Correlates of Nonanemic Iron Deficiency in Restless Legs Syndrome.

Objective: Iron deficiency anemia (IDA) is a well-known cause of secondary restless legs syndrome (RLS). Iron deficiency without anemia (IDNA) is insidious, and its association with RLS is less evaluated. We investigate prevalence and features of IDNA in a consecutive cohort of patients with RLS. Methods: We included sequential primary RLS patients and RLS patients with IDA. We also recruited age- and gender-matched healthy controls. RLS mimics and other comorbidities were carefully excluded. Results: One-hundred and ninety-six RLS patients without anemia, 26 RLS patients with IDA, and 63 controls were included. 42.3% of RLS patients without anemia had iron deficiency. Women were much more susceptible for IDNA with a relative risk of 5.51 (p < 0.0001). Women with IDNA and RLS had younger age both at interview and at RLS onset compared to women with RLS without iron deficiency (NID) (P < 0.01). IDNA RLS patients showed a tendency to higher risk of severe/very severe tiredness or sleepiness during the day as compared to NID RLS patients. Furthermore, IDNA RLS patients had longer duration of RLS (P < 0.01 in men, P < 0.05 in women) and younger age at onset (only in men, P < 0.05) compared to IDA RLS patients. Conclusion: IDNA is frequent in RLS and iron deficiency may be severe despite a normal hemoglobin level. Women are at much higher risk for IDNA, and IDNA in women presents some specific clinical features. Features of IDNA RLS are different from IDA RLS. Regular screening of peripheral iron parameters even in patients with normal blood counts is recommended for timely optimal management.

Clinical features and subtypes of restless legs syndrome in Chinese population: a study of 359 patients.

BACKGROUND: The clinical spectrum of restless legs syndrome (RLS) has not been described in a Chinese population. We aim to evaluate the detailed clinical profile in a cohort of unselected RLS patients in China. METHODS: We enrolled RLS patients continuously according to the diagnostic criteria. Laboratory examinations were performed to exclude mimics and notable comorbidities. RESULTS: A total of 359 patients with RLS were enrolled. RLS symptoms were mostly symmetrical (65.2%), and purely unilateral RLS was not common (5.6%); however, unilateral dominant RLS was relatively more common. Only 1.1% of RLS patients reported no unpleasant sensations in the legs. The largest proportion of RLS patients described their uncomfortable sensation as indescribable (43.5%) and reported soreness (40.4%). In all, 8.9% of RLS patients described their abnormal sensation as painful, and 34.5% of RLS patients reported their symptoms fluctuated with seasonal trends. This population had a higher likelihood of an RLS family history. RLS patients with summer exacerbation had a younger age at RLS onset and longer disease duration (p < 0.01). Iron deficiency without anemia was common in Chinese RLS patients. Early-onset RLS patients were more likely to have a positive family history (p < 0.01), more summer worsening of symptoms (p < 0.01) and more severely disturbed peripheral iron status (p < 0.01) when compared to late-onset RLS patients. CONCLUSION: The subjective description is somewhat different, with Chinese RLS patients reporting less pain and more soreness than patients from Western countries. Seasonal fluctuation and iron deficiency without anemia are frequently seen in Chinese RLS patients and predict some other features. Differentiating these various subtypes can facilitate optimal management.

Restless legs syndrome in end stage renal disease patients undergoing hemodialysis.

BACKGROUND: The prevalence of Restless legs syndrome (RLS) in End Stage Renal Disease (ESRD) patients is higher than that in the general population. However, the associations of RLS within the ESRD population are inconsistent and RLS is usually neglected in dialysis centers, although it impairs the life quality among ESRD patients. We aim to investigate the prevalence of RLS in patients with ESRD undergoing maintenance hemodialysis and evaluate the risk factors of developing RLS and the effect of RLS on quality of life among ESRD patients. METHODS: ESRD patients undergoing maintenance hemodialysis in Shanghai General Hospital dialysis unit from July 2016 to October 2016 were enrolled in the study. RLS was diagnosed according to the criteria of the International Restless Legs Syndrome Study Group (IRLSSG). IRLSSG Severity Scale was used to evaluate the severity of RLS. Pittsburgh Sleep Quality Index (PSQI) was used to evaluate sleep quality, and Hospital Anxiety and Depression Scale (HADS) was used to estimate anxiety and depression. Serologic and historic variables were analyzed to determine predictors of RLS in the ESRD population. RESULTS: A total of 137 ESRD patients were enrolled. The prevalence of RLS among the ESRD patients was 20.44%. The risk of RLS was increased significantly in females (OR = 2.729, p = 0.032) and daily alcohol drinkers (OR = 4.716, p = 0.022). RLS increased the risks of sleep disorders (25/28, 89.3% vs 73/109, 67.0%, p = 0.02) and sedative hypnotics intake (7/28, 25.0% vs 10/109, 9.2%, p = 0.047) and impaired the sleep quality (7/109 vs 11/28, p = 0.001) according to PSQI sum scores. CONCLUSION: A high RLS prevalence among the ESRD patients undergoing hemodialysis was confirmed. ESRD patients who are women and drinking alcohol have a higher risk of RLS. The sleep quality was significantly impaired and sleeping medication use was more common among the ESRD patients with RLS.