Executive functions of postweaning protein malnutrition in mice

Longitudinal relationship of favorable weight change to academic performance in children

Although there is a growing consensus about the positive relationship between prevention of overweight/obesity and academic performance in children, relevant studies targeting the relationship between underweight and academic performance are scarce. This study aimed to examine the longitudinal relationship of favorable weight change to academic performance in schoolchildren. We analyzed 2-year longitudinal data derived from 197 seventh-grade children aged 12-13 years. Academic performance was assessed using the total grade points of five academic subjects. Body mass index (BMI) was calculated as body weight (kg)/height (m²). A significant interaction effect of baseline BMI and BMI changes over 2 years (B = -0.10, SE B = 0.03, β = -0.40, t = -3.37, p < 0.001) was noted after controlling for confounders such as socioeconomic status, afterschool learning duration, screen time, exercise habits, and cardiorespiratory fitness. When the centered baseline BMI was outside the interval [-2.49, 3.21], the slope of the change in BMI was significant (p < 0.05). Simple slope analyses revealed a positive relationship of weight gain when baseline BMI = mean - 1 SD (B = 0.40, SE B = 0.18, β = 0.31, t = 2.20, p = 0.03) and weight loss when baseline BMI = mean + 1 SD (B = -0.26, SE B = 0.13, β = -0.20, t = -1.97, p = 0.05) to total grade points of five school subjects. A split-group validation was performed and robust results of original analyses were detected (i.e., significant interaction effect of baseline BMI and BMI changes over 2 years (group A: B = -0.11, SE B = 0.05, β = -0.47, t = -2.39, p = 0.02; group B: B = -0.14, SE B = 0.05, β = -0.47, t = -2.78, p = 0.007). Favorable changes in weight status, i.e., weight loss in children with overweight/obesity and weight gain in children with mild underweight/underweight, have a positive influence on academic performance in children independent of socioeconomic factors, learning habits, screen time, exercise habits, and cardiorespiratory fitness.

Contribution of maternal oxygenic state to the effects of chronic postnatal hypoxia on mouse body and brain development

1-2% of live births are to very low birth weight, premature infants that often show a developmental trajectory plagued with neurological sequelae including ventriculomegaly and significant decreases in cortical volume. We are able to recapitulate these sequelae using a mouse model of hypoxia where early postnatal pups are exposed to chronic hypoxia for one week. However, because the timing of hypoxic exposure occurs so early in development, dams and pups are housed together in the hypoxic chamber, and therefore, dams are also subjected to the same hypoxic conditions as the pups. To understand the relative contribution of hypoxia directly on the pups as opposed to the indirect contribution mediated by the effects of hypoxia and potential alterations in the dam's care of the pups, we examined whether reducing the dams exposure to hypoxia may significantly increase pup outcomes on measures that we have found consistently changed immediately following chronic hypoxia exposure. To achieve this, we rotated dams between normoxic and hypoxic conditions, leaving the litters untouched in their respective conditions and compared gross anatomical measures of normoxic and hypoxic pups with non-rotating or rotating mothers. As we expected, hypoxic-rearing decreased pup body weight, brain weight and cortical volume. Reducing the dam's exposure to hypoxic conditions actually amplified the effects of hypoxia on body weight, such that hypoxic pups with rotating mothers showed significantly less growth. Interestingly, rotation of hypoxic mothers did not have the same deleterious effect on brain weight, suggesting the presence of compensatory mechanisms conserving brain weight and development even under extremely low body weight conditions. The factors that potentially contribute to these compensatory changes remain to be determined, however, nutrition, pup feeding/metabolism, or changes in maternal care are important candidates, acting either together or independently to change pup body and brain development.