Increase in vertebral fracture risk in postmenopausal women using omeprazole.

Proton pump inhibitors are taken by millions of patients for prevention and treatment of gastroesophageal diseases. Case-control studies have suggested that use of omeprazole is associated with an increased risk of hip fractures. The aim of this prospective study was to assess the risk of vertebral fractures in postmenopausal women using omeprazole. We studied 1,211 postmenopausal women enrolled in the Osteoporosis and Ultrasound Study from the general population. Information on omeprazole and other risk factors for fractures including prevalent fractures and bone mineral density was obtained at baseline. Vertebral fractures were assessed on X-rays obtained at baseline and at the end of the 6-year follow-up and analyzed centrally. At baseline, 5% of this population was using omeprazole. Age-adjusted rates for vertebral fractures were 1.89 and 0.60 for 100 person-years for omeprazole users and nonusers, respectively (P = 0.009). In the multivariate analysis, omeprazole use was a significant and independent predictor of vertebral fractures (RR = 3.50, 95% CI 1.14-8.44). The other predictors were age higher than 65 years (RR = 2.34, 95% CI 1.02-5.34), prevalent vertebral fractures (RR = 3.62, 95% CI 1.63-8.08), and lumbar spine T score </= -2.5 (RR = 2.38, 95% CI 1.03-5.49). Omeprazole use is associated with an increased risk of vertebral fractures in postmenopausal women. Further studies are required to determine the mechanism of the association between the underlying gastric disease, omeprazole use, and risk of osteoporotic fractures.