Relationship between body mass index and timing of maturation

Abstract

Background: Menarche is the first menstrual period. The increasing incidence of overweight/obesity and decline in the median age at menarche had led investigators to hypothesize potential associations of age at menarche with body mass index (BMI). We assess these associations between reproductive and nonreproductive age females. Aim: The present study assessed the relationship between BMI and the timing of menarche among contemporary Nigerian girls. Methods: The present cross‑sectional anthropometric study was performed in 2014 using 600 menstruating and 200 non-menstruating girls aged 11–18 years in Nigeria. We classified the menarcheal age of our participants into early, ideal, and late. Participants were also categorized based on their nutritional status into underweight, normal, and overweight. Results: Mean age at menarche was 13.54 years. Age at onset of menarche was inversely associated with BMI. Precocious menarche (<12 years) when compared to ideal (12–13 years) or late (≥14 years) menarche was found to be associated with a higher BMI (F = 10.64, P < 0.05). Overweight girls also reach maturation earlier than their contemporaries with moderate to lean body status (F = 15.32, P < 0.05). Conclusion: Girls with high BMI or overweight reach menarche earlier in life than their lean or low BMI counterparts.