Lifestyle Factors and Risk of Restless Legs Syndrome: Prospective Cohort Study.

STUDY OBJECTIVES: To examine the association between modifiable lifestyle factors, and the risk of developing restless legs syndrome (RLS). METHODS: This is a Prospective Cohort study of population including 12,812 men participating in Health Professionals Follow-up Study and 42,728 women participating in the Nurses' Health study II. The participants were free of RLS at baseline (2002 for the HPFS and 2005 for the NHS II) and free of diabetes and arthritis through follow-up. RLS was assessed via a set of questions recommended by International Restless Legs Syndrome Study group. The Information was collected on height, weight, level of physical activity, dietary intake, and smoking status via questionnaires. RESULTS: During 4-6 years of follow-up, we identified 1,538 incident RLS cases. Participants with normal weight, and who were physically active, non-smoker, and had some alcohol consumption had a lower risk of developing RLS. When we combined the effects of these four factors together, we observed a dose response relationship between the increased number of healthy lifestyle factors and a low risk of RLS: after adjusting for potential confounders the pooled odds ratio was 0.67 (95% CI: 0.47-0.97) for 4 vs.0 healthy factors (p trend < 0.001). In contrast, we did not observe significant associations between caffeine consumption or diet quality as assessed by the Alternate Healthy Eating Index, and altered RLS risk in men and women. CONCLUSIONS: Several modifiable lifestyle factors may play an important role in RLS risk.

Validation of a risk prediction tool for coronary heart disease in middle-aged women.

BACKGROUND: Health risk appraisal tools may be useful for identifying individuals who would benefit from lifestyle changes and increased surveillance. We evaluated the validity of the Your Disease Risk tool (YDR) for estimating relative risk of coronary heart disease (CHD) among middle-aged women. METHODS: We included 55,802 women in the Nurses' Health Study who completed a mailed questionnaire about risk factors in 1994 and had no history of heart disease at that time. Participants were followed through 2004 for the occurrence of CHD. We estimated each woman's 10-year relative risk of CHD using YDR, and we compared the estimated YDR relative risk category (ranging from "very much below average" to "very much above average") to the observed relative risk for each category using logistic regression. We also examined the discriminatory accuracy of YDR using concordance statistics (c-statistics). RESULTS: There were 1165 CHD events during the 10-year follow-up period. Compared to the "about average" category, the observed age-adjusted relative risk was 0.43 (95 % confidence interval: 0.33, 0.56) for the "very much below average" category and 2.48 (95 % confidence interval: 1.68, 3.67) for the "very much above average" category. The age-adjusted c-statistic for the model including the YDR relative risk category was 0.71 (95 % confidence interval: 0.69, 0.72). The model performed better in younger than older women. CONCLUSION: The YDR tool appears to have moderate validity for estimating 10-year relative risk of CHD in this population of middle-aged women. Further research should aim to improve the tool's performance and to examine its validity in other populations.

Prospective study of obesity, hypertension, high cholesterol, and risk of restless legs syndrome.

Because previous cross-sectional studies suggest an association between metabolic disorders and restless legs syndrome (RLS), we prospectively evaluated whether obesity, hypercholesterolemia, and hypertension were associated with increased risk of RLS. Our study consisted of 42,728 female participants from the Nurses' Health Study II and 12,812 male participants from the Health Professionals Follow-up Study, free of RLS at baseline (2002 for men and 2005 for women), and free of diabetes and arthritis through follow-up (2002-2008 for men and 2005-2009 for women). RLS symptoms were assessed using the International RLS Study Group's standardized questionnaire. We considered RLS symptoms a "case" if the symptoms occurred ≥5 times/month and met International RLS Study Group criteria. We found that obesity was associated with an increased risk RLS among both men and women (P difference for sex >0.5). The pooled multivariate-adjusted odds ratio (OR) for RLS was 1.57 (95% confidence interval [CI]: 1.33-1.85; P trend <0.0001) for body mass index >30 versus ≤23 kg/m(2) and 1.56 (95% CI: 1.29-1.89; P trend = 0.0001) comparing two extreme waist circumference quintiles, adjusting for age, ethnicity, smoking, physical activity, use of antidepressant, and other covariates. A similar significant association was found for high cholesterol; the pooled adjusted OR for total serum cholesterol >240 versus <159 mg/dL was 1.33 (95% CI: 1.11-1.60; P trend = 0.002). There was no significant association between hypertension and RLS risk (adjusted OR: 0.90; 95% CI: 0.79-1.02). In this large, prospective study, we found that obesity and high cholesterol, but not high blood pressure, were significantly associated with an increased risk of developing RLS. © 2014 International Parkinson and Movement Disorder Society.