Spirometry values in Himalayan high altitude residents (Sherpas).

We compared the spirometric values of the isolated racial group of Himalayan Sherpas with those predicted for the European Coal and Steel Community (EC&S). 146 normal adult Sherpas (64 males, 82 females) and 103 adolescents (37 females and 66 males, age 10-18 years) resident at an altitude of 3,840 m were studied. Predicted values for each adult individual were calculated using the EC&S reference equations and separate Caucasian values for children were used, and new predictive equations for the Sherpa population derived. The FEV(1) of boys, adult male and female Sherpas are all significantly greater than predicted (% Predicted (PP) (95% Confidence Interval (CI)), 113% (110-116), 110% (107-114) and 116% (112-121), P < 0.0001 for all groups) as is forced vital capacity (FVC) (112% (111-119), 113% (109-117) and 121% (117-125) respectively, P < 0.0001 for all groups). Sherpa girls displayed a smaller difference in FEV(1) and FVC (PP(CI), 104% (99-109) P<0.1 and 108% (103-114) P = 0.005, respectively). We conclude that the Sherpa race has significantly larger spirometric values than Caucasians. We speculate that this is an adaptation in response to chronic hypoxia and high levels of habitual exercise.