{"doi":"10.1093/sleep/zsab018","title":"Heart rate variability during wakefulness as a marker of obstructive sleep apnea severity","abstract":"STUDY OBJECTIVES: Patients with obstructive sleep apnea (OSA) exhibit heterogeneous heart rate variability (HRV) during wakefulness and sleep. We investigated the influence of OSA severity on HRV parameters during wakefulness in a large international clinical sample. METHODS: 1247 subjects (426 without OSA and 821 patients with OSA) were enrolled from the Sleep Apnea Global Interdisciplinary Consortium. HRV parameters were calculated during a 5-minute wakefulness period with spontaneous breathing prior to the sleep study, using time-domain, frequency-domain and nonlinear methods. Differences in HRV were evaluated among groups using analysis of covariance, controlling for relevant covariates. RESULTS: Patients with OSA showed significantly lower time-domain variations and less complexity of heartbeats compared to individuals without OSA. Those with severe OSA had remarkably reduced HRV compared to all other groups. Compared to non-OSA patients, those with severe OSA had lower HRV based on SDNN (adjusted mean: 37.4 vs. 46.2 ms; p < 0.0001), RMSSD (21.5 vs. 27.9 ms; p < 0.0001), ShanEn (1.83 vs. 2.01; p < 0.0001), and Forbword (36.7 vs. 33.0; p = 0.0001). While no differences were found in frequency-domain measures overall, among obese patients there was a shift to sympathetic dominance in severe OSA, with a higher LF/HF ratio compared to obese non-OSA patients (4.2 vs. 2.7; p = 0.009). CONCLUSIONS: Time-domain and nonlinear HRV measures during wakefulness are associated with OSA severity, with severe patients having remarkably reduced and less complex HRV. Frequency-domain measures show a shift to sympathetic dominance only in obese OSA patients. Thus, HRV during wakefulness could provide additional information about cardiovascular physiology in OSA patients. CLINICAL TRIAL INFORMATION: A Prospective Observational Cohort to Study the Genetics of Obstructive Sleep Apnea and Associated Co-Morbidities (German Clinical Trials Register - DKRS, DRKS00003966) https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00003966.","journal":"SLEEP","year":2021,"id":154587,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":62,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9375,"is_data_producer":false,"deposit_databanks":null,"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":774,"name":"Brendan T Keenan","orcid":"0000-0002-9070-847X","position":1,"is_corresponding":false},{"id":49907,"name":"Diego R. Mazzotti","orcid":"0000-0003-3924-9199","position":2,"is_corresponding":false},{"id":393532,"name":"Fernando Vaquerizo-Villar","orcid":"0000-0002-5898-2006","position":3,"is_corresponding":false},{"id":655094,"name":"Jan F. Kraemer","orcid":"0000-0001-7529-841X","position":4,"is_corresponding":false},{"id":655095,"name":"Niels Wessel","orcid":"0000-0003-0922-9971","position":5,"is_corresponding":false},{"id":372154,"name":"Sérgio Tufik","orcid":"0000-0002-3804-8865","position":6,"is_corresponding":false},{"id":372142,"name":"Lia Bittencourt","orcid":"0000-0001-7738-0927","position":7,"is_corresponding":false},{"id":372144,"name":"Peter A. Cistulli","orcid":"0000-0002-7920-4924","position":8,"is_corresponding":false},{"id":655096,"name":"Philip de Chazal","orcid":"0000-0002-2091-207X","position":9,"is_corresponding":false},{"id":372147,"name":"Kate Sutherland","orcid":"0000-0001-6106-7303","position":10,"is_corresponding":false},{"id":275613,"name":"Bhajan Singh","orcid":"0000-0001-8662-7928","position":11,"is_corresponding":false},{"id":57826,"name":"Allan I Pack","orcid":"0000-0002-2879-0484","position":12,"is_corresponding":false},{"id":372143,"name":"Ning‐Hung Chen","orcid":"0000-0002-8387-9318","position":13,"is_corresponding":false},{"id":372148,"name":"Ingo Fietze","orcid":"0000-0001-5567-5206","position":14,"is_corresponding":false},{"id":372149,"name":"Þórarinn Gíslason","orcid":"0000-0002-6773-9876","position":15,"is_corresponding":false},{"id":655097,"name":"Steven Holfinger","orcid":"0000-0002-2851-9504","position":16,"is_corresponding":false},{"id":57811,"name":"Ulysses J. Magalang","orcid":"0000-0002-5052-2494","position":17,"is_corresponding":false},{"id":372151,"name":"Thomas Penzel","orcid":"0000-0002-4304-0112","position":18,"is_corresponding":false},{"id":655093,"name":"Hua Qin","orcid":"0000-0003-1870-6194","position":0,"is_corresponding":true}],"reference_count":67,"raw_metadata":null,"created_at":"2026-07-18T23:43:54.469024Z","pmid":"33506267","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":[]}