Menstrual Cycle Related Fluctuations in Circulating Markers of Bone Metabolism at Rest and in Response to Running in Eumenorrheic Females

Abstract

The aim of this study was to investigate potential fluctuations in bone metabolic markers across the menstrual cycle both at rest and after a 30-minute bout of vigorous-intensity running at 80% of 𝑉 ̇O₂max. Resting and post-exercise (0, 30, 90 min) sclerostin (inhibitor of bone formation), parathyroid hormone (PTH, regulator of calcium homeostasis), carboxy-terminal cross-linking telopeptide of type I collagen (β-CTX, marker of bone resorption), and procollagen type 1 N propeptide (P1NP, marker of bone formation) were assessed in 10 young, eumenorrheic women (21.7 ± 3.2 years, 23.2 ± 3 kg . m 2 ) during the mid-to late-follicular (FP: day 8.0 ± 1.4) and midluteal (LP: day 22.0 ± 2.5) phases of the menstrual cycle. Ovulation was determined using ovulation kits and daily measurement of oral body temperature upon awakening. Menstrual phase was subsequently confirmed by measurement of plasma estradiol and progesterone taken on study days, confirming an increase in both hormones during the mid-luteal phase. At rest, there were no

Influence of menstrual cycle and oral contraceptive phases on bone (re)modelling markers in response to intervallic running

“…Bone formation, measured by P1NP concentrations, and bone resorption, determined by β- CTX-1, were affected by MC-related fluctuations following exercise, showing greater bone formation in the LFP and reduced bone resorption during the MLP. These results are not in line with those shown by Guzman et al 12 where no differences were shown between MC phases [mid-late follicular phase (day 8±1) and luteal phase (day 22±3)] in a group of seven eumenorrheic females. Nevertheless, it should be noted that the Guzman et al 12 study did not measure the EFP (in this study day 4±1) nor the LFP (as defined in the present study as 1-3 days before the ovulation day, day 12±2), but rather measured the mid or late follicular phase, depends on the individual characteristics of each female’s MC.…”

“…These results are not in line with those shown by Guzman et al 12 where no differences were shown between MC phases [mid-late follicular phase (day 8±1) and luteal phase (day 22±3)] in a group of seven eumenorrheic females. Nevertheless, it should be noted that the Guzman et al 12 study did not measure the EFP (in this study day 4±1) nor the LFP (as defined in the present study as 1-3 days before the ovulation day, day 12±2), but rather measured the mid or late follicular phase, depends on the individual characteristics of each female’s MC. Moreover, luteal phase testing was scheduled 1 week after a positive LH detection kit test (day 22±3) in the Guzman et al 12 trial, coinciding with our timing of MLP measurement (day 21±3).…”

“…Nevertheless, it should be noted that the Guzman et al 12 study did not measure the EFP (in this study day 4±1) nor the LFP (as defined in the present study as 1-3 days before the ovulation day, day 12±2), but rather measured the mid or late follicular phase, depends on the individual characteristics of each female’s MC. Moreover, luteal phase testing was scheduled 1 week after a positive LH detection kit test (day 22±3) in the Guzman et al 12 trial, coinciding with our timing of MLP measurement (day 21±3). These differences in the timing of measurement during the MC between the present study and the Guzman et al 12 trial could explain the discordant results, since the participants included in the Guzman et al 12 study were not evaluated when progesterone concentrations were as low as our participants in the EFP (follicular phase 12 : 4.12±2.36 ng·ml −1 ) and did not reach as high 17β-oestradiol values in the follicular phase 12 (46.3±8.9 pg·ml −1 ) or the luteal phase 12 (67.3±23.4 pg·ml −1 ) as our participants in the LFP (see Table 2).…”

“…9,10 Some studies suggest that hormonal fluctuations throughout the menstrual cycle (MC) should be considered when measuring bone remodelling markers, 11 although not all studies agree. 12,13…”

High‐impact jumping mitigates the short‐term effects of low energy availability on bone resorption but not formation in regularly menstruating females: A randomized control trial

“…Estrogen inhibits osteoclast activity to regulate bone resorption and can become chronically suppressed during longer‐term LEA 53,54 . Recent evidence suggests that hormonal fluctuations during the menstrual cycle do not cause predictable variations in bone marker concentrations, 55,56 but, nonetheless, all conditions in the current study were completed within the early follicular phase of the menstrual cycle to minimize estrogen fluctuations. 17β‐estradiol concentrations remained stable during all conditions, suggesting changes in β‐CTx (or P1NP) during 3 days of LEA are not greatly influenced by estrogen.…”