Atorvastatin enhances bone density in ovariectomized rats given 17beta-estradiol or human parathyroid hormone(1-34)

We investigated the in vivo effect of atorvastatin on bone mineral density (BMD) in ovariectomized (OVX) rats. Eight-week-old female rats underwent either a sham operation or ovariectomy, and treatments with vehicle, atorvastatin, 17beta-estradiol (E2) and human parathyroid hormone(1-34) [hPTH(1-34)] were initiated 6 wk after the surgery. E2 (10 microg/kg) treatment for 12 wk significantly increased lumbar BMD (L2-L4), whereas atorvastatin did not affect lumbar BMD. The combination of atorvastatin (2 mg/kg) and E2 significantly enhanced the BMD of lumbar vertebrae (L2-L4) and femoral metaphyseal area (2/10-4/10 segments from the most proximal point) compared to that of either E2 or atorvastatin alone. A low dose 1 micro g/kg of hPTH (1-34) did not alter lumbar or femoral BMD, whereas a high dose 17.5 micro g/kg of the peptide significantly increased BMD. Concomitant injections of atorvastatin (2 mg/kg) with hPTH(1-34) (1 microg/kg) for 8 wk significantly enhanced the BMD of lumbar vertebrae and the metaphyseal area of the femur in OVX rats. These findings demonstrate that chronic administration of atorvastatin appears to modestly enhance the BMD of the lumbar vertebrae and femoral metaphysis of OVX rats treated with submaximal doses of E2 and hPTH(1-34).