Vitamin D receptor gene polymorphisms in rheumatoid arthritis patients associating osteoporosis

Rheumatoid arthritis and osteoporosis are major causes of disability associated with aging and are increasing in public health importance. Biostatisticians work to advance public health through biomedical research. Polymorphisms allow not only the detection of susceptible individuals to a certain disease but also the evaluation of the severity of the disease. The aim of this research is to study the influence of vitamin D receptor polymorphisms on rheumatoid arthritis patients with or without osteoporosis. Osteoporosis is a measurement of rheumatoid arthritis severity in the affected patients. Four single nucleotide polymorphisms (ApaI, BsmI, FokI, and TaqI) were tested by genotyping 17 rheumatoid arthritis patients with osteoporosis and 72 rheumatoid arthritis patients without osteoporosis. Associations were tested using multiplicative, dominant, recessive, and co-dominant models. Also, the linkage disequilibrium between the polymorphisms was measured to detect any indirect variant. The FokI variant was significantly associated with risk of osteoporosis in rheumatoid arthritis.