Vitamin D insufficiency and severe asthma exacerbations in Puerto Rican children.
BACKGROUND
Vitamin D insufficiency (a serum 25(OH)D <30 ng/ml) has been associated with severe asthma exacerbations, but this could be explained by underlying racial ancestry or disease severity. Little is known about vitamin D and asthma in Puerto Ricans.


OBJECTIVE
To examine whether vitamin D insufficiency is associated with severe asthma exacerbations in Puerto Rican children, independently of racial ancestry, atopy, and time outdoors.


METHODS
A cross-sectional study was conducted of 560 children ages 6-14 years with (n = 287) and without (n = 273) asthma in San Juan, Puerto Rico. We measured plasma vitamin D and estimated the percentage of African racial ancestry among participants using genome-wide genotypic data. We tested whether vitamin D insufficiency is associated with severe asthma exacerbations, lung function, or atopy (greater than or equal to one positive IgE to allergens) using logistic or linear regression. Multivariate models were adjusted for African ancestry, time outdoors, atopy, and other covariates.


RESULTS
Vitamin D insufficiency was common in children with (44%) and without (47%) asthma. In multivariate analyses, vitamin D insufficiency was associated with higher odds of greater than or equal to one severe asthma exacerbation in the prior year (odds ratio [OR], 2.6; 95% confidence interval [CI], 1.5-4.9; P = 0.001) and atopy, and a lower FEV(1)/FVC in cases. After stratification by atopy, the magnitude of the association between vitamin D insufficiency and severe exacerbations was greater in nonatopic (OR, 6.2; 95% CI, 2-21.6; P = 0.002) than in atopic (OR, 2; 95% CI, 1-4.1; P = 0.04) cases.


CONCLUSIONS
Vitamin D insufficiency is associated with severe asthma exacerbations in Puerto Rican children, independently of racial ancestry, atopy, or markers of disease severity or control.
Division of Pediatric Pulmonary Medicine, Allergy and Immunology, Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, 4401 Penn Avenue, Pittsburgh, PA 15224, USA.
John M
JM
Brehm
Edna
E
Acosta-Pérez
Lambertus
L
Klei
Kathryn
K
Roeder
Michael
M
Barmada
Nadia
N
Boutaoui
Erick
E
Forno
Roxanne
R
Kelly
Kathryn
K
Paul
Jody
J
Sylvia
Augusto A
AA
Litonjua
Michael
M
Cabana
María
M
Alvarez
Angel
A
Colón-Semidey
Glorisa
G
Canino
Juan C
JC
Celedón
D000293:Adolescent; D001249:Asthma / Q000209:etiology*; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D011647:Puerto Rico; D044469:Racial Groups; D012129:Respiratory Function Tests; D012720:Severity of Illness Index; D014807:Vitamin D / Q000097:blood; D014808:Vitamin D Deficiency / Q000150:complications*
D014807:Vitamin D