The effect of circulating nitric oxide level on axial bone mineral density in postmenopausal Turkish women with rheumatoid arthritis: a preliminary report

The aim is to investigate the differences in the circulating nitric oxide (NO) levels of rheumatoid arthritis (RA) patients, healthy controls and osteoporotic (OP) patients. We also examined whether the circulating NO levels may be correlated with bone mineral density (BMD) in RA patients. Forty-five patients with RA, 30 healthy women and 30 osteoporotic patients were recruited from the outpatient clinic. All the subjects were female and postmenopausal. Serum NO levels were measured (Nitrite/Nitrate, calorimetric method 1746081, Roche diagnostics, Mannheim, Germany) and BMD was measured at the spine and hip using dual energy X-Ray absorbtiometry (DEXA, Norland XR-46). Height and weight were measured and body mass index was calculated. Circulating NO levels were significantly higher in RA patients than other groups. Moreover, the RA group showed significantly higher BMD at lumbar spine and femoral neck regions compared to osteoporotic patients. However, the RA group showed significantly lower BMD at all sites than the controls. There was no correlation between circulating NO levels and BMD in all groups. We suggest that, unlike postmenopausal osteoporosis, inflammation induced osteoporosis is associated with RA is characterised by relatively preserved bone mass at the axial bone regions, and circulating NO levels as a parameter or determinant of inflammation are not correlated with axial BMD in RA patients.