The associations between anger expression and insomnia among community-dwelling older adults in Korea

Objective: Sleep disturbance is one of the most common health problems in older adults. Anger expression tendency has been studied on many aspects of health. Some studies have reported that individuals with poor anger regulation were more likely to have insomnia. Considering emotional arousal affects insomnia, anger expression tendency could be associated with inaomnia in older adults. The objective of this study is to investigate correlation between anger expressions and insomnia symptoms among community-dwelling older adults in Korea. Methods: A total of 235 older adults (mean age 75 years, 67.2% female) were enrolled to this study. We interviewed the participants to gather demographic information, medical history, stress level using the Perceived Stress Scale, sleep quality using the Pittsburgh Sleep Quality Index and anger expression using Korean adaptation of the State-Trait Anger Scale. Simple and logistic regression analyses were used to find correlations between anger expression and insomnia symptoms. Results: Forty percent of the participants had sleep initiation difficulty (sleep latency >30 min). Higher anger expression tendency (odds ratio=1.122, p=0.009) was significantly related to sleep initiation difficulty after controlling age, sex, education, socioeconomic status, perceived stress, depression, and total sleep time. Meanwhile, anger expression tendency was not associated with total sleep time after controlling covariates. Conclusion: Older adults with higher anger expressions showed a tendency to have sleep initiation difficulty. Further studies are needed to determine whether modifying of anger expression can control physiological and cognitive arousal and improve sleep disturbance.