Heart rate variability is decreased in chronic kidney disease but may improve with hemoglobin normalization

• Background: Cardiac autonomic function can be measured by heart rate variability (HRV). Dialysis patients have an abnormally low HRV and are at increased risk for sudden death. A reduction in HRV is associated with anemia. HRV was therefore measured in patients with chronic kidney disease (CKD) after hemoglobin normalization. Methods: Sixteen nondiabetic patients with CKD stage 4 (glomerular filtration rate 23.7 13.9 ml/min) and renal anemia received epoetin aiming at a hemoglobin level of 135-150 g/L. HRV was measured by 24-hour Holter electrocardiogram at baseline and after hemoglobin normalization and in a reference group consisting of 16 volunteers without impairment of renal function. Results: Hemoglobin level increased from 100.7 12.6 g/L to 142.4 7.2 g/L during the study. At baseline, HRV measured in the time domain as the standard deviation of all normal RR intervals in the entire 24-hour electrocardiogram (SDNN) was 116.3 39.2 ms compared with 147.5 27.2 ms in the reference group (p<0.05). The frequency domain measures low-frequency power and total power were 367.7 350.2 ms2 and 1,368.9 957.4 ms2 compared with 717.3 484.5 ms2 and 2,228.3 1142.4 ms2 (p<0.05) in the reference group. After hemoglobin normalization there was an increase in low-frequency power to 498.3 432.7 ms2 (p<0.05) and in total power to 1,731.0 1,069.4 ms2 (p<0.05) while SDNN remained at 120.9 33.8 ms (p=ns). Conclusions: CKD patients not yet on dialysis had a reduced HRV, indicating impaired autonomic function, compared with a reference group without impaired renal function. Hemoglobin normalization improved but did not fully normalize HRV. The clinical significance of this deserves further investigation. 

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine (hsv//eng)

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Urologi och njurmedicin (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Urology and Nephrology (hsv//eng)

Nyckelord

Adult

Aged

Anemia/physiopathology

Blood Pressure

Chronic Disease

Female

Heart Rate

Hemoglobins/*analysis

Humans

Kidney Diseases/blood/*physiopathology

Male

Middle Aged

MEDICINE

MEDICIN

Internal medicine

Invärtesmedicin

Kidney diseases

Njursjukdomar

Invärtesmedicin

Internal Medicine

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)