Age at menarche and body mass index (BMI) among adolescent secondary school girls in Port Harcourt, Nigeria

Background: menarche is one of the most significant milestones in a woman’s life with nutritional status being one of the important non genetic determinants of menarcheal age. Objective: to determine the relationship between age at menarche and anthropometric measurements among adolescent secondary school girls in Port Harcourt, Nigeria. Methods: four hundred and seventy nine adolescent girls were interviewed on age at menarche and their weights and height were measured. Body Mass Index (BMI) was calculated in kg/m2. The relationship between ages at menarche and anthrometric measurements were ascertained. Results: three hundred and fifty (73.1%) of the subjects were post menarcheal while 129 (26.9%) were pre menarcheal. The mean age at menarche was 12.80 ± 1.22 years. Obesity and overweight were more prevalent in post menarcheal subjects while underweight was more prevalent in the premenarcheal group. Post menarcheal subjects were comparably more stunted. Subjects who had attained menarche in early adolescence had significantly higher BMI at 10, 12 and 13 years respectively. Conclusion:The mean age at menarche in adolescent secondary school girls in Port Harcourt was 12.80 ± 1.22 years. Anthropometric indices which were associated with a reduced menarcheal age were obesity, overweight and stunting.