Complete blood count variation in relation to high and low altitude in different areas of Albaha Region, Saudi Arabia: a comparative study

Background: Hematological values are influenced by many factors and their determination can be crucial for clinical diagnoses. This study aimed to study hematological parameters in low and high-altitude residents of the Al-Baha area, KSA. Methods: This cross-sectional study was conducted between 2019 and 2020 at Al-Baha, KSA. Data were collected from the ministry of health for complete blood count of routinely investigated healthy Saudi adults. Residents were divided into low and high lands according to altitude. Results: A total of 701 individuals were analyzed of which 501 were living in high altitudes. Individuals were predominantly females (55.8%), and those of high altitude was also predominantly females (n = 391). Red blood cell, hematocrit, and hemoglobin was found to be significantly higher in males versus females, high altitude versus low altitude, high altitude males versus low altitude male, and high altitude female versus low altitude females. White blood cells were also found to be significantly higher in high altitude residents, male, and females versus low altitude residents, males, and females. Platelets were significantly lower in males versus female individuals. Conclusions: Our findings demonstrate that the hematological reference ranges in the high-altitude provinces are significantly different from that of low altitude provinces of the Al-Baha area, other regions of the Kingdom of Saudi Arabia, and the western reference ranges. Our reference ranges for blood parameters can be used in clinical practice and research.