Association of free vitamin D3 concentrations and asthma treatment failures in the VIDA Trial.
Ann Allergy Asthma Immunol
; 121(4): 444-450.e1, 2018 10.
Article
em En
| MEDLINE
| ID: mdl-29908319
ABSTRACT
BACKGROUND:
Use of vitamin D3 serum concentrations as a biomarker of vitamin D status is questionable because of variation in vitamin D binding protein.OBJECTIVE:
To determine associations between free vitamin D3 concentrations and rates of treatment failure and exacerbations in patients with asthma participating in the Vitamin D Add-on Therapy Enhances Corticosteroid Responsiveness in Asthma (VIDA) trial.METHODS:
Free concentrations were directly measured by enzyme-linked immunosorbent assay and stratified into low, medium, and high groups less than 5pg/mL (nâ¯=â¯65), 5 to 9pg/mL (nâ¯=â¯84), and greater than 9pg/mL (nâ¯=â¯48) after 12 weeks of supplementation with oral vitamin D3 and associated with outcomes.RESULTS:
Outcomes did not associate with free concentrations overall treatment failure rates were 0.60 (95% confidence interval [CI] 0.46-0.78), 0.53 (95%CI 0.40- 0.70), and 0.69 (95%CI 0.54-0.90)/person-year (Pâ¯=â¯.51), respectively; overall exacerbation rates were 0.28 (95%CI 0.17-0.48), 0.15 (95%CI 0.08-0.30) and 0.42 (95%CI 0.27-0.66)/person-year (Pâ¯=â¯.22). Mean (standard deviation) baseline free concentrations were lower in non-Hispanic blacks and Hispanics compared with non-Hispanic whites 4.10 (1.33) and 4.38 (1.11) pg/mL vs 5.16 (1.65) pg/ml, (P < .001 and Pâ¯=â¯0.038), respectively. Mean (standard deviation) baseline free concentrations differed between females and males 4.57 (1.58) and 5.08 (1.41) (Pâ¯=â¯.026); and between non-overweight (body mass index [BMI] < 25) and overweight (BMI > 25) 5.45 (1.86) vs 4.54 (1.39) (P < .001). The free fraction differed by race and sex but not by BMI.CONCLUSION:
The use of free concentrations was inferior to total concentrations as a biomarker of efficacy of vitamin D3 supplementation in VIDA trial participants. Future studies of vitamin D status in patients with asthma should measure both free and total concentrations to better understand which marker of vitamin D function is most informative.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Asma
/
Fatores Sexuais
/
Falha de Tratamento
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Colecalciferol
/
Suplementos Nutricionais
Tipo de estudo:
Clinical_trials
/
Diagnostic_studies
/
Etiology_studies
/
Risk_factors_studies
Limite:
Adult
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Female
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Humans
/
Male
Idioma:
En
Revista:
Ann Allergy Asthma Immunol
Assunto da revista:
ALERGIA E IMUNOLOGIA
Ano de publicação:
2018
Tipo de documento:
Article