Relationship of Focal Erosions, Bone Mineral Density, and Parathyroid Hormone in Rheumatoid Arthritis

Abstract

Objective. To investigate the relationship among focal bone erosions and bone mineral density (BMD), 25(OH) vitamin D (25OHD), and parathyroid hormone (PTH) values in patients with rheumatoid arthritis (RA). Methods. The study included 1191 RA patients (1014 women, 177 men, mean age 58.9 +/- 11.1 yrs) participating in a multicenter, cross-sectional study. Results. Radiographic evidence of typical bony erosions on hands or forefeet was found in 64.1% of patients. In those with bone erosions as compared to those without, mean BMD Z score values were significantly lower at both the spine (-0.74 +/- 1.19 vs 0.46 +/- 1.31; p = 0.05) and the hip (-0.72 +/- 1.07 vs -0.15 +/- 1.23; p <0.001). In the subgroup of patients not taking vitamin D supplements, PTH levels were significantly higher in those with erosive arthritis (25.9 +/- 14.0 vs 23.1 +/- 11.6 pg/ml; p = 0.01); whereas the 25OHD concentrations were very similar in the 2 groups. The mean differences for BMD and PTH among the erosive and nonerosive RA remained statistically significant when values were simultaneously adjusted for all disease and mineral metabolism factors (i.e., age, sex, menopause, disease duration, Disease Activity Score 28-joint count, Health Assessment Questionnaire, activities of daily living, Steinbrocker functional state, glucocorticoid therapy, body weight, and bisphosphonate treatment). Conclusion. Our results suggest that the presence of bone erosions in RA correlates with low BMD levels and high PTH levels, and that these associations are independent of the degree of functional impairment and other common determinants of bone mass and mineral metabolism in adults with RA. These findings suggest that treatments to prevent bone loss or suppress PTH levels might positively affect the progression of bone erosions in RA. (First Release April 1 2011; J Rheumatol 2011;38:997-1002; doi:10.3899/jrheum.100829

Vitamin D, inflammatory markers, steroid use and systemic factors: which is the culprit in rheumatoid arthritis associated osteoporosis?

“…Similar to this study, Rossini and his colleagues, 2011 [41] found vitamin D level to be very similar among the erosive and nonerosive RA. Low BMD level was only dependent on parathyroid hormone (PTH) values.…”

Prevalence and incidence of osteoporotic fractures in patients on long-term glucocorticoid treatment for rheumatic diseases: the Glucocorticoid Induced OsTeoporosis TOol (GIOTTO) study

“…A recent study has shown that ACPA can stimulate osteoclast differentiation, and that in ACPA-positive patients with RA there is more frequent evidence of bone loss and thinning of cortical thickness than in APCA-negative patients with RA (46)(47)(48). Recently, a significant correlation has been observed between RA related osteoporosis and risk of erosions (49,50). The incidence of new fragility fractures during GCs treatment in our cohort of patients was 12% in CTDs, 10% in PMR, and 23% in RA.…”

Osteoporosis in rheumatoid arthritis: role of the vitamin D/parathyroid hormone system

“…2 This result has been confirmed in a further paper, in which we observed that suppression of secondary hyperparathyroidism in autoimmune rheumatic patients was impaired with respect to patients affected by osteoarthritis after a cholecalciferol regimen used to correct hypovitaminosis D. 69 Similarly, in a multicentric study, RA patients with erosive evolution presented with higher PTH and lower BMD in comparison to patients with less aggressive arthritis, despite possessing similar vitamin D concentrations. 70 These observations raise the attention on the possible presence of a "relative hypovitaminosis D" in RA and in other inflammatory rheumatic diseases, which could explain the reduction in the physiological actions of this molecule; in these patients, indeed, the mechanisms that regulate PTH synthesis seem to be more refractory to vitamin D suppression.…”

“…We have demonstrated that only a high dose supplementation regimen (300,000 IU orally once) followed by a maintenance dose was superior, also if still suboptimal, in the correction of hypovitaminosis D and of secondary hyperparathyroidism in rheumatic patients. 70 …”