Table 2.

Correlations between the studied variables in bad sleepers with PSQI score > 5.

	Age	Weight	Hb	Vitamin D	Duration of HD	PSQI	Ca	P	PTH	Ca × P
Age, r	1	-0.391∗∗	-0.125	0.132	-0.182	-0.210	0.026	0.127	-0.140	0.127
p value		0.005	0.381	0.356	0.201	0.140	0.856	0.381	0.349	0.378
Weight, r	-0.391∗∗	1	0.181	-0.087	-0.015	0.084	-0.050	-0.033	0.155	-0.033
p value	0.005		0.203	0.543	0.915	0.558	0.731	0.819	0.299	0.819
Hemoglobin, r	-0.125	0.181	1	-0.086	0.085	0.199	0.212	-0.259	-0.123	-0.205
p value	0.381	0.203		0.549	0.553	0.161	0.140	0.070	0.411	0.154
Vitamin D, r	0.132	-0.087	-0.086	1	-0.085	-0.397∗∗	-0.061	-0.188	-0.187	-0.187
p value	0.356	0.543	0.549		0.553	0.004	0.673	0.191	0.209	0.194
Duration of HD	-0.182	-0.015	0.085	-0.085	1	0.141	-0.057	-0.122	0.155	-0.119
p value	0.201	0.915	0.553	0.553		0.324	0.696	0.397	0.298	0.0410
PSQI, r	-0.210	0.084	0.199	-0.397∗∗	0.141	1	0.024	-0.153	-0.127	-0.142
p value	0.140	0.558	0.161	0.004	0.324		0.867	0.288	0.394	0.327
Calcium, r	0.026	-0.050	0.212	-0.061	-0.057	0.024	1	0.199	-0.383∗∗	0.387∗∗
p value	0.856	0.731	0.140	0.673	0.696	0.867		0.167	0.008	0.006
Phosphate, r	0.127	-0.033	-0.259	-0.188	-0.122	-0.153	0.199	1	0.008	0.979∗∗
p value	0.381	0.819	0.070	0.191	0.397	0.288	0.167		0.959	0.000
PTH, r	-0.140	0.155	-0.123	-0.187	0.155	-0.127	-0.383∗∗	0.008	1	-0.064
p value	0.349	0.299	0.411	0.209	0.298	0.394	0.008	0.959		0.670
Ca × P, r	0.127	-0.033	-0.205	-0.187	-0.119	-0.142	0.387∗∗	0.979∗∗	-0.064	1
p value	0.378	0.819	0.154	0.194	0.410	0.327	0.006	<0.001	0.670

Abbreviations: HD: hemodialysis; PSQI: Pittsburgh sleep quality index; PTH: parathyroid hormone.