Table 1.

Baseline characteristics of men according to serum 25(OH)D level

Quartile (n) (ng/mL)	Quartile 1 (n = 245) (4.20–14.19)	Quartile 2 (n = 245) (14.20–18.99)	Quartile 3 (n = 249) (19.00–24.19)	Quartile 4 (n = 248) (24.20–51.90)	P value
25(OH)D, ng/mL	10.90 ± 2.28	16.53 ± 1.39	21.41 ± 1.50	29.67 ± 5.34	<  0.001
Age, yr	73.01 ± 4.87	72.38 ± 4.14	72.59 ± 4.47	73.27 ± 4.87	0.132
BMI, kg/m2	23.99 ± 2.63	24.19 ± 2.61	23.65 ± 2.67	23.60 ± 2.90†	0.053
Waist, cm	87.49 ± 8.13	86.68 ± 8.44	86.43 ± 8.78	83.48 ± 9.33*†‡	<  0.001
SBP, mmHg	125.89 ± 14.50	128.51 ± 14.24	129.70 ± 14.41	128.86 ± 13.88	0.370
DBP, mmHg	74.10 ± 8.91	73.68 ± 9.28	75.23 ± 8.35	73.02 ± 7.90	0.420
Current smoking	42 (17.1)	53 (21.6)	36 (14.5)	53 (21.4)	0.117
Current drinking	205 (66.6)	194 (64.2)	138 (58)	72 (51.8)	0.011
Exercise	151 (61.4)	164 (66.9)	164 (65.9)	132 (53.2)	0.007
eGFR	77.5 ± 15.11	79.8 ± 14.03	81.06 ± 13.19*	80.13 ± 13.44	0.036
PTH	39.68 ± 14.13	38.07 ± 17.25	35.80 ± 12.07	33.83 ± 11.62*†	<  0.001
Glucose, mg/dL	101.59 ± 23.61	100.47 ± 20.17	99.91 ± 19.90	97.50 ± 19.93	0.171
Insulin, IU/L	7.53 ± 8.31	7.57 ± 12.22	6.12 ± 4.26	5.18 ± 3.26*†	0.001
HOMA-IR	1.93 ± 2.24	1.86 ± 2.42	1.55 ± 1.24	1.29 ± 0.99*†	<  0.001
Total cholesterol, mg/dL	174.51 ± 32.91	172.92 ± 33.72	173.93 ± 33.09	163.70 ± 29.95*†‡	<  0.001
Triglyceride, mg/dL	138.69 ± 78.55	128.43 ± 71.30	125.45 ± 61.22	110.31 ± 46.04*†	<  0.001
HDL cholesterol, mg/dL	45.99 ± 12.13	47.89 ± 12.56	46.98 ± 10.45	48.15 ± 11.26	0.157
Number of MetS components	2.22 ± 1.30	2.16 ± 1.23	2.02 ± 1.25	1.73 ± 1.18*†	<  0.001

Data were shown as mean ± SD or number (%). 25(OH)D, vitamin D3, BMI body mass index, SBP systolic blood pressure, DBP diastolic blood pressure, eGFR estimated glomerular filtration rate, HOMA-IR homeostatic model assessment - insulin resistance, HDL high density lipoprotein, MetS metabolic syndrome. * vs. Q1, † vs. Q2, ‡ vs. Q3