Restless legs syndrome in older people: a community-based study on its prevalence and association with major depressive disorder in older Korean adults.

OBJECTIVE: The prevalence of restless legs syndrome (RLS) and its relationship with the demographic variables in an older Korean population were examined. METHODS: A face-to-face household survey was conducted in five different regions of Korea from June 2008 to August 2008. Among a total of 3074 individuals who were aged more than 65, 1990 participants were interviewed, and the response rate was 64.7%. The diagnosis of RLS was made using an RLS questionnaire. The medical review of systems was assessed by a self-report questionnaire containing 15 items. Depression was diagnosed with the diagnostic section of depressive disorder of the Korean version of the Composite International Diagnostic Interview (CIDI) and the short form of the Geriatric Depression Scale (GDS). RESULTS: The prevalence of RLS in the older Korean population was 9.5% (men, 7.1%; women, 11.3%). RLS had a significant association with anemia (odds ratio (OR), 1.66; 95% confidence interval (CI), 1.29-2.12; P < 0.001) and renal diseases (OR, 2.57; 95% CI, 1.95-3.38; P < 0.001). RLS seemed to have a significant relationship with depression by using the CIDI (adjusted OR 2.01; 95% CI, 1.45-2.79. P < 0.001) and GDS (adjusted OR, 1.62; 95% CI, 1.34-1.94; P < 0.001). CONCLUSIONS: Restless legs syndrome might be a risk factor for major depressive disorder in older Koreans. Future investigations should focus on the causality and mechanism underlying the relationship between RLS and major depressive disorder.