8-hydroxy-2--deoxyguanosine and Infant--Premature--Diseases

The role of oxidative stress remains unclear in the multifactorial pathophysiologic mechanism of lung disease in preterm infants.. The aim of this study was to examine the associations among chronic lung disease (CLD), oxidative stress, and oxygen requirements in preterm infants.. Prospective, longitudinal, and correlational design.. Preterm infants born at <32 weeks' gestation (N = 31), median gestation of 29.0 weeks (range 24.9-31.7).. The diagnosis of CLD was obtained from the medical record. Oxidative stress was measured using 8-hydroxydeoxyguanosine (8-OHdG) in the cord blood at birth and urine on Days 1 and 7. Oxygen requirements were measured using fraction of inspired oxygen (FIO2) recorded in the first hour after birth/admission and the average FIO2 during the first 12 hr and 7 days after birth. Descriptive statistics are presented. Comparison analyses were performed using Kruskal-Wallis and Fisher's exact tests.. Infants with CLD (n = 12) had lower gestational age (p = .04) and weight (p = .04) at birth, more days on the ventilator (p = .004), and longer neonatal intensive care unit stay (p = .04) compared to infants without CLD (n = 19). CLD was associated with lower oxidative stress levels (p = .03) and higher oxygen requirements during the first 12 hr (p = .025) and on Day 7 (p = .001). Lower oxidative stress levels on Day 7 were associated with higher oxygen requirements in the first 12 hr (p = .01) and on Day 7 (p = .03).. Our results linking CLD and higher oxygen requirements with low oxidative stress contradict previous reports. Findings identify a gap in knowledge for postresuscitation oxygen therapy in preterm infants and expose the role of oxidative stress from inflammation and intermittent hypoxia in the etiology of CLD.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Administration, Inhalation; Child; Deoxyguanosine; Female; Humans; Infant; Infant, Newborn; Infant, Premature; Infant, Premature, Diseases; Intensive Care Units, Neonatal; Lung Diseases; Male; Oxidative Stress; Oxygen Inhalation Therapy; Prospective Studies

Feeding intolerance (FI) in preterm infants is common but the etiology remains unclear. This study examined FI as a stress-related disease involving brain-gut interactions and tested the model of allostatic load and complications of prematurity. Specific aims were to describe demographic/medical variables and biomarker levels at each time and over time for the sample; describe/compare variables and biomarker levels at each time for infants with/without FI; and compare biomarker interquartile/interpercentile distributions between infants with/without FI.. Preterm infants <32 weeks' gestation were recruited. The primary outcome was FI by day 7 defined as a feeding withheld, discontinued, or decreased because the infant was not tolerating enteral feedings. Allostatic load was operationalized using cortisol and 8-hydroxydeoxyguanosine (8-OHdG) from cord blood and from saliva and urine on days 1, 7, and 14. Descriptive statistics and comparative analyses were performed.. Seven of 31 infants enrolled met criteria for FI. Infants with FI had lower median urinary cortisol on day 1 (P = 0.007) and trended to have lower cortisol in the cord blood (P = 0.056). Interquartile distributions were significantly different between infants with/without FI for urinary cortisol on day 1 (P = 0.034) and trended for differences in 8-OHdG on day 14 (P = 0.087). Interpercentile distributions were significantly different in salivary cortisol on day 14 (P = 0.034) and trended for differences in 8-OHdG on day 1 (P = 0.079).. Results support further testing of the model in a larger sample; investigation of the cellular mechanisms associated with the stress and the free radical/antioxidant systems; and inclusion of prenatal factors.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Allostasis; Biomarkers; Deoxyguanosine; Enteral Nutrition; Fetal Blood; Gestational Age; Humans; Hydrocortisone; Infant; Infant, Premature; Infant, Premature, Diseases; Saliva; Stress, Physiological