This is a population-based prospective cohort study that assesses the association between abdominal fat depots and lung function as well as asthma outcomes in 13-year-old children. The study is well-articulated, features a robust methodology, and its findings significantly contribute to understanding the link between asthma and obesity, especially in adolescents.
However, I have a few minor suggestions and comments:
- In the abstract, the last sentence should either be removed or rephrased since the study did not investigate the impact of specifically altering abdominal fat in certain compartments as an intervention to enhance respiratory health in adolescents. Additionally, both visceral and subcutaneous fat were associated with decreased lung function parameters.
- In the methods section, on page 4, lines 86-87 mention the evaluation of asthma medications. Was this information factored into the analysis?
- The asthma definition is constrained by the absence of objective measures to corroborate self-reporting. Were lung function tests with bronchodilation performed in this population? Such testing could potentially increase the number of participants diagnosed with asthma.
- Approximately 29% of the patients lacked information on Tanner stage and pubertal status, which was only considered as an interaction. Could this information be regarded as a confounder? Does the absence of this crucial information at this age limit the reliability of the results?
- Regarding the clinical significance of changes found in lung function, particularly since no significant association was observed with reported asthma diagnosis, consider evaluating if the differences are clinically meaningful. On page 7 of the results section, it is mentioned that higher levels of visceral fat were linked to an obstructive lung pattern at age 13 (lines 159-160). Would it be worthwhile to assess children with an FEV1 predicted percentage below 70%?
- The magnitude of z-score difference in FEV1 might not be clinically significant, and this should be acknowledged in the discussion section