title: Genetic variant in vitamin D-binding protein is associated with metabolic syndrome and lower 25-hydroxyvitamin D levels in polycystic ovary syndrome: A cross-sectional study.
abstract: Vitamin D deficiency has been related to metabolic syndrome (MetS) in polycystic ovary syndrome (PCOS). The vitamin D-binding protein (DBP) is the main protein involved in vitamin D transport. Two single-nucleotide polymorphisms (SNPs) of the DBP gene, rs4588 and rs7041, have been associated with low circulating levels of 25-hydroxyvitamin D [25(OH)D] in various populations, but not in women with PCOS. Therefore, we determined the genotype and haplotype distribution of DBP gene polymorphisms and investigated the associations between these genetic variants and their haplotypes with PCOS, MetS, and 25(OH)D levels in women with PCOS and controls from the South of Brazil. The sample included 291 women (191 with PCOS and 100 controls). All participants were genotyped for polymorphisms rs2282679, rs4588, and rs7041. Serum 25(OH)D levels were determined in a subset of 102 participants. Women with PCOS were younger and had significantly higher body mass index, blood pressure, and insulin resistance than the control group (p<0.05). The prevalence of MetS in PCOS and controls was 26.5% and 4.8% respectively. Levels of 25(OH)D were lower in PCOS women with MetS, even after adjustment for age (p = 0.033). No associations were observed between PCOS and the polymorphisms or their haplotypes. A higher frequency of genotype TT of rs7041 was found in PCOS participants with MetS (OR: 2.21, 95%CI:1.08-4.52; p = 0.027). This same genotype was associated with lower 25(OH)D levels in both PCOS and control women (OR: 4.40, 95%CI:1.62-12.00; p = 0.002). In conclusion, these findings indicate that DBP gene polymorphisms and their haplotypes are not directly associated with PCOS. In contrast, the TT genotype of SNP rs7041 was associated with MetS in PCOS women, and with lower 25(OH)D levels in both PCOS and control groups.
authors.affiliation: Gynecological Endocrinology Unit, Division of Endocrinology, Hospital de Clínicas de Porto Alegre, Porto Alegre, Rio Grande do Sul, Brazil.|Laboratory of Molecular Endocrinology, Department of Physiology, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Betânia Rodrigues
authors.initials: BR
authors.lastname: Santos
authors.affiliation: Gynecological Endocrinology Unit, Division of Endocrinology, Hospital de Clínicas de Porto Alegre, Porto Alegre, Rio Grande do Sul, Brazil.|Department of Diagnostic Methods, Federal University of Health Sciences of Porto Alegre, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Sheila Bünecker
authors.initials: SB
authors.lastname: Lecke
authors.affiliation: Gynecological Endocrinology Unit, Division of Endocrinology, Hospital de Clínicas de Porto Alegre, Porto Alegre, Rio Grande do Sul, Brazil.|Laboratory of Molecular Endocrinology, Department of Physiology, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Poli Mara
authors.identifier: http://orcid.org/0000-0002-6734-7688
authors.initials: PM
authors.lastname: Spritzer
mesh_terms: D000328:Adult; D001938:Brazil; D002112:Calcifediol / Q000097:blood*; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D007333:Insulin Resistance; D024821:Metabolic Syndrome / Q000097:blood / Q000209:etiology*; D011085:Polycystic Ovary Syndrome / Q000097:blood / Q000150:complications* / Q000235:genetics; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D012307:Risk Factors; D014808:Vitamin D Deficiency / Q000097:blood / Q000209:etiology*; D014809:Vitamin D-Binding Protein / Q000235:genetics*; D055815:Young Adult
chemical_list: D014809:Vitamin D-Binding Protein; D002112:Calcifediol