Table 3.

Association Between Dietary Niacin Intake and Rheumatoid Arthritis in Categorical Variables

Participants	OR	95% CI1	P-value	P for interaction
Age				0.855
<40	0.98	0.94–1.02	0.300
≥40	0.97	0.96–0.99	0.001
Race				0.225
Mexican American	0.96	0.93–0.99	0.007
Other Hispanic	0.96	0.92–0.99	0.009
Non-Hispanic White	0.97	0.95–0.99	<0.001
Non-Hispanic Black	0.97	0.96–0.99	0.008
Other race	1.00	0.96–1.03	0.800
PIR				0.008
≤1.3	0.98	0.97–0.99	0.042
1.3–3.5	0.97	0.95–0.99	0.017
>3.5	0.95	0.92–0.99	0.007
Education				0.002
Did not graduate from high school	0.98	0.96–1.00	0.088
Graduated from high school	0.99	0.97–1.02	0.500
College education or above	0.95	0.93–0.97	<0.001
BMI (kg/m2)				0.027
<25	0.96	0.93–0.98	0.002
25–30	0.98	0.96–1.01	0.200
≥30	0.97	0.95–0.99	<0.001
Smoking				0.001
Never smoking	0.96	0.94–0.98	<0.001
Former smoking	0.96	0.94–0.98	<0.001
Now Smoking	0.99	0.97–1.01	0.400
Alcohol drinking				0.614
No	0.97	0.95–0.99	0.002
Yes	0.97	0.95–0.99	0.002
Diabetes				0.247
No	0.97	0.96–0.99	<0.001
Yes	0.96	0.93–0.99	0.004
Hypertension				0.874
No	0.97	0.94–0.99	0.011
Yes	0.97	0.96–0.99	0.004

Note: Interaction term p-values adjusted for age, race, PIR, education level, BMI, alcohol consumption, smoking, diabetes, hypertension, white blood cell count, red blood cell count, mean platelet volume, systemic immune-inflammatory index.