Periodic Limb Movements in Sleep Contribute to Further Cardiac Structure Abnormalities in Hemodialysis Patients with Restless Legs Syndrome

Study Objectives: In hemodialysis (HD) patients, restless legs syndrome (RLS) and periodic limb movements in sleep (PLMS) constitute common sleep disorders. Recent findings indicate a role for PLMS as a risk factor in the development of new or the aggravation of existing cardiovascular disease. The aim of the current study was to investigate the association of PLMS with indices of cardiac morphology and function in HD patients with RLS as a potential pathway by which PLMS could alter cardiovascular risk. Methods: Based on PLMS diagnosis by an overnight polysomnographic evaluation, 19 stable HD-RLS patients were divided into the PLMS group (n = 10) and the non-PLMS group (n = 9). During the overnight assessment, nocturnal blood pressure (BP) indices were also assessed. Left ventricular (LV) dimensions were examined by M-mode echocardiography, whereas LV diastolic function was evaluated by conventional Doppler and tissue Doppler imaging the following day. Results: LV internal diameter in diastole was significantly increased in the PLMS group (4.96 +/- 0.61 vs 4.19 +/- 0.48 cm, p = 0.007), leading to a significantly increase in LV mass (202 +/- 52 vs 150 +/- 37 g, p = 0.026). In contrast, no between group differences were observed in diastolic function indices (p > 0.05). Conclusions: These are the first data to associate severe PLMS with further LV structure abnormalities in HD patients with RLS