Ethnic differences in the prevalence and predictors of restless legs syndrome between Hispanics of Mexican descent and non-Hispanic Whites in San Diego county: a population-based study

Abstract

Study objectives: To investigate the prevalence and predictors of RLS in Hispanics of Mexican descent (HMD) and non-Hispanic whites (NHW).

Design: A population-based random digit dialing telephone questionnaire.

Setting: San Diego County California

Participants: 1,754 HMD and 1,913 NHW adults ≥ 18 years of age able to participate in a telephone interview in English or Spanish.

Interventions: None.

Measurements and results: RLS was defined by the presence of all 4 criteria of the International Restless Legs Study Group. Sleepiness was measured by the Epworth Sleepiness Scale. Acculturation was evaluated using the Short Acculturation Scale for Hispanics. Risk factors for RLS were by self-report. The survey was conducted in the subject's language of choice. RLS prevalence was significantly lower in HMD than in NHW (14.4% vs.18.3%, p = 0.002). High acculturation HMD had a significantly greater RLS prevalence than the low acculturation group (17.4% vs. 12.8%, p = 0.008). Predictors of RLS varied between HMD and NHW. Female gender (OR 1.40, 95% CI 1.04, 1.90, p = 0.027), smoking (OR 1.82, 95% CI 1.27, 2.61, p = 0.001), and acculturation (OR 1.47, 95% CI 1.10, 1.97, p = 0.009) were independent predictors of RLS in HMD, while only older age (OR 1.01, 95% CI 1.0, 1.02) was an independent predictor of RLS for NHW.

Conclusion: The prevalence of RLS was significantly lower in HMD than in NHW, and significantly greater in high acculturation HMD. Our data suggest that risk factors for RLS vary by race/ethnicity and acculturation is an independent risk for RLS in HMD.

Figure 1. Prevalence of restless legs syndrome by ethnicity, age, and gender

The RLS prevalence was significantly lower in HMD than in NHW (14.4% vs.18.3%, p = 0.002). Younger HMD men* (age 18 to 47 years) had significantly lower prevalence of RLS than younger NHW men (10.9% vs. 14.9%; Pearson χ² 2-sided, p = 0.068; Fisher exact test, 1-sided, p = 0.043). The prevalence of RLS was not different in older men and women regardless of ethnicity.

Figure 2. Prevalence of restless legs syndrome by acculturation, age, and gender

The high acculturation HMD group had significantly higher prevalence of RLS when compared to the low acculturation group (17.4% vs. 12.8%, p = 0.008). The low acculturation younger men* had significantly lower prevalence of restless legs syndrome (7.4% vs. 15.4%) than the high acculturation younger men (Pearson χ², 2-sided, p = 0.003). There was also a large difference in the RLS prevalence of the low and high acculturation older men, but this was not statistically significant (p = 0.147).