Do Aromatase Inhibitors (AIs) Decrease Intestinal Calcium Absorption?

September 13, 2012 updated by: University of Wisconsin, Madison

Research Question: Do Aromatase Inhibitors Decrease Intestinal Calcium Absorption?

Study Design: Postmenopausal women with early stage breast cancer initiating aromatase inhibitor adjuvant therapy will participate in this two-month study. The primary study outcome is the change in intestinal calcium absorption following such therapy. Secondary outcomes are the changes in bone resorption markers and musculoskeletal signs and symptoms after initiation of therapy.

We will interview women and review their medical records to determine eligibility. Eligible subjects will undergo two calcium absorption studies. The first study will determine their baseline calcium absorption, and the second study will occur after taking an aromatase inhibitor daily for at least 6 weeks. Women will present to the research unit in the early morning and receive an oral and intravenous stable calcium tracer with breakfast. Over the next 24 hours, we will collect all urine for measurement of its calcium content. During each inpatient stay, we will assess musculoskeletal symptoms by questionnaire and joint examination. Each woman will complete a four-day diet diary twice during the study.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

12

Phase

  • Phase 4

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • ADULT
  • OLDER_ADULT
  • CHILD

Accepts Healthy Volunteers

No

Genders Eligible for Study

Female

Description

Inclusion Criteria:

  • Women at least 5 years past menopause, defined as date of last menses or bilateral oophorectomy
  • Newly diagnosed breast cancer and starting an AI as initial adjuvant therapy

Exclusion Criteria

  • Recent, current or planned chemotherapy for breast cancer, as this may have independent effects on intestinal health, calcium homeostasis and bone turnover
  • Allergy or intolerance to orange juice, as one isotope is given with orange juice
  • Current use of over-the-counter or prescription antacids, as they may influence Ca-Ab
  • Intestinal conditions associated with malabsorption or low gastric acid levels including Crohn's disease, ulcerative colitis, pernicious anemia, bacterial overgrowth, celiac sprue, chronic diarrhea or use of antibiotics within the past month
  • Known Stage 4 or 5 Chronic Kidney Disease, defined as an estimated GFR <30 cc/minute
  • Use of medications known to interfere with calcium or vitamin D metabolism, including oral steroids or anticonvulsants
  • Significant lymphedema precluding adequate intravenous access

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: DIAGNOSTIC
  • Allocation: NA
  • Interventional Model: SINGLE_GROUP
  • Masking: NONE

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
EXPERIMENTAL: aromatase inhibitor therapy
aromatase inhibitor therapy for six weeks
Drug: Aromatase Inhibitor
Any aromatase inhibitor started as initial adjuvant therapy

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Intestinal Calcium Absorption Related to Aromatase Inhibitor Therapy
Time Frame: baseline and 6 weeks later
intestinal calcium absorption
baseline and 6 weeks later

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Wisconsin, Madison

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

January 1, 2009

Primary Completion (ACTUAL)

October 1, 2010

Study Completion (ACTUAL)

October 1, 2010

Study Registration Dates

First Submitted

October 2, 2008

First Submitted That Met QC Criteria

October 2, 2008

First Posted (ESTIMATE)

October 6, 2008

Study Record Updates

Last Update Posted (ESTIMATE)

September 14, 2012

Last Update Submitted That Met QC Criteria

September 13, 2012

Last Verified

September 1, 2012

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • H-2008-0144

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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