Are Body Composition Estimates Affected by the Menstrual Cycle in Females With or Without Hormonal Contraception?-A...

Area of Science:

• Exercise Physiology
• Human Biology
• Body Composition Analysis

Background:

• Hormonal fluctuations during the menstrual cycle (MC) can influence hydration status.
• This potential water retention may affect body composition (BC) measurements, particularly those sensitive to tissue hydration or volume.
• Methods like bioelectrical impedance analysis (BIA) and air-displacement plethysmography (ADP) might be susceptible, unlike skin-fold calipometry (CAL).

Purpose of the Study:

• To investigate the influence of the menstrual cycle on body composition measurements.
• To compare the effects of hormonal contraception versus no hormonal contraception on these measurements.
• To assess the reliability of BIA, ADP, and CAL across different phases of the MC.

Main Methods:

• A case-control study with repeated measurements was conducted.
• 54 participants (19 hormonal contraceptive users, 17 non-users, 18 males) were assessed.
• Body composition was measured using BIA, ADP, and CAL on four distinct menstrual cycle days.

Main Results:

• Minimal intra-individual variations in body composition (CV% 0.5-5.2) were observed across the MC.
• No significant time effects or time*group interactions were found for any BC parameter or measurement device.
• Hormonal-induced water retention did not demonstrably affect BC estimates from BIA, ADP, or CAL.

Conclusions:

• The menstrual cycle phase, with or without hormonal contraception, does not significantly alter body composition estimates obtained via BIA, ADP, or CAL.
• The observed variations in body composition measurements are too small to be detected by these methods.
• These findings support the use of BIA, ADP, and CAL for consistent body composition assessment throughout the menstrual cycle.