Abstract
To the Editor:
We read the article titled “HMOX1 promoter microsatellite polymorphism is not associated with high altitude pulmonary edema in Han Chinese” by Cao et al with profound interest. 1 The authors of this study have concluded that the microsatellite polymorphism in the HMOX1 gene promoter is not associated with high altitude (HA) pulmonary edema (HAPE) in Han Chinese. There has been a worldwide shift in focus among the scientific community toward research involving the proteomics and genomics aspects of this disease process. This is also evident in the present study, but the presentation of the physiologic/clinical aspects of the data appears to have taken a backseat.
We would like to seek more information regarding the status of the non-HAPE lowland participants in terms of the time spent at HA before their clinical examination was done and blood samples collected. Hematological parameters like hemoglobin level are definitely affected by the duration and quantum of hypoxia exposure in all individuals at HA. 2 Elaboration on this aspect would enable better understanding of the results of the comparison of the 2 groups. Similarly, a word on the average time for presentation of HAPE symptoms in patients after entry in HA before they were hospitalized could have elucidated their clinical presentation further. It would also be interesting to know the duration and details of HAPE treatment (oxygen/nifedipine) provided to these patients and the timing of clinical examination measurements in the hospital. If it was not done at the time of hospitalization, then clarification on cessation of treatment before the examination was carried out would be remarkable. It is evident that from the mean resting heart rate (118±17 beats·min−1) of HAPE participants (n=83) that they had a moderate grade of HAPE. 3 Especially in the background of the very low blood oxygen level of HAPE participants (54±19%), additional information on respiratory rate of these participants would complete their clinical profile.