|概要||Background : Our previous pilot study suggested high rates of insomnia among 140 patients with Yusho, a condition caused by exposure to dioxins and dioxin-like compounds. Moreover, higher blood concen...trations of dioxin were associated with lower subjective sleep quality.
Objectives : In this cross-sectional study, we analyze data from a Japanese nationwide survey that was designed to investigate the relationship between insomnia and dioxin toxicity among patients with Yusho.
Methods : For this study, 899 participants (46.3% men, median age [IQR] : 66 [58-78] years) were recruited. Symptoms related to insomnia were assessed. Toxicity of dioxins and dioxin-like compounds was evaluated with the total toxic equivalent quantity (TEQ), which is the summation of each TEQ calculated from the blood concentrations of 21 congeners of dioxin and dioxin-like compounds. Logistic regression analysis for insomnia were adjusted by age, sex, body mass index, habitual drinking, and smoking status.
Results : The number of participants with difficulty initiating and/or maintaining sleep (DIMS) was 753 (53.4％). Total TEQ was categorized on the following quartiles : first quartile (Q1)＜20 (reference, second quartile (Q2) = 20-35, third quartile (Q3) =35-62, and fourth quartile (Q4)≧62 pg-TEQ/g lipid). Adjusted odds ratios (95% confidence interval) for DIMS of Q2-4 were 1.89 (1.23-2.89), 1.62 (1.02-2.57), and 2.09 (1.24-3.53), respectively.
Conclusions : Insomnia was frequent among patients with Yusho. Insomnia was associated with not only the apparently high level of total TEQ, but also the level of total TEQ observed among general population. In the pathophysiology of insomnia, dioxins and dioxin-like compounds, which persist in environment and human body for a long time, might be one of the environmental factors among patients with Yusho and general population.続きを見る