{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T20:35:11Z","timestamp":1790800511826,"version":"4.1.0"},"reference-count":46,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2026,3,5]],"date-time":"2026-03-05T00:00:00Z","timestamp":1772668800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"\u201cFondo Semilla\u201d from Universidad Aut\u00f3noma de Guadalajara"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Background\/Objectives: Long COVID has emerged as a significant public health concern, characterized by persistent symptoms following SARS-CoV-2 infection. Cognitive impairment is a common sequela, particularly among older adults (OAs). Although olfactory dysfunction and malnutrition have been previously associated with cognitive decline, it remains elusive to what extent sex-specific variations in these and additional factors will be pivotal to guiding targeted interventions in a sex-specific manner. To fill this gap in knowledge, we undertook a study with the purpose of investigating the contribution of sex-specific risk factors to the development of cognitive impairment (CI) in a cohort of OAs hospitalized with long COVID. Methods: We undertook a cross-sectional study among OAs hospitalized at a geriatric care unit. Olfactory function was assessed using the Sniffin\u2019 Stick Test. Cognitive impairment was evaluated by the Mini-Mental State Examination, and nutritional status was assessed with the Mini Nutritional Assessment (MNA). Statistical analyses included linear regression. Results: A total of 45 patients with long COVID were included, of whom 51% were female. The prevalence of CI was lower in men compared to women. In the single variable analysis, nutritional factors were associated with CI only in women; importantly, the loss of olfactory function was associated with CI in the whole group and to CI in women after multivariate analysis. Conclusions: Olfactory dysfunction is a potential biomarker for cognitive impairment in OAs with long COVID in a sex-specific manner. In our study nutritional status and probable obesity could be additional factors associated with CI; nevertheless, this was not confirmed in our multivariate analysis; therefore, this hypothesis would need to be tested in larger studies.<\/jats:p>","DOI":"10.3390\/jcm15051994","type":"journal-article","created":{"date-parts":[[2026,3,5]],"date-time":"2026-03-05T11:52:11Z","timestamp":1772711531000},"page":"1994","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Sex-Specific Differences in Nutritional Status and Olfaction in Association with Cognitive Impairment Amongst Older Adults with Long COVID Syndrome"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0009-0004-4291-6866","authenticated-orcid":false,"given":"Alma L.","family":"Guzm\u00e1n-Gurrola","sequence":"first","affiliation":[{"name":"High Specialty Geriatric Care Unit, Hospital Civil de Guadalajara Fray Antonio Alcalde, Guadalajara 44200, Mexico"},{"name":"Centro Universitario de Tlajomulco, Universidad de Guadalajara, Tlajomulco 45641, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Laura","family":"Gonz\u00e1lez-L\u00f3pez","sequence":"additional","affiliation":[{"name":"Research Department, Universidad del Valle de Atemajac Campus Guadalajara, Guadalajara 45050, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2786-6667","authenticated-orcid":false,"given":"Jonathan S.","family":"Ch\u00e1vez-\u00cd\u00f1iguez","sequence":"additional","affiliation":[{"name":"Nephrology Department, Hospital Civil de Guadalajara Fray Antonio Alcalde, Guadalajara 44200, Mexico"},{"name":"Centro Universitario Ciencias de la Salud, Universidad de Guadalajara, Guadalajara 44340, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mariana","family":"Verduzco V\u00e1zquez","sequence":"additional","affiliation":[{"name":"Immunology Research Laboratory, Decanato de Medicina, Universidad Aut\u00f3noma de Guadalajara, Guadalajara 45129, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Efra\u00edn I.","family":"Flores-Hern\u00e1ndez","sequence":"additional","affiliation":[{"name":"Decanto Ciencia y Tecnolog\u00eda, Universidad Aut\u00f3noma de Guadalajara, Guadalajara 45129, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jos\u00e9 A.","family":"Novoa-Burquez","sequence":"additional","affiliation":[{"name":"Instituto de Seguridad y Servicios Sociales de los Trabajadores del Gobierno y Municipios del Estado de Baja California, Tijuana 22520, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6508-9657","authenticated-orcid":false,"given":"Maria G.","family":"Zavala-Cerna","sequence":"additional","affiliation":[{"name":"Immunology Research Laboratory, Decanato de Medicina, Universidad Aut\u00f3noma de Guadalajara, Guadalajara 45129, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,3,5]]},"reference":[{"key":"ref_1","first-page":"115","article-title":"Post-COVID-19 syndrome","volume":"158","year":"2022","journal-title":"Gac. 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