Body mass index (BMI) significantly affects total and central airway resistance in children with sickle cell disease (SCD) but not in non-SCD children with asthma, according to study findings published in Respiratory Medicine.
The longitudinal, retrospective study evaluated the influence of BMI on airway resistance and other impulse oscillometry (IOS) estimates in children with SCD and non-SCD children with asthma from a tertiary children’s hospital in the United States between 2015 and 2020.
The analysis included 55 children with SCD and 35 children with asthma who did not have SCD, selected for the control group (all of whom were Black). IOS data were obtained for total airway resistance (R5), central airway resistance (R20), peripheral airway resistance (R5-20), and reactance metrics such as X5 and resonant frequency (Fres); pharmacotherapy records were also reviewed.
Among the 55 children with SCD (31 male) and 35 children with asthma (18 male), 161 and 58 IOS observations, respectively, were analyzed. The median age of the children with SCD was 153.00 months vs 137.00 months in the children with asthma. The median BMI was 18.19 in the SCD group and 20.00 in the asthma group.
“
These findings suggest that IOS can help evaluate respiratory function in children with SCD and identify those at higher risk of developing pulmonary complications.
BMI’s effect on airway resistance and reactance was evaluated with generalized linear mixed models (GLMM) in the 161 IOS observations for children with SCD and 58 observations for children with asthma. Among the children with SCD, BMI had significant effects on R5 and R20 (P <.05) but not on R5-20, X5, or Fres. BMI did not affect any of the IOS estimates in children with asthma other than Fres (negative correlation).
Children with SCD had significantly greater total airway resistance, central airway resistance, and airway reactance (Fres) vs those with asthma, although age and BMI were not statistically different between the 2 groups.
In a post-hoc power analysis with a preset alpha of 0.05, the study’s power was .81, which was greater than the desired cutoff of .8.
Study limitations include the single-center, retrospective design; potential selection bias; and limited generalizability of the results. In addition, the analysis did not include an adequate number of race-matched individuals without asthma in the control group, and specific normative equations were not available for Black children.
“These findings suggest that IOS can help evaluate respiratory function in children with SCD and identify those at higher risk of developing pulmonary complications,” the researchers stated.
