Somatic and psychological complaints and their correlates with insomnia inthe Japanese general population

Objective: This cross-sectional study was conducted to estimate the prevale nce of somatic and psychological complaints (SPCs) and to investigate the a ssociation of SPCs with insomnia in a sample of the general adult populatio n of Japan. Methods: We randomly selected 4000 adult residents (greater tha n or equal to 20 years old) from five areas of Japan using stratified sampl ing and conducted interviews using a structured questionnaire. The question naire solicited information about eight somatic symptoms, eight psychologic al symptoms. three sleep problems, and demographic and health-related infor mation. A total of 3030 subjects completed questionnaires, giving a respons e rate of 75.8%. Results: Stiff neck/shoulder (45.3%), backache (35.1%), an d fatigue (31.4%) were the most common complaints in this population. In ge neral, SPCs were more prevalent in younger persons and in women. Logistic r egression analyses, controlling for other factors, showed that insomnia was significantly associated with a number of SPCs: backache [odds ratio [OR] = 1.4, 95% confidence interval [CI] = 1.1-1.6), epigastric discomfort (OR = 1.7, 95% CI = 1.3-2.2), weight loss (OR = 2.0, 95% CI = 1.2-3.3), headache (OR = 1.7, 95% CI = 1.3-2.2), fatigue (OR = 1.7, 95% CI = 1.4-2.1), worryi ng (OR = 1.6, 95% CI = 1.1-2.3), irritability (OR = 1.4, 95% CI = 1.1-1.7), and loss of interest (OR = 1.8, 95% CI = 1.2-2.7). Conclusions: SPCs were common and were largely associated with insomnia in the general adult popul ation of Japan. Further study is needed to examine the causal links between SPCs and insomnia.