Body composition and somatic indices: determinants of timing of menarche

Menarche is the signal of initiation of reproductive age of girls. Age at menarche is associated with health outcome at adulthood. Body fat mass and BMI influence menarcheal age. The aim of this study was to investigate the possible association of body composition and body fat distribution with age at menarche. This was a cross sectional questionnaire based study conducted among school girls having age limit 10-14 years who experienced menarche not more than previous three months. Only unmarried adolescent females were included in the study however, females with gynecological, psychological or other medical problems were excluded from the study. Quantitative data were presented as percentage and/or mean + standard deviation. T-test was done to determine significance of difference between physical characteristics of females early age at menarche and reference age at menarche. T-test, chi square test and logistic regression analysis were done. We also evaluated correlation between age at menarche and physical parameters. The significance levels of the tests were considered at a significance level of 0.05. About one-four of study population acquired menarche at age below 12 years and remaining three-fourth acquired menarche at 12-14 years. Significant negative correlation was noted between age at menarche and body weight, BMI, body fat percentage, Waste circumference, Hip circumference, waist – hip ratio and waist- height ratio. Significant positive correlation was obtained between age at menarche and neck circumference. Significant association was observed between menarcheal age and study parameters. Logistic regression analysis suggests that body fat percentage, BMI, body weight, body fat distribution may be considered as risk factors for early menarche. Age at menarche is negatively correlate with BMI, body fat percentage, Waste circumference, Hip circumference, waist – hip ratio and waist- height ratio. Thus BMI, Body fat% and central obesity markers are considered as determinant of age at menarche.