Table 2.
Hazard ratios (95% CIs) of chronic obstructive pulmonary disease by quintiles of energy-adjusted baseline dietary fiber intake (1997) in 35,339 Swedish women, follow-up 2002–2014
| Quintiles of dietary fiber intake, g/day (median)a | Dietary fiber intake up to 25 g/daya | ||||||
|---|---|---|---|---|---|---|---|
| Per 1-g | P trend | ||||||
| Total fiber intake | < 17.6 (15.6) | 17.6–20.5 (19.2) | 20.6–23.1 (21.8) | 23.2–26.4 (24.6) | ≥ 26.5 (29.1) | ||
| No. of cases/no. women | 446/7016 | 314/7073 | 290/7072 | 248/7091 | 259/7087 | ||
| Age-adjusted HR (95% CI) | 1.00 | 0.67 (0.58–0.77) | 0.61 (0.53–0.71) | 0.51 (0.44–0.59) | 0.53 (0.46–0.62) | 0.92 (0.91–0.94) | < 0.001 |
| Age and smoke-adjusted HR (95% CI) | 1.00 | 0.81 (0.70–0.94) | 0.80 (0.69–0.93) | 0.72 (0.61–0.84) | 0.77 (0.66–0.90) | 0.96 (0.95–0.97) | < 0.001 |
| Multivariable-adjusted HR (95% CI)b | 1.00 | 0.84 (0.73–0.98) | 0.83 (0.72–0.97) | 0.74 (0.63–0.87) | 0.78 (0.67–0.91) | 0.97 (0.95–0.98) | < 0.001 |
| Cereal fiber | < 9.4 (7.9) | 9.4–11.6 (10.6) | 11.7–13.5 (12.5) | 13.6–16.2 (14.7) | ≥ 16.3 (18.6) | ||
| No. of cases/no. women | 372/7261 | 306/7261 | 268/7261 | 282/7261 | 329/7261 | ||
| Multivariable-adjusted HR (95% CI)b | 1.00 | 0.89 (0.76–1.03) | 0.80 (0.68–0.93) | 0.83 (0.71–0.97) | 0.84 (0.72–0.98) | 0.98 (0.96–1.00) | 0.01 |
| Fruit fiber | < 2.6 (1.8) | 2.6–4.0 (3.2) | 4.1–5.3 (4.6) | 5.4–7.5 (6.3) | ≥ 7.6 (9.4) | ||
| No. of cases/no. women | 497/7244 | 369/7278 | 242/7261 | 221/7261 | 228/7261 | ||
| Multivariable-adjusted HR (95% CI)b | 1.00 | 1.00 (0.87–1.14) | 0.78 (0.66–0.90) | 0.73 (0.61–0.86) | 0.77 (0.65–0.91) | 0.95 (0.92–0.97) | < 0.001 |
| Vegetable fiber | < 2.2 (1.6) | 2.2–3.0 (2.6) | 3.1–3.9 (3.5) | 4.0–5.3 (4.5) | ≥ 5.4 (6.7) | ||
| No. of cases/no. women | 411/7261 | 317/7261 | 282/7261 | 243/7261 | 304/7261 | ||
| Multivariable-adjusted HR (95% CI)b | 1.00 | 0.92 (0.79–1.07) | 0.90 (0.77–1.05) | 0.81 (0.69–0.96) | 0.97 (0.83–1.13) | 0.97 (0.94–1.01) | 0.08 |
HR hazard ratio, CI confidence interval
aEnergy-adjusted to 1700 kcal/day (mean energy intake in the study cohort based on FFQ 1997) using the residual method
bAdjusted for age (continuous), education (less than high school, high school, or university), BMI (< 18.5; 18.5–24.9; 25.0–29.9, or ≥ 30.0 kg/m2), walking or cycling (< 20, 20–60, > 60 min/day), smoking status and pack-years of smoking (never; past < 20, 20–39, or ≥ 40 pack-years; or current < 20, 20–39, or ≥ 40 pack-years), intake of energy (kcal/day, quintiles) and alcohol consumption (g/day, quintiles)