Norboo, T. | Search bioRxiv

bioRxiv2024

A sneak peek at the high altitude adaptation of the Ladakh populations

The physiological response to high-altitude stress (for individuals living at 2,400m and above sea level) has been evident. However, recent advances in genomics have allowed us to explore the molecular genetic basis of these adaptive responses and their relationship with physiological responses. In the current study, we focused on thirteen biological parameters to understand the adaptive response to the high altitude of populations living across regions of Sakti, Korzok, Hanle, Aryan and Zanskar valleys of Ladakh and to understand the variation between and across individuals. Interestingly, we found a negative correlation between haemoglobin levels and partial oxygen pressure, thereby testifying to higher haemoglobin levels as an adaptive response in these individuals. The lipid profiles, including cholesterol, triglyceride, LDL and HDL levels, varied significantly across the five regions studied. Notably, individuals from Sakti Valley showed higher LDL (>140) and cholesterol values. These variations in health parameters and lipid profiles may be attributed to diet and altitude adaptations specific to the region. Overall, the study provides valuable insights into the adaptations of highlanders living at different altitudes in the Ladakh region. The findings can have implications for better understanding the molecular mechanism of physiological responses of humans to high-altitude environments.

evolutionary biology↗

bioRxiv2020

Hematological parameters of high and low altitude Tibetan populations

High altitude hypoxia is believed to be experienced at elevations more than 2500 meters. A few studies have shed light on the biochemical aspects of high altitude acclimatization that profoundly included the subjects sojourning to the high altitude from low altitude and observation of the transient changes. However, information regarding the difference between the adapted people in high altitude and their counterpart, who reside in the low altitude are lacking. To address that issue, we have measured various hematological parameters and level of serum erythropoietin (EPO) in Tibetan population, who are residing in both high and low altitudes. We observed significant difference (p value < 0.0001) between high and low altitude Tibetan, in various hematological parameters, including red blood cells (RBC) count, hematocrit (HCT) or packed cell volume (PCV), and hemoglobin concentration (Hb). In case of mean corpuscular volume (MCV), significant difference was observed only in females (p value < 0.0001). Mean corpuscular hemoglobin concentration (MCHC) was significantly different between both males and females, but age was a potential confounder. There was no significant difference in serum EPO level between these two groups, either in males or females, which might be due to blunted erythropoietin response in the Tibetan population. We have also analyzed correlation between serum EPO with Hb and serum EPO with HCT and found no significant correlation. In multiple regression analysis, low altitude and male-gender showed significant impact on both Hb and HCT. In conclusion, our study suggests significant perturbation of hematological parameters, when native high altitude populations migrated to low altitude and inhabited for a long period.

physiology↗