Long COVID-Related Musculoskeletal Inflammation: A 12-Month Longitudinal Feasibility Cohort

Background: Long COVID (LC) causes persistent symptoms, including fatigue, Musculo-skeletal (MSK) pain, and a lower quality of life. It's hypothesised that chronic low-grade inflammation in LC could impact bone, joints, and muscle microcirculation, but evidence is limited. Aim: To assess health-related quality of life (HRQoL) and circulating inflam-mation, bone turnover markers (BTM), and vitamin D in LC individuals to explore their potential association with MSK function. Methods: A longitudinal prospective cohort study involving 45 adults with LC and 40 well-recovered (WR) post-COVID-19 controls was conducted over 12 months. Baseline and follow-up assessments included evaluations of HRQoL and pain rating questionnaires; blood analysis of inflammatory and bone turnover markers (BTM). Results: More females were in the LC group. LC reported significantly lower HRQoL compared to WR, with no change over 12 months. LC had higher Vitamin D levels at baseline compared to WR 15.9 vs 23.7 ng/ml (p=0.0021). Both groups experienced significant increases in Vitamin D after 12 months: WR from 21.4 to 28.5 ng/ml (p=0.0001) and LC from 32.6 to 35.8ng/ml (p=0.0023). LC also experienced more hand pain at baseline (p=0.003), which improved over time. No differences between groups in BTM or cytokines over time. Conclusion: Existing evidence suggests that this cohort study on LC adults and controls found a reduction in HRQoL and joint symptoms, indicating the need for ongoing monitoring. Future studies should explore MSK, muscle function via imaging, and ways to enhance musculoskeletal health and well-being.