Association of Hypovitaminosis D with Poor Bone Health in Patients of Rheumatoid Arthritis – A Case–Control Study

Abstract

Abstract Background: Data on correlation between hypovitaminosis D and disease activity indices in patients with rheumatoid arthritis (RA) are varied. In this context, this prospective, case–control study aimed to evaluate the contribution of hypovitaminosis D toward bone health in patients with RA and correlate it with clinical, functional, and radiological disease activity indices. The study objectives were to assess the occurrence of hypovitaminosis D, to determine baseline bone mineral density (BMD), and to evaluate factors likely to contribute to poor bone health in patients of RA. Results: Hypovitaminosis D was observed in 76% of patients of RA with all of them having poor bone health as evident by statistically significant correlation between low Vitamin D levels and poor BMD. Poor bone health was observed in 80% of patients with femoral measurements, exhibiting greater severity of reduced BMD than lumbar spine values. Bivariate analysis revealed significant correlation of low Vitamin D, parathyroid hormone, Modified Sharp Score (MSS), and steroid intake with poor BMD at both spine and femur neck. Furthermore, binary logistic regression analysis among these four variables showed that only MSS had statistically significant association with osteoporosis, and there was a trend towards significance with poor BMD. Conclusions: This study has observed that RA patients indeed have poor bone health. Consequent osteoporosis has multifactorial etiology, and hypovitaminosis D remains one of the prime contributors, yet underappreciated and consequently undertreated.