Table 5. Hazard ratios and 95% confidence intervals for the prospective associations between serum 25-OH vitamin D status and incident fatal and non-fatal COPD stratified by FEV1% predicted.
| Fatal and non-fatal COPD¤ | Number of events (total number) | Model 1$ HR (95% CI) | Model 2& HR (95% CI) | Model 3% HR (95% CI) |
| FEV1% predicted<60% | 68 (145) | |||
| per 10 nmol/l higher 25-OH-D | 0.96 (0.87, 1.1) | 0.95 (0.86, 1.1) | 0.96 (0.85, 1.1) | |
| P = 0.408 | P = 0.344 | P = 0.501 | ||
| 1st vitamin D quartile | 1 (reference) | 1 (reference) | 1 (reference) | |
| 2nd vitamin D quartile | 0.95 (0.52, 1.7) | 0.97 (0.52, 1.8) | 1.4 (0.66, 2.9) | |
| 3rd vitamin D quartile | 1.1 (0.55, 2.2) | 0.94 (0.46, 1.9) | 1.0 (0.49, 2.2) | |
| 4th vitamin D quartile | 0.62 (0.29, 1.3) | 0.59 (0.26, 1.3) | 0.59 (0.24, 1.4) | |
| Ptrend = 0.349 | Ptrend = 0.235 | Ptrend = 0.277 | ||
| FEV1% predicted 60–80% | 136 (885) | |||
| per 10 nmol/l higher 25-OH-D | 0.97 (0.90, 1.0) | 0.97 (0.90, 1.0) | 0.98 (0.91, 1.1) | |
| P = 0.367 | P = 0.442 | P = 0.650 | ||
| 1st vitamin D quartile | 1 (reference) | 1 (reference) | 1 (reference) | |
| 2nd vitamin D quartile | 0.58 (0.36, 0.93) | 0.59 (0.37, 0.96) | 0.56 (0.34, 0.92) | |
| 3rd vitamin D quartile | 0.67 (0.42, 1.1) | 0.69 (0.43, 1.1) | 0.74 (0.45, 1.2) | |
| 4th vitamin D quartile | 0.74 (0.47, 1.2) | 0.75 (0.47, 1.2) | 0.78 (0.47, 1.3) | |
| Ptrend = 0.176 | Ptrend = 0.221 | Ptrend = 0.392 | ||
| FEV1% predicted >80% | 171 (9493) | |||
| per 10 nmol/l higher 25-OH-D | 0.92 (0.87, 0.98) | 0.92 (0.86, 0.98) | 0.96 (0.90, 1.0) | |
| P = 0.011 | P = 0.013 | P = 0.222 | ||
| 1st vitamin D quartile | 1 (reference) | 1 (reference) | 1 (reference) | |
| 2nd vitamin D quartile | 0.55 (0.35, 0.84) | 0.55 (0.35, 0.84) | 0.63 (0.41, 0.98) | |
| 3rd vitamin D quartile | 0.79 (0.54, 1.2) | 0.81 (0.55, 1.2) | 1.0 (0.70, 1.6) | |
| 4th vitamin D quartile | 0.51 (0.33, 0.79) | 0.52 (0.33, 0.81) | 0.68 (0.43, 1.1) | |
| Ptrend = 0.018 | Ptrend = 0.025 | Ptrend = 0.405 |
¤
Persons with a diagnosis of COPD before baseline were excluded. Complete case analysis.
$
Adjusted for study population.
&
Further adjusted for gender, education, and season.
%
Further adjusted for alcohol consumption, smoking, leisure time physical activity, intake of fish, and BMI.
Abbreviations: CI, confidence interval; COPD, chronic obstructive pulmonary disease; BMI, body mass index; HR, hazard ratio; 25-OH-D, 25-hydroxyvitamin D; FEV1% predicted, forced expiratory volume in one second in % of predicted.