m, but the difference disappeared by day 5. Testosterone increased in both altitude groups acutely, but declined over time in DEF only. Adiponectin and leptin did not change significantly from SL baseline values in either altitude group regardless of energy intake. These data suggest that hypoxia tends to increase blood hormone concentrations, but anorexia suppresses elements of the endocrine response. Such suppression results in the preservation of energy stores, but may sacrifice the facilitation of oxygen delivery and the use of oxygen efficient fuels. |
Barnholt KE, Hoffman AR, Rock PB, Muza SR, Fulco CS, Braun B, Holloway L, Mazzeo RS, Cymerman A, Friedlander AL.
Endocrine responses to acute and chronic high altitude exposure (4300 m): modulating effects of caloric restriction.
Am J Physiol Endocrinol Metab. 2005 Dec 27; [Epub ahead of print]
PMID: 16380390 |
|
| Back to top |
|
 |
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
|
|
|
Search
Log in
