Table 2.

Association of dietary niacin intake and erectile dysfunction risk before propensity score matching

Variable	Model 1		Model 2		Model 3		Model 4
	OR (95% CI)	P	OR (95% CI)	P	OR (95% CI)	P	OR (95% CI)	P
Dietary niacin	0.97 (0.96–0.98)	<0.0001	0.98 (0.97–0.99)	<0.001	0.98 (0.97–0.99)	0.01	0.98 (0.97–0.99)	0.01
Stratified by dietary niacin tertiles
Tertile 1	1		1		1		1
Tertile 2	0.66 (0.49–0.88)	0.01	0.67 (0.48–0.93)	0.02	0.69 (0.50–0.96)	0.03	0.67 (0.46–0.99)	0.05
Tertile 3	0.43 (0.32–0.58)	<0.0001	0.51 (0.37–0.71)	<0.001	0.58 (0.41–0.82)	0.01	0.56 (0.37–0.85)	0.01
P for trend		<0.0001		<0.001		0.004		0.009

Model 1: unadjusted; Model 2: adjusted for age and race; Model 3: adjusted for age, race, marital status, education level, PIR, BMI categories, recreational activity, smoking status, drinking status, and total daily energy intake; Model 4: additionally adjusted for CVD, hypercholesterolemia, hypertension, diabetes, as well as testosterone levels. OR: odds ratio; CI: confidence interval; BMI: body mass index; PIR: poverty-to-income ratio; CVD: cardiovascular disease