Role of Proton Pump Inhibitors in Calcium Absorption, Bone Resorption, and Risk of Hip Fracture

Abstract

Objective: To review the influence of proton pump inhibitors (PPIs) on calcium absorption, bone remodeling, and fracture risk. Data Sources: A search via MEDLINE (1966–April 2007) was performed using the search terms proton pump inhibitors, omeprazole, calcium absorption, calcium malabsorption, bone resorption, and fracture risk. Study Selection and Data Extraction: English-language literature, including abstracts, preclinical and clinical trials, and review articles, were identified from the data sources and reviewed. Data Synthesis: Data on the effect of PPIs on calcium absorption are conflicting; however, the majority of data indicate that PPIs decrease intestinal calcium absorption, which could negatively affect bone strength. In particular, calcium carbonate may be more difficult to absorb in an environment with elevated pH due to PPI use. Data on the role of PPIs in osteoclast function are also conflicting, with one human study indicating decreased bone resorption due to inhibition of osteoclast function and another human study indicating no association between PPIs and osteoclast function. The risk of fracture with PPI use was evaluated in 2 studies, and both studies found an increased risk of fracture of 14–44% after PPI use. Conclusions: PPI use may increase a patient's risk of fracture. Additional studies are needed before causality can be established.