Serum 25-hydroxyvitamin D levels and lung function in adults with asthma: the HUNT Study.
The association between vitamin D status and lung function in adults with asthma remains unclear. We studied this cross-sectional association and possible modification by sex and allergic rhinitis in 760 adults (aged 19-55 years) with self-reported asthma in the Nord-Trøndelag Health Study. Serum 25-hydroxyvitamin D (25(OH)D) level <50 nmol·L(-1) was considered deficient. Lung function measurements included forced expiratory volume in 1 s (FEV1) % predicted, forced vital capacity (FVC) % predicted and FEV1/FVC ratio. Multiple linear regression models were used to estimate adjusted regression coefficients (β) and 95% confidence intervals. 44% of asthma adults had serum 25(OH)D levels <50 nmol·L(-1). Its associations with lung function measures seemed to be modified by sex and allergic rhinitis (p<0.03 for three-way interaction term). Overall, a serum 25(OH)D level <50 nmol·L(-1) was not associated with lung function measurements in subjects with allergic rhinitis in this asthma cohort. In men with asthma but without allergic rhinitis, however, a serum 25(OH)D level <50 nmol·L(-1) was significantly associated with lower FEV1/FVC ratio (β=-8.60%; 95% CI: -16.95%- -0.25%). Low serum 25(OH)D level was not associated with airway obstruction in most asthma adults with the exception of men with asthma but without allergic rhinitis.
Department of Public Health and General Practice, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway tricia.larose@ntnu.no.
Tricia L
TL
Larose
Department of Public Health and General Practice, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway.
Arnulf
A
Langhammer
Department of Epidemiology and Community Medicine, University of Ottawa, Ontario, Canada.
Yue
Y
Chen
Department of Emergency Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA.
Carlos A
CA
Camargo
Department of Public Health and General Practice, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway.
Pål
P
Romundstad
Department of Public Health and General Practice, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway.
Xiao-Mei
XM
Mai
D000328:Adult; D001249:Asthma / Q000097:blood* / Q000503:physiopathology*; D015415:Biomarkers; D016001:Confidence Intervals; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012016:Reference Values; D012129:Respiratory Function Tests; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
D015415:Biomarkers; D014807:Vitamin D; C104450:25-hydroxyvitamin D