Conditions: Osteoporosis Achlorhydria GERD Hip Fracture
Keywords: Calcium Absorption Fractional Calcium Absorption Omeprazole Stable Calcium Isotopes Proton Pump Inhibitor Intestinal Absorption of Calcium
Allocation: NON_RANDOMIZED | Intervention model: SINGLE_GROUP
Enrollment: 23
Healthy volunteers: yes

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.

Arms:
arm 1: Subjects will receive omeprazole 40 mg daily for 30 days

Interventions: intervention 1: Omeprazole
Intervention descriptions: intervention 1: 40 mg po qAM one-half hour before breakfast for 30 days

Protocol document: