Multi-organ structural and functional deficits in association with long COVID: a population-based case-control study

BackgroundMulti-system impacts of long COVID remain unknown. We compared multi-system deficits between people with long COVID and controls. MethodsA case-control study recruited from the Avon Longitudinal Study of Parents and Children and TwinsUK population cohorts. Cases (141) had long COVID (evidence of COVID-19 infection and persistent symptoms [&ge;]4 weeks post infection); controls (280) included people making a full recovery in <4 weeks, people self-reporting long COVID like symptoms but without wild-type SARS-CoV-2 virus antibodies, and people without symptoms or history of COVID-19 infection. Participants underwent multi-system MRI, (cardiac, brain, lung, kidney), measurement of blood pressure and autonomic function, tests of exercise performance, spirometry, renal function, strength and physical capability. System-specific deficits were summed to a total potential score of 27. FindingsParticipants attended clinic between 2021-23. Overall deficit score in cases was 0.22 (95% CI -0.44,0.88) units greater than controls, adjusted for age, sex, ethnicity, cohort membership and relatedness. This estimate was little changed (0.32 (-0.34, 0.98)) when additionally adjusted for educational status, index of multiple deprivation, physical activity, smoking and co-morbidity. Restricting cases to those reporting at least fatigue (46) increased the excess deficit score to 0.81 (-0.19,1.81) units in the minimally adjusted model. A difference was only observed in the vascular domain, largely attributable to elevated blood pressure, showing a 1.76 (1.04,2.97) multivariable adjusted odds ratio excess in cases, and 3.04 (1.36,6.80) when restricted to cases with fatigue. InterpretationPeople with community-based long COVID should be reassured that there is not marked residual deficit across multiple systems. However, blood pressure measurement and control should be included in clinical follow-up. FundingJointly funded by the National Institute for Health and Care Research and UK Research and Innovation (CONVALESCENCE, COV-LT-0009, MC_PC_20051).