Children who had low blood sugar as newborns did not show any different school performance outcomes 10 years later compared to children without hypoglycemia, new results from the CHYLD study suggest, contradicting previous findings on neonatal hypoglycemia and school performance.
In this latest report of the study, among the 480 children studied, exposure to neonatal hypoglycemia was not significantly associated with poorer academic performance at ages 9 to 10 (adjusted risk ratio [aRR] 0.95, 95% CI 0.78-1.15), said Christopher McKinlay, PhD, of the University of Auckland in New Zealand, and colleagues.
Indeed, children with neonatal hypoglycemia were less likely to be classified by teachers as having sub-curricular reading than children who did not (aRR 0.72, 95% CI 0.53-0.99, P=0.04), the study group reported in JAMA.
A previous studies A study conducted in the same cohort at age 4.5 found that children with neonatal hypoglycemia had impairments in executive and visual motor function compared to children without hypoglycemia.
“The reason why hypoglycemia was associated with adverse neurodevelopmental effects in this cohort at age 4.5 but not at age 9 to 10 is unclear,” wrote McKinlay and colleagues. “Early disorders in brain development may have waning effects over time due to neuroplasticity, ie a reorganization of neural networks, or delayed maturation with a catch-up in neurocognitive function in mid-infancy. It is also possible that rich preschool and school experiences could enhance the intelligence and academic skills of exposed children.”
The author of one accompanying editorial noted that the study was not a randomized clinical trial testing the effectiveness of any particular hypoglycemia management strategy. Additionally, because nearly half of the children who were not exposed to hypoglycemia had poor academic performance, more than twice what investigators expected, more research should focus on “defining an optimal treatment strategy,” said Dr. Paul Rozance of the University of Colorado at Aurora.
The new study results also contradict those of a 2015 study conducted in Arkansas that transient hypoglycemia in newborns is associated with lower test scores by age 10, Rozance continued. This study focused on early and transient hypoglycemia – “not sustained hypoglycemia as in the current cohort, and raised the possibility that management strategies may detect hypoglycemia too late for effective intervention,” he wrote.
In the present study, there were no differences in primary or secondary outcomes between children who also had different degrees or frequencies of neonatal hypoglycemia.
The CHYLD (Children with Hypoglycaemia and Their Later Development) study was a prospective longitudinal cohort study conducted from 2006 to 2010 at Waikato Women’s Hospital in Hamilton, New Zealand, in 614 moderately preterm to term infants (born at or after 32 weeks gestation ) was carried out.
Infants were included in the study if they had at least one risk factor for neonatal hypoglycemia, such as B. a mother with diabetes and a premature baby, small or large. Infants were excluded if they had congenital malformations, terminal diseases, congenital hyperinsulinism, or congenital metabolic disorders.
Infants were regularly evaluated for hypoglycemia, defined as a blood glucose concentration of less than 47 mg/dL, until clinical concern resolved. Hypoglycemia was treated with a combination of supplemental feeding, buccal dextrose gel, or intravenous dextrose.
The new study assessed the academic achievement, executive functioning, visual-motor functioning, psychosocial adjustment and general health of 480 children aged 9 to 10 years from the original CHYLD cohort, representing 82% of beneficiaries. Academic achievement was measured in either English or Māori using a standardized online achievement test.
Children assessed at 9–10 years of age were more likely to be Māori and admitted to the NICU (P
The study authors acknowledged that they did not measure all aspects of cognition and the results of their previous study of the 4.5-year-old cohort were not adjusted for IQ at that age. In addition, 8% of the original study group was unassessed in this follow-up study, “which could introduce bias if there are systematic differences in exposures or outcomes between those that were studied and those that were unassessed,” the researchers noted .
The study was funded by grants from the Health Research Council of New Zealand and the Maurice and Phyllis Paykel Trust.
McKinlay made no disclosures; A co-author notified the University of Auckland of an intellectual property license from Objective Acuity Limited and a patent pending with Auckland UniServices Limited.
Rozance reported receiving a Nova StatStrip from Nova Biomedical for use in his lab.