Asthma associated with memory issues in children

Study finds that asthma in children is linked to memory difficulties, with earlier onset potentially exacerbating the impact and extending to executive function challenges.

In a recent study published in JAMA Network Open, doctors from the University of California Davis School of Medicine examined the potential link between childhood asthma and memory difficulties, especially in episodic memory.

They analyzed longitudinal data on cognitive and brain development in adolescents to compare memory and cognitive development in children with and without asthma. The findings indicated lower memory scores for children with asthma.

Background

Asthma is a prevalent chronic respiratory condition among children and manifests primarily through symptoms such as wheezing and breathing difficulties. However, recent studies on animal models have indicated that asthma could lead to neurological changes, including memory deficits.

In rodent models, asthma is associated with neuroinflammation and hippocampal injury, which impair memory functions. The hippocampus, crucial for episodic memory, appears especially vulnerable to inflammation and hypoxia from chronic respiratory conditions.

Research on childhood asthma has primarily focused on physical symptoms and has largely overlooked potential cognitive implications, especially related to memory and attention. The few studies that have examined cognitive differences reported that children with severe asthma have lower verbal memory than their peers.

However, confounding factors, such as socioeconomic background, make it challenging to attribute the cognitive deficits solely to asthma, and further research is needed to clarify whether asthma impacts memory and cognitive abilities in children.

About the study

The present study utilized data obtained from the Adolescent Brain Cognitive Development study, a large, longitudinal assessment of brain development and cognitive health in children across the United States (U.S.) funded by the National Institutes of Health (NIH). The study enrolled children aged 9 or 10 years who were followed up over two years.

A history of asthma, identified through parent reports, was used to categorize the participants into three groups — children with early asthma onset, children with later onset asthma, and a comparison group consisting of children without asthma. The cross-sectional examination compared children with asthma to children without asthma at different assessment points.

Furthermore, the researchers measured cognitive performance using specific tasks from the NIH Toolbox, consisting of various neurological and behavioral assessments. The tasks were chosen based on their sensitivity to potential asthma-related deficits. Key assessments included the picture sequence memory test — a task measuring episodic memory dependent on hippocampal function. Pattern comparison processing speed test, which assessed processing speed, and the flanker inhibitory control and attention test to measure attention and response inhibition were also included.

Propensity score matching was used to match controls based on factors such as age, sex, and parental income. Additional analyses controlled for socioeconomic status to address potential confounding effects.

In the longitudinal analysis, linear growth models assessed changes in episodic memory, processing speed, and attention across time while considering age-related improvements. Additionally, for the cross-sectional analysis, the researchers used linear regression models to evaluate differences in cognitive performance between children with and without a history of asthma.

Results

The study found that children with asthma, particularly those with early-onset asthma, displayed slower memory development compared to their peers without asthma. More specifically, children with early-onset asthma showed lower improvements in episodic memory over time than the comparison group, suggesting that early and prolonged asthma could potentially impact memory development.

In contrast, children with later-onset asthma did not show significant differences in memory development rates compared to children without asthma. However, the cross-sectional analysis showed that children with any history of asthma performed worse than children without asthma on episodic memory, processing speed, and inhibitory control and attention tests.

These findings suggested that asthma may broadly affect cognitive functions and extend beyond memory to impact other executive functions. While previous studies in animals suggested that asthma-related brain inflammation might impair memory, this study presented evidence of similar patterns in children.

Furthermore, across both longitudinal and cross-sectional models, children with asthma showed consistently lower performance in memory and cognitive tasks, regardless of socioeconomic factors or race. These results supported the hypothesis that asthma, especially if experienced from an early age, could hinder cognitive development in children, potentially impacting academic and social skills as well.

Conclusions

To summarize, the study reported a significant association between childhood asthma and slower development of memory and executive function in children. These findings highlighted the importance of understanding the cognitive impacts of asthma and its potential implications for managing academic and developmental outcomes in children with asthma.