Risk factors for metabolic bone disease in preterm infants in a neonatal unit in Ecuador

Abstract

Metabolic bone disease (MBD) is a common condition in preterm newborns, with an incidence ranging from 16% to 60%, depending on birth weight. Several factors—such as prolonged immobilization, parenteral nutrition, and intestinal malabsorption syndrome—have been implicated in its development. In this study, conducted in the neonatal unit of a tertiary-level hospital, we prospectively evaluated the clinical, biochemical, and therapeutic factors associated with the presence of MBD in a cohort of preterm neonates with a gestational age of less than 34 weeks. The design was a prospective observational cohort with longitudinal follow-up, including systematic collection of clinical and biochemical data from admission until the fourth week of life or hospital discharge. Results showed that each additional week of gestation was significantly associated with a reduced risk of MBD (RR=0.84; 95% CI: 0.75– 0.94; p=0.003), while each extra day of hospitalization increased the risk by 1% (RR=1.01; 95% CI: 1.00–1.02; p=0.001). Higher birth weight acted as a protective factor (RR=0.99; 95% CI: 0.99–0.99; p=0.004), as did a greater volume of enteral feeding by day 14 (RR=0.99; 95% CI: 0.98–0.99; p=0.008). From a biochemical standpoint, elevated alkaline phosphatase levels were significantly associated with MBD (RR=1.00; 95% CI: 1.00–1.00; p<0.001); although the RR appears neutral, the statistical precision and clinical relevance confirm its value as a sensitive marker. Additionally, clinical conditions such as necrotizing enterocolitis (RR=2.12; 95% CI: 1.27–3.53; p=0.001), corticosteroid use (RR=1.76; 95% CI: 1.30–2.38; p=0.001), diuretics (RR=1.59; 95% CI: 1.25–2.02; p=0.031), and methylxanthines (RR=1.99; 95% CI: 1.09–3.66; p=0.004) were significantly associated with an increased risk of developing this complication.