THE ROLE OF MENOPAUSE IN THE DEVELOPMENT OF CHRONIC MOUNTAIN-SICKNESS

The objective of this study was to investigate the role of menopause i n the appearance of the physiopathological sequence that leads to chro nic mountain sickness (CMS) in a high-altitude female population. The females studied are 30-54 yr old (n = 152) and have permanent residenc e in Cerro de Pasco (Pasco, Peru; 4,300 m). The sample was divided int o postmenopausal and premenopausal groups for comparison. Blood oxygen saturation (SaO(2)), excessive erythrocytosis [EE, measured by the le vel of hematocrit (Hct)], peak expiratory flow rates (PEFR), and a sco re that represents the main signs and symptoms of CMS (CMS(score)) wer e measured. Postmenopausal women had higher Hct (50.2 +/- 4.04 vs. 47. 4 +/- 4.13%, P < 0.001), lower SaO(2) (81.9 +/- 4.12 vs. 84.7 +/- 3.14 %, P < 0.001) and PEFR values (489 +/- 101 vs. 534 +/- 90 l/min, P < 0 .02), and slightly higher CMS(score) (19.1 +/- 3.37 vs. 17.9 +/- 3.48, P < 0.06) than premenopausal women. The prevalence of women with EE ( EE = Hct >56%) was found to be 8.8%. Forty-five percent of the postmen opausal subjects presented a high CMS(score) (>21), whereas only 22% o f the premenopausal subjects presented this high value (P < 0.02). We can therefore conclude that menopause may represent a contributing fac tor for the development of CMS.