Table 3 Different collection and preparation conditions between the two studies

Collection locality

Lhasa

Chengdu

Preparation time of SRBCs

One week after whole-blood collection

Within 6 h of whole-blood collection

Population

Han Chinese who migrated to the Tibetan plateau for more than 1 year

Local Tibetan volunteers, resident of Tibet (> 3600 m) for more than 10 years, and blood was collected within 30 days of leaving the Tibetan Plateau

Grouping

No further grouping was performed in high altitude population

Volunteers were divided into the high-altitude control (HAC) group (120 g/L < males ≤ 185 g/L, 115 g/L < females ≤ 165 g/L) and the HAPC group (males ≥ 210 g/L, females ≥ 190 g/L)