Background and aim of the study: Rheumatic mitral stenosis (RMS) is a chronic disease related to autoimmune heart valve damage after streptococcal infection. Epidemiological evidence supports an association between vitamin D and the susceptibility and severity of autoimmune disorders. The study aim was to assess the serum levels of 25-hydroxyvitamin D and their correlation with Wilkins calcification score in patients with RMS.
Methods: Thirty-four patients with RMS and 29 healthy age- and gender-matched controls were enrolled in the study. All subjects underwent transthoracic echocardiography after a complete medical evaluation and laboratory examination. The planimetric mitral valve area and Wilkins score were evaluated for all patients, and biochemical parameters and serum levels of 25-hydroxyvitamin D and calcitriol were determined.
Results: The mean patient age was similar in the RMS and control groups (50 +/- 10 versus 52 +/- 10 years; p = NS). The serum level of 25-hydroxyvitamin D was significantly lower in RMS patients than in controls (8.6 ng/ml; range: 4.9-26.3 ng/ml versus 12.3 ng/ml; range: 4-158 ng/ml; p = 0.031). A significantly moderate inverse correlation was identified between the serum 25-hydroxyvitamin D level and the Wilkins score (r = -0.567, p < 0.001), but no correlation was identified between 25-hydroxyvitamin D levels and other echocardiographic parameters of mitral stenosis. The serum level of calcitriol was also significantly lower in RMS patients than in controls (19.8 pg/ml; range: 16.0-54.6 pg/ml versus 26.1 pg/ml; range: 13.2-47.0 pg/ml; p = 0.013).
Conclusion: The study results showed that serum levels of 25-hydroxyvitamin D were significantly lower in RMS patients than in controls, and also correlated with the Wilkins calcification score. Thus, a link may exist between 25-hydroxyvitamin D and the calcification process in RMS.