Altitude and Haematological Adaptation: Red Blood Cell Indices Among Residents of the Jos Plateau Compared to Sea-Level Dwellers in Benue State, North Central Nigeria

Background: The Jos Plateau, situated at approximately 1,200 metres above sea level, provides a natural setting to investigate haematological responses to chronic mild hypobaric hypoxia among Nigerian residents. Comparative studies with low-altitude populations in Benue State can illustrate classical physiological adaptation principles in a Nigerian context. Objectives: This study aims to compare red blood cell count, haemoglobin concentration, haematocrit, and mean corpuscular haemoglobin concentration between adult residents of Jos Plateau and sea-level dwellers in Makurdi, Benue State. Methods: Sixty plateau residents and sixty age- and sex-matched Benue State lowland dwellers will be recruited. Venous blood samples will be analysed using an automated haematology analyser. A questionnaire will document duration of residence, physical activity levels, and dietary iron intake. Independent t-tests will compare haematological parameters between groups. Expected Outcomes: Jos Plateau residents are anticipated to demonstrate significantly higher red cell counts, haemoglobin concentrations, and haematocrit values, consistent with acclimatisation to mild hypoxic conditions. Conclusion: This study will provide locally grounded evidence of altitude-induced haematological adaptation among Nigerians. Keywords: altitude, haematological adaptation, haemoglobin, Jos Plateau, hypoxia.