Table 2.
Multilevel Linear Regression Modelinga of Associations Between 25-Hydroxyvitamin D and FEV1 % Predicted at Baseline and First Year of Follow-Up
| FEV1 % Predicted (Continuous Vitamin D) |
FEV1 % Predicted (Vitamin D Deficiency Status) |
|||||
|---|---|---|---|---|---|---|
| FEV1 (% Predicted) | 95% CI | P Value | FEV1 (% Predicted) | 95% CI | P Value | |
| 25-OH-vitamin D (per 10-ng/mL decrease) | –1.04 | –1.96 to –0.12 | .03 | … | … | … |
| Annual FEV1 rate of change, % predicted (per 10-ng/mL decrease) | –0.19 | –0.53 to 0.15 | .28 | … | … | … |
| 25-OH-vitamin D (< 20 vs ≥ 20 ng/mL) | … | … | … | –4.11 | –6.90 to –1.34 | .004 |
| Annual FEV1 rate of change, % predicted (< 20 vs ≥ 20 ng/mL) | … | … | … | –1.27 | –2.32 to –0.22 | .02 |
| Visit 1 vs baseline | –1.19 | –0.15 to 0.53 | .04 | –0.36 | –0.83 to 0.12 | .14 |
| Current smoking | –0.37 | –1.69 to 0.96 | .58 | –0.27 | –1.59 to 1.06 | .69 |
| Pack-years smoking (per 10 pack-years) | –0.16 | –0.56 to 0.25 | .45 | –0.16 | –0.57 to 0.24 | .43 |
| Season of blood draw | ||||||
| Spring | 3.04 | –0.23 to 6.31 | .07 | 3.07 | –0.20 to 6.33 | .07 |
| Summer | 5.56 | 2.26 to 8.85 | .001 | 5.38 | 2.09 to 8.67 | .001 |
| Fall | –1.88 | –5.19 to 1.42 | .26 | –2.02 | –5.32 to 1.28 | .23 |
| Winter | (Ref) | … | … | (Ref) | … | … |
25-OH-vitamin D = 25-hydroxyvitamin D; Ref = referent.
a
Adjusted for all covariates in table.