Circadian Rhythms and Burn Recovery: A Scoping Review of Biological Disruptions and Clinical Implications

Burn injuries present significant physiological challenges. Emerging evidence has found that circadian rhythms-the body's intrinsic 24-hour cycles-play a key role in regulating immune responses, hormonal secretion, and tissue repair, all essential for recovery. However, their specific impact on burn healing remains underexplored. This scoping review aimed to evaluate how circadian rhythms affect recovery outcomes in burn patients and animal models. PubMed, Embase, and Scopus were searched using terms, including "circadian rhythms" and "burn trauma." Nine studies met inclusion criteria, comprising 516 human patients (unweighted mean age and total body surface area (TBSA) across studies was 42.88 years and 19.7%) and several animal models. Burn-related circadian disruptions were consistently observed. Studies reported elevated daytime cortisol in burn patients, reduced nighttime melatonin, and a reduction in PER3 expression. Burn timing impacted outcomes: nighttime burns were associated with slower healing and increased complications. Reduced light exposure was linked to delayed sleep phase syndrome. Due to heterogeneity and small sample sizes, a meta-analysis was not feasible. These findings underscore circadian biology's relevance in burn recovery. Further clinical studies are needed to explore how timing-based strategies can be effectively integrated into burn care.