{"doi":"10.1152/physiol.2024.39.s1.241","title":"Cerebrovascular Carbon Dioxide Reactivity Is Intact in Chronic Kidney Disease","abstract":"Introduction: Chronic Kidney Disease (CKD) is associated with a substantially elevated risk of stroke. One factor that might contribute to this heightened risk is an impairment in cerebrovascular carbon dioxide reactivity (CVR), the mechanism through which cerebral vessels dilate and constrict in response to fluctuations in arterial carbon dioxide tension (PaCO 2 ). CVR is known to be impaired in other chronic disease states associated with stroke risk; thus, we aimed to determine if CVR is also impaired in patients with moderate to severe CKD (stages III-IV). We hypothesized that CKD patients would exhibit impaired CVR compared to a control group (CON) matched for age, hypertension, and diabetes status. Methods: 9 CKD participants (age=56 ± 17y, eGFR=39 ± 4 mL/min/1.73m 2 ), and 9 CON participants (age=61 ± 6y) underwent a single experimental protocol in which PaCO 2 was manipulated via 2-min of hypercapnia (5% CO 2 ) followed by 2-min hypocapnia (voluntary hyperventilation) while heart rate (via ECG), blood pressure (via finger photoplethysmography), middle cerebral artery blood velocity (MCAv; via transcranial Doppler ultrasonography), and end-tidal carbon dioxide (etCO 2 ) were measured continuously. CVR was quantified as the slope of the linear relationship between breath-by-breath etCO 2 and MCAv while accounting for blood pressure as a covariate. Hyper-, hypo- and, integrated (hyper + hypo) CVR was compared between groups via a 2-tailed, unpaired T-test. Results: We observed no differences in CVR between groups. Hypercapnic CVR: CKD = 1.4 ± 1.0 cm/s/mmHg, CON = 1.5 ± 0.8 cm/s/mmHg, Hypocapnic CVR: CKD = 1.5 ± 0.8 cm/s/mmHg, CON = 1.5 ± 0.8 cm/s/mmHg, Integrated CVR: CKD = 1.7 ± 1.2 cm/s/mmHg, CON = 1.7 ± 0.6 cm/s/mmHg, P ≥ 0.90. Conclusions: Contrary to our hypothesis, CVR remains intact in CKD stages III-IV. These findings suggest that other mechanisms contribute to the elevated stroke risk observed in this population. Funding: This work was supported by the American Heart Association (Career Development Award #929040, PI: Sprick), and NIH grants R01HL135183 and R33AT010457. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.","journal":"Physiology","year":2024,"id":497754,"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":0,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9691,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2024-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1053144,"name":"Jeann L. Sabino‐Carvalho","orcid":"0000-0002-8482-5135","position":1,"is_corresponding":false},{"id":1225986,"name":"Elsa Mekonnen","orcid":"0000-0002-0710-7228","position":2,"is_corresponding":false},{"id":1324435,"name":"Melissa McGranahan","orcid":null,"position":3,"is_corresponding":false},{"id":1225987,"name":"Matias Zanuzzi","orcid":"0000-0002-8598-4998","position":4,"is_corresponding":false},{"id":828105,"name":"Dana DaCosta","orcid":null,"position":5,"is_corresponding":false},{"id":239675,"name":"Jeanie Park","orcid":"0000-0002-5799-9172","position":6,"is_corresponding":false},{"id":420938,"name":"Justin D. Sprick","orcid":"0000-0001-9782-1865","position":0,"is_corresponding":true}],"reference_count":0,"raw_metadata":null,"created_at":"2026-07-19T02:09:34.764412Z","pmid":null,"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":[]}