Background: Reference values for a complete blood count (CBC) can vary due to multiple factors, including geographical location, environmental influences, nutrition, genetic characteristics, lifestyle, and the physical-chemical properties of the blood. Mongolia’s high-altitude geography (an average of 1,580 meters above sea level) reduces oxygen supply and activates hematopoiesis through the body’s physiological adaptation mechanisms. As a result, the number of red blood cells, hemoglobin, and hematocrit levels tend to increase, as studied by researchers Ch. Sharav and A. Ulziikhutag. Considering the unique geographical regions of Mongolia (urban, rural, steppe, desert, and high mountain areas), studying the physiological blood parameters of the population and identifying regional differences are crucial for improving diagnostic accuracy and the reliability of clinical assessments, which form the basis for conducting this study. Aim: Select a healthy group from the population that participated in the ‘National Preventive Screening and Early Diagnosis Program’ for preventing and early detecting infectious and non-infectious diseases based on age, gender, and health risks. Establish reference values for comprehensive blood test indicators by geographical location. Materials and Methods: In Mongolia, from 2022 to May 2023, a comprehensive blood analysis was conducted on 7,301 individuals aged 18 and above who participated in the ‘National Preventive Screening and Early Diagnosis Program’ aimed at preventing and early detecting infectious and non-infectious diseases based on age, gender, and health risks. The analysis included red blood cells (RBC), hemoglobin (HGB), hematocrit (HCT), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), white blood cell count (WBC), and platelet count (PLT) in relation to their geographical location. The study results were calculated using IBM SPSS (20) software. Statistical significance was considered at p<0.05. Results: In our study, 7,301 people aged 18-87 participated, of whom 36.4% (2,644) were male and 63.6% (4,657) were female. The average age was 30.2±0.2 years for men and 35.1±0.1 years for women. Among them, there were 1,764 males and 1,774 females aged 18-30, 603 males and 2,069 females aged 31-45, 199 males and 670 females aged 46-60, and 78 males and 144 females over 61 years old. A total of 26.6% (1,944) of the study participants were from Ulaanbaatar, 12.75% (931) from the western region, 10.12% (739) from the eastern region, 33.18% (2,423) from the Khangai region, and 17.31% (1,264) from the central region. In the Ulaanbaatar region, HGB, HCT, MCV, MCH, and WBC increased with age, while PLT showed a tendency to decrease. Differences in HGB, HCT, MCV, MCH, MCHC, WBC, and PLT indicators were observed between the western, eastern, Khangai, and central regions depending on the area (p<0.05). Conclusion Statistically significant differences in blood parameters were observed across different regions of Mongolia, indicating the necessity of establishing reference values for blood tests that reflect the influences of geographical location, lifestyle, and environmental factors (p<0.05).

Background: A Complete Blood Count (CBC) is essential for early disease detection, diagnosis, treatment, monitoring therapeutic progress, and evaluating a patient’s overall health status. Therefore, establishing reference values for blood tests tailored to the demographic characteristics of a specific population plays a crucial role in improving diagnostic accuracy and treatment outcomes. In our country, there is a lack of studies determining reference values for blood test parameters based on age, gender, body weight, and quality of life, which serves as the basis for conducting this research. Aim: To select a healthy population from those participating in the ‘preventive screening, early detection, and diagnosis of infectious and non-communicable diseases based on age, sex, and health risk factors,’ and to establish the reference range for red blood cells and their additional parameters in relation to body mass index, gender, and age groups. Materials and Methods: A total of 7,301 individuals aged 18 and above who participated in the ‘preventive screening, early detection, and diagnosis of infectious and non-communicable diseases based on age, sex, and health risk factors’ conducted from 2022 to May 2023 in Mongolia were included in the study. The study involved complete blood count (CBC) analysis, including red blood cells (RBC), hemoglobin (HGB), hematocrit (HCT), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC). The data were analyzed in relation to age and sex. The statistical analysis was performed using IBM SPSS (version 20), and results with P<0.05 were considered statistically significant. Results: Our study included 7,301 individuals aged 18 to 87, of whom 36.3% (2,644) were male and 63.7% (4,657) were female. The average age was 30.23±0.22 years for males and 35.11±0.15 years for females. Specifically, there were 1,764 males and 1,774 females in the 18-30 age group, 603 males and 2,069 females in the 31-45 age group, 199 males and 670 females in the 46-60 age group, and 78 males and 144 females in the >61 age group. In the 18-30 age group, RBC, HGB, MCV, MCHC, and HCT levels showed statistically significant differences between males and females. In the 31-45 age group, RBC, HGB, MCH, MCHC, and HCT levels also showed statistically significant differences. In the 46-60 age group, RBC, HGB, and HCT showed statistically significant differences, while in the >61 age group, only RBC levels showed statistically significant differences between males and females. When analyzing red blood cells and their associated parameters in relation to BMI, no statistically significant differences were observed between the groups (p>0.05). Conclusion By including the general population in early screening programs, it has become possible to establish reference values for red blood cells and their additional parameters specific to the Mongolian people. Future studies should focus on examining these parameters in relation to geographical location, genetic characteristics, and environmental influences.