Asthma Is Associated With Restless Leg Syndrome in Females: A Retrospective Population-Based Cohort Study

Abstract

Background:

Evidence regarding the association between asthma and restless leg syndrome is limited and inconsistent. The goal of the study was to investigate whether women diagnosed as having asthma were at a greater risk of restless leg syndrome than age-matched unaffected women.

Methods:

We conducted a nationwide population-based retrospective study by using data retrieved from the Taiwan National Health Insurance Research Database during the period of 2000—2008 with follow-up through 2013. The current analysis included 33, 964 women aged above 20 years with newly diagnosed asthma and using asthma-related medications and 37, 220 age-matched women without asthma. A Cox proportional hazards regression model was used to estimate the risks of restless leg syndrome in women with asthma as compared with those without asthma.

Results:

The overall risk of restless leg syndrome in the asthma group was 1.40-fold higher (95% confidence interval = 1.11—1.77) than that in the non-asthma group. A stratified analysis by age and asthma comorbidity further revealed that the risk of restless leg syndrome was significantly higher, regardless of asthma status, in those age > 60 y than in the younger age group (20—39 years old).

Conclusions:

Compared with women without asthma, women with asthma of above 65 age are at a higher risk of restless leg syndrome. Additional studies are warranted to elucidate the mechanism (s) underlying the association between asthma and a higher risk of restless leg syndrome.