The Relationship between Body Mass Index and Cranial Index in Early Childhood: An Observational Study in Abraka, Nigeria

Abstract

Aims: In pediatric studies, Body Mass Index (BMI) and Cranial Index (CI) are widely used indices for growth tracking and nutritional evaluation. Although each of these metrics have been extensively investigated independently, their interrelationship in early childhood is poorly studied, especially in sub-Saharan Africa where baseline data appears to be limited. The aim of this study therefore is to investigate the relationship between BMI and CI among children aged 1–5 years in Abraka, and to examine sex-related differences in measured parameters. Study Design: Quantitative, cross-sectional observational study design. Place and Duration of Study: Delsu Nursery and Primary School, Abraka Model School, Great Beginners Montessori School. Between January 2025 and August 2025. Methodology: 500 children (250 male and 250 female participants; aged 1–5 years) were recruited into the study by stratified random sampling. Weight and height were measured using a digital body tracker to calculate BMI, while cranial length and breadth were measured with spreading calipers to derive CI. Data were analyzed using SPSS v.25. Descriptive statistics summarized the data, independent-samples t-tests assessed sex differences, and Pearson’s correlation coefficient evaluated associations between BMI and CI. A P-value ≤ 0.05 was considered statistically significant. Results: Analyzed data revealed no statistically significant correlation between BMI and CI (r = 0.035, P = .437). Sex-related differences in BMI were also not statistically significant (P = 0.078). However, non-random differences in CI between sexes were evident indicating sexual dimorphism in cranial morphology within the studied age group (obtained P-value: 0.009). Distribution of cranial types revealed a predominance of mesocephaly (50%), followed by brachycephaly (26%) and dolichocephaly (24%), patterns that are consistent with reports from comparable pediatric populations. Conclusion: The absence of a significant correlation between BMI and CI in early childhood suggests that nutritional status and craniofacial morphology may develop independently during this stage of growth. The predominance of mesocephaly provides baseline craniofacial data for Nigerian pediatric populations, underscoring the need for multicenter studies.