The relationship between vitamin D level and echocardiographically detected pulmonary artery stiffness in young adult patients presenting with dyspnea.

Aims: Vitamin D plays a role in controlling the function of vascular smooth muscle and endothelial cells, even in the pulmonary artery. We hypothesized that pulmonary artery elasticity were comprimised in individuals with relatively low vitamin D levels. Methods: Adult individuals with the complaint of shortness of breath were enrolled. They were divided into 2 groups according to vitamin D levels, with a cut-off of 20 ng/mL. Pulmonary artery stiffness (PAS) was calculated using the following formula: PAS (kHz/sec) = maximal frequency shift/pulmonary acceleration time. The six-minute walk distance (6MWD) was used to assess the functional exercise capability of subjects. Results: A total of 71 individuals (male: 31%) were enrolled. Subjects with low vitamin D levels had lower 6MWD than subjects with higher vitamin D levels (443.58±56.20 m vs. 483.20±58.43 m, p=0.007). The PAS was significantly higher in individuals with vitamin D level <20 ng/mL compared with subjects with vitamin D level > 20 ng/mL (11.65±3.76 vs. 9.46±2.53, respectively, p=0.011). Multiple regression showed that vitamin D level was inversely associated with PAS (ß=-0.280, p=0.009). Conclusions: We found that PAS was associated with lower vitamin D levels. Vitamin D deficiency might involved in the dynamics of the pulmonary artery vasculature, even in the absence of significant pulmonary artery pressure elevation. [ABSTRACT FROM AUTHOR]