The assessment of P-wave dispersion and myocardial repolarization parameters in patients with chronic kidney disease

Figures & data

Table 1. Demographic characteristics of study population.

	Patients (n = 133)	Controls (n = 32)	p value^a
Age (y)	60.8 ± 14.2	61.0 ± 12.9	.937
Gender (M/F)	79/54	20/12	.842
Diabetes Mellitus (n, %)	52 (39.1%)	None
Hypertension (n, %)	92 (69.2%)	None
Coronary artery disease (n, %)	17 (12.8%)	None
eGFR (ml/min)	25.04 ± 12.1	84.28 ± 15.7	<.001
Creatinine (mg/dL)	2.93 ± 1.36	0.88 ± 0.14	<.001
Sodium (mEq/L)	137.63 ± 3.2	136.37 ± 3.23	.054
Potassium (mEq/L)	4.99 ± 0.67	4.23 ± 0.34	<.001
Calcium (mg/dL)	8.77 ± 0.75	9 ± 0.62	.076
Phosphorus (mg/dl)	3.83 ± 0.9	3.28 ± 0.6	<.001
Albumin (g/dL)	3.9 ± 0.42	3.92 ± 0.47	.805
Uric acid (mg/dL)	7.16 ± 1.63	5.17 ± 1.33	<.001
Hemoglobline (g/dl)	12.37 ± 2.03	13.32 ± 2.05	.022

^a Significant results are given in bold.

eGRF: estimated glomerular filtration rate.

Table 2. Electrocardiography parameters of study population.

	Patients (n = 133)	Controls (n = 32)	p value^a
Pmax (msec)	106.88 ± 14.08	94.28 ± 7.20	<.001
Pmin (msec)	61.02 ± 11.15	67.10 ± 4.35	.003
P-WD (msec)	45.85 ± 12.42	27.17 ± 6.6	<.001
QTc-max (msec)	438.12 ± 49.06	428.40 ± 23.4	.104
QTc-min (msec)	366.99 ± 42.31	387.15 ± 20.5	<.001
QTc (msec)	411.1 ± 26.2	415.8 ± 23.0	.319
QTc disp (msec)	71.13 ± 27.95	41.25 ± 14.55	<.001
Tp-e max (msec)	81.04 ± 10.34	75.49 ± 10.9	.012
Tp-e min (msec)	62.25 ± 7.58	54.8 ± 6.72	<.001
Tp-e interval (msec)	71.7 ± 8.4	66.5 ± 7.4	.001
Tp-e disp (msec)	18.79 ± 7.56	20.69 ± 9.87	.314
Tp-e/QT ratio	0.19 ± 0.02	0.18 ± 0.01	.001

P_max: maximum p wave duration; P_min: minimum p-wave duration; P-WD: p-wave dispersion; QTc-max: maximum corrected QT duration; QTc-min: minimum corrected QT duration; QTc disp: QTc dispersion; Tp-e max: maximum Tp-e duration; Tp-e min: minimum Tp-e duration.

^a Significant results are given in bold.

Table 3. Bivariate correlation and multivariate linear regression analyses between increased Tp-e/QT ratio (average of all leads) and study parameters.

	Bivariate correlation		Multivariate linear regression
Parameters	r	p value	β	p value^a
Uric acid (mg/dL)	−0.164	.060	−0.156	.712
Calcium (mg/dL)	0.224**	.009	0.894	.414
Phosphorus (mg/dl)	−0.229**	.008	0.139	.875
Potassium (mEq/L)	−0.263**	.002	−2.711	.013
Hemoglobline (g/dl)	0.320**	<.001	0.116	.817
i-PTH	−0.335**	<.001	−0.015	.002
eGFR (ml/min)	0.290**	.001	0.029	.704
Age (years)	−0.110	.210	–	–
Male	−0.056	.520	–	–
Diabetes Mellitus	0.028	.751	–	–
Hypertension	0.058	.508	–	–
Coronary artery disease	0.088	.315	–	–
Albumin (g/dL)	0.109	.210	–	–
Sodium (mEq/L)	0.046	.597	–	–
Magnesium (mg/dL)	−0.112	.217	–	–
CRP (mg/dl)	−0.012	.893	–	–
Ferrite (mg/dl)	−0.075	.390	–	–

CRP: C-reactive protein; eFGR: estimated glomerular filtration rate; i-PTH: intact parathyroid test

^a Significant results are given in bold.

Table 4. Bivariate correlation and multivariate linear regression analyses between increased P-WD (average of all leads) and study parameters.

	Bivariate correlation		Multivariate linear regression
Parameters	r	p value	β	p value
Uric acid (mg/dL)	0.046	.600	–	–
Calcium (mg/dL)	−0.124	.154	–	–
Phosphorus (mg/dl)	−0.096	.273	–	–
Potassium (mEq/L)	−0.002	.983	–	–
Hemoglobine (g/dl)	−0.085	.328	–	–
i-PTH	−0.038	.668	–	–
eGFR (ml/min)	0.096	.273	–	–
Age (years)	−0.134	.124	–	–
Male	0.007	.933	–	–
Diabetes Mellitus	<0.001	1	–	–
Hypertension	0.001	.988	–	–
Coronary artery disease	0.15	.189	–	–
Albumin (g/dL)	−0.047	.589	–	–
Sodium (mEq/L)	0.132	.130	–	–
Magnesium (mg/dL)	−0.109	.228	–	–
CRP (mg/dl)	−0.067	.455	–	–
Ferrite (mg/dl)	0.062	.478	–	–

CRP: C-reactive protein; eFGR: estimated glomerular filtration rate; i-PTH: intact parathyroid test

Table 5. Results of binary logistic regression models differentiating between patients and controls groups.

Compared Outcomes	Models	% Correct	r^2	Variables	p value	Exp β (OR)	95% CI of Exp β
Patients?control groups	Y = 23.45 − 1.288 × uric acid −3.478 × potassium	96.9	0.842	Uric acid	.003	0.266	0.110–0.645
				Potassium	.003	0.031	0.003–0.299

CI: confident interval; OR: odds ratio.