0742 EPIDEMIOLOGY OF RESTLESS LEGS SYNDROME AND PERIODIC LIMB MOVEMENT IN THE EPISONO COHORT

Abstract

Introduction: Restless legs syndrome (RLS) and periodic limb movement (PLM) are sleep related movement disorders associated with several medical conditions and a poor quality of life. The aim of the present study was to determine the prevalence of RLS and PLM as well as to establish the predictive factors related to both sleep disturbances in a representative sample of general population. Methods: This is a cross-sectional study performed in an adult population-based sample of 1,042 participants from EPISONO cohort (Sao Paulo, Brazil). RLS was assessed according to the International Restless Legs Syndrome Study Group criteria. PLM was diagnosed by polysomnography using cut-off value of PLM index (PLMI) ≤15/h and >15/h. All volunteers underwent polysomnography, answered questionnaires and had their blood collected for quantification of iron, ferritin and inflammatory markers as well as DNA extraction for investigation of MEIS1, BTBD9 and MAP2K5 polymorphisms. Results: Prevalence of RLS was 4.9% (9.2% women; 4.3% men) and PLMI>15/h was 2.4% (2.4% women; 3.4% men). Those with PLMI>15/h were older and had a higher frequency of obstructive sleep apnea, and higher levels of TNF-alpha and IL-6. RLS individuals showed poor quality of life and worse subjective sleep quality. No association between RLS and PLMI>15/h was found. Age was predictor of both sleep disturbances. Fatigue and anxiety were independently associated with RLS while single marital status, insomnia, and TNFα levels were predictors of PLMI>15/h. No significant differences in the frequencies of genotypes were observed for the 3 polymorphisms analyzed. Conclusion: RLS is more prevalent than PLM in the Brazilian population. Although poor quality of life only affected individuals with RLS, the presence of PLMI>15/h suggested its role as a possible inflammatory marker.