High HbA1c levels associated with poor asthma control in children

Key takeaways:

• HbA1c results ranged from 4.2% to 6.1% among children with asthma.
• 28 of 128 children with asthma had HbA1c at or above 5.7%.
• High HbA1c levels were associated with high asthma questionnaire scores.

SAN DIEGO — High HbA1c levels consistent with prediabetes were associated with worse asthma control in a population of urban children, according to a presentation at the American Thoracic Society International Conference.

Previous studies have indicated that insulin resistance may influence asthma morbidity, Hewlett Pham, BS, research program assistant, pulmonary and critical care medicine, Johns Hopkins School of Medicine, and colleagues wrote.

“We were interested in studying the relationship between metabolic health and asthma control,” Pham told Healio. “Past studies have found associations between metabolic dysfunction and worse asthma outcomes such as exacerbations and hospitalizations in adult populations, so we wanted to examine a similar question in a pediatric population.”

The AIRWEIGHS Study included 164 children with asthma from Baltimore whose HbA1c levels were analyzed continuously and categorized as normal at less than 5.7% or consistent with prediabetes at 5.7% and higher.

The cohort had an average age of 11 ± 2 years and was 85% African American and 41% girls, with 60% from households with incomes below $34,999 and 83% on public insurance. Also, 59% had active moderate or severe asthma, with an average of 4 symptom days (standard deviation, 4.4).

The researchers excluded 36 children from the analysis because they had unsuccessful blood draws or because of participant refusal, leading to missing HbA1c results. The results of the remaining 128 children ranged from 4.2% to 6.1%, including 28 whose levels were at or above 5.7%.

There were associations between worse asthma control, indicated by an increase in Asthma Therapy Assessment Questionnaire scores, and increased HbA1c levels, including a beta of 0.75 (95% CI, 0.09-1.42; P = .026) in continuous models and a beta of 0.9 (95% CI, 0.18-1.61; P = .014) in dichotomous models.

“Contrary to past studies, we did not find significant associations between higher HbA1c levels and outcomes such as lung function, airway inflammation or exacerbations,” Pham said.

Based on these findings and previous studies, the researchers said that insulin resistance can influence asthma morbidity. These findings also indicate that insulin resistance may be a future therapeutic target for children with asthma, they said.

Additionally, the researchers said, HbA1c testing may have potential in identifying children at risk for asthma exacerbations, with appropriate treatment to follow.

“Doctors can consider implementing a multi-prong approach to caring for children with asthma, such as promoting physical activity and healthy diet as lifestyle interventions,” Pham said. “Medications that target metabolic pathways may also hold promise for improving asthma control.”

The researchers have two more studies in progress to further investigate the relationship between metabolic health and asthma.

“Phenotyping Asthma to Plan Intervention aims to characterize metabolic biomarkers in adults with asthma who could most benefit from future interventions,” Pham said. “The Metformin in Asthma study is a pilot test that will investigate the role of the metformin as an intervention to improve asthma morbidity.”

For more information:

Hewlett Pham can be reached at hpham28@jhmi.edu.