NCT02367846

Assessing the Impact of Contraceptives on Bone Health Using 41Ca

The Effect of Oral vs. Non-oral Contraceptive Therapy on Bone Turnover Using 41Ca Methodology

• Status: Active Not Recruiting
• Phase: Phase 4
• Study type: Interventional
• Enrollment: 6 (actual)
• Sponsor: Penn State University · Academic / Other
• Sex: Female
• Age: 18 Years – 25 Years
• Healthy volunteers: Accepted

Summary

This preclinical randomized crossover study will examine the effects of oral versus non-oral contraceptive therapy on bone turnover in young exercising women. In an effort to expose the route-dependent effects of oral versus non-oral contraceptive therapy on bone turnover, the investigators will examine 1) the effects of ethinyl estradiol on bone calcium balance using the 41Ca technology and 2) the underlying physiological mechanisms associated with the effects of oral versus non-oral contraceptive therapy on net bone calcium balance.

Detailed description

This study is a preclinical, multi-site study (Penn State University and Purdue University) that will determine whether the negative effects of combined oral contraceptive (COC) therapy on bone turnover are dependent on the route of administration such that an attenuation of these effects is observed when a comparable dose of non-oral contraceptive therapy, such as vaginal contraceptive (CVR) therapy is also tested. Millions of women use COC therapy for birth control purposes or regulation of menstrual cycles. CVR therapy is a relatively new FDA-approved contraceptive alternative to COC. The purpose of the proposed project is to investigate whether oral ethinyl estradiol (EE) may negatively impair bone turnover when compared to vaginally-administered EE in young physically-active women. A novel calcium tracer technology suitable to rapidly assess changes in net bone calcium balance in a small sample size will be applied to evaluate the effects of COC and CVR therapy on bone turnover. The radioisotope Calcium-41 (41Ca) demonstrates increased sensitivity when compared to dual x-ray absorptiometry (DXA) and increased specificity for bone mineralization and precision when compared to biochemical markers of bone turnover. This study will be the first study to examine how the route of estrogen administration affects bone turnover in young physically active women by assessing changes in net bone calcium balance with different forms of contraceptive therapy. The overall purpose of this study is to explore the effects of oral versus vaginal contraceptive therapy on bone turnover in young exercising women using 41Ca technology. In an effort to expose the route-dependent effects of oral versus non-oral contraceptive therapy on bone turnover, the investigators will examine 1) the effects of ethinyl estradiol on bone calcium balance using the 41Ca technology and 2) the underlying physiological mechanisms associated with the effects of oral versus vaginal contraceptive therapy on net bone calcium balance.

Conditions

• Other Disorders of Bone Development and Growth

Interventions

Type	Name	Description
DRUG	Combined Oral Contraceptive (COC)	The proposed study is a preclinical, multi-site trial comparing the short-term effects of oral vs. non-oral ethinyl estradiol on net bone calcium balance. A prospective crossover study with repeated measures and a simple random assignment will be used to test the effects of 49 days of COC use on bone metabolism using 41Ca to determine net bone calcium balance. Subjects will be randomized to receive COC during either the first or second intervention period.
DRUG	Contraceptive Vaginal Ring (CVR)	The proposed study is a preclinical, multi-site trial comparing the short-term effects of oral vs. non-oral ethinyl estradiol on net bone calcium balance. A prospective crossover study with repeated measures and a simple random assignment will be used to test the effects of 49 days of CVR use on bone metabolism using 41Ca to determine net bone calcium balance. Subjects will be randomized to receive CVR during either the first or second intervention period.

Timeline

• Start date: 2015-01-01
• Primary completion: 2026-12-01
• Completion: 2026-12-01
• First posted: 2015-02-20
• Last updated: 2025-05-13

Locations

1 site across 1 country: United States