Role of the Oral Glucose Tolerance Test (OGTT) in the idiopathic restless legs syndrome.
BACKGROUND
Restless legs syndrome (RLS) is a sensorimotor disorder characterised by a distressing urge to move the legs. Several clinical conditions have been associated with RLS, such as iron deficiency, uraemia, pregnancy, polyneuropathy and Diabetes Mellitus (DM). However the causes remain unknown in about 70-80% of cases.


OBJECTIVE
To evaluate the role of glucose metabolism abnormalities in idiopathic RLS.


METHODS
We enrolled 132 consecutive patients with idiopathic RLS associated with normal fasting glycaemia and 128 control subjects. We evaluated glucose and insulin levels after a 2-h oral glucose tolerance test (2h-OGTT) in patients and control subjects. In addition we determined Insulin Resistance (IR) by Homa-Index.


RESULTS
After 2h-OGTT, the prevalence of glucose metabolism abnormalities was significantly higher in patients with RLS than in controls (P=.002). Impaired Glucose Tolerance (IGT) was found in 54 (41%) patients and in 23 (18%) controls, while a new-diagnosed DM (NDDM) was found in 25 (19%) patients and in 8 (6%) controls. The IR showed no significant differences between patients and controls.


CONCLUSIONS
Our study suggests that IGT (prediabetes) is frequently associated with idiopathic RLS. We propose to perform a 2h-OGTT in idiopathic RLS patients with normal fasting glycaemia.
Bosco
Domenico
D
Department of Neuroscience, S Giovanni di Dio Hospital, 88900 Crotone, Italy. nico_bosco@libero.it
Plastino
Massimiliano
M
Fava
Antonietta
A
Ettore
Maria
M
Bosco
Francesca
F
Ermio
Caterina
C
Tallarigo
Federico
F
Pirritano
Domenico
D
Consoli
Domenico
D
D001706:Biopsy; D015331:Cohort Studies; D003929:Diabetic Neuropathies / Q000150:complications / Q000378:metabolism / Q000503:physiopathology; D005260:Female; D005947:Glucose / Q000378:metabolism*; D005951:Glucose Tolerance Test / Q000379:methods*; D006801:Humans; D006943:Hyperglycemia / Q000150:complications / Q000175:diagnosis / Q000378:metabolism; D007333:Insulin Resistance / Q000502:physiology; D007866:Leg / Q000294:innervation / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated / Q000378:metabolism / Q000473:pathology; D036421:Nerve Fibers, Unmyelinated / Q000378:metabolism / Q000473:pathology; D010525:Peripheral Nerves / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D011236:Prediabetic State / Q000150:complications* / Q000175:diagnosis / Q000378:metabolism*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012148:Restless Legs Syndrome / Q000209:etiology* / Q000378:metabolism* / Q000503:physiopathology; D012307:Risk Factors; D012680:Sensitivity and Specificity
D005947:Glucose