Age at menarche and its association with overweight/obesity among adolescents in Kano

Abstract

Background: There was a dramatic decline of adolescents’ menarcheal age worldwide; Africa is witnessing a secular trend of this reducing menarcheal age among its black adolescents. A transition of overweight/obesity among adolescent is believed to be associated with reduced menarcheal age. Materials and Methods: It was a descriptive cross-sectional study that was conducted among female adolescent girls from January to December, 2016. Ethical approval was obtained from the management concerned. All consenting adolescents were recruited for the survey. Information was recorded on a structured, pretested questionnaire. Their respective weight and height were also measured. Body mass index (BMI) was calculated using the formula: BMI = weight (kg)/height (m2). The data obtained were analyzed using the Statistical Package for the Social Sciences version 18.0 (SPSS Inc., SPSS Statistics for Windows, Chicago, IL, USA). Fishers’ exact test was used, and the P ≤ 0.05 was considered statistically significant. Results: Two hundred and nineteen female adolescents participated in the survey. The mean age ± SD at menarche was 12.83 ± 1.312 years. The median and modal ages were both 13 years. There was no statistically significant association between the mean age at menarche and the ethnic groups (P(Fishers’) = 0.150). However, mean age at menarche was statistically associated with their BMI (P(Fishers’) = 0.00). Obesity was associated with reduced menarcheal age. Conclusion: The median and mean ages at menarche were 13.0 and 12.8 years respectively, which were in accordance with secular trend of reduced menarcheal age among black adolescents. Our study also showed an inverse association between the age at menarche and overweight or obesity among adolescents.