Browsing by Subject "Vitamin D deficiency"

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Genetic loci associated with skin pigmentation in African Americans and their effects on vitamin D deficiency
    (Public Library of Science, 2021-02-18) Batai, Ken; Cui, Zuxi; Arora, Amit; Shah-Williams, Ebony; Hernandez, Wenndy; Ruden, Maria; Hollowell, Courtney M. P.; Hooker, Stanley E.; Bathina, Madhavi; Murphy, Adam B.; Bonilla, Carolina; Kittles, Rick A.; Medical and Molecular Genetics, School of Medicine
    A recent genome-wide association study (GWAS) in African descent populations identified novel loci associated with skin pigmentation. However, how genomic variations affect skin pigmentation and how these skin pigmentation gene variants affect serum 25(OH) vitamin D variation has not been explored in African Americans (AAs). In order to further understand genetic factors that affect human skin pigmentation and serum 25(OH)D variation, we performed a GWAS for skin pigmentation with 395 AAs and a replication study with 681 AAs. Then, we tested if the identified variants are associated with serum 25(OH) D concentrations in a subset of AAs (n = 591). Skin pigmentation, Melanin Index (M-Index), was measured using a narrow-band reflectometer. Multiple regression analysis was performed to identify variants associated with M-Index and to assess their role in serum 25(OH)D variation adjusting for population stratification and relevant confounding variables. A variant near the SLC24A5 gene (rs2675345) showed the strongest signal of association with M-Index (P = 4.0 x 10-30 in the pooled dataset). Variants in SLC24A5, SLC45A2 and OCA2 together account for a large proportion of skin pigmentation variance (11%). The effects of these variants on M-Index was modified by sex (P for interaction = 0.009). However, West African Ancestry (WAA) also accounts for a large proportion of M-Index variance (23%). M-Index also varies among AAs with high WAA and high Genetic Score calculated from top variants associated with M-Index, suggesting that other unknown genomic factors related to WAA are likely contributing to skin pigmentation variation. M-Index was not associated with serum 25(OH)D concentrations, but the Genetic Score was significantly associated with vitamin D deficiency (serum 25(OH)D levels less than 12 ng/mL) (OR, 1.30; 95% CI, 1.04-1.64). The findings support the hypothesis suggesting that skin pigmentation evolved responding to increased demand for subcutaneous vitamin D synthesis in high latitude environments.
  • Thumbnail Image
    Item
    Genome-wide association study in 79,366 European-ancestry individuals informs the genetic architecture of 25-hydroxyvitamin D levels
    (Nature Publishing Group, 2018-01-17) Jiang, Xia; O’Reilly, Paul F.; Aschard, Hugues; Hsu, Yi-Hsiang; Richards, J. Brent; Dupuis, Josée; Ingelsson, Erik; Karasik, David; Pilz, Stefan; Berry, Diane; Kestenbaum, Bryan; Zheng, Jusheng; Luan, Jianan; Sofianopoulou, Eleni; Streeten, Elizabeth A.; Albanes, Demetrius; Lutsey, Pamela L.; Yao, Lu; Tang, Weihong; Econs, Michael J.; Wallaschofski, Henri; Völzke, Henry; Zhou, Ang; Power, Chris; McCarthy, Mark I.; Michos, Erin D.; Boerwinkle, Eric; Weinstein, Stephanie J.; Freedman, Neal D.; Huang, Wen-Yi; Van Schoor, Natasja M.; Velde, Nathalie van der; de Groot, Lisette C. P. G. M.; Enneman, Anke; Cupples, L. Adrienne; Booth, Sarah L.; Vasan, Ramachandran S.; Liu, Ching-Ti; Zhou, Yanhua; Ripatti, Samuli; Ohlsson, Claes; Vandenput, Liesbeth; Lorentzon, Mattias; Eriksson, Johan G.; Shea, M. Kyla; Houston, Denise K.; Kritchevsky, Stephen B.; Liu, Yongmei; Lohman, Kurt K.; Ferrucci, Luigi; Peacock, Munro; Gieger, Christian; Beekman, Marian; Slagboom, Eline; Deelen, Joris; Heemst, Diana van; Kleber, Marcus E.; März, Winfried; de Boer, Ian H.; Wood, Alexis C.; Rotter, Jerome I.; Rich, Stephen S.; Robinson-Cohen, Cassianne; Heijer, Martin den; Jarvelin, Marjo-Riitta; Cavadino, Alana; Joshi, Peter K.; Wilson, James F.; Hayward, Caroline; Lind, Lars; Michaëlsson, Karl; Trompet, Stella; Zillikens, M. Carola; Uitterlinden, Andre G.; Rivadeneira, Fernando; Broer, Linda; Zgaga, Lina; Campbell, Harry; Theodoratou, Evropi; Farrington, Susan M.; Timofeeva, Maria; Dunlop, Malcolm G.; Valdes, Ana M.; Tikkanen, Emmi; Lehtimäki, Terho; Lyytikäinen, Leo-Pekka; Kähönen, Mika; Raitakari, Olli T.; Mikkilä, Vera; Ikram, M. Arfan; Sattar, Naveed; Jukema, J. Wouter; Wareham, Nicholas J.; Langenberg, Claudia; Forouhi, Nita G.; Gundersen, Thomas E.; Khaw, Kay-Tee; Butterworth, Adam S.; Danesh, John; Spector, Timothy; Wang, Thomas J.; Hyppönen, Elina; Kraft, Peter; Kiel, Douglas P.; Medicine, School of Medicine
    Vitamin D is a steroid hormone precursor that is associated with a range of human traits and diseases. Previous GWAS of serum 25-hydroxyvitamin D concentrations have identified four genome-wide significant loci (GC, NADSYN1/DHCR7, CYP2R1, CYP24A1). In this study, we expand the previous SUNLIGHT Consortium GWAS discovery sample size from 16,125 to 79,366 (all European descent). This larger GWAS yields two additional loci harboring genome-wide significant variants (P = 4.7×10-9 at rs8018720 in SEC23A, and P = 1.9×10-14 at rs10745742 in AMDHD1). The overall estimate of heritability of 25-hydroxyvitamin D serum concentrations attributable to GWAS common SNPs is 7.5%, with statistically significant loci explaining 38% of this total. Further investigation identifies signal enrichment in immune and hematopoietic tissues, and clustering with autoimmune diseases in cell-type-specific analysis. Larger studies are required to identify additional common SNPs, and to explore the role of rare or structural variants and gene-gene interactions in the heritability of circulating 25-hydroxyvitamin D levels
  • Thumbnail Image
    Item
    Vitamin D Deficiency, Inflammation, and Diminished Endogenous Regenerative Capacity in Coronary Heart Disease
    (Elsevier, 2024-01-04) Desai, Shivang R.; Ko, Yi-An; Liu, Chang; Hafeez, Zaki; Park, Jiwon; Faaborg-Andersen, Christian; Alvi, Zain; Alras, Zahran; Alkhoder, Ayman A.; Martini, Afif; Varughese, Anil; Ejaz, Kiran; Cheung, Brian; Wang, Maggie; Gold, Daniel A.; Gold, Matthew E.; Jain, Vardhmaan; Vatsa, Nishant; Islam, Shabatun J.; Almuwaqqat, Zakaria; Dhindsa, Devinder S.; Mehta, Anurag; Kim, Jonathan H.; Wilson, Peter; Waller, Edmund K.; Vaccarino, Viola; Quyyumi, Arshed A.; Medicine, School of Medicine
    Background: Vitamin D deficiency (VDD) is associated with coronary heart disease (CHD) and poor outcomes, but supplementation does not improve prognosis. VDD has been implicated in and may promote greater risk through inflammation and impaired progenitor cell function. Objectives: The authors examined VDD, high-sensitivity C-reactive protein (hsCRP), circulating progenitor cell (CPC) counts, and outcomes in patients with CHD. They hypothesized that the higher risk with VDD is mediated by inflammation and impaired regenerative capacity. Methods: A total of 5,452 individuals with CHD in the Emory Cardiovascular Biobank had measurement of 25-hydroxyvitamin D, subsets of whom had hsCRP measurements and CPCs estimated as CD34-expressing mononuclear cell counts. Findings were validated in an independent cohort. 25-hydroxyvitamin D <20 ng/mL was considered VDD. Cox and Fine-Gray models determined associations between marker levels and: 1) all-cause mortality; 2) cardiovascular mortality; and 3) major adverse cardiovascular events, a composite of adverse CHD outcomes. Results: VDD (43.6% of individuals) was associated with higher adjusted cardiovascular mortality (HR: 1.57, 95% CI: 1.09-2.28). There were significant interactions between VDD and hsCRP and CPC counts in predicting cardiovascular mortality. Individuals with both VDD and elevated hsCRP had the greatest risk (HR: 2.82, 95% CI: 2.16-3.67). Only individuals with both VDD and low CPC counts were at high risk (HR: 2.25, 95% CI: 1.46-3.46). These findings were reproduced in the validation cohort. Conclusions: VDD predicts adverse outcomes in CHD. Those with VDD, inflammation and/or diminished regenerative capacity are at a significantly greater risk of cardiovascular mortality. Whether targeted supplementation in these high-risk groups improves risk warrants further study.