Effects of Nonsteroidal Anti-inflammatory Drugs (NSAIDs) on Osteoporosis.

Abstract

Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used agents for backache and various joint pains. We suspected that a continuous administration of NSAIDs might suppress bone formation and/or promote bone loss in patients with low bone mineral density (BMD) because the biosynthesis of prostagrandins is inhibited by these drugs. In this study we surveyed the effect of NSAIDs on the bone metabolism in patients with low BMD by comparing a group with NSAIDs administered every day over a period of 1 year and a control group with NSAIDs only occasionally used.Dual energy x-ray absorptiometry (DXA) was performed on a total of 272 female at our department from April 1999 to September 1999. As a result, 163 cases were found to have BMD less than 80% of the nation's young adult mean values and considered non-secondary in nature. Out of the 163, we chose 14 cases for the NSAID group, and 51 cases for the control group.The average age, height and body weight were 73.6 years, 149.1cm and 52.1kg for the NSAID group and 71.7 years, 146.7cm and 48.0kg for the control group. There were no statistical differences in all these items. For the treatment of low BMD, 64.9% of the patients in the NSAID group and 52.9% in the control group had anti-osteoporotic medication. In the NSAID group, the relative changes in BMD between the values of the first measurements and those after a 1-year interval were 2.7% decrease at 2nd lumbar vertebra (L2), 12.4% decrease at 3rd lumbar vertebra (L3), 3.9% decrease at 4th lumbar vertebra (L4) and 4.4% decrease at 2nd-4th lumbar vertebra (L2-4). In the control group these were at each site 2.9% increase, 3.6% increase, 2.3% increase and 2.8% increase, respectively. In the NSAID group, BMD changes at neck, Wards, trochanter and shaft of the femur were 3.6% decrease, 4.6% decrease, 4.2% decrease and 3.9% decrease, respectively in the control group, they were 1.0% decrease, 2.2% increase, 1.6% increase and 0.1% increase, respectively. A comparison between the two groups showed thaf the percent changes in BMD of L3, L2-4, Wards, trochanter and shaft of the femur were statistically significant in the NSAID groups.The present data suggest that the regular use of NSAIDs enhances bone loss in patients with low bone density detected by DXA examination.