Bone Metabolism Markers in Aortic Stenosis and the Role of Vitamin D Deficiency

Abstract

Aortic stenosis (AS) is of the most prevalent acquired heart valve defects; the role calcium is serious in its development. One of the key mediators of calcium metabolism is vitamin D. Aim. To reveal the relation of the sufficiency of vitamin D with mineral bone density (MBD) and other biomarkers of calcification in AS patients. Material and methods. Totally, 89 patients studied, with severe AS (aortic valve flow velocity more than 4 m/s) at the age 40-76 year old. The controls were almost healthy participants, blood donors (n=31). All patients underwent 25(OH)D in serum measurement, of osteopontin, C-reactive protein and lipid profile, as bienergetic x-ray absorptiometry of lumbar spine and of proximal femur. Results. According to the data of absorptiometry, there was no osteoporosis or osteopenia in AS patients. However, the pressure gradient on aortic valve was related with MBD and T-criteria value. Vitamin D deficiency was found in 46% of patients. Content of 25(OH)D in serum of AS patients was lower and did not differ between bi-and tricuspid aortic valve patients. There was higher level of osteopontin in AS patients comparing to the controls. Decrease of 25(OH)D was associated with the decrease of osteopontin and atherogenety coefficient. There was no relation of the gradient on aortic valve and the level of vitamin D sufficiency. Conclusion. Vitamin D deficiency might impact pathogenesis of AS regardless the anatomic specifics of aortic valve. Its action probably is mediated by the regulation with proinflammatory cytokines, such as osteopontin.