Gao X, Schwarzschild MA, Wang H, Ascherio A
Obesity and restless legs syndrome (RLS) are both associated with hypofunction of dopamine in the CNS. We therefore examined whether individuals who are obese have an increased risk of RLS in two ongoing US cohorts, the Nurses' Health Study II and the Health Professional Follow-up Study.
We included 65,554 women and 23,119 men free of diabetes, arthritis, and pregnancy in the current analyses. Information on RLS was assessed using a set of standardized questions. Participants were considered to have RLS if they met four RLS diagnostic criteria recommended by the International RLS Study Group and had restless legs>or =5 times/month. Odds ratios (ORs) and 95% confidence intervals (CIs) were computed using logistic regression models adjusting for age, smoking, use of antidepressant, phobic anxiety score, and other covariates. Log ORs from the two cohorts were pooled by a fixed-effects model.
There were 6.4% of women and 4.1% of men who were considered to have RLS. Multivariate adjusted ORs for RLS were 1.42 (95% CI: 1.3, 1.6; p trend<0.0001) for participants with body mass index (BMI)>30 vs<23 kg/m(2) and 1.60 (95% CI: 1.5, 1.8; p trend<0.0001) for highest vs lowest waist circumference quintiles. Greater BMI in early adulthood (age 18-21 years) and weight gain were also associated with a higher prevalence of RLS (p trend<0.01 for both).
Both overall and abdominal adiposity are associated with increased likelihoods of having restless legs syndrome (RLS). Further prospective studies are warranted to clarify causative association between obesity and risk of developing RLS.
Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, and Harvard Medical School, Boston, MA 02115, USA. firstname.lastname@example.org