Abstract
OBJECTIVE: Vitamin D deficiency is an independent risk factor for cardiovascular mortality. The relationship between vitamin D level and left ventricle (LV) myocardial performance index (MPI=Tei index), which incorporates both LV systolic function and diastolic function, was not investigated in previous studies. We hypothesized that vitamin D level may be associated with LV function and geometry. We aimed to investigate the association between serum 25-hydroxyvitamin D (25 [OH] D) levels and MPI and LV hypertrophy in hypertensive patients with newly diagnosed and preserved ejection fraction. METHODS: We studied 151 sequential newly diagnosed hypertensive subjects who lived in the Çukurova region without known cardiovascular risk factors or overt heart disease (mean age: 62.8±10.4 years). Serum 25 (OH) D was measured using a direct competitive chemiluminescent immunoassay. The patients were divided into two groups according to serum 25 (OH) D level: vitamin D-non-deficient group (vitamin D≥ 20.00 ng/mL, n=53) and vitamin D-deficient group (vitamin D< 20.00 ng/mL, n=98). MPI was defined as the sum of isovolumic contraction and relaxation times divided by the ejection time. LV mass index (LVMI) was calculated by using the Devereux formula and body surface area. RESULTS: MPI and LVMI values were lower and low-density lipoprotein (LDL) levels were higher in patients who were vitamin D-non-deficient than patients who were vitamin D-deficient (p<0.05 for all). Multivariate linear regression analysis showed that serum 25 (OH) D was independently associated with MPI (β=-0.426, p<0.001), LVMI (β=-0.345, p=<0.001), and LDL (β=0.140, p<0.026). CONCLUSION: Lower serum 25 (OH) D levels are significantly associated with impaired myocardial performance and LVMI.