. "13. Endocrinological Responses to Dietary Salt Restriction During Heat Acclimation." Nutritional Needs in Hot Environments: Applications for Military Personnel in Field Operations. Washington, DC: The National Academies Press, 1993.
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Nutritional Needs in Hot Environments: Applications for Military Personnel in Field Operations
were quite similar, but, of course, on that day the volunteers in both groups were coming off the same stabilization diet and level of salt intake. By day 4 of heat acclimation, the T1 values for PRA and ALD were remarkably different due to the low-salt diet.
And clearly, if acclimation increases plasma volume, which it has been reported to do up to 18 percent, there should indeed be a reduction in both the T1 levels and the responses as acclimation progresses.
In fact, at one time we infused hyperoncotic albumin to test volunteers to increase plasma volume in a matter of hours versus the six or eight days that Dr. Armstrong showed were required here in this study.
And in that condition also we had repression of baseline levels of those hormones, not great, but statistically significant.
PARTICIPANT: Did you measure blood pressure during that period of time? Because that could change glomerular filtration rate and explain some of these differences.
DR. FRANCESCONI: There were actually some decreases in blood pressure during heat acclimation. In fact, I think Lt. Colonel William Curtis has much data on that which he is about to present at a different meeting. There were some decrements in blood pressure.
PARTICIPANT: I am trying to remember, from the military initiatives study, what was the sodium intake of soldiers in garrison? What were measured in some of those studies?
PARTICIPANT: At least 4500 mg of sodium per day.
PARTICIPANT: So that would be roughly 9 grams of salt, or 11 or 12. So maybe a little more.
Would you speculate that if you were to take soldiers coming right off the food that they would be consuming normally when they are on base and were dropped into Saudi Arabia and eating only MREs getting 4 grams of salt, that you would see the same kinds of results that you saw there?
DR. FRANCESCONI: I think I probably would. If they had responsive and well-functioning endocrinological systems, young, healthy adult males and if they were drinking well, yes.
DR. NESHEIM: Any other questions?
PARTICIPANT: Just point of clarification. Our current MRE is much higher in salt than the 4 grams.
DR. FRANCESCONI: Yes. That is true.
PARTICIPANT: Do you expect any differences in that level for women?