Relationship Between Disease Activity and Serum Levels of Vitamin D Metabolites and PTH in Rheumatoid Arthritis

Abstract

In several studies on patients with rheumatoid arthritis, an association of bone loss with a persistently high disease activity has been found. The aim of our study was to investigate the relation between disease activity and serum levels of vitamin D metabolites, parathyroid hormone (PTH), and parameters of bone turnover in patients with rheumatoid arthritis. A total of 96 patients (83 women and 13 men) were divided into three groups according to disease activity measured by serum levels of C-reactive protein (CRP). In the whole group, serum levels of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) (P < 0.001) and PTH (P < 0.05) were negatively correlated to disease activity. The urinary excretion of collagen crosslinks--pyridinoline (Pyd) (P < 0.001) and deoxypyridinoline (Dpd) (P < 0.05)--showed a positive correlation with disease activity. The inverse correlation between serum 1,25(OH)2D3 and disease activity was separately evident in patients with (P < 0.001) and without (P < 0.01) glucocorticoid treatment, in pre- (P < 0.01) and postmenopausal (P < 0.001) women, and in men (P < 0.01). 1,25(OH)2D3 and PTH serum levels were positively correlated to serum bone alkaline phosphatase (ALP) (P < 0.01). The results indicate that high disease activity in patients with rheumatoid arthritis is associated with an alteration in vitamin D metabolism and increased bone resorption. The decrease of 1,25(OH)2D3 levels in these patients may contribute to a negative calcium balance and inhibition of bone formation. Furthermore, low levels of 1,25(OH)2D3 as an endogenous immunomodulator suppressing activated T cells and the proliferation of cells may accelerate the arthritic process in rheumatoid arthritis.

Association between serum vitamin D metabolite levels and disease activity in patients with early inflammatory polyarthritis

“…We can speculate from our findings of a weak association between circulating levels of 1,25(OH) 2 D and disease activity that there is also an endocrine mechanism for immunomodulation. In support of this are intervention studies of oral and parenterally administered 1,25(OH) 2 D in animals (7) and humans (20) Two previous clinical studies have examined vitamin D levels in patients with RA, but unlike the present investigation, those studies examined patients with established disease of long duration (21,22). Neither study measured joint counts; they used only the CRP level or only the erythrocyte sedimentation rate (ESR) as a measure of RA disease activity.…”

“…An inverse association between the 1,25(OH) 2 D level and the ESR, but not the CRP level, was demonstrated, but only in blood samples obtained during the winter (21). Conversely, an inverse association between the 1,25(OH) 2 D level and the CRP level was observed (Spearman's r ϭ 0.52, P Ͻ 0.001), but again, only in samples obtained during the winter (22). The interpretation of these data is difficult, not least because of the long duration of RA (0.4-18 years in one study and 0.5-38 years in the other), as well as because patients were taking DMARDs and other treatments that would confound any relationship to disease activity.…”

Dietary manipulation in musculoskeletal conditions

“…In 96 RA patients grouped according to disease activity, serum concentration of 1,25(OH) 2 D correlated negatively (P < 0.001) with disease activity both in patients with and without glucocorticoid treatment [114].…”

Oxidative stress and calcium-phosphorus levels in Rheumatoid arthritis

“…As calcium and phosphorous are important constituent of bone, ultimately bone metabolism is altered in RA, the event observed by many workers (22,23). Negative correlation between calcium/phosphorus ratio and lipid peroxide (r = -0.76) suggests that the generation of reactive oxygen species in excess may be particularly important in the bone resorption that occurs in association with inflammatory diseases (24).…”

“…Negative correlation between calcium/phosphorus ratio and lipid peroxide (r = -0.76) suggests that the generation of reactive oxygen species in excess may be particularly important in the bone resorption that occurs in association with inflammatory diseases (24). Decrease in calcitriol level may contribute to a negative calcium balance and acceleration of immunomodulatory effects (23,25). Significant positive correlation between vitamin E and calcium (r= + 0.67) suggest that vitamin E may also be an important for immunity of an organism along with calcium.…”