Effects of rabeprazole on bone metabolic disorders in a gastrectomized rat model

Proton pump inhibitors (PPIs) are frequently prescribed to patients with gastroesophageal reflux disease; however, the number of bone fractures reportedly increased in these patients. Although PPIs have been shown to inhibit the bone resorption by osteoclasts, the effect of PPIs on skeletal metabolism remains controversial. The aim of the present study was to determine the effect of the PPI rabeprazole on skeletal metabolism using gastrectomized rats. Male Wistar rats were divided into four groups: i) Sham-surgery (n=15); ii) total gastrectomy (TG) control (n=20); iii) TG plus rabeprazole (n=20); and iv) TG plus the bisphosphonate minodronic acid (n=20). Twenty-two weeks after TG, the rats were sacrificed, and bone mineral density (BMD), bone strength and markers for bone metabolism were measured. Compared with the control group (50.0±8.1%), the TG-induced decrease in BMD was significantly ameliorated in the rabeprazole group (56.5±7.5%) and the minodronic acid group (59.0±6.0%). However, rabeprazole did not improve bone strength. In conclusion, rabeprazole does not appear to exacerbate bone metabolic disorders in gastrectomized rats, but rather ameliorates the TG-induced BMD decrease.