@article {8044, title = {Associations of variants In the hexokinase 1 and interleukin 18 receptor regions with oxyhemoglobin saturation during sleep.}, journal = {PLoS Genet}, volume = {15}, year = {2019}, month = {2019 04}, pages = {e1007739}, abstract = {

Sleep disordered breathing (SDB)-related overnight hypoxemia is associated with cardiometabolic disease and other comorbidities. Understanding the genetic bases for variations in nocturnal hypoxemia may help understand mechanisms influencing oxygenation and SDB-related mortality. We conducted genome-wide association tests across 10 cohorts and 4 populations to identify genetic variants associated with three correlated measures of overnight oxyhemoglobin saturation: average and minimum oxyhemoglobin saturation during sleep and the percent of sleep with oxyhemoglobin saturation under 90\%. The discovery sample consisted of 8,326 individuals. Variants with p < 1 {\texttimes} 10(-6) were analyzed in a replication group of 14,410 individuals. We identified 3 significantly associated regions, including 2 regions in multi-ethnic analyses (2q12, 10q22). SNPs in the 2q12 region associated with minimum SpO2 (rs78136548 p = 2.70 {\texttimes} 10(-10)). SNPs at 10q22 were associated with all three traits including average SpO2 (rs72805692 p = 4.58 {\texttimes} 10(-8)). SNPs in both regions were associated in over 20,000 individuals and are supported by prior associations or functional evidence. Four additional significant regions were detected in secondary sex-stratified and combined discovery and replication analyses, including a region overlapping Reelin, a known marker of respiratory complex neurons.These are the first genome-wide significant findings reported for oxyhemoglobin saturation during sleep, a phenotype of high clinical interest. Our replicated associations with HK1 and IL18R1 suggest that variants in inflammatory pathways, such as the biologically-plausible NLRP3 inflammasome, may contribute to nocturnal hypoxemia.

}, keywords = {Adolescent, Adult, Aged, Aged, 80 and over, Cell Adhesion Molecules, Neuronal, Computational Biology, Extracellular Matrix Proteins, Female, Gene Regulatory Networks, Genetic Variation, Genome-Wide Association Study, Hexokinase, Humans, Hypoxia, Interleukin-18 Receptor alpha Subunit, Male, Middle Aged, Nerve Tissue Proteins, NLR Family, Pyrin Domain-Containing 3 Protein, Oxygen, Oxyhemoglobins, Polymorphism, Single Nucleotide, Quantitative Trait Loci, Serine Endopeptidases, Sleep, Sleep Apnea Syndromes, Young Adult}, issn = {1553-7404}, doi = {10.1371/journal.pgen.1007739}, author = {Cade, Brian E and Chen, Han and Stilp, Adrienne M and Louie, Tin and Ancoli-Israel, Sonia and Arens, Raanan and Barfield, Richard and Below, Jennifer E and Cai, Jianwen and Conomos, Matthew P and Evans, Daniel S and Frazier-Wood, Alexis C and Gharib, Sina A and Gleason, Kevin J and Gottlieb, Daniel J and Hillman, David R and Johnson, W Craig and Lederer, David J and Lee, Jiwon and Loredo, Jose S and Mei, Hao and Mukherjee, Sutapa and Patel, Sanjay R and Post, Wendy S and Purcell, Shaun M and Ramos, Alberto R and Reid, Kathryn J and Rice, Ken and Shah, Neomi A and Sofer, Tamar and Taylor, Kent D and Thornton, Timothy A and Wang, Heming and Yaffe, Kristine and Zee, Phyllis C and Hanis, Craig L and Palmer, Lyle J and Rotter, Jerome I and Stone, Katie L and Tranah, Gregory J and Wilson, James G and Sunyaev, Shamil R and Laurie, Cathy C and Zhu, Xiaofeng and Saxena, Richa and Lin, Xihong and Redline, Susan} } @article {8096, title = {Epigenome-wide association analysis of daytime sleepiness in the Multi-Ethnic Study of Atherosclerosis reveals African-American-specific associations.}, journal = {Sleep}, year = {2019}, month = {2019 May 29}, abstract = {

STUDY OBJECTIVES: Daytime sleepiness is a consequence of inadequate sleep, sleep-wake control disorder, or other medical conditions. Population variability in prevalence of daytime sleepiness is likely due to genetic and biological factors as well as social and environmental influences. DNA methylation (DNAm) potentially influences multiple health outcomes. Here, we explored the association between DNAm and daytime sleepiness quantified by the Epworth Sleepiness Scale (ESS).

METHODS: We performed multi-ethnic and ethnic-specific epigenome-wide association studies for DNAm and ESS in the Multi-Ethnic Study of Atherosclerosis (MESA; n = 619) and the Cardiovascular Health Study (n = 483), with cross-study replication and meta-analysis. Genetic variants near ESS-associated DNAm were analyzed for methylation quantitative trait loci and followed with replication of genotype-sleepiness associations in the UK Biobank.

RESULTS: In MESA only, we detected four DNAm-ESS associations: one across all race/ethnic groups; three in African-Americans (AA) only. Two of the MESA AA associations, in genes KCTD5 and RXRA, nominally replicated in CHS (p-value < 0.05). In the AA meta-analysis, we detected 14 DNAm-ESS associations (FDR q-value < 0.05, top association p-value = 4.26 {\texttimes} 10-8). Three DNAm sites mapped to genes (CPLX3, GFAP, and C7orf50) with biological relevance. We also found evidence for associations with DNAm sites in RAI1, a gene associated with sleep and circadian phenotypes. UK Biobank follow-up analyses detected SNPs in RAI1, RXRA, and CPLX3 with nominal sleepiness associations.

CONCLUSIONS: We identified methylation sites in multiple genes possibly implicated in daytime sleepiness. Most significant DNAm-ESS associations were specific to AA. Future work is needed to identify mechanisms driving ancestry-specific methylation effects.

}, issn = {1550-9109}, doi = {10.1093/sleep/zsz101}, author = {Barfield, Richard and Wang, Heming and Liu, Yongmei and Brody, Jennifer A and Swenson, Brenton and Li, Ruitong and Bartz, Traci M and Sotoodehnia, Nona and Chen, Yii-der I and Cade, Brian E and Chen, Han and Patel, Sanjay R and Zhu, Xiaofeng and Gharib, Sina A and Johnson, W Craig and Rotter, Jerome I and Saxena, Richa and Purcell, Shaun and Lin, Xihong and Redline, Susan and Sofer, Tamar} }