Measures of body composition via dual X-ray absorptiometry, ultrasound and skinfold are not impacted by the menstrual cycle in active Eumenorrheic females

Abstract Objectives (1) Compare changes in body composition estimates over the menstrual cycle in active females using dual energy X-ray absorptiometry, standardised brightness-mode ultrasound and skinfolds (2) Compare the predictability of dual energy X-ray absorptiometry fat mass estimate via standardised brightness-mode ultrasound versus skinfolds measurements. Design Thirty active females (27 ± 5 y) with regularly occurring menstrual cycles participated in a cross sectional study. Methods Participants completed four assessment sessions scheduled according to each individual's menstrual cycle. These sessions took place during their (1) early follicular, (2) mid-to-late follicular, (3) mid-luteal and (4) second early follicular phases. Body composition estimates were acquired using dual energy X-ray absorptiometry, subcutaneous adipose tissue thickness was measured at eight sites using standardised brightness-mode ultrasound and skinfolds. Results Total and regional dual energy X-ray absorptiometry estimates of lean and fat mass were not different between cycle phases (p > 0.05) and any changes were within the 95% confidence intervals of their respective least significant change values (LSC-95% CI). Body mass (weighing scales), dual energy X-ray absorptiometry estimate of total mass, sum of eight ultrasound measurements and sum of eight skinfolds between the cycle phases were also not different (p > 0.05). Conclusions There were no meaningful and true changes in body composition estimates using dual energy X-ray absorptiometry, standardised brightness-mode ultrasound and skinfolds measured at eight sites across the menstrual cycle in active eumenorrheic females. Body composition may thus be assessed via these methods in this population at any cycle phase with standardised participant presentation.