Vitamin D Deficiency and Relation to the New York Heart Association Functional Class in Chronic Heart Failure

OBJECTIVE
Heart failure is an important mortality and morbidity. In this study, we aimed to investigate the frequency of vitamin D deficiency in chronic heart failure patients who live in a sunny region and to evaluate its relationship with the New York Heart Association (NYHA) functional classes.

METHODS
The study included 657 patients. Demographic clinical, and laboratory parameters were evaluated according to the NYHA classes. Ordinal regression analysis was used to determine the parameters defining the NYHA class.

RESULTS
The median serum 25-hydroxy-vitamin D [25(OH)D] level of study population was 16.88 ng/mL. It was <20 ng/mL in 63.8% and 20-29 ng/mL in 32.9% of the patients. A 25(OH) D <20 ng/mL was significantly more common in women compared to men (74.1% vs. 60%, P <.001). Moreover, 109 patients (16.6%) had severe vitamin D deficiency [25(OH)D <10 ng/mL]. Only 22 (3.3%) patients had a 25(OH)D level >30 ng/mL. 25(OH)D level was positively correlated with eGFR, calcium, albumin, hemoglobin, transferrin saturation, serum iron, while a negative correlation was found with heart rate, parathormon, NT-proBNP, and CRP. Together with dereased ß blocker use, increase in N-terminal pro-brain natriuretic peptide levels and left atrial diameter, a decrease in vitamin D level (OR: 0.970, 95% CI: 0.945-0996, P =.024) was independently associated with an increase in the New York Heart Association class.

CONCLUSION
Vitamin D deficiency and insufficiency are common in patients with chronic heart failure, and vitamin D level is an important determinant of the NYHA functional class in patients with heart failure.