Table 3.

Multiple stepwise regression models predicting 24-hour heart rate variability parameters (n=118)

Dependent VariableIndependent VariableCorrelation CoefficientRegression Coefficient (95% Confidence Interval)P
Mean NNiPTH−0.25−0.03 (−0.05 to −0.01)0.007
SDNNDBP−0.21−0.68 (−1.26 to −0.10)0.02
SDANNHemoglobin0.220.58 (0.10 to 1.07)0.02
SDANNCalcium−0.19−8.66 (−16.96 to −0.35)0.04
rMSSDHemoglobin0.310.13 (0.06 to 0.20)0.001
rMSSDTriglyceride−0.18−1.63 (−3.26 to −0.00)0.05
pNN50%SBP−0.27−0.05 (−0.08 to −0.02)0.004
pNN50%Glucose0.190.33 (0.01 to 0.65)0.04
Mean heart rateiPTH0.260.00 (0.00 to 0.01)0.004
ln VLFAlbumin0.220.04 (0.01 to 0.07)0.02
ln VLFHemoglobin0.330.01 (0.01 to 0.02)<0.001
ln VLFPhosphorus0.220.11 (0.02 to 0.21)0.02
ln VLFTriglyceride−0.29−0.26 (−0.42 to −0.10)0.002
ln VLFAge−0.26−0.02 (−0.03 to −0.01)0.005
ln VLFiPTH−0.200.00 (0.00 to 0.00)0.04
ln LFAge−0.35−0.04 (−0.05 to −0.02)<0.001
ln LFHemoglobin0.300.02 (0.01 to 0.03)0.001
ln LFTriglyceride−0.22−0.27 (−0.50 to −0.04)0.02
ln HFBMI−0.23−0.12 (−0.21 to −0.03)0.01
ln LF/HFAlbumin0.320.05 (0.02 to 0.08)<0.001
ln LF/HFPhosphorus0.220.12 (0.02 to 0.21)0.02
  • Mean NN, mean normal-to-normal R–R intervals; iPTH, intact parathyroid hormone; SDNN, SD of normal-to-normal R–R intervals; DBP, diastolic BP; 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 RR intervals differing by >50 ms over 24 hours; SBP, systolic BP; VLF, very low frequency; LF, low frequency; HF, high frequency; BMI, body mass index.