Effect of Gender on Metabolic and Neurodevelopmental Parameters of Postnatally Growth-Restricted Rats Undergoing Catch-Up Growth.

Objective: To determine the long-term effects of early postnatal malnutrition and various degrees of catch-up growth on metabolic (serum glucose, leptin, triacylglycerides) and neurodevelopmental parameters (learning and memory) among male and female rodent models, mimicking human preterm infants.

Study design: Randomized controlled trial. Place and Duration of the Study: CMH Multan Insitute of Medical Sciences, from September 2021 to December 2021.

Methdology: This study included 142 neonatal Wister rats, stratified into subgroups to mimic the human preterm infant model of postnatal malnutrition and catch-up growth. Metabolic consequences were assessed via serum analysis of glucose, leptin, and triacylglycerides. The neurocognitive comparison was made among subgroups via a passive avoidance test. Gender-specific comparison of all quantitative parameters was made among subgroups.

Results: Malnourished rats with accelerated catch-up growth achieved similar weight gain as normally fed rats when provided with adlibitum feeding in both males (p = 0.92) and females (p >0.99). Rats undergoing accelerated catch-up growth exhibited higher fasting serum glucose levels compared to those undergoing no, or normal catch-up growth (p <0.001). Malnourished female rats undergoing accelerated (p = 0.007), or no catchup growth (p = 0.004) exhibited significant deficits in learning and memory as compared to normally fed rats. Female malnourished rats with normal catchup growth exhibited no neurocognitive deficit as compared to normally fed rats (p = 0.08).

Conclusion: Accelerated catch-up growth effectively addresses somatic growth disparities, while normal catch-up growth offers more favourable metabolic and neurodevelopmental outcomes. Particularly, female malnourished rats exhibited poor neurodevelopment in response to both accelerated and no catch-up growth. Gender-specific variations in neurodevelopment underscore the need for personalised care approaches for preterm nutritional care.

Key words: Growth retardation, Leptin, Extrauterine growth restriction, Malnutrition, Neurodevelopment.