Anemia and iron metabolism in chronic diseases and their relationships with functional outcomes
DOI:
https://doi.org/10.62827/fb.v27i9.1339Keywords:
Fatigue; Exercise Tolerance; Quality of Life; Hemoglobins.Abstract
Introduction: Anemia and iron metabolism alterations may coexist with fatigue and functional limitations in chronic diseases. Objective: To analyze their association with fatigue, exercise intolerance, and functional capacity in adults with chronic diseases. Methods: An integrative review searched PubMed/MEDLINE, SciELO, and the Virtual Health Library on September 30, 2026. Primary studies reporting hematological parameters and functional outcomes were included. Two reviewers independently selected studies; disagreements were resolved by consensus or a third reviewer. Narrative synthesis included critical appraisal using design-specific tools. Results: Of 70 records identified, 20 duplicates were removed, 50 records were screened, and 30 full texts were assessed; six studies were included. In paroxysmal nocturnal hemoglobinuria, hemoglobin correlated with lower fatigue (r = 0.47; p < 0.0001). In chronic obstructive pulmonary disease, anemic participants walked shorter distances in six minutes (267.9 ± 86.7 versus 373.0 ± 122.8 meters; p = 0.001). Associations with poorer physical function and exercise capacity were also observed in renal and cardiovascular populations. Improvements during interventions cannot be attributed exclusively to anemia correction or iron replacement. Conclusion: The studies suggest associations between hematological alterations and functional outcomes in the populations assessed. Heterogeneity, small samples, confounding, and limited search sensitivity restrict generalization and causal inference.
References
Asanov DAU, Kadyrov AN, Ismailova AMK. Iron deficiency without anaemia in adults with fatigue and chronic disease. Ann Innov Med [Internet]. 2026 May 28 [cited 2026 Oct 1]; 4(2). Available from: https://journals.eikipub.com/index.php/AIM-Medicine/article/view/978. doi: 10.59652/t0k7n264.
Carrasco A, Navren M, Larsson I, Taube F, Björkman F. Systematic review and meta-analysis: iron deficiency and iron deficiency anemia among military recruits undergoing basic combat training. Mil Med [Internet]. 2025 Feb 27 [cited 2026 Oct 1]; 190(3-4):541-553. Available from: https://pubmed.ncbi.nlm.nih.gov/39301668/. doi: 10.1093/milmed/usae437.
Cella D, Sarda SP, Hsieh R, Fishman J, Hakimi Z, Hoffman K, Al-Adhami M, Nazir J, Cutts K, Lenderking WR. Changes in hemoglobin and clinical outcomes drive improvements in fatigue, quality of life, and physical function in patients with paroxysmal nocturnal hemoglobinuria: post hoc analyses from the phase III PEGASUS study. Ann Hematol [Internet]. 2022 Sep [cited 2026 Oct 1]; 101(9):1905-1914. Available from: https://pubmed.ncbi.nlm.nih.gov/35869984/. doi: 10.1007/s00277-022-04887-8.
Dawood NA. Anemia of chronic disease in rheumatoid arthritis through multidisciplinary management in rehabilitation settings. Sarcouncil J Intern Med Public Health [Internet]. 2026 [cited 2026 Oct 1]; 5(2):14-20. Available from: https://sarcouncil.com/2026/03/anemia-of-chronic-disease-in-rheumatoid-arthritis-through-multidisciplinary-management-in-rehabilitation-settings. doi: 10.5281/zenodo.19094223.
Ferrari M, Manea L, Anton K, Bruzzone P, Meneghello M, Zamboni F, Purgato L, Cazzoletti L, Ferrari P, Testi R. Anemia and hemoglobin serum levels are associated with exercise capacity and quality of life in chronic obstructive pulmonary disease. BMC Pulm Med [Internet]. 2015 May 8 [cited 2026 Oct 1]; 15:58. Available from: https://pubmed.ncbi.nlm.nih.gov/25952923/. doi: 10.1186/s12890-015-0050-y.
Whittemore R, Knafl K. The integrative review: updated methodology. J Adv Nurs [Internet]. 2005 [cited 2026 Sep 2];52(5):546-553. Available from: https://pubmed.ncbi.nlm.nih.gov/16268861/. doi: 10.1111/j.1365-2648.2005.03621.x.
Mendes KDS, Silveira RCCP, Galvão CM. Revisão integrativa: método de pesquisa para a incorporação de evidências na saúde e na enfermagem. Texto Contexto Enferm [Internet]. 2008 [cited 2026 Sep 2];17(4):758-764. Available from: https://www.scielo.br/j/tce/a/XzFkq6tjWs4wHNqNjKJLkXQ/?lang=pt. doi: 10.1590/S0104-07072008000400018
Barker TH, Stone JC, Sears K, Klugar M, Tufanaru C, Leonardi-Bee J, Aromataris E, Munn Z. The revised JBI critical appraisal tool for the assessment of risk of bias for randomized controlled trials. JBI Evid Synth. 2023;21(3):494-506. doi: 10.11124/JBIES-22-00430.
Barker TH, Habibi N, Aromataris E, Stone JC, Leonardi-Bee J, Sears K, et al. The revised JBI critical appraisal tool for the assessment of risk of bias for quasi-experimental studies. JBI Evid Synth. 2024;22(3):378-388. doi: 10.11124/JBIES-23-00268.
Barker TH, Hasanoff S, Aromataris E, Stone JC, Leonardi-Bee J, Sears K, et al. The revised JBI critical appraisal tool for the assessment of risk of bias for analytical cross-sectional studies. JBI Evid Synth. 2026;24(3):401-408. doi: 10.11124/JBIES-24-00523.
Kassianides X, Bhandari S. Patient reported outcome measures and cardiovascular outcomes following high dose modern intravenous iron in non-dialysis dependent chronic kidney disease: secondary analysis of ExplorIRON-CKD. Sci Rep [Internet]. 2023 Oct 26 [cited 2026 Oct 1]; 13(1):18401. Available from: https://pubmed.ncbi.nlm.nih.gov/37884522/. doi: 10.1038/s41598-023-44578-6.
Odden MC, Whooley MA, Shlipak MG. Association of chronic kidney disease and anemia with physical capacity: the Heart and Soul Study. J Am Soc Nephrol [Internet]. 2004 Nov [cited 2026 Oct 1]; 15(11):2908-2915. Available from: https://pubmed.ncbi.nlm.nih.gov/15504944/. doi: 10.1097/01.ASN.0000143743.78092.E3.
Parashuram, Faseeh KM, Sankar K. Impact of anemia on dyspnea severity, systemic inflammation, and exercise capacity in chronic lung disease: a cross-sectional observational study. SSR Inst Int J Life Sci [Internet]. 2026 [cited 2026 Oct 1]; 12(4):10394-10400. Available from: https://iijls.com/currentissue/Anemia_Dyspnea_Severity_Inflammation_Chronic_Lung_Disease.pdf. doi: 10.21276/SSR-IIJLS.2026.12.4.34.
Harrabi MA, Fendri T, Chaari F, Ayed R, Hadadi A, Boughattas W, Mezghani I, Kallel C, Rebai H, Turki M, Ayadi F, Sahli S. Efficacy of 8-week oral iron supplementation on fatigue and physical capacity in young women with iron deficiency anemia: an uncontrolled pilot clinical trial. PLoS One [Internet]. 2025 Oct 16 [cited 2026 Oct 1]; 20(10):e0334499. Available from: https://pubmed.ncbi.nlm.nih.gov/41100554/. doi: 10.1371/journal.pone.0334499.
Houston BL, Hurrie D, Graham J, Perija B, Rimmer E, Rabbani R, Bernstein CN, Turgeon AF, Fergusson DA, Houston DS, Abou-Setta AM, Zarychanski R. Efficacy of iron supplementation on fatigue and physical capacity in non-anaemic iron-deficient adults: a systematic review of randomised controlled trials. BMJ Open [Internet]. 2018 Apr 5 [cited 2026 Oct 1]; 8(4):e019240. Available from: https://pubmed.ncbi.nlm.nih.gov/29626044/. doi: 10.1136/bmjopen-2017-019240.
Sahoo DP, Gupta A, War GA, Deb S. Unmasking anemia in the elderly: a systematic review of prevalence, causes, and consequences. J Family Med Prim Care [Internet]. 2025 Nov 29 [cited 2026 Oct 1]; 14(11):4466-4475. Available from: https://pubmed.ncbi.nlm.nih.gov/41403540/. doi: 10.4103/jfmpc.jfmpc_829_25.
Świątczak M, Młodziński K, Sikorska K, Raczak A, Lipiński P, Daniłowicz-Szymanowicz L. Chronic fatigue syndrome in patients with deteriorated iron metabolism. Diagnostics (Basel) [Internet]. 2022 Aug 25 [cited 2026 Oct 1]; 12(9):2057. Available from: https://pubmed.ncbi.nlm.nih.gov/36140459/. doi: 10.3390/diagnostics12092057.
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Copyright (c) 2026 Suellen Taujiro Correia Rocha Rodrigues , Enzo Freire, Victor Rodrigues de Souza Pantuza, Pedro Henrique da Silva Andrade , Filipe Alves Costa Barbosa (Autor)
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