Loss of fractal heart rate dynamics in depressive hemodialysis patients.
OBJECTIVE
To assess the relationship between depression, reduced heart rate (HR) variability, and altered HR dynamics among patients with end-stage renal disease who are receiving hemodialysis (HD) therapy.


METHODS
We analyzed the 24-hour electrocardiograms of 119 outpatients receiving chronic HD. HR variability was quantified with the standard deviation of normal-to-normal R-R intervals, the triangular index, and the powers of the high- (HF), low- (LF), very-low (VLF), and ultra-low frequency (ULF) components. Nonlinear HR dynamics was assessed with the short-term (alpha(1)) and long-term (alpha(2)) scaling exponents of the detrended fluctuation analysis and approximate entropy. The depression level was assessed using the Beck Depression Inventory, Second Edition (BDI-II). HR variability and dynamics measurements were compared by gender, diabetes, and depression with adjustment for age and serum albumin concentration.


RESULTS
Most indices of HR variability and dynamics were negatively correlated with age, serum albumin concentration, depression score, and were lower in women and patients with diabetes. The alpha(2) was inversely associated with these variables. Depressed men had significantly lower HF, LF, VLF, and marginally lower ULF than nondepressed persons after adjustment for diabetes and other covariates; no difference in depression was observed in women. The alpha(2) showed marginally significant difference in depression independent from gender and diabetes.


CONCLUSIONS
Among the patients who received HD, depression is associated with reduced HR variability and loss of fractal HR dynamics. However, the influence of depression on HR variability may vary by gender and physiological backgrounds. Further prospective studies are necessary to confirm their association with poor prognosis.
Kojima
Masayo
M
Department of Health Promotion and Preventive Medicine, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan. masayok@med.nagoya-cu.ac.jp
Hayano
Junichiro
J
Fukuta
Hidekatsu
H
Sakata
Seiichiro
S
Mukai
Seiji
S
Ohte
Nobuyuki
N
Seno
Hachiro
H
Toriyama
Takanobu
T
Kawahara
Hirohisa
H
Furukawa
Toshiaki A
TA
Tokudome
Shinkan
S
D000367:Age Factors; D000704:Analysis of Variance; D001341:Autonomic Nervous System; D015897:Comorbidity; D003866:Depressive Disorder / Q000453:epidemiology / Q000503:physiopathology*; D003920:Diabetes Mellitus / Q000453:epidemiology; D015716:Electrocardiography, Ambulatory; D005260:Female; D017709:Fractals; D006339:Heart Rate; D006801:Humans; D007564:Japan / Q000453:epidemiology; D007676:Kidney Failure, Chronic / Q000453:epidemiology / Q000523:psychology* / Q000628:therapy*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D017711:Nonlinear Dynamics; D006435:Renal Dialysis; D012307:Risk Factors; D012709:Serum Albumin; D012737:Sex Factors
D012709:Serum Albumin