Arthritis & Rheumatism, Volume 60,
October 2009 Abstract Supplement
The 2009 ACR/ARHP Annual Scientific Meeting
Philadelphia October 16-21, 2009.
Relationship of Vitamin D and Parathyroid Hormone to Functional Disability and Disease Activity in RA
Doherty1, Colleen, Vokes2, Tamara, Mileti3, Linda M., Badaracco1, Maria, Drum2, Melinda, Utset1, T.O.
Vitamin D has immunomodulatory effects, and deficiency of this nutrient may impact inflammatory conditions such as rheumatoid arthritis. Conversely, the effect of chronic inflammation on calcium homeostasis is largely unstudied. We sought to determine if 25(OH) vitamin D level correlates with disease activity and functionality in RA, and whether parathyroid hormone (PTH) and calcium levels are impacted by chronic inflammation.
In this cross-sectional study, the levels of 25(OH) vitamin D, calcium, and PTH were measured in postmenopausal women with RA. Disease activity was measured by erythrocyte sedimentation rate (ESR) and functional disability by the Health Assessment Questionnaire-II (HAQ-II). Statistical analysis of relevant clinical variables with ESR, HAQ-II score, and PTH were performed using t tests, and univariate and multivariate linear regression.
Ninety-two subjects were analyzed. Average age was 66 years (SD 9.4), and mean disease duration was 12.1 yrs (SD 10.2); 61% of subjects were African-American, 32% Caucasian, and 8% Latino. Mean HAQ-II score was 0.91 (SD 0.68), and mean ESR was 41.2 (SD 28.4). Mean ESR was higher in African-American subjects (46.0 versus 33.8 mm/hour, p=0.046). Mean 25(OH) vitamin D level was 28.0 ng/mL (SD 11.3, range 2.554), and was lower in African-American subjects (25.5 versus 31.9 ng/mL, p=0.01). In univariate analysis, ESR trended closely toward association with 25(OH) vitamin D (p=0.06). After adjustment for age, creatinine, and ethnicity, the association of ESR with 25(OH) vitamin D was significant (p= 0.03). African-American ethnicity no longer significantly associated with ESR when adjusted for 25(OH) vitamin D (p=0.26). HAQ-II score correlated inversely with 25(OH) vitamin D level (p=0.03). Creatinine, African-American ethnicity, and calcium also correlated with HAQ-II score. In multivariate regression, HAQ-II score was positively associated with serum calcium (p=0.01) and serum creatinine (p=0.003), and trended closely toward an inverse association with 25(OH) vitamin D (p=0.06), but no longer varied by ethnicity. PTH level was positively correlated with ESR on both univariate regression (p=0.04) and multivariate regression adjusting for calcium, creatinine and 25(OH)vitamin D (p=0.01).
25(OH) vitamin correlates inversely with ESR and trends toward correlation with HAQ-II score in RA, after adjustment for covariates. This supports a possible contribution of vitamin D insufficiency to disease activity and functional impairment in RA. The positive association of PTH with ESR suggests that parathyroid hormone production may be increased by a chronic inflammatory state.
To cite this abstract, please use the following information:
Doherty, Colleen, Vokes, Tamara, Mileti, Linda M., Badaracco, Maria, Drum, Melinda, Utset, T.O.; Relationship of Vitamin D and Parathyroid Hormone to Functional Disability and Disease Activity in RA [abstract]. Arthritis Rheum 2009;60 Suppl 10 :337