Association between periodic limb movements and co-morbidities in heart failure

Abstract

Introduction Periodic limb movements (PLMs) were shown to be associated with cardiovascular diseases. There are many factors that can potentially contribute to PLMs occurrence in heart failure (HF), however, the incidence, role and causes of PLMs in HF are not fully understood. The objective of this study was to assess the incidence, severity of PLMs and their relation with co-morbidities in moderate-severe chronic HF. Materials and methods Sixty-six patients were enrolled (57 males and 9 females), median age – 56.5 (27; 77) years, body mass index – 27.6 (18.9; 49.2) kg/m 2 . HF resulted from coronary heart disease in 46 (43 males and 3 females) subjects, and from different types of cardiomyopathy in 20 (14 males and 6 females) subjects. The main inclusion criteria were the diagnosis of systolic HF, verified by Simpson ejection fraction ⩽45% at heart ultrasound (GE Vivid 7, Norway, 2008), and increased N-terminal brain natriuretic pro-hormone level. All patients underwent full polysomnography (Embla N7000, Natus, US, 2007). Results According to the sleep study 33 subjects had no abnormal limb movements [27 males and 6 females, median age – 56 years (27; 71), median PLM index – 0.6 (0; 4.7) episodes per hour of sleep). The distribution of PLMs by severity in the left 33 patients was the following. Ten patients showed mild PLMs [9 males and 1 female, median age – 56 years (48; 67); median PLM index – 11.3 (7.3; 24.1) per hour]. Nine patients had moderate PLMs [8 males and 1 female; median age – 55 (39; 77) years; median PLM index – 37 (27.1; 49.6) per hour of sleep]. Eight subjects showed severe PLMs [7 males and 1 female; median age – 59 (31; 77) years; median PLM index – 67.2 (50.8; 80.4) per hour of sleep]. There was no significant association between PLMs and co-morbid disorders, including underlying heart disease ( χ 2 = 0.8; p > 0.05); varicose veins of lower limbs ( χ 2 = 0.06; p > 0.05); sleep disordered breathing ( χ 2 = 0.1; p > 0.05); sleep apnea type ( χ 2 = 1.3; p > 0.05). However, there was a tendency towards the higher prevalence of PLMs in patients with mild and severe sleep apnea ( χ 2 = 5.2; p = 0.07). There was no significant association between PLMs incidence and prescribed therapy, including calcium channel antagonists ( χ 2 2 = 0.8; p > 0.05), beta-blockers ( χ 2 2 = 1,5; p > 0.05), any kind of diuretic( χ 2 2 = 3.6; p > 0.05), acetazolamide ( χ 2 = 0.2; p > 0.05), and thiazide diuretics ( χ 2 2 = 0.1; p > 0.05). However, there was a trend towards higher incidence of PLMs in patients taking potassium saving diuretics ( χ 2 = 3.4; p = 0.06) and loop diuretics ( χ 2 = 2.9; p = 0.08). Conclusion PLMs are highly prevalent in patients with moderate-to-severe HF, and are likely to be associated with diuretic treatment; possible association between PLMs and electrolyte changes in HF patients and their impact on prognosis needs further investigation. Acknowledgements The research leading to these results has received funding from the European Union Seventh Framework Programme [FP7/2007–2013] under grant agreement no 241558 (SICA-HF). The research leading to these results has received funding from the Russian Ministry of Science and Education within the FTP ”R&D in priority fields of the S&T complex of Russia 2007–2012” under state contract no 02.527.11.0007.