STRESS TEST DATA FROM MOON WALKERS.                                                                                               SPACEFLIGHT 52:29, 2010.

About a year ago I obtained, through the Freedom Of Information Act, the bicycle stress test data on Alan Shepard, Commander Apollo 14, in order to compare his data with Irwin's extraordinary stress test blood pressure (BP); for comparison Irwin's BP was > 275/125 at the 3rd. minute of exercise with a heart rate of 132 on the day after his return from his Apollo 15 mission. This had not been published by NASA. (1,2) Unfortunately NASA will only release medical data on those astronauts who are deceased and no stress test data was available on Conrad after his Apollo 12 mission. (1-3) Shepard's stress test BP was considerably lower than Irwin's on the day after return from his mission with a BP of 200/75 at the same heart rate of 132 and presumably similar workload but not reaching this level until 13 minutes of exercise.

I have published various mechanisms for the extraordinary hypertension in Irwin's case emphasizing that the underlying problem is dysfunction of the endothelium ( lining of the blood vessels ), possibly precipitated by his mission in the presence of underlying vascular disease. (1,4) Irwin's BP was elevated at rest i.e. 145/110 a month prior to his mission (5) with the normal BP at that time (1971) considered to be < 140/90.

This discrepancy in stress test -BP between Irwin's levels and Shepard's could be related not only to variability in underlying function of the endothelium in the 2 moon walkers but could also be related to variations in the amount and chemical nature (at various sites) of the dust inhaled in the habitats - brought in with the space suits. (4)

These findings of Irwin and Shepard by stress tests point out the value of this relatively simple test by its use as a screening test for endothelial dysfunction (6) before resorting to invasive diagnostic procedures.

William J. Rowe M.D. FBIS

References:

1. Rowe WJ. The Apollo 15 Space Syndrome. Circulation 1998; 97:119-20.
2. Berry CA. Medical legacy of Apollo. Aerospace Med. 1974; 45 : 1046-57.
3. Apollo 15 Medical status briefing. Manned Spacecraft Center, Aug 13, 1971. Apollo 15, PC-59.
4. Rowe WJ. Moon dust may simulate vascular hazards of urban pollution. JBIS 2007; 60:133-36.
5. Rowe WJ. Extraordinary hypertension after a lunar mission. Am. J. Med. 2009; 22:e1.
6. Chang H-J, Chung J, Choi SY et.al. Endothelial dysfunction in patients with exaggerated blood pressure response during treadmill test. Clin Cardiol. 2004; 27: 421-25.