Sleep disturbances and their correlates in elderly Japanese American men residing in Hawaii.

BACKGROUND Elderly people frequently report the presence of chronically disturbed sleep. However, most data are derived from predominantly Caucasian populations. The current study is an investigation of the prevalence and correlates of sleep disturbances in a cohort of elderly Japanese American men residing in Hawaii. The importance of this population lies in its representation of an ethnic group living in a culture different from their ancestry. METHODS This study is a cross-sectional cohort analysis of data pertaining to sleep disturbances and their potential correlates from 3,845 elderly Japanese American men residing in Hawaii (mean age. 78 years; range, 71-93 years) who participated in the fourth survey of the Honolulu Heart Program (1991-1994), which is the baseline exam for the Honolulu-Asia Aging Study. Information collected included an extensive survey of medication use, medical history, and assessments of physical and mental function, quality of life, and sleep. RESULTS The prevalence of insomnia (DIMS) was 32.6%, a rate similar to that reported in predominantly Caucasian populations. Depression, benzodiazepine use, and several chronic health problems were the most important factors associated with DIMS. In contrast, excessive daytime sleepiness (EDS) had a prevalence of 8.9%, a rate lower than that found in elderly Caucasian populations but close to that reported among native Japanese. Important factors related to EDS were symptoms of nocturnal respiratory disturbance, depression, perception of adverse quality of life, Parkinson's disease, and digitalis use. CONCLUSIONS Elderly Japanese men are less likely than elderly Caucasian men to report excessive daytime sleepiness. However, their insomnia rates are similar.