Increased levels of subcutaneous and visceral fat mass at age 13 years are associated with reduced lung function in these adolescents, independent of their adiposity and body mass index (BMI) measures at 10 years of age, researchers reported in Pediatric Allergy and Immunology.
Researchers sought to determine whether elevated amounts of certain abdominal fat depots in childhood and adolescence could lead to negative respiratory
outcomes in adolescents. The researchers conducted a population-based cohort study using data from 2877 children 13 years of age who were included in the Generation R Study in the Netherlands.
Participants’ subcutaneous fat and visceral fat were measured at ages 10 and 13 years, and lung function parameters were measured by spirometry. Data regarding physician-diagnosed asthma and wheezing were obtained from a parental questionnaire. Primary outcomes were lung function measures and asthma at age 13 years.
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[T]he accumulation of subcutaneous and visceral fat may have a greater impact on lung function during adolescence compared to earlier school-age years.
Among the cohort, current asthma was observed in 6.0% (n=154) of the children. The mothers’ mean (SD) pre-pregnancy age was 31.2 (4.9) years.
An increased subcutaneous fat mass index was associated with reduced forced expiratory volume in 1 second (FEV1), FEV1/forced vital capacity (FVC), and forced expiratory flow after exhaling 75% of FVC (FEF75) in the confounder model. Greater visceral fat mass index was associated with a reduction in FEV1/FVC and FEF75.
After further adjustment for the child’s BMI, subcutaneous and visceral fat mass index were consistently associated with reduced FEV1 (Z-score difference: −0.06; 95% CI, −0.11 to −0.01, and −0.09; 95% CI, −0.14 to −0.04, respectively), FEV1/FVC (Z-score difference: −0.10; 95% CI, −0.15 to −0.05, and −0.08; 95% CI, −0.13 to −0.04, respectively), and FEF75 (Z-score difference: −0.10; 95% CI, −0.15 to −0.05, and −0.10; 95% CI, −0.15 to −0.06, respectively).
Each unit increase in the change of subcutaneous fat mass index and visceral fat mass index from ages 10 to 13 years was associated with a reduction in FEV1, FEV1/FVC, and FEF75 (range Z-score difference: −0.13 [95% CI, −0.18 to −0.08] to −0.06 [95% CI, −0.11 to −0.01]), according to the main model and after accounting for lung function at age 10 years. No associations regarding change in abdominal fat depots with change in asthma were found.
In addition, no consistent interaction was found between specific abdominal fat depot measures and the child’s sex, allergic sensitization, or puberty status for the associations with lung function and asthma (P >.05) in the main models, except for subcutaneous fat mass index at age 13 years with child’s sex for the associations with FEV1 (P =.012) and FVC (P =.010).
In analyses stratified by sex, the size of effect estimates for the associations of subcutaneous and visceral fat mass index at age 13 years with lower FEV1 and FVC at age 13 years was greater for boys vs girls.
Among several limitations, there may have been a nonresponse bias that resulted in the selection of a more healthy and affluent population, and nondifferential misclassification from parental-reported asthma could have occurred. Also, residual confounding may be present, and the observed sizes of effect estimates were relatively small to moderate and may not have clinical significance at an individual level for adolescents.
“[T]he accumulation of subcutaneous and visceral fat may have a greater impact on lung function during adolescence compared to earlier school-age years,” the study authors stated. “These findings suggest that reducing abdominal fat mass in specific compartments in adolescents may be an effective strategy for improving respiratory health,” they added.
