en Health Health Original Article Original Article <span style="font-size:14px;"><span style="font-family:Times New Roman;"><span style="line-height:13.5pt"><b><i><span style="color:blue">Background</span></i></b><i><span style="color:blue">:</span></i> Intrinsic capacity (IC) decline, infection susceptibility, and post-COVID sequelae in older adults, intensified by the pandemic, demand probing IC domains&#39; infection/outcome links and population-level strategies for sustaining functional health.</span><br> <span style="line-height:13.5pt"><b><i><span style="color:blue">Methods:</span></i></b> This cross-sectional study enrolled 600 older adults. IC was assessed using the World Health Organization&rsquo;s ICOPE framework. Post-COVID-19 condition was defined according to Centers for Disease Control and Prevention criteria, and late complications were evaluated via the culturally adapted and validated Persian C19-YRS questionnaire. COVID-19 infection status was confirmed through polymerase chain reaction testing of nasopharyngeal swabs or serological antibody assays. Statistical analyses were conducted using SPSS Version 22, including independent t-tests, analysis of variance, and regression models.</span><br> <span style="line-height:13.5pt"><b><i><span style="color:blue">Results:</span></i></b> Overall, most participants demonstrated relatively preserved IC across domains, although greater variability was observed in the psychological domain. In multivariable analysis, higher scores in the psychological IC domain were independently associated with COVID-19 infection (OR = 1.04, 95% CI: 1.00&ndash;1.08). Lower cognitive and sensory IC scores were significantly associated with poorer functional ability (B = &minus;0.35, 95% CI: &minus;0.66 to &minus;0.04; and B = &minus;0.50, 95% CI: &minus;0.90 to &minus;0.10, respectively), while higher sensory IC scores were associated with better general health among participants with post-COVID-19 complications (B = 0.24, 95% CI: 0.01&ndash;0.47).</span><br> <span style="line-height:13.5pt"><b><i><span style="color:blue">Conclusion</span></i></b><i><span style="color:blue">:</span></i> These findings indicate meaningful associations between IC and both COVID-19 infection status and post-infectious health outcomes in older adults. Monitoring and supporting IC may be relevant for maintaining functional independence and quality of life in ageing populations during and after widespread infectious disease outbreaks.</span></span></span><br> &nbsp; COVID-19, Intrinsic Capacity, Aging, Post-COVID Conditions 572 581 http://caspjim.com/browse.php?a_code=A-10-801-3&slc_lang=en&sid=1 Hossein-Ali Nikbakht ep.nikbakht@gmail.com 100319475328460057810 100319475328460057810 No Social Determinants of Health Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran Afsaneh Bakhtiari afbakhtiari@gmail.com 100319475328460057811 100319475328460057811 Yes Social Determinants of Health Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran Negar Tamadoni negar.tamadonij@gmail.com 100319475328460057812 100319475328460057812 No Student Research Committee, Babol University of Medical Sciences, Babol, Iran Manoj Sivan M.Sivan@leeds.ac.uk 100319475328460057813 100319475328460057813 No Royal Australasian College of Physicians, Royal College of Physicians of Edinburgh, University of Leeds, University of Leeds School of Medicine, University of Manchester, World Health Organisation Europe Maryam GHorbanzadeh m.ghorbanzadeh9296@gmail.com 100319475328460057814 100319475328460057814 No Social Determinants of Health Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran