TABLE 2.
VITAMIN D, SELECTED COVARIATES, SEVERE ASTHMA EXACERBATIONS, AND MEASURES OF ALLERGY AND LUNG FUNCTION IN PUERTO RICAN CHILDREN*
| Cases |
Control Subjects |
|||||
| Covariates | Vitamin D <30 ng ml | Vitamin D ≥30 ng ml | P for Difference† | Vitamin D <30 ng ml | Vitamin D ≥30 ng ml | P for Difference† |
| Age, yr | 11 (3) | 9.5 (2.5) | <0.001 | 11 (2) | 9.7 (2.7) | <0.001 |
| Female sex | 64 (50%) | 52 (33%) | 0.002 | 78 (61%) | 64 (44%) | 0.006 |
| Body mass index, z score | 0.89 (1.08) | 0.56 (1.23) | 0.02 | 0.6 (1.13) | 0.4 (1.14) | 0.1 |
| At least one parent graduated from high school | 104 (82%) | 131 (82%) | 1 | 106 (83%) | 109 (75%) | 0.1 |
| Household income <$15,000 per yr | 83 (66%) | 110 (71%) | 0.5 | 74 (59%) | 99 (73%) | 0.01 |
| Private or employer-based health insurance | 42 (33%) | 45 (28%) | 0.4 | 50 (39%) | 45 (31%) | 0.2 |
| Parental history of asthma | 82 (65%) | 111 (70%) | 0.3 | 43 (34%) | 43 (30%) | 0.5 |
| Current exposure to environmental tobacco smoke | 53 (42%) | 78 (49%) | 0.2 | 47 (37%) | 52 (36%) | 0.9 |
| Use of inhaled corticosteroids in the prior 6 mo | 44 (35%) | 46 (29%) | 0.3 | |||
| Bla g in house dust, μg/g‡ | 0.37 (0.76) | 0.32 (0.7) | 0.6 | 0.2 (0.63) | 0.37 (0.71) | 0.04 |
| Der p in house dust, μg/g‡ | 0.78 (0.47) | 0.58 (0.52) | 0.001 | 0.63 (0.52) | 0.67 (0.49) | 0.5 |
| Percent African ancestry | 26 (11) | 25 (12) | 0.6 | 25 (13) | 24 (12) | 0.3 |
| Virtually always outdoors | 28 (22%) | 50 (31%) | 0.08 | 29 (23%) | 39 (27%) | 0.4 |
| Vitamin D drawn in the summer | 39 (31%) | 54 (34%) | 0.6 | 58 (45%) | 60 (41%) | 0.5 |
| High vitamin D intake in diet | 80 (63%) | 119 (75%) | 0.03 | 59 (46%) | 88 (61%) | 0.02 |
| Prebronchodilator FEV1, ml§ | 2,030 (685) | 1,787 (638) | 0.003 | 2,225 (727) | 1,877 (733) | 0.0001 |
| Prebronchodilator FEV1/FVC | 80 (10) | 82 (9) | 0.1 | 84 (8) | 83 (9) | 0.2 |
| Total IgE, IU/ml‡ | 2.5 (0.7) | 2.4 (0.7) | 0.3 | 2.2 (0.7) | 2.2 (0.7) | 0.9 |
| ≥1 positive allergen-specific IgE to allergens | 97 (76%) | 98 (62%) | 0.01 | 64 (50%) | 70 (49%) | 0.8 |
| ≥1 severe asthma exacerbation in the prior year | 80 (63%) | 73 (46%) | 0.003 | |||
| ≥1 hospitalization for asthma in the prior year | 35 (28%) | 25 (16%) | 0.01 | |||
| ≥1 Emergency department/urgent care visit requiring steroids in the prior year | 43 (34%) | 37 (23%) | 0.04 | |||
| Intravenous or oral steroids for asthma in the prior year | 66 (52%) | 64 (40%) | 0.04 | |||
*
Values are the number (%) for binary variables or mean (SD) for continuous variables.
†
P for difference between insufficient and sufficient vitamin D levels, t test for continuous variables, chi-square for binary variables.
‡
Allergen levels and total IgE were transformed to a logarithmic (log10) scale.
§
FEV1 presented as absolute values because of lack of predicted values for Puerto Ricans.