The association between metabolic syndrome and sleep symptoms and sleep hygiene in the elderly in Northern Taiwan

Background: Sleep symptoms can predict the development of metabolic syndrome (MetS) in the general population. This study focused on the association between MetS and commonly reported sleep symptoms and personal sleep hygiene habits. The goal of this study was to help individuals to make healthier decisions and thereby prevent MetS. Methods: A cross-sectional survey was conducted among elderly people (age ≥ 65 years) who underwent a senior citizen health examination between March and November 2009. A total of 1181 participants (433 men, 36.7%; 748 women, 63.3%) were surveyed. MetS was defined using the modified Adult Treatment Panel III (ATP III). The participants completed a sleep questionnaire and a MetS evaluation. Multiple linear regression analysis was used to examine the relationship of the number of MetS components with individual sleep symptoms and sleep hygiene. Results: The specific symptom of insomnia (difficulty falling asleep [DFA]) increased the number of MetS risk factors significantly (coefficient = 0.252, p = 0.003, R = 0.8). The duration of insomnia was not associated with the risk of MetS. Sleep hygiene habits, including taking a nap lasting longer than 1 hour during the day (coefficient = 0.256, p = 0.001, R = 0.7), drinking caffeine-containing drinks during the day (coefficient = 0.233, p = 0.013, R = 0.5), and getting regular exercise each day (coefficient = −0.179, p = 0.024, R = 0.4), affected the number of MetS risk factors. Conclusion: DFA and unhealthy personal sleep hygiene habits increased the number of MetS risk factors in the community-dwelling elderly population in northern Taiwan. We propose that early evaluation of sleep symptoms and sleep hygiene can help identify individuals at risk for MetS, and early intervention would result in lower occurrence rates of MetS in elderly Taiwanese.