Body mass index and age of menarche in young girls

Background Currently the age at onset of menarche is earlier than in the past. Nutritional status has an important role in the onset of menarche. Past studies have shO\vn an association between body mass index (BMI) in young girls and earlier onset of menarche. Objective To assess an association between BMI and age at onset of menarche. Methods This cross?sectional study was conducted in young girls aged 10 to 15 years from Immanuel Elementary and Junior High School, Medan in June 2010. We used purposive sampling to recruit subjects. After subjects underwent height and weight measurements, we calculated their BMIs. The association between BMI and initial age of menarche was assessed by Chi square test (P 95th percentile ofBMI (obese). All obese subjects had an earlier onset of menarche at ages 1O? 11 years, compared to that of non?obese subjects (P=O.OOOl). Conclusion Young girls v.ith BMI > 95th percentile had an earlier age at onset of menarche than young girls v.ith lower BMls. [Paediatr lndanes. 2012,52:309-12].