Clinical Trial: Assessing the Impact of Contraceptives on Bone Health Using 41Ca

Study Status: Active, not recruiting
Recruit Status: Active, not recruiting
Study Type: Interventional

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

Brief 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 Summary:

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 us
Sponsor: Penn State University

Current Primary Outcome: Changes in 41Ca:Ca ratio [ Time Frame: 49 days of contraceptive therapy ]

Changes in the 41Ca:Ca ratio in 24-h urine samples measured every 10-14 days during and after oral and non-oral contraceptive therapy as determined by Accelerometer Mass Spectrometry


Original Primary Outcome: Same as current

Current Secondary Outcome:

  • Changes in serum concentrations of insulin-like growth factor-1 (IGF-1), IGF-binding proteins (IGFBP-1, IGFBP-3), and acid labile subunit (ALS) [ Time Frame: 49 days of contraceptive therapy ]
    Changes in fasting serum concentrations of IGF-1, IGFBP-1, IGFBP-3, and ALS after oral and non-oral contraceptive therapy
  • Changes in serum concentrations of markers of bone formation and bone resorption [ Time Frame: 49 days of contraceptive therapy ]
    Changes in fasting serum concentrations of markers of bone formation (osteocalcin, P1NP) and bone resorption (CTx) after oral and non-oral contraceptive therapy


Original Secondary Outcome: Same as current

Information By: Penn State University

Dates:
Date Received: January 27, 2015
Date Started: January 2015
Date Completion: February 2018
Last Updated: May 3, 2017
Last Verified: May 2017