Changes in haemoglobin and haematocrit values in children aged 6 to 13 1/2 years in Mexico City
Related Experiment Videos
Insights
Hematocrit (Ht) and hemoglobin (Hb) levels in children aged 6-13 years show increases linked to physical development, not just chronological age. Boys exhibit a delayed Ht rise compared to girls, aligning with weight, height, and sexual maturity milestones.
Area of Science:
- Pediatric Hematology
- Human Growth and Development
- Biostatistics
Background:
- Childhood hematological parameters like hemoglobin (Hb) and hematocrit (Ht) are crucial indicators of health.
- Understanding age-related and sex-specific changes in these parameters is essential for accurate clinical interpretation.
- Socio-economic factors and geographical location can influence these physiological markers.
Purpose of the Study:
- To investigate the relationship between chronological age, physical development (weight, height, surface area), and sexual maturity with Hb, Ht, and MCHC levels in healthy children.
- To identify sex-specific patterns in hematological development during pre-adolescence.
- To determine if physical growth milestones are better predictors of hematological changes than chronological age.
Main Methods:
- Cross-sectional study involving 523 boys and 350 girls aged 6-0 to 13-5 years from a middle socio-economic class in Mexico City.
- Clinical assessment of height, weight, and Tanner stage of sexual development.
- Laboratory determination of hemoglobin (Hb), hematocrit (Ht), and mean corpuscular hemoglobin concentration (MCHC) levels.
Main Results:
- In girls, Hb and MCHC showed no significant age-related differences, while Ht increased significantly between 10-0 and 10-5 years.
- In boys, Hb and Ht increased significantly between 10-5 and 11-0 years, with a further rise from 12-5 years onwards; MCHC remained unchanged.
- Boys demonstrated a 6-12 month delay in Ht increase compared to girls, with values converging at similar mean weights, heights, and surface areas, coinciding with Tanner stage 2 sexual development.
- Distinct sex differences emerged at 11-5 years, with boys exhibiting higher Hb and Ht values.
Conclusions:
- Hemoglobin and hematocrit changes in children are more closely associated with physical development milestones (weight, height, surface area) and sexual maturity than with chronological age alone.
- The observed delay in hematocrit increase in boys suggests a different pace of physiological maturation compared to girls.
- These findings underscore the importance of considering developmental stage over strict chronological age when interpreting hematological parameters in pediatric populations.
Abstract:
Levels of haemoglobin (Hb), haematocrit (Ht) and mean corpuscular haemoglobin concentration (MCHC) were determined in 523 boys and 350 girls, clinically healthy, ages 6-0 to 13-5 years, middle socio-economic class living in Mexico City. In girls no significant differences according to age were observed in Hb or MCHC; however, Ht was significantly greater at 10-5 than at 10-0 years, without subsequent modifications. In boys, Hb and Ht had a first increase between 10-5 and 11-0 years and a second rise from 12-5 years on: MCHC remained unchanged. Boys were six to twelve months behind girls in regard to Ht increase; however, Ht increased when boys and girls reached similar mean weights (34 kg), heights (138 cm) and surface areas (1-15 m2); concomitantly, they had progressed to stage 2 of sexual development. Clear sex differences began to appear at age 11-5 when boys had higher Hb and Ht values than girls. These data suggest that Hb and Ht changes in these children are not related to chronological age but can be better interpreted if compared to weight, height, surface area or stage of sexual development.