Vitamin D deficiency and low bone mineral density in native Chinese rheumatoid arthritis patients.

Objective We aimed to examine the risk factors related to the development of osteoporosis in rheumatoid arthritis ( RA) patients and whether there is an association among the changes in bone mineral density ( BMD), disease activities (modified DAS28), serum 25-hydroxyvitamin D (25 OHD) levels, and disease duration. Methods There were 110 patients with RA and 110 age- and sex-matched healthy controls who were concurrently studied. All of the patients underwent the following measurements: erythrocyte sedimentation rate, C-reactive protein, rheumatoid factor, and serum 25 OHD. Dual-energy X-ray absorptiometry ( DEXA) was also used to measure the BMD of the left femur at the time of recruitment. Patients taking vitamin D supplement or corticosteroids were excluded. Results The incidences of osteopenia (45.6% vs. 36.4%, P = 0.170) and osteoporosis (33.6% vs. 5.45%, P = 0.000) were higher in the RA patients than in the healthy controls. There was a significant negative correlation between vitamin D levels and DAS28 ( r = -0.325, P = 0.001) and a significant positive correlation between vitamin D levels and BMD ( r = 0.422, P = 0.000). The multiple regression analysis revealed that 25 OHD levels were significantly correlated with disease activity and BMD ( F = 11.087, P = 0.000). Stepwise multiple regression analysis showed that serum 25 OHD levels were the significant predictors for low BMD and high disease activity ( DAS28) in RA patients. Conclusion The incidences of osteoporosis and osteopenia were higher in RA patients compared to the age- and gender-matched healthy controls. Low serum 25 OHD levels correlate with low BMD and high disease activity in RA patients. [ABSTRACT FROM AUTHOR]