IJCS | Volume 32, Nº5, September/October 2019

509 In a recent review of the literature, Lagoeiro et al., 7 demonstrated that the efficacy of Vitamin D supplementation is not clear yet. It is unknown whether the unfavorable results are a consequence of inadequate supplementation dosage or the inability of the vitamin in exerting favorable metabolic effects on already established diseases. 7 On the other hand, Vitamin D deficiency has been associated with the worsening of quality of life and a decrease in functional performance, due to abnormal LV systolic and diastolic functions and vascular system, and thus may contribute to the genesis or progression of HF. 5-8-10 Vitamin D is associated with the worsening of diastolic function and activation of the renin-angiotensin- aldosterone system (RAAS). 8-9 The study is based on the fact that left atrial volume (LAV) measurement is a marker of the presence of diastolic dysfunction and that Vitamin D deficiency may be associated with ventricular remodeling, worsened LV systolic and diastolic function and RAAS activation. The objective of this study is to evaluate whether LAV changes are related to Vitamin D deficiency and to verify whether there is a relationship with ventricular remodeling and other parameters of systolic function (S') and diastolic function (LV relaxation and filling pressure). Methodology Cross-sectional, population-based, unicentric study, and part of the Digitalis Study, 11 involving 640 randomly selected individuals, aged over 45 years, enrolled in the Niterói’s Médico de Família program. Vitamin D dosage and cardiac structural and functional abnormalities, assessed using transthoracic echocardiography, were included among the criteria for classification of hypovitaminosis D. The presence or absence of hypovitaminosis D, associated with structural and functional abnormalities, was compared between each group. The units and individuals at each unit were selected through computer-generated random sequence, where the weight of each unit was proportional to the number of individuals assisted. All individuals selected in the study underwent a single-day evaluation, which consisted of the following procedures: blood collection (including a Vitamin D test), urine collection, consultation and clinical examination, nutritional assessment, measurement of blood pressure, heart rate, body weight, height and abdominal-waist circumference, filling out of a questionnaire adapted for this study, 12-lead electrocardiogram (ECG) and tissue Doppler echocardiogram (TDE). Figure 1 - Volume index versus diastolic dysfunction. The volume index increases as the diastolic function worsens.³ Macedo et al. Increased left atrial volume Int J Cardiovasc Sci. 2019;32(5):508-516 Original Article