Restless Legs Syndrome in patients after renal transplantation.
BACKGROUND
There is an almost complete lack of information on the epidemiology of sleep disorders in kidney-transplanted patients. In this report the authors assess the prevalence and clinical correlates of restless legs syndrome (RLS) in kidney-transplanted (Tx) patients. They also analyze the impact of declining renal function on this condition in the Tx population. Finally, the prevalence of RLS was compared between waitlisted dialysis patients (WL), and the Tx group.


METHODS
In a cross-sectional study enrolling 992 patients (816 Tx and 176 WL), the presence of RLS was assessed using the Restless Legs Syndrome Questionnaire. Clinical and sociodemographic data were collected from the patients' medical records.


RESULTS
In transplanted patients, the prevalence of RLS was 4.8%. RLS was associated strongly with declining renal function. In groups formed on the basis of estimated glomerular filtration rate (eGFR), the prevalence of RLS was 1.8%, 5.1%, 6.5%, and 23.5% in patients with eGFR greater than 60 mL/min/1.73 m 2 ; eGFR 30 to 59 mL/min/1.73 m 2 ; eGFR 15 to 29 mL/min/1.73 m 2 ; and eGFR less than 15 mL/min/1.73 m 2 , respectively (P < 0.001). There was also a significant association between RLS and lower serum hemoglobin, higher number of self-reported comorbid conditions, and higher prevalence of iron deficiency. RLS was significantly less frequent in patients taking steroids than in patients not taking this medication (4% versus 9%, P < 0.05). In multivariate analysis, not taking steroids, eGFR, self-reported comorbidity, and iron deficiency were significant and independent predictors of RLS. Dialysis treatment was associated with increased odds for RLS (odds ratio 2.2; 95% confidence interval 1.11 to 4.35; P < 0.05) even after adjusting for serum hemoglobin and comorbidity.


CONCLUSIONS
The prevalence of RLS is significantly lower in Tx patients than in patients on maintenance dialysis. Declining renal function is associated with increasing prevalence of the condition.
Molnar
Miklos Zsolt
MZ
Institute of Behavioral Sciences, Semmelweis University, Budapest, Hungary.
Novak
Marta
M
Ambrus
Csaba
C
Szeifert
Lilla
L
Kovacs
Agnes
A
Pap
Judit
J
Remport
Adam
A
Mucsi
Istvan
I
D000740:Anemia; D018798:Anemia, Iron-Deficiency; D015992:Body Mass Index; D015897:Comorbidity; D003430:Cross-Sectional Studies; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007668:Kidney / Q000098:blood supply / Q000503:physiopathology; D016030:Kidney Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011159:Population Surveillance / Q000379:methods; D015995:Prevalence; D006435:Renal Dialysis / Q000009:adverse effects; D051437:Renal Insufficiency / Q000097:blood / Q000503:physiopathology; D012148:Restless Legs Syndrome / Q000453:epidemiology* / Q000503:physiopathology / Q000517:prevention & control; D016353:Self-Examination
D007166:Immunosuppressive Agents