Clinical Trial: Does Omeprazole Decrease Intestinal Calcium Absorption?

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: Does Omeprazole Decrease Intestinal Calcium Absorption?

Brief Summary: The purpose of this study is to measure the effect of omeprazole on intestinal calcium absorption in postmenopausal women.

Detailed Summary:

Existing literature makes it unclear whether proton pump inhibitor therapy truly decreases intestinal calcium absorption. Up to 25 postmenopausal women will participate in this study. The primary study outcome is the change in intestinal calcium absorption following omeprazole therapy 40 mg daily for 30 days. The secondary outcomes include the change in urine n-telopeptide.

We will interview women and review their medical records to determine eligibility. Eligible subjects will undergo three calcium absorption studies. The first 2 studies will determine the monthly variation in calcium absorption, while the 3rd study will occur after taking 40 mg of omeprazole daily for 30 days. Women will present to the research unit in the early morning and receive an oral and intravenous calcium tracer with breakfast. Over the next 24 hours, we will collect all urine for measurement of its calcium content. During the first stay, we will measure each subject's gastric pH by collecting gastric fluid from a temporary nasogastric tube. In consenting subjects we will collect one tube of blood, isolate its DNA.


Sponsor: University of Wisconsin, Madison

Current Primary Outcome: Change in Intestinal Calcium Absorption From Baseline to One Month [ Time Frame: change in calcium absorption from baseline to 1 month ]

percent calcium absorption


Original Primary Outcome: Change in intestinal calcium absorption after one month of omeprazole therapy [ Time Frame: 2 months ]

Current Secondary Outcome: Change in Bone Resorption From Baseline to 1 Month [ Time Frame: change in bone resorption from baseline to 1 month ]

urine n-telopeptide (normalized to creatinine levels)


Original Secondary Outcome: The change in bone resorption (urine n-telopeptide) after one month of omeprazole therapy and the month-to-month variability in intestinal calcium absorption. [ Time Frame: 2 months ]

Information By: University of Wisconsin, Madison

Dates:
Date Received: December 19, 2007
Date Started: January 2008
Date Completion:
Last Updated: February 14, 2013
Last Verified: February 2013