Healthy lifestyle for the prevention of post-COVID-19 multisystem sequelae, hospitalization, and death: a prospective cohort study

Background Post-COVID complications are emerging as a global public health crisis. Effective prevention strategies are needed to inform patients, clinicians and policy makers, and to reduce their cumulative burden. We aimed to investigate whether a habitual healthy lifestyle predated pandemic is associated with lower risks of multisystem sequelae and other adverse outcomes of COVID-19, and whether the potential protective effects are independent of pre-existing comorbidities. Methods The prospective population-based cohort study enrolled participants with SARS-CoV-2 infection confirmed by a positive polymerase chain reaction test result between March 1, 2020, and March 1, 2022. Participants with no history of the related outcome one year before infection were included and followed up for 210 days. Exposures included ten modifiable healthy lifestyle factors including past or never smoking, moderate alcohol intake (≤4 times week), body mass index <30 kg/m 2 , at least 150 minutes of moderate or 75 minutes of vigorous physical activity per week, less sedentary time (<4 hours per day), healthy sleep duration (7-9 hours per day), adequate intake of fruit and vegetables (≥400 g/day), adequate oily fish intake (≥1 portion/week), moderate intake of red meat (≤4 portions week) and processed meat (≤4 portions week). Outcomes included multisystem COVID-19 sequelae (consisting of 75 diseases/symptoms in 10 organ systems), death, and hospital admission following SARS-CoV-2 infection, confirmed by hospital inpatient and death records. Risk was reported in relative scale (hazard ratio [HR]) and absolute scale (absolute risk reduction [ARR]) during both the acute (the first 30 days) and post-acute (30-210 days) phases of infection using Cox models. Findings A total of 68,896 participants (mean [SD] age, 66.6 [8.4]; 32,098 women [46.6%]) with COVID-19 were included. A favorable lifestyle (6-10 healthy lifestyle factors; 46.4%) was associated with a 36% lower risk of multisystem sequelae of COVID-19 (HR, 0.64; 95% CI, 0.58-0.69; ARR, 7.08%; 95% CI, 5.98-8.09), compared with unfavorable lifestyle (0-4 factors; 12.3%). Risk reductions were observed across all 10 prespecified organ systems including cardiovascular, coagulation, metabolic and endocrine, gastrointestinal, kidney, mental health, musculoskeletal, neurologic, and respiratory disorders, and general symptoms of fatigue and malaise. This beneficial effect was largely attributable to direct effects of healthy lifestyle, with mediation proportion ranging from 44% to 93% across organ systems. A favorable lifestyle was also associated with lower risk of post-COVID death (HR, 0.59; 95% CI, 0.52-0.66; ARR, 1.99%; 95% CI, 1.61-2.32) and hospitalization (HR, 0.78; 95% CI, 0.73-0.84; ARR, 6.14%; 95% CI, 4.48-7.68). These associations were observed after accounting for potential misclassification of lifestyle factors, and during acute and post-acute infection, in those tested positive in the hospital and..