Does settlement and season of birth influence body size? A cross-sectional study of school children and adolescents in Republic of Niger

Background: The objective of the present study was to examine the effect of season of birth and settlement on body dimensions of children and adolescents from Niger Republic. The study group comprises 1547 boys and 1660 girls from Niger Republic. Materials and Methods: The study was conducted in rural, urban, and semi-urban regions in the Southeast Region of Niger Republic. Data were collected with structured questionnaire followed by anthropometric measurements of stature and weight. Others are head, hip, waist, leg, and mid-upper arm circumference (MUAC). Biceps, triceps, subscapular, and supra-iliac skinfolds were also measured. Statistical analyses included Student's t- test, one-way analysis of variance. Results: Birth weight, weight, stature, and body mass index showed little sexual dimorphism across various age groups. There were significant differences in all anthropometric variables based on settlements (P < 0.01) except menstrual cycle and duration (P > 0.05). Individuals residing in semi-urban area have significantly higher body dimensions than those from the other two settlements except for stature, weight, and MUAC. Individuals born in dry season have higher body dimensions than their counterparts born in wet season. Marked significant differences in body dimensions based on the season of birth were observed among boys than girls. Conclusion: The present study reveals difference in body sizes based on settlements while the magnitude of the impact of season of birth is more among boys than girls.