Vitamin D Serum Levels and its Relation To The Echocardiography Parameters Of Cardiac Systolic And Diastolic Functions In Patients With Systolic Heart Failure

Abstract

Vitamin D is a fat-soluble vitamin, it is unique because it can be ingested as cholecalciferol (vitamin D3) or ergocalciferol (vitamin D2) and also the body can also synthesize it (from cholesterol) when sun exposure is adequate (hence its nickname, the "sunshine vitamin"). The major source of vitamin D is sunlight exposure. It contributes 80% to 90% of vitamin D supply in free-living persons. Very few foods in nature contain vitamin D. Cod fish oil and the fleshes of fatty fish (such as salmon, tuna, and mackerel) are among the best sources. It has skeletal and non skeletal functions such as regulation of cell proliferation and differentiation, regulation of hormone secretion, regulation of immune function and blood pressure regulation. Vitamin D insufficiency/deficiency is a worldwide, public health problem in both developed and developing countries.

Vitamin D insufficiency has been defined as a 25(OH) D concentration of 50–75nmol/L (20–30ng/mL), deficiency below 20ng/mL (50nmol/L), and severe deficiency below 10ng/mL (25nmol/L). There are many causes of deficiency such as reduced skin synthesis as a result of inadequate exposure to sunlight, decreased bioavailability as in malabsorption and obesity, decreased activation as in hepatic and renal failure, increased catabolism due to some drugs (Anticonvulsants, glucocorticoids) and breast-feeding. It is linked to many diseases such as osteoporosis, diabetes, dyslipidaemia, cardiovascular, autoimmune, cancers, infections and increased mortality. This prospective study was carried out at department of cardiology Ain Shams University from Nov. 2013 to Sep. 2014. the aim of our study was to study the relation between serum 25-hydroxy vit. D levels and parameters of cardiac systolic and diastolic function in patients with LV systolic heart failure. The study included 60 patients admitted to our hospital for management of symptomatic heart failure with systolic dysfunction. The mean age was 58.5±7.7 years, and 9 patients (15%) were females. All patients were in sinus rhythm. Patients were admitted with a New York heart association (NYHA) functional class of 2.48±0.6. 22(37%) patients were diabetics, 26(43%) were hypertensive, 40(67%) were smokers, and (8%) were hyperlipidemic. Overall, the mean vitamin D level was 18.9±8.3 microgram per deciliter (ng/ml). 42(70%) patients had their vitamin D levels below 20 ng/ml (considered deficient) and 18 (30%) had Vitamin D levels≥20 ng/ml (considered within normal range). It was found that, compared to patients with vitamin D≥20 ng/ml, patients with vitamin D level <20 ng/ml had significantly higher average e’ (5.4±1.7 vs. 6.3±1.8 cm/s, p=0.033), significantly shorter IVRT (116.7±18 vs. 100.5±22.1 ms, p=0.011), and significantly lower E/e’ (18.5±8.4 vs. 18.5±8.4, p=0.002). Which is suggestive of a better diastolic function. There was no significant difference between both groups regarding average a’, E wave velocity, A wave velocity, E-DcT, LAV, E/A, and e’/a’.