Vitamin D Levels and Cardiopulmonary Status in Infants with Acute Bronchiolitis.

Background: To assess association of Vitamin D deficiency with cardiac and pulmonary status in infants with acute bronchiolitis.

Methods: Infants hospitalized with acute bronchiolitis were enrolled and classified as those with serum 25 hydroxyvitamin D (25-OHD) below or equal and above 20 ng/mL. The primary outcomes were cardiopulmonary involvement defined by elevation of NT-ProBNP, alteration of echocardiographic parameters and respiratory support requirements. The secondary outcomes were the need for PICU admission and duration of hospitalization.

Results: Ninety two (50 males) infants with median (IQR) age 1 (0.5 - 3) months were included with median (IQR) serum 25 - OHD level 27.4 (11.4 - 40.3) ng/mL. Forty-three (47%) patients had serum below 20 ng/mL with left ventricle dysfunction (P=0.008), right ventricle dysfunction (P=0.008) and pulmonary hypertension (P=0.007) on echocardiography than those with serum 25 - OHD > 20 ng/mL. The median (IQR) serum NT - ProBNP levels were higher in those with low 25 - OHD levels than normal 25 - OHD levels [2232.2 (461.4 - 4313.3) and 830.4 (312.7 - 2579.5)], respectively; P=0.003. Low 25-OHD levels were associated with increased risk for PICU admission (OR 3.9 (95% CI 1.5-10.1); P=0.004), higher rates of non-invasive ventilation, (P= 0.048), mechanical ventilation (P=0.005), and longer duration of hospitalization (P=0.015).

Conclusion: Low serum vitamin D level was associated with clinical severity and impaired cardiac and pulmonary status in infants with acute bronchiolitis.