Parental metabolic markers of obesity associated with asthma in children

Key takeaways:

• Reduced parental HDL was significantly associated with uncontrolled asthma in children.
• Maternal elevated total cholesterol was significantly associated with severe childhood asthma.

SAN DIEGO — Parental metabolic markers of obesity were associated with pediatric asthma, according to a presentation at the American Thoracic Society International Conference.

These markers included elevated triglycerides, reduced HDL, elevated LDL and elevated total cholesterol, Kaitlyn Kuntzman, DO, fellow, pediatric pulmonology, Children’s National Hospital, said during her presentation.

“Obesity is an independent risk factor for asthma. Obesity-related asthma is less responsive to medications,” Kuntzman said.

Also, children with both obesity and asthma have a higher risk for metabolic syndrome, including insulin resistance, dyslipidemia and other associated abnormalities, she continued.

“And we know according to multiple studies, actually, that maternal pre-pregnancy and gestational weight gain are associated with incident wheeze and asthma in children,” she said.

Kuntzman and her colleagues then hypothesized that in addition to maternal pre-pregnancy weight, maternal metabolic parameters were associated with asthma severity, control and exacerbations in their children.

Metabolic parameters in children

The researchers examined records from 29,851 children (59% boys) aged 2 to 17 years with asthma treated with at least two canisters of inhaled corticosteroids (ICS) as recorded by nationwide databases in Denmark in 2015.

ICS doses were considered below low for 22% of the cohort, low for 32%, moderate for 30% and high for 17%. Also, 23% used long-acting beta 2 agonists and 22% used leukotriene receptor antagonists as add-on therapy.

With 7.9% of the cohort reporting exacerbations, 2.1% reported moderate exacerbations, 6.1% reported severe exacerbations and 0.2% reported near-fatal exacerbations.

The 4,750 children with poor asthma control included 19% with reduced HDL cholesterol (aOR = 1.49; 95% CI, 1.04-2.1), 20% with elevated triglycerides (aOR = 1.33; 95% CI, 0.92-1.88) and 19% whose mothers reported pre-pregnancy obesity (aOR = 1.4; 95% CI, 1.27-1.54).

Further, 8.4% reported WHO weight-for-gestational age zscores of –2 or less (aOR = 1.44; 95% CI, 1.27-1.62), and 5.1% reported WHO weight-for-gestational age z scores of 2 and higher (aOR = 0.91; 95% CI, 0.78-1.05).

Similarly, 2,353 children had exacerbating asthma, defined as one hospitalization or one course of oral corticosteroid use. This group included 21% with reduced HDL cholesterol (aOR = 1.54; 95% CI, 1.1-2.11) and 19% with elevated triglycerides (aOR = 1.46; 95% CI, 1.04-2.03).

“Finally, we looked at severity as defined by genome,” Kuntzman said. “Elevated LDL cholesterol and maternal pre-pregnancy underweight BMI were statistically significantly associated with more severe asthma.”

Elevated LDL cholesterol was reported by 21% of the 1,430 children categorized with severe asthma (aOR = 2.26; 95% CI, 1.41-3.53), and 5.1% reported maternal pre-pregnancy underweight (aOR = 0.97; 95% CI, 0.79-1.17).

Parental metabolic parameters

“Next, we looked at the metabolic markers of the parents of this cohort, specifically the moms,” Kuntzman said. “We found that maternal reduced HDL is significantly associated with childhood uncontrolled asthma and that elevated total cholesterol is significantly associated with childhood severe asthma.”

With 21% of the group of children with uncontrolled asthma reporting maternal reduced HDL, the adjusted odds ratio was 1.14 (95% CI, 1.02-1.27). With 26% of the group of children with severe asthma reporting maternal elevated total cholesterol, the adjusted odds ratio was 0.96 (95% CI, 0.81-1.14).

“We did the same thing on the fathers’ data and found that reduced paternal HDL was significantly associated with uncontrolled asthma, whereas the elevated paternal total cholesterol and elevated LDL were significantly associated with exacerbating asthma, but in a protected way,” Kuntman said.

Among the 27% of children with uncontrolled asthma and reduced paternal HDL cholesterol, the adjusted odds ratio was 1.18 (95% CI, 1.06-1.31).

Among the 38% of children with exacerbating asthma and elevated paternal total cholesterol, the adjusted odds ratio was 0.86 (95% CI, 0.76-0.97).

Additionally, the adjusted odds ratio among the 40% of children with exacerbating asthma and elevated paternal LDL was 0.86 (95% CI, 0.75-0.97).

Further analysis, conclusions

“Finally, we took the same cohort and narrowed it down to the patients that had two or more abnormal lipid blood samples,” Kuntzman said.

Uncontrolled asthma had an association with reduced HDL (6.2%; aOR = 1.97; 95% CI, 1.06-3.43) and a significant association with elevated triglycerides (8.8%; aOR = 1.77; 95% CI, 1.01-2.98).

Exacerbating asthma also had a significant association with reduced HDL (7.6%; aOR = 2.17; 95% CI, 1.27-3.53) and elevated triglycerides (7.8%; aOR = 2.23; 95% CI, 1.32-3.62) as well as with elevated total cholesterol (5.2%; aOR = 1.85; 95% CI, 1.01-3.2; P < .05).

Severe asthma had a significant association with elevated triglycerides (8.8%; aOR = 2.18; 95% CI, 1.1-3.98).

Overall, Kuntzman said that maternal pre-pregnancy weight severe uncontrolled and exacerbating asthma in the child were independently associated with maternal and paternal metabolic markers of obesity, including elevated triglycerides, reduced HDL, elevated LDL and elevated total cholesterol.

“Hopefully, targeted interventions against maternal body weight at the time of pregnancy and against their lipid abnormalities can potentially influence incident asthma in the child,” she said.