Ventilatory parameters at rest after months of stay at 3300 m: A comparison between acclimatized lowlanders and natives at Leh

Abstract

Background: Increased pulmonary ventilation helps lowlanders and natives to maintain arterial oxygenation at high altitudes. Natives of Ladakh have been shown to have similar ventilatory parameters as Tibetans at 3300 m. But there is limited literature comparing these parameters in Ladakhi natives with acclimatized lowland sojourners.Methods: End-tidal carbon dioxide partial pressure (EtCO 2 ), blood oxygen saturation (SpO 2 ) and hemoglobin concentration (Hb) were measured in 276 participants, 126 native highlanders (NHL -40 females, 86 males) and 150 acclimatized lowlanders (ALL -60 females, 90 males).Results: EtCO 2 was greater in the NHL compared to the ALL, (33.8 AE 3.3 vs 31 AE 2.5 mmHg) although SpO 2 was lower (90.9 AE 2.4 vs 91.7 AE 2.3%). When grouped by sex, NHL males had significantly greater EtCO 2 than NHL females, ALL males and ALL females. Hb and calculated arterial oxygen content was similar in Ladakhis and acclimatized lowlanders, although greater in males compared to females. Systemic blood pressure, heart rate and the proportion of hypertensives was significantly greater in the ALL. Conclusion:Native Ladakhis, have a significantly greater resting EtCO 2 (especially in males) and lower SpO 2 than acclimatized lowlanders. Blood Hb concentration and oxygen content is, however, similar in natives and acclimatized lowlanders of the same sex.

Near-Infrared Spectroscopy Monitoring of Cerebral Oxygenation and Influencing Factors in Neonates from High-Altitude Areas

“…After >25,000 years of life living at an altitude of 4,000 m, the Tibetan people have mutations in the EGLN1 and EPAS1 genes. These 2 genes participate in the hypoxia-inducible factor transcription pathway and mediate the human body’s response to hypoxia [21], which ultimately result in the upregulation of a considerable number of target genes that aid during the adaptation to hypoxia, including the erythropoietin gene (resulting in the generation of more red cells) and vascular endothelial growth factor gene (resulting in the generation of more blood vessels). In addition, some genes are downregulated, such as pyruvate dehydrogenase kinase 1, leading to decreased mitochondrial oxygen consumption [22].…”

Climate change vis-a-vis climate and change: the military public health paradigm

“…With decades of experience in deployment at these altitudes, the doctors of the Indian Armed Forces have developed a remarkable body of knowledge on matters related to health at altitude. A case series on imaging modalities for cerebrovascular thrombosis is being published in this issue; Sikri et al 13 have reported on a nuanced study of a variation of the time-tested acclimatization schedule followed in inducting troops to the higher altitudes in mountainous regions, and Dua et al 14 have compared acclimatized lowlanders with natives of the Himalayan heights.…”