Table 3.

Adjusted associations between vitamin D biomarkers and venous neointimal hyperplasia

Vitamin D metabolite	Tertile	Mean NIH %	Model 1a (n = 345)		Model 2b (n = 336)
			NIH % diff (95% CI)	p value	NIH % diff (95% CI)	p value
1,25(OH)2D, pm/mL	>20.49	30.4	Ref.	.22	Ref.	.57
	8.48–20.49	30.8	−0.2 (−7.67–7.27)		0.44 (−7.27–8.15)
	<8.48	35.7	5.64 (−2.01–13.28)		3.92 (−4.24–12.09)
25(OH)D, ng/mL	>30	29.7	Ref.	.28	Ref.	.36
	20–30	32.2	2.41 (−5.14–9.97)		4.35 (−3.68–12.38)
	<20	35	6 (−1.43–13.44)		5.81 (−2.38–14.01)
Bioavailable 25(OH)D, ng/mL	>2.95	30.9	Ref.c	.15	Ref.d	.25
	1.67–2.95	31.1	1.59 (−5.98–9.14)		1.75 (−6.01–9.50)
	<1.67	35.4	7.56 (−0.65–15.77)		7.1 (−1.78–15.98)
24,25(OH)2D3, ng/mL	>0.44	32.7	Ref.	.81	Ref.	.72
	0.18–0.44	32.5	2.47 (−5.16–10.10)		2.97 (−4.96–10.90)
	<0.18	31.8	1.01 (−7.32–9.33)		0.66 (−7.94–9.26)

NIH = neointimal hyperplasia; diff = difference; CI = confidence interval.

^aModel 1 adjusted for age, sex, and black race.

^bModel 2 adds adjustment for body mass index, maintenance dialysis status, previous diabetes, education, systolic blood pressure, smoking status, and use of calcitriol, paricalcitol, and vitamin D supplementation.

^cn = 344 overall.

^dn = 335 overall.