Clinical trial NCT00582972: Does Omeprazole Decrease Intestinal Calcium Absorption?
Official title: Does Omeprazole Decrease Intestinal Calcium Absorption?
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE4
Conditions: Osteoporosis
Achlorhydria
GERD
Hip Fracture
Keywords: Calcium Absorption
Fractional Calcium Absorption
Omeprazole
Stable Calcium Isotopes
Proton Pump Inhibitor
Intestinal Absorption of Calcium
Lead sponsor: University of Wisconsin, Madison
Sponsor class: OTHER
First posted: 2007-12-28
Enrollment: 23
Sex: FEMALE
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: NON_RANDOMIZED
Intervention model: SINGLE_GROUP

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

Detailed description: 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.

Eligibility criteria: Inclusion Criteria:

* Women at least 5 years past menopause, defined as the last date of menses

Exclusion Criteria:

* Allergy/Intolerance to orange juice
* Allergy/Intolerance to omeprazole or other PPI therapy
* Use of drugs that interact with omeprazole including oral anti-fungal agents, coumadin, diazepam, phenytoin \& tacrolimus
* Use of antacids, PPI or H2-blocker therapy within the past two months
* 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 metabolism, including oral steroids or anticonvulsants

Primary outcomes:
measure: Change in Intestinal Calcium Absorption From Baseline to One Month
timeFrame: change in calcium absorption from baseline to 1 month
Secondary outcomes:
measure: Change in Bone Resorption From Baseline to 1 Month
timeFrame: change in bone resorption from baseline to 1 month
Other outcomes:
Locations:
city: Madison
country: United States
facility: University of Wisconsin Hospital and Clinics
state: Wisconsin
Study officials:
affiliation: Univeristy of Wisconsin School of Medicine and Public Health
name: Karen E Hansen, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Hansen KE, Jones AN, Lindstrom MJ, Davis LA, Ziegler TE, Penniston KL, Alvig AL, Shafer MM. Do proton pump inhibitors decrease calcium absorption? J Bone Miner Res. 2010 Dec;25(12):2786-95. doi: 10.1002/jbmr.166. Epub 2010 Jun 24.
citation: Jones AN, Shafer MM, Keuler NS, Crone EM, Hansen KE. Fasting and postprandial spot urine calcium-to-creatinine ratios do not detect hypercalciuria. Osteoporos Int. 2012 Feb;23(2):553-62. doi: 10.1007/s00198-011-1580-7. Epub 2011 Feb 24.