{"doi":"10.1186/s12931-021-01658-3","title":"Metformin use and respiratory outcomes in asthma-COPD overlap","abstract":"BACKGROUND: Metformin is associated with improved respiratory outcomes in asthma; however, metformin in COPD and asthma-COPD overlap (ACO) remains unexplored. OBJECTIVE: To determine the association between metformin use and respiratory outcomes in COPD and ACO. STUDY DESIGN AND METHODS: Participants with COPD (FEV1/FVC < 0.70) in the Genetic Epidemiology of COPD study (COPDGene®) were categorized as ACO (n = 510), defined as concurrent physician-diagnosed asthma before age 40 years, or COPD alone (n = 3459). We estimated the association of baseline metformin use with (1) rate of total and severe respiratory exacerbations during follow-up, (2) cross-sectional St. George's Respiratory Questionnaire (SGRQ) score, six-minute walk distance (6MWD), and post-bronchodilator FEV1 percent predicted (FEV1pp), and (3) 5-year change in SGRQ, 6MWD, and FEV1pp. We also examined change in SGRQ, 6MWD and FEV1pp among participants who initiated metformin during follow-up (n = 108) compared to persistent metformin non-users (n = 2080). Analyses were adjusted for sociodemographic factors, medications, and comorbidities. RESULTS: Among participants with ACO, metformin use was associated with lower rate of total (adjusted incidence rate ratio [aIRR] 0.3; 95% confidence interval [95%CI] 0.11, 0.77) and severe exacerbations (aIRR 0.29; 95%CI 0.10, 0.89). Among participants with COPD alone, there was no association between metformin use with total (aIRR 0.98; 95%CI 0.62, 1.5) or severe exacerbations (aIRR 1.3; 95% CI 0.68, 2.4) (p-interaction < 0.05). Metformin use was associated with lower baseline SGRQ score (adjusted mean difference [aMD] - 2.7; 95%CI - 5.3, - 0.2) overall. Metformin initiation was associated with improved SGRQ score (aMD -10.0; 95% CI - 18.7, - 1.2) among participants with ACO but not COPD alone (p-interaction < 0.05). There was no association between metformin use and 6MWD or FEV1pp in any comparison. CONCLUSIONS: Metformin use was associated with fewer respiratory exacerbations and improved quality of life among individuals with ACO but not COPD alone. Results suggest a potential role for metformin in ACO which requires further prospective study. TRIAL REGISTRY: NCT00608764.","journal":"Respiratory Research","year":2021,"id":166084,"datarank":0.5333022092234121,"base_score":3.5553480614894135,"endowment":3.5553480614894135,"self_citation_contribution":0.5333022092234121,"citation_network_contribution":0.0,"self_endowment_contribution":0.5333022092234121,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":34,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.776,"is_data_producer":true,"deposit_databanks":{"ClinicalTrials.gov":["NCT00608764"]},"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2021-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":493993,"name":"Ashraf Fawzy","orcid":"0000-0002-6089-366X","position":1,"is_corresponding":false},{"id":24982,"name":"Gregory L. Kinney","orcid":"0000-0002-5218-4986","position":2,"is_corresponding":false},{"id":390627,"name":"Jessica Bon","orcid":"0000-0002-4336-3835","position":3,"is_corresponding":false},{"id":690789,"name":"Maniraj Neupane","orcid":"0000-0002-0947-489X","position":4,"is_corresponding":false},{"id":528625,"name":"Vickram Tejwani","orcid":"0000-0003-2100-6148","position":5,"is_corresponding":false},{"id":250087,"name":"Nadia N. Hansel","orcid":"0000-0002-8740-9751","position":6,"is_corresponding":false},{"id":350029,"name":"Robert A. Wise","orcid":"0000-0002-8353-2349","position":7,"is_corresponding":false},{"id":319953,"name":"Nirupama Putcha","orcid":"0000-0002-0688-1836","position":8,"is_corresponding":false},{"id":313967,"name":"Meredith C. McCormack","orcid":"0000-0003-1702-3201","position":9,"is_corresponding":false},{"id":690788,"name":"Tianshi David Wu","orcid":"0000-0003-4906-3232","position":0,"is_corresponding":true}],"reference_count":24,"raw_metadata":null,"created_at":"2026-07-18T23:45:45.220559Z","pmid":"33637087","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}