Table 2.

Baseline heart rate variability parameters of study groups

VariableControl (n=87)Stage 5 CKD Patients (n=118)PNon-PTX Group (n=81)PTX Group (n=37)
Nonfollow-Up (n=16)Successful PTX Follow-Up (n=17)Unsuccessful PTX Follow-Up (n=4)Total (n=37)
Mean 24-h HR (beats/min)76.8±8.082.3±10.9<0.00180.9±11.086.4±8.387.1±10.773.0±8.185.5±9.9
Time domain measures
 Mean NN (ms)789.3±80.7743.0±103.5<0.001756.9±107.8701.4±70.1699.7±91.5833.0±91.5712.6±87.2
 SDNN (ms)140.9±34.982.7±48.4<0.00185.8±54.980.9±33.167.8±24.694.0±27.076.1±29.3
 SDANN (ms)128.4±34.274.7±61.5<0.00178.4±71.571.9±31.157.9±25.481.0±28.166.6±28.7
 rMSSD (ms)29.8±11.219.2±9.3<0.00119.6±9.716.9±6.919.5±9.918.0±5.718.3±8.3a
 pNN50%9.2±8.73.2±4.7<0.0013.4±4.71.8±2.73.7±6.51.7±1.72.7±4.9
Frequency domain measures
 VLF (ms2)1012.8 (646.0–1571.8)232.7 (112.1–473.6)<0.001210.1 (107.4–459.2)381.2 (139.4–472.4)164.4 (107.8–484.6)570.1 (154.8–1147.5)311.8 (119.6–485.4)
 LF (ms2)177.5 (16.8–395.2)59.5 (21.6–150.5)0.0250.8 (18.3–149.2)72.9 (24.8–124.4)79.1 (46.3–165.6)65.2 (9.2–533.5)74.2 (35.7–159.7)
 HF (ms2)56.7 (1.6–189.0)26.0 (10.3–61.6)0.3727.4 (9.6–63.4)21.0 (8.0–45.7)27.6 (18.5–81.4)22.1 (3.1–84.4)24.0 (12.1–56.1)
 LF/HF4.0 (2.0–11.8)2.8 (1.5–5.3)<0.0012.3 (1.3–5.1)3.9 (2.7–5.9)3.1 (1.6–4.3)8.4 (2.0–15.3)3.5 (2.3–5.9)
 ln VLF [ln(ms2)]6.9±0.65.5±1.0<0.0015.4±1.15.7±1.15.4±1.06.1±1.15.6±1.0
 ln LF [ln(ms2)]4.5±1.74.0±1.40.033.9±1.44.2±1.54.4±1.04.0±2.14.3±1.3
 ln HF [ln(ms2)]2.9±2.63.0±1.60.673.0±1.72.8±1.83.4±1.12.4±2.43.1±1.6
 ln LF/HF1.6±1.01.0±1.0<0.0010.9±1.01.4±0.81.0±0.81.6±1.61.2±0.9
  • Data are mean ± SD or median (25th to 75th percentile). Independent samples t test was used to compare stage 5 CKD patients (n=118) with controls (n=87) and nonfollow-up patients (n=16) with successful PTX follow-up patients (n=17). The Wilcoxon rank sum test was used to compare medians of untransformed frequency domain measures. Multiple linear regression analysis was used to compare the PTX group (n=37) with the non-PTX group (n=81) and the successful PTX follow-up group (n=17) with the non-PTX group (n=81) with adjustment for age, sex, dialysis vintage, diabetes, and hypertension. PTX, parathyroidectomy; HR, heart rate; mean NN, mean normal-to-normal R–R intervals; SDNN, SD of normal-to-normal R–R intervals; SDANN, SD of 5-minute average of normal R–R intervals; rMSSD, root mean square of differences between adjacent normal R–R intervals; pNN50%, proportion of adjacent R–R intervals differing by >50 ms over 24 hours; VLF, very low frequency; LF, low frequency; HF, high frequency.

  • a P<0.05 versus non-PTX group.