1: Department of Rheumatology, St. Paul’s Hospital, Thessaloniki, Greece
2: Department of Endocrinology, Red Cross Hospital, Athens, Greece
3: Department of Physiology, Medical School, University of Athens, GreeceSign in to download the Issue in PDF format.
Vitamin D is a hormone which belongs to the group of secosteroids and it is involved in bone metabolism.1,2 It contributes to calcium absorption from the gut and regulates bone mineralization3,4. Vitamin D is synthesized in the skin from cholesterol by the action of ultraviolet radiation from the sun.5 Living in an environment which is either protected from the sun, such as modern buildings, or where there is insufficient exposure to the sun due to geographic location, or use of protective clothing from the sun, such as the black clothes used by Orthodox priests, or clothes offering complete body shielding, such as the clothing used by women in the Muslim world, contribute to insufficient vitamin D biosynthesis in the skin. Moreover, dark skin color with excessive levels of melanin protects from sun photons and does not allow sufficient vitamin D biosynthesis within the skin.
Vitamin D has many extraskeletal actions.6,7 It seems to be involved in the regulation of the immune system.8,9 It has immunomodulatory action.10 Its immunomodulatory action is expressed both as immunosuppressive action as well as immune-enhancing; action contributing to the defense of the organism against microbial infections. It appears that vitamin D insufficiency may be related to the susceptibility of the organism to autoimmune diseases, as vitamin D insufficiency may be related to loss of immune tolerance. Vitamin D exists as a group of molecules; the active hormone thought to be 1,25(OH)2D3. Vitamin D sufficiency is estimated by the measurement of 25(OH)D3 blood levels. It appears that vitamin D sufficiency may be related to the appearance of autoimmune diseases.
The aim of the study is to measure vitamin D levels in patients with ankylosing spondylitis and psoriatic arthritis and to estimate the relationship between vitamin D levels and disease activity n ankylosing spondylitis and psoriatic arthritis.
Vitamin D -25(OH)D3 – levels will be measured in the blood in 50 patients with ankylosing spondylitis and psoriatic arthritis. Parathyroid hormone (PTH) levels will also be measured. In ankylosing spondylitis and psoriatic arthritis disease activity will be estimated by the measurement of ESR, c-reactive protein levels, BASDAI index for ankylosing spondylitis and HAQ for psoriatic arthritis.
It is anticipated that low vitamin D -25(ΟΗ)D3- levels will be found in patients with ankylosing spondylitis and psoriatic arthritis. The relationship of vitamin D levels with disease activity in ankylosing spondylitis and psoriatic arthritis will be estimated.
Vitamin D deficiency is related with the susceptibility to autoimmune diseases. The finding of vitamin D deficiency in patients with ankylosing spondylitis will confirm the immunomodulatory role of vitamin D. Vitamin D deficiency is related with diffuse musculoskeletal pain. The detection of vitamin D deficiency in seronegative spondyloarthritis may assist in pain management with the exogenous administration of vitamin D. This study will help to define the involvement of vitamin D in skeletal integrity both by the maintenance of calcium homeostasis and muscle health, as well as its involvement in acting against the development and the management of pain in diseases. The systemic inflammatory diseases such as ankylosing spondylitis are characterized by the development of osteoporosis. The detection of vitamin D deficiency in these diseases will also contribute to the prevention and management of osteoporosis.