Table 4.
Association Between Dietary Niacin Intake and Rheumatoid Arthritis by Age, PIR, Education Level, BMI, Smoking (95% Confidence Interval), NHANES, 2003–2016
| OR (95% CI) | |||
|---|---|---|---|
| Participants | Crude | Model I | Model II |
| Age | |||
| <40 | 0.98 (0.94–1.02) | 0.98 (0.94–1.02) | 0.98 (0.94–1.02) |
| ≥40 | 0.97 (0.96–0.99)** | 0.98 (0.97–0.99)* | 0.98 (0.97–0.99)* |
| PIR | |||
| ≤1.3 | 0.98 (0.97–0.99)* | 1.00 (0.98–1.01) | 1.00 (0.98–1.01) |
| 1.3–3.5 | 0.97 (0.95–0.99)* | 0.98 (0.96–1.01) | 0.98 (0.96–1.01) |
| >3.5 | 0.95 (0.92–0.99)** | 0.96 (0.93–0.99)* | 0.96 (0.93–0.99)* |
| Education | |||
| Did not graduate from high school | 0.98 (0.96–1.00) | 0.99 (0.97–1.01) | 0.99 (0.97–1.01) |
| Graduated from high school | 0.99 (0.97–1.02) | 1.00 (0.98–1.03) | 1.00 (0.98–1.03) |
| College education or above | 0.95 (0.93–0.97)*** | 0.97 (0.94–0.99)** | 0.97 (0.94–0.99)** |
| BMI (kg/m2) | |||
| <25 | 0.96 (0.93–0.98)** | 0.97 (0.94–1.00) | 0.97 (0.94–1.00) |
| 25–30 | 0.98 (0.96–1.01) | 1.00 (0.97–1.02) | 1.00 (0.97–1.03) |
| ≥30 | 0.97 (0.95–0.99)*** | 0.98 (0.96–0.99)* | 0.98 (0.96–0.99)* |
| Smoking | |||
| Never smoking | 0.96 (0.94–0.98)*** | 0.97 (0.95–0.99)** | 0.97 (0.95–0.99)** |
| Former smoking | 0.96 (0.94–0.98)*** | 0.97 (0.95–0.99)* | 0.98 (0.95–0.99)* |
| Now Smoking | 0.99 (0.97–1.01) | 1.00 (0.98–1.03) | 1.00 (0.98–1.03) |
Note: Crude: Unadjusted; Model I: Adjusted for age, race, PIR, education level, BMI, alcohol consumption, smoking; Model II: 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.*P-value<0.05, **P-value<0.01, ***P-value< 0.001.