Pathophysiology
Despite quitting smoking, ex-smokers exhibit persistent alterations in miRNA expression within the small airway epithelium, indicating ongoing biologic processes influenced by past smoking [PMID:25886353].
Epidemiology
Epidemiologic evidence supports that even after smoking cessation, the risk for smoking-induced lung diseases like COPD remains elevated, likely due to persistent molecular dysregulation such as miRNA alterations [PMID:25886353].
Among 14,144 participants aged 40 years and older from the NHANES 2007-2018 dataset, WWI was significantly higher in individuals with COPD compared to controls [PMID:41926776].
Management
Given that molecular changes like miRNA dysregulation persist post-smoking cessation, comprehensive management of COPD should consider these enduring biological effects [PMID:25886353].
Participants in the highest quartile of WWI had a notably higher odds ratio (2.13) of having COPD compared to those in the lowest quartile, suggesting its potential role in early detection and risk stratification [PMID:41926776].
A FIFmax threshold of 220 L/min was identified as optimal for minimizing the risk of exacerbations [PMID:41467991]. Patients sustaining FIFmax above this threshold had a significantly lower risk of exacerbations (adjusted hazard ratio = 0.722, p = 0.022) [PMID:41467991].
Factors including younger age, fewer comorbidities, and superior baseline lung function were linked to maintaining FIFmax above the optimal threshold [PMID:41467991].
Prognosis & Follow-up
Advanced age, severe comorbidities, and inadequate inhaler technique were associated with a quicker decline in FIFmax levels [PMID:41467991].
Key Recommendations
The positive association between WWI and COPD risk was consistent across different demographic factors including sex, age, and smoking status, indicating its broad applicability in clinical settings [PMID:41926776]. (Evidence: Moderate)
References
1 Wang G, Wang R, Strulovici-Barel Y, Salit J, Staudt MR, Ahmed J et al.. Persistence of smoking-induced dysregulation of miRNA expression in the small airway epithelium despite smoking cessation. PloS one 2015. link 2 Li Y, Li B. Evaluating weight-adjusted waist index as a risk factor for chronic obstructive pulmonary disease: A cross-sectional analysis of NHANES data. Advances in clinical and experimental medicine : official organ Wroclaw Medical University 2026. link 3 Choi KY, Park H, Lee HJ, Lee JK, Heo EY, Kim DK et al.. Optimal Maximal Forced Inspiratory Flow for Dry Powder Inhalers in Reducing Exacerbations in COPD. Journal of aerosol medicine and pulmonary drug delivery 2026. link
3 papers cited of 4 indexed.