INTRODUCTION: Low vitamin D levels have been associated with asthma severity in children. Young, urban African Americans (AAs) have high rates of hypovitaminosis D and asthma. Our objective was to determine associations between variants in vitamin D metabolism genes and asthma characteristics in a pilot study of young urban AAs. MATERIALS AND METHODS: Two urban AA cohorts of subjects aged 6 to 20 years (139 subjects with asthma and 74 subjects without asthma) were genotyped for 12 single nucleotide polymorphisms (SNPs) in 3 vitamin D metabolism genes: VDR (vitamin D receptor), CYP24A1 (cytochrome P450 vitamin D 24-hydroxylase), and CYP2R1 (cytochrome P450 vitamin D 25-hydroxylase). In a case-control analysis, SNPs were studied for associations with an asthma diagnosis. Within the asthmatic cohort, SNPs were analyzed for associations with quantitative asthma characteristics. All analyses were adjusted for age, sex, and body mass index percentile. RESULTS: Only the CYP2R1 SNP rs10766197 homozygous minor genotype was associated with asthma (P = 0.044). CYP24A1 SNP rs2248137 was associated with lower vitamin D levels (P = 0.006). Within the asthma cohort, multiple significant associations between SNPs and asthma characteristics were identified; VDR SNP rs2228570 was associated with the higher nighttime asthma morbidity scores (P = 0.04), lower baseline spirometric measures (P < 0.05), 1 or more positive aeroallergen skin test (P = 0.003), and increased immunoglobulin E levels (P < 0.001). DISCUSSION: This pilot study demonstrates that variants in vitamin D metabolism genes are associated with quantitative asthma characteristics in young, urban AAs. The collection of these associations provides evidence for the need for a large population-based study of vitamin D-relevant SNPs in this cohort.
INTRODUCTION: Low vitamin D levels have been associated with asthma severity in children. Young, urban African Americans (AAs) have high rates of hypovitaminosis D and asthma. Our objective was to determine associations between variants in vitamin D metabolism genes and asthma characteristics in a pilot study of young urban AAs. MATERIALS AND METHODS: Two urban AA cohorts of subjects aged 6 to 20 years (139 subjects with asthma and 74 subjects without asthma) were genotyped for 12 single nucleotide polymorphisms (SNPs) in 3 vitamin D metabolism genes: VDR (vitamin D receptor), CYP24A1 (cytochrome P450vitamin D 24-hydroxylase), and CYP2R1 (cytochrome P450vitamin D 25-hydroxylase). In a case-control analysis, SNPs were studied for associations with an asthma diagnosis. Within the asthmatic cohort, SNPs were analyzed for associations with quantitative asthma characteristics. All analyses were adjusted for age, sex, and body mass index percentile. RESULTS: Only the CYP2R1 SNP rs10766197 homozygous minor genotype was associated with asthma (P = 0.044). CYP24A1 SNP rs2248137 was associated with lower vitamin D levels (P = 0.006). Within the asthma cohort, multiple significant associations between SNPs and asthma characteristics were identified; VDR SNP rs2228570 was associated with the higher nighttime asthma morbidity scores (P = 0.04), lower baseline spirometric measures (P < 0.05), 1 or more positive aeroallergen skin test (P = 0.003), and increased immunoglobulin E levels (P < 0.001). DISCUSSION: This pilot study demonstrates that variants in vitamin D metabolism genes are associated with quantitative asthma characteristics in young, urban AAs. The collection of these associations provides evidence for the need for a large population-based study of vitamin D-relevant SNPs in this cohort.
Authors: Shanna Nesby-O'Dell; Kelley S Scanlon; Mary E Cogswell; Cathleen Gillespie; Bruce W Hollis; Anne C Looker; Chris Allen; Cindy Doughertly; Elaine W Gunter; Barbara A Bowman Journal: Am J Clin Nutr Date: 2002-07 Impact factor: 7.045
Authors: Diana L Ersfeld; D Sudhaker Rao; Jean-Jacques Body; James L Sackrison; Andrew B Miller; Nayana Parikh; Tar Lisha Eskridge; Amy Polinske; Gregory T Olson; Gordon D MacFarlane Journal: Clin Biochem Date: 2004-10 Impact factor: 3.281
Authors: D A Loisel; G Du; T S Ahluwalia; C J Tisler; M D Evans; R A Myers; R E Gangnon; E Kreiner-Møller; K Bønnelykke; H Bisgaard; D J Jackson; R F Lemanske; D L Nicolae; J E Gern; C Ober Journal: Clin Exp Allergy Date: 2016-01 Impact factor: 5.018
Authors: Andrzej T Slominski; Michal A Zmijewski; Igor Semak; Blazej Zbytek; Alexander Pisarchik; Wei Li; Jordan Zjawiony; Robert C Tuckey Journal: Anticancer Agents Med Chem Date: 2014-01 Impact factor: 2.505
Authors: Aledie Navas-Nazario; Fang Yong Li; Veronika Shabanova; Pnina Weiss; David E C Cole; Thomas O Carpenter; Alia Bazzy-Asaad Journal: Ann Allergy Asthma Immunol Date: 2014-04-16 Impact factor: 6.347
Authors: Suneil Malik; Lei Fu; David James Juras; Mohamed Karmali; Betty Y L Wong; Agnes Gozdzik; David E C Cole Journal: Crit Rev Clin Lab Sci Date: 2013-02-22 Impact factor: 6.250