Gender not a factor for altitude decompression sickness risk.
BACKGROUND
Early, retrospective reports of the incidence of altitude decompression sickness (DCS) during altitude chamber training exposures indicated that women were more susceptible than men. We hypothesized that a controlled, prospective study would show no significant difference.


METHODS
We conducted 25 altitude chamber decompression exposure profiles. A total of 291 human subjects, 197 men and 94 women, underwent 961 exposures to simulated altitude for up to 8 h, using zero to 4 h of preoxygenation. Throughout the exposures, subjects breathed 100% oxygen, rested or performed mild or strenuous exercise, and were monitored for precordial venous gas emboli (VGE) and DCS symptoms.


RESULTS
No significant differences in DCS incidence were observed between men (49.5%) and women (45.3%). However, VGE occurred at significantly higher rates among men than women under the same exposure conditions, 69.3% and 55.0% respectively. Women using hormonal contraception showed significantly greater susceptibility to DCS than those not using hormonal contraception during the latter two weeks of the menstrual cycle. Significantly higher DCS incidence was observed in the heaviest men, in women with the highest body fat, and in subjects with the highest body mass indices and lowest levels of fitness.


CONCLUSIONS
No differences in altitude DCS incidence were observed between the sexes under our test conditions, although men developed VGE more often than women. Age and height showed no significant influence on DCS incidence, but persons of either sex with higher body mass index and lower physical fitness developed DCS more frequently.
Webb
James T
JT
Air Force Research Laboratory (Wyle Laboratories, Inc.) San Antonio, TX 78232, USA. james.webb@brooks.af.mil
Kannan
Nandini
N
Pilmanis
Andrew A
AA
D000337:Aerospace Medicine / Q000379:methods; D000367:Age Factors; D000531:Altitude; D001273:Atmosphere Exposure Chambers; D001823:Body Composition / Q000502:physiology; D001824:Body Constitution / Q000502:physiology; D015992:Body Mass Index; D016009:Chi-Square Distribution; D016001:Confidence Intervals; D003278:Contraceptives, Oral, Hormonal / Q000009:adverse effects; D003665:Decompression Sickness / Q000453:epidemiology* / Q000503:physiopathology*; D004618:Embolism, Air / Q000503:physiopathology; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008597:Menstrual Cycle / Q000502:physiology; D008991:Monitoring, Physiologic; D010809:Physical Fitness / Q000502:physiology; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors
D003278:Contraceptives, Oral, Hormonal