Blood parameters of people alter when they change their altitude, a study done on Tibetans by the CSIR-Centre for Cellular and Molecular Biology (CCMB), Hyderabad, has found.
Tibetans are one of the oldest high-altitude inhabitants in the world. There are known genetic and physiological factors that help them endure low-oxygen conditions. However, their population has now moved to low-altitude regions such as Karnataka.
Dr K. Thangaraj and his team from CSIR-CCMB studied changes in physiological factors of Tibetans who now inhabit low-altitude regions.
Physiological factors of the people of the Tibetan ethnicity from various regions of the high altitudes of Ladakh at 4,500-4,900 metres were compared with those inhabiting in the Tibetan settlements in Bylakuppe, Karnataka at an altitude of around 850 metres.
“The population in Karnataka had migrated from Tibet following the atrocities by the People’s Liberation Army of China during or after the Tibetan uprising in 1959. They have been in Karnataka for the last 50 years. The researchers found that the blood parameters in Tibetans in Karnataka, are significantly different compared to their high-altitude counterparts," says the study recently published in the Journal of Blood Medicine.
“We found that the red blood cells, haemoglobin concentration and haematocrit are significantly lower in the low-altitude Tibetans. Their haemoglobin levels are much closer to those living on the plains than the other Tibetans who live beyond 4,500 meters," said Nipa Basak, the first author of the study.
“Our study suggests that, when Tibetan people reside in the non-native, low-altitude area for a long time, their body undergoes various adaptations to cope with the relatively hyperoxic environment in low-altitude areas," said Dr Thangaraj, the lead investigator of this study, and presently Director of the DBT-Centre for DNA Fingerprinting and Diagnostics (CDFD), Hyderabad.
Earlier studies had shown that among the Tibetan population, those with lower haemoglobin concentration have better reproductive fitness in women and exercise capacity among men. “It would be interesting to explore exercise capacity and reproductive fitness in the low-lander Tibetans. It will also be worthwhile noting how long these changes persist if the Tibetan inhabited in Karnataka migrates back to high-altitude," he added.
“Such population-based studies conducted by the CCMB help us in understanding adaptation in people who migrate to different environments from a molecular point of view," said Dr V.M. Tiwari, Director in-charge, CCMB.
This work was done in collaboration with researchers from Ladakh and Karnataka. This includes Dr Tsering Norboo from Ladakh Institute of Prevention, Ladakh, and Dr M S Mustak from Mangalore University, Karnataka.