Longitudinal changes in sleep quality in male patients with alcohol dependence receiving far-infrared ray therapy: associations with alterations in circulating pro-inflammatory cytokines

Sleep disturbance is common in alcohol dependence (AD). Far-infrared ray (FIR) therapy has anti-inflammatory properties and may improve sleep, offering a potential non-pharmacological treatment during withdrawal. The primary objective of this study was to compare sleep quality and serum pro-inflammatory cytokine levels between AD patients who received FIR therapy and those who received standard care only. A total of 114 male AD patients who completed a two-week withdrawal program were randomized to a control group (n = 61) receiving supportive care, or a treatment group (n = 53) receiving supportive care plus five FIR sessions. Sleep quality was assessed using cardiopulmonary coupling (CPC), and serum levels of 10 cytokines were measured via Luminex assay before and after the intervention. Analysis of covariance (ANCOVA) compared post-treatment outcomes between groups, controlling for baseline values. Pearson correlation analysis examined relationships between changes in sleep parameters and cytokine levels. Compared to controls, the treatment group showed significantly increased total sleep time and sleep efficiency. Moreover, serum levels of IL-1β, IL-6, and TNF-α were significantly reduced in the treatment group. Addtionally, improvements in total sleep time and sleep efficiency were negatively correlated with changes in IL-1β and TNF-α levels. FIR therapy may improve sleep quality and reduce pro-inflammatory cytokines in AD patients during withdrawal, suggesting its potential as an alternative to hypnotic medications for sleep management.