Pregnancy accounts for most of the gender difference in prevalence of familial RLS

Received 27 February 2009; received in revised form 8 April 2009; accepted 16 April 2009.

Abstract

Objective

This study was designed to evaluate the associated risk of RLS with pregnancy in relation to the family history and the age of symptom onset of RLS.

Methods and subjects

Data from a prior RLS family history study in which 1019 subjects (527 males, 492 females) were interviewed, provided a diagnosis and characterization of RLS and determination of pregnancy status on which the current study analysis was undertaken.

Results

In the family members of RLS probands, the prevalence of RLS was significantly higher for parous women than for nulliparous women (49.5% vs. 33.7%, OR=1.92, 95% CI=1.16–3.19) or for men (49.5% vs. 30.0%, OR 2.29, 1.69–3.10), but no different for nulliparous women compared to men (33.7% vs. 30.0%, OR 1.19, 0.72–1.96). When only those whose RLS started at or after age 30 were considered, similar differences occurred. These differences were not observed among family members of control probands.

Conclusions

These data indicate pregnancy has a major impact on the risk of developing RLS for those with a family history of RLS. This pregnancy effect appears to account for most of the gender differences often reported in overall RLS prevalence data.

Keywords: Pregnancy and RLS, RLS, Restless legs syndrome, Familial RLS, RLS prevalence, Gender and RLS

a Dept. of Psychology and Brain Science, Johns Hopkins Univ., Baltimore, MD, USA

b UMDNJ-RW Johnson Medical Center, New Brunswick, NJ, USA

c Dept. of Neurology, Johns Hopkins Univ., Baltimore, MD, USA

Corresponding author. Address: Dept. of Neurology, Johns Hopkins Univ., Asthma and Allergy, Rm. 1B75B, 5501 Hopkins Bayview Circle, Baltimore, MD 21224, USA. Tel.: +1 410 550 2609; fax: +1 410 550 3364.

1 Deceased.

PII: S1389-9457(09)00189-0

doi:10.1016/j.sleep.2009.04.005

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