Fig 2. Association between dietary niacin intake and COPD odds ratio.

Solid and dashed lines represent the predicted value and 95% confidence intervals. They were adjusted for sex, age, race/ethnicity, family income, physical activity, smoking status, education level, marital status, body mass index, Serum cotinine, total energy, hypertension, high cholesterol, diabetes, coronary heart disease, stroke, cancer. only 99.5% of the data is shown.