Oestrogen replacement improves bone mineral density in oligo-amenorrhoeic athletes: a randomised clinical trial

Abstract

Objective: Normal-weight oligo-amenorrhoeic athletes (OAA) are at risk for low bone mineral density (BMD). Data are lacking regarding the impact of oestrogen administration on bone outcomes in OAA. Our objective was to determine the effects of transdermal versus oral oestrogen administration on bone in OAA engaged in weight-bearing activity.

Methods: 121 patients with OAA aged 14-25 years were randomised to receive: (1) a 17β-estradiol transdermal patch continuously with cyclic oral micronised progesterone (PATCH), (2) a combined ethinyl estradiol and desogestrel pill (PILL) or (3) no oestrogen/progesterone (NONE). All participants received calcium and vitamin D supplementation. Areal BMD was assessed at the lumbar spine, femoral neck, total hip and total body less head using dual-energy X-ray absorptiometry at baseline, 6 and 12 months. Intention-to-treat (ITT) and completers analyses were performed.

Results: Randomised groups did not differ for age, body mass index or BMD Z-scores at baseline. For ITT analysis, spine and femoral neck BMD Z-scores significantly increased in the PATCH versus PILL (p=0.011 and p=0.021, respectively) and NONE (p=0.021 and p=0.033, respectively) groups, and hip BMD Z-scores significantly increased in the PATCH versus PILL group (p=0.018). Similar findings were noted in completers analysis.

Conclusion: Transdermal estradiol over 12 months improves BMD in young OAA, particularly compared with an ethinyl estradiol-containing contraceptive pill/oral contraceptives.

Trial registration number: NCT00946192; Pre-results.

Keywords: adolescent; bone; bone mineral density; endocrine; female athlete triad.

Conflict of interest statement

Competing interests: MM has served on the Scientific Advisory Board of Novo Nordisk, is a coinvestigator on an investigator-initiated grant from Novo Nordisk and is a consultant for Sanofi Pharmaceuticals.

© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.

Figures

Figure 1

Numbers of oligo-amenorrhoeic athletes (OAAs) recruited for the study and attrition over the 12-month study duration in the three randomisation groups (PATCH, PILL and NONE). COCs, combined oral contraceptives.

Figure 2

Percent change in bone mineral density (BMD) in completers at 6 months (A) and 12 months (B). TBLH, total body less head. *Significant at p