Prospective Changes in Bone in Adolescent and Young Adult Oligo-Amenorrheic and Eumenorrheic Athletes and Non-Athletes

Presentation Number: MON 333
Date of Presentation: April 3rd, 2017

Vibha Singhal*1, Karen Joanie Campoverde Reyes2, Kathryn E Ackerman2, Alexander Toth2 and Madhusmita Misra1
1Massachusetts General Hospital/Harvard Medical School, Boston, MA, 2Massachusetts General Hospital, Boston, MA

Abstract

Background: Mechanical loading improves bone mineral density (BMD) and strength while decreasing fracture risk. Our cross-sectional studies show that this exercise advantage is lost in oligo-amenorrheic athletes (OA). Longitudinal studies examining the opposing effects of exercise and hypogonadism on bone are lacking in adolescents/young adults.

Objective: To examine differences in bone accrual over 12 months in OA, eumenorrheic athletes (EA) and non-athletes (NA). We hypothesized that bone accrual would be lower in OA than EA and NA, with differences most pronounced at non-weight bearing and predominantly trabecular sites.

Methods: 25 OA, 24 EA and 22 NA 14-25 years old completed 12 months of the prospective study. Athletes were weight-bearing endurance athletes. Oligo-amenorrhea was defined as absence of menses for ≥ 3 months within a period of menstrual irregularity (cycle length > 6 weeks) for ≥ 6 months prior to study participation. Subjects were assessed for areal BMD (aBMD) using DXA at the whole body (WB), hip and spine. Volumetric BMD (vBMD), bone geometry and microarchitecture were assessed using high resolution peripheral quantitative CT (HRpQCT) at the distal radius and tibia. Extended cortical analysis and individual trabecula segmentation were performed. Strength estimates were assessed using microfinite element analysis.

Results: Groups did not differ for age, height or BMI. Percent body fat was lower in both OA and EA compared to NA. OA attained menarche later than EA and NA. Over the follow-up period, OA gained 2.2±2.6 kg of weight compared to 0.5±2.6 kg and 1.0±2.2 kg in EA and NA respectively (p=0.06). 26% of OA resumed menses.

Changes in areal hip, spine and WB BMD Z-scores did not differ among groups. At follow up, EA had higher hip and WB BMD Z-scores than OA and NA (p<0.02).

At the non-weight bearing radius, NA had greater increases in cortical area (p=0.07) and reductions in trabecular area (p=0.02) than OA and NA. No differences were observed over time for trabecular parameters. At follow-up, OA and EA had lower cortical bone volume, area and tissue mineral density compared to NA (p<0.05 for all). Stiffness and failure load were lower in OA than NA at follow-up (p<0.02 for both).

At the weight bearing tibia, groups did not differ for changes in cortical parameters over 12 months. For trabecular parameters, plate bone volume and rod thickness decreased in OA compared with EA (p<0.05). At follow-up, total cross-sectional area was lower in OA and NA than EA (p=0.01), and measures of cortical porosity were higher and cortical vBMD lower in OA and EA than NA (p<0.02 for all). Stiffness and failure load were lower in OA and NA than EA at follow-up (p<0.03 for both).

Conclusions: Despite weight gain and menses recovery in many OA during follow-up, residual deficits persist without catch-up.

 

Nothing to Disclose: VS, KJC, KEA, AT, MM