Investigation of Biochemical Data in Pregnant Women Diagnosed with Restless Legs Syndrome

The Prevalence, Severity, and Predictive Factors of Restless Legs Syndrome in Pregnancy

OBJECTIVES

 The current study aimed to search the prevalence and severity of restless legs syndrome (RLS) in pregnancy according to the three trimesters and predictive factors of RLS in pregnancy based on validated diagnostic tools and a thorough literature review.

METHODS

The cross-sectional descriptive study included 500 pregnant women without comorbidities who were interviewed face-to-face. Age, height, weight, week of pregnancy, smoking, alcohol, caffeine use, regular exercise, and lab test results from the last visit were all included in the data. Only women satisfying the RLS diagnostic criteria were given the Restless Legs Syndrome Rating Scale.

RESULTS

The prevalence of RLS was found to be 29.2% with the highest rate in the third trimester (64.4%). In all trimesters, low ferritin (first trimester: p = 0.004; second trimester: p < 0.001; third trimester: p < 0.001), folic acid (first trimester: p = 0.001; second trimester: p < 0.001; third trimester: p < 0.001), vitamin B12 (first trimester: p = 0.003; second trimester: p < 0.001; third trimester: p < 0.001), and hemoglobin (first trimester: p < 0.001; second trimester: p < 0.001; third trimester: p < 0.001) levels were associated with RLS. In the second and third trimesters, low magnesium (p < 0.001 and p < 0.001, respectively) and high creatinine (p = 0.027 and p < 0.001, respectively) levels were associated with RLS. Higher thyroid-stimulating hormone and free T4 levels were associated with RLS in the third trimester but not in the first and second trimesters (median: 2.4 vs. 2.1, p < 0.001; median: 1.5 vs. 1.2, p < 0.001). In the multivariate regression analysis, age (p = 0.034, OR: 1.060, 95% CI: 1.005-1.119), present BMI (p < 0.001, OR: 1.8884, 95% CI: 1.597-2.222), BMI before conception (p < 0.001, OR: 0.607, 95% CI: 0.513-0.718), gravida (p < 0.001, OR: 2.172, 95% CI: 1.547-3.049), low ferritin level (p < 0.001, OR: 6.396, 95% CI: 0.00744-0.010405), low vitamin B12 (p < 0.001, OR: 10.347, 95% CI: 0.00120-0.00176), low folate (p < 0.001, OR: 5.841, 95% CI: 0.00616-0.01240), RLS history before conception (p = 0.013, OR: 4.963, 95% CI: 1.402-17.57), and RLS family history (p < 0.001, OR: 7.914, 95% CI: 0.18760-0.31151) were found to be predictive factors for RLS in pregnancy.

CONCLUSION

More attention is needed to RLS during pregnancy to prevent or treat this syndrome.

The Prevalence of Restless Legs Syndrome Among Pregnant Women in Saudi Arabia

INTRODUCTION

Pregnancy has been associated with restless legs syndrome (RLS). RLS is underdiagnosed in most countries. The purpose of this study was to assess the prevalence of RLS among Saudi pregnant women.

METHODS

This cross-sectional study included 459 pregnant women from all Saudi provinces between December 2022 and March 2023. A structured online questionnaire assessing demographic and pregnancy characteristics, medical conditions, sleep quality, and RLS symptoms was conducted.

RESULTS

The prevalence of RLS was 26.6% among the participants. Calcium deficiency was significantly associated with RLS (adjusted odds ratio (OR)=2.16, 95% confidence interval (CI)=1.2-3.9, p=0.01), but there was no significant association between RLS and vitamin D and iron deficiencies (p>0.05), according to multivariate binary logistic regression analysis. Moreover, RLS increased the risk of insomnia and frequent waking up (adjusted OR=4.95, 95% CI=2.50-9.83, p<0.001, and adjusted OR=2.87, 95% CI=1.55-5.32, p=0.001, respectively).

CONCLUSION

RLS is common among pregnant women in Saudi Arabia. The study indicates that RLS during pregnancy is linked to calcium deficiency and negatively affects sleep quality.

Is Restless Legs Syndrome De Facto Thyroid Disease?

While a primary role in the pathogenesis of restless legs syndrome (RLS) has been attributed to dysfunction of the dopaminergic system and impaired iron metabolism (particularly in the central nervous system), it has been hypothesized that an imbalance between thyroid hormones and dopaminergic activity may be the starting point for all aspects of RLS. Although this hypothesis was proposed more than a decade ago, it has not yet been verified beyond doubt. The main aim of this study is to compare the prevalence of RLS in a population of patients with the most common thyroid gland diseases with a population of individuals with a healthy thyroid gland. The study included 237 participants divided into smaller groups according to the thyroid disease concerning them. Each participant had a laboratory diagnosis, an ultrasound scan and an assessment of the fulfilment of RLS criteria according to the International Restless Legs Syndrome Study Group (IRLSSG) criteria. The results obtained were subjected to statistical analysis. RLS is significantly more common in patients with known thyroid disease; Hashimoto’s disease, among others, manifests a 2.56× higher risk of a positive diagnosis for RLS than the general population. The association of RLS with thyroid disease is notable, although it is difficult to conclude unequivocally that there is a cause-and-effect relationship between the two. Further investigation into a potentially autoimmune cause of restless legs syndrome should be considered.