Impact of Intermittent Hypoxia on Growth in Very- and Extremely-Preterm Infants

Abstract

Background. Premature infants are at risk for many complications. Among these, growth failure and intermittent hypoxia (IH) can independently impact the outcomes of other comorbidities. Recent data suggest that IH may directly affect postnatal growth. Our study aims to evaluate the impact of IH on growth velocity in preterm infants. Methods. This prospective cohort study utilized inpatient oximetry, nutrition, and growth data to evaluate the relationship between IH and growth velocity. Enrolled infants were dichotomized by high- versus low-exposure to IH. This relationship was explored in both unadjusted analyses and generalized linear models with repeated measures. Results. The study population included 19 preterm infants, with average birth gestational age of 29 weeks, each contributing one or more measures of weekly data. Infants in the high-exposure cohort had lower birth weight, higher rates of bronchopulmonary dysplasia, and longer duration of respiratory support and caffeine treatment. The unadjusted analysis revealed a marginally significant trend towards higher IH rates during weeks of slower growth. The logistic regression with repeated measures analysis also supported increased odds of slower growth associated with higher IH rates, but this relationship was also only marginally significant. Conclusion. Our study suggests a relationship between exposure to IH and slower growth velocity in preterm infants. The prospectively collected data allowed for accurate measures of IH, growth, and nutrition, but the small sample size likely contributed to the lack of significance of our results.