Purpose: The purpose of this study was to predict calcaneal QUS measurements in healthy adolescent females as a function of anthropometric measures, pubertal stage and menarchal status.
Methods: This was a secondary data analysis from a 2-year intervention designed to increase bone accretion. Simple Pearson correlation and Spearman's rank correlation analyses, followed by linear stepwise regression analyses were conducted.
Setting: 12 middle schools.
Participants: 672 female students, baseline; 587 students at 18 months.
Main outcome measure: Calcaneal stiffness index (SI) by quantitative ultrasound.
Results: Eighty percent of the subjects were premenarchal at baseline; 33% at 18 months. Although SI correlated with self-assessed pubic hair (rho = .21) and menarchal status (rho = .23, p < .01 for both) at baseline, the model for predicting SI included menarchal status, not pubic hair, and calf circumference, controlling for BMI (R(2) = .22, p < .01). At 18 months, SI correlated with self-assessed pubic hair (rho = .21) and menarchal status (rho = .25, p < .01 for both). The best model to predict SI included calf circumference and pubic hair stage (R(2) = .14, p < .01), and not menarchal status as 67% of the subjects at 18 months were postmenarchal.
Conclusions: In research assessing calcaneal SI in groups of adolescents, assessment of pubertal stage could be replaced with menarchal status and calf circumference when the majority of subjects are premenarchal. When the majority is postmenarchal, pubic hair stage and calf circumference together may be used to assess for pubertal maturation without menstrual status.