@article {6545, title = {Association of mitochondrial DNA levels with frailty and all-cause mortality.}, journal = {J Mol Med (Berl)}, volume = {93}, year = {2015}, month = {2015 Feb}, pages = {177-186}, abstract = {

Mitochondrial function is altered with age and variants in mitochondrial DNA (mtDNA) modulate risk for several age-related disease states. However, the association of mtDNA copy number, a readily available marker which reflects mitochondrial depletion, energy reserves, and oxidative stress, on aging and mortality in the general population has not been addressed. To assess the association between mtDNA copy number and two primary outcomes--prevalent frailty and all-cause mortality--we utilize data from participants who were from two multicenter, multiethnic, community-based, prospective studies--the Cardiovascular Health Study (CHS) (1989-2006) and the Atherosclerosis Risk in Communities (ARIC) study (1987-2013). A total of 4892 participants (43.3\% men) from CHS and 11,509 participants (44.9\% men) from ARIC self-identifying as white or black were included in the analysis. mtDNA copy number, the trait of interest, was measured using a qPCR-based method in CHS and an array-based method in ARIC from DNA isolated from whole blood in participants from both cohorts. In race-stratified meta-analyses, we observe a significant inverse association of mtDNA copy number with age and higher mtDNA copy number in women relative to men. Lower mtDNA copy number was also significantly associated with prevalent frailty in white participants from CHS (OR 0.91, 95\% CI 0.85-0.97). Additionally, mtDNA copy number was a strong independent predictor of all-cause mortality in an age- and sex-adjusted, race-stratified analysis of 16,401 participants from both cohorts with a pooled hazard ratio of 1.47 (95\% CI 1.33-1.62) for the lowest quintile of mtDNA copy number relative to the highest quintile. Key messages: Mitochondrial DNA (mtDNA) copy number is associated with age and sex. Lower mtDNA copy number is also associated with prevalent frailty. mtDNA copy number is a significant predictor of all-cause mortality in a multiethnic population.

}, keywords = {African Americans, Aged, Aged, 80 and over, Aging, DNA, Mitochondrial, European Continental Ancestry Group, Female, Follow-Up Studies, Gene Dosage, Geriatric Assessment, Humans, Kaplan-Meier Estimate, Male, Mortality, Odds Ratio, Population Surveillance, Prospective Studies, Surveys and Questionnaires, United States}, issn = {1432-1440}, doi = {10.1007/s00109-014-1233-3}, author = {Ashar, Foram N and Moes, Anna and Moore, Ann Z and Grove, Megan L and Chaves, Paulo H M and Coresh, Josef and Newman, Anne B and Matteini, Amy M and Bandeen-Roche, Karen and Boerwinkle, Eric and Walston, Jeremy D and Arking, Dan E} } @article {7594, title = {Association Between Telomere Length and Risk of Cancer and Non-Neoplastic Diseases: A Mendelian Randomization Study.}, journal = {JAMA Oncol}, volume = {3}, year = {2017}, month = {2017 May 01}, pages = {636-651}, abstract = {

Importance: The causal direction and magnitude of the association between telomere length and incidence of cancer and non-neoplastic diseases is uncertain owing to the susceptibility of observational studies to confounding and reverse causation.

Objective: To conduct a Mendelian randomization study, using germline genetic variants as instrumental variables, to appraise the causal relevance of telomere length for risk of cancer and non-neoplastic diseases.

Data Sources: Genomewide association studies (GWAS) published up to January 15, 2015.

Study Selection: GWAS of noncommunicable diseases that assayed germline genetic variation and did not select cohort or control participants on the basis of preexisting diseases. Of 163 GWAS of noncommunicable diseases identified, summary data from 103 were available.

Data Extraction and Synthesis: Summary association statistics for single nucleotide polymorphisms (SNPs) that are strongly associated with telomere length in the general population.

Main Outcomes and Measures: Odds ratios (ORs) and 95\% confidence intervals (CIs) for disease per standard deviation (SD) higher telomere length due to germline genetic variation.

Results: Summary data were available for 35 cancers and 48 non-neoplastic diseases, corresponding to 420 081 cases (median cases, 2526 per disease) and 1 093 105 controls (median, 6789 per disease). Increased telomere length due to germline genetic variation was generally associated with increased risk for site-specific cancers. The strongest associations (ORs [95\% CIs] per 1-SD change in genetically increased telomere length) were observed for glioma, 5.27 (3.15-8.81); serous low-malignant-potential ovarian cancer, 4.35 (2.39-7.94); lung adenocarcinoma, 3.19 (2.40-4.22); neuroblastoma, 2.98 (1.92-4.62); bladder cancer, 2.19 (1.32-3.66); melanoma, 1.87 (1.55-2.26); testicular cancer, 1.76 (1.02-3.04); kidney cancer, 1.55 (1.08-2.23); and endometrial cancer, 1.31 (1.07-1.61). Associations were stronger for rarer cancers and at tissue sites with lower rates of stem cell division. There was generally little evidence of association between genetically increased telomere length and risk of psychiatric, autoimmune, inflammatory, diabetic, and other non-neoplastic diseases, except for coronary heart disease (OR, 0.78 [95\% CI, 0.67-0.90]), abdominal aortic aneurysm (OR, 0.63 [95\% CI, 0.49-0.81]), celiac disease (OR, 0.42 [95\% CI, 0.28-0.61]) and interstitial lung disease (OR, 0.09 [95\% CI, 0.05-0.15]).

Conclusions and Relevance: It is likely that longer telomeres increase risk for several cancers but reduce risk for some non-neoplastic diseases, including cardiovascular diseases.

}, keywords = {Adult, Aged, Aged, 80 and over, Cardiovascular Diseases, Female, Genetic Predisposition to Disease, Genome-Wide Association Study, Germ-Line Mutation, Humans, Male, Mendelian Randomization Analysis, Middle Aged, Neoplasms, Polymorphism, Single Nucleotide, Risk Assessment, Telomere, Telomere Homeostasis}, issn = {2374-2445}, doi = {10.1001/jamaoncol.2016.5945}, author = {Haycock, Philip C and Burgess, Stephen and Nounu, Aayah and Zheng, Jie and Okoli, George N and Bowden, Jack and Wade, Kaitlin Hazel and Timpson, Nicholas J and Evans, David M and Willeit, Peter and Aviv, Abraham and Gaunt, Tom R and Hemani, Gibran and Mangino, Massimo and Ellis, Hayley Patricia and Kurian, Kathreena M and Pooley, Karen A and Eeles, Rosalind A and Lee, Jeffrey E and Fang, Shenying and Chen, Wei V and Law, Matthew H and Bowdler, Lisa M and Iles, Mark M and Yang, Qiong and Worrall, Bradford B and Markus, Hugh Stephen and Hung, Rayjean J and Amos, Chris I and Spurdle, Amanda B and Thompson, Deborah J and O{\textquoteright}Mara, Tracy A and Wolpin, Brian and Amundadottir, Laufey and Stolzenberg-Solomon, Rachael and Trichopoulou, Antonia and Onland-Moret, N Charlotte and Lund, Eiliv and Duell, Eric J and Canzian, Federico and Severi, Gianluca and Overvad, Kim and Gunter, Marc J and Tumino, Rosario and Svenson, Ulrika and van Rij, Andre and Baas, Annette F and Bown, Matthew J and Samani, Nilesh J and van t{\textquoteright}Hof, Femke N G and Tromp, Gerard and Jones, Gregory T and Kuivaniemi, Helena and Elmore, James R and Johansson, Mattias and Mckay, James and Scelo, Ghislaine and Carreras-Torres, Robert and Gaborieau, Valerie and Brennan, Paul and Bracci, Paige M and Neale, Rachel E and Olson, Sara H and Gallinger, Steven and Li, Donghui and Petersen, Gloria M and Risch, Harvey A and Klein, Alison P and Han, Jiali and Abnet, Christian C and Freedman, Neal D and Taylor, Philip R and Maris, John M and Aben, Katja K and Kiemeney, Lambertus A and Vermeulen, Sita H and Wiencke, John K and Walsh, Kyle M and Wrensch, Margaret and Rice, Terri and Turnbull, Clare and Litchfield, Kevin and Paternoster, Lavinia and Standl, Marie and Abecasis, Goncalo R and SanGiovanni, John Paul and Li, Yong and Mijatovic, Vladan and Sapkota, Yadav and Low, Siew-Kee and Zondervan, Krina T and Montgomery, Grant W and Nyholt, Dale R and van Heel, David A and Hunt, Karen and Arking, Dan E and Ashar, Foram N and Sotoodehnia, Nona and Woo, Daniel and Rosand, Jonathan and Comeau, Mary E and Brown, W Mark and Silverman, Edwin K and Hokanson, John E and Cho, Michael H and Hui, Jennie and Ferreira, Manuel A and Thompson, Philip J and Morrison, Alanna C and Felix, Janine F and Smith, Nicholas L and Christiano, Angela M and Petukhova, Lynn and Betz, Regina C and Fan, Xing and Zhang, Xuejun and Zhu, Caihong and Langefeld, Carl D and Thompson, Susan D and Wang, Feijie and Lin, Xu and Schwartz, David A and Fingerlin, Tasha and Rotter, Jerome I and Cotch, Mary Frances and Jensen, Richard A and Munz, Matthias and Dommisch, Henrik and Schaefer, Arne S and Han, Fang and Ollila, Hanna M and Hillary, Ryan P and Albagha, Omar and Ralston, Stuart H and Zeng, Chenjie and Zheng, Wei and Shu, Xiao-Ou and Reis, Andre and Uebe, Steffen and H{\"u}ffmeier, Ulrike and Kawamura, Yoshiya and Otowa, Takeshi and Sasaki, Tsukasa and Hibberd, Martin Lloyd and Davila, Sonia and Xie, Gang and Siminovitch, Katherine and Bei, Jin-Xin and Zeng, Yi-Xin and F{\"o}rsti, Asta and Chen, Bowang and Landi, Stefano and Franke, Andre and Fischer, Annegret and Ellinghaus, David and Flores, Carlos and Noth, Imre and Ma, Shwu-Fan and Foo, Jia Nee and Liu, Jianjun and Kim, Jong-Won and Cox, David G and Delattre, Olivier and Mirabeau, Olivier and Skibola, Christine F and Tang, Clara S and Garcia-Barcelo, Merce and Chang, Kai-Ping and Su, Wen-Hui and Chang, Yu-Sun and Martin, Nicholas G and Gordon, Scott and Wade, Tracey D and Lee, Chaeyoung and Kubo, Michiaki and Cha, Pei-Chieng and Nakamura, Yusuke and Levy, Daniel and Kimura, Masayuki and Hwang, Shih-Jen and Hunt, Steven and Spector, Tim and Soranzo, Nicole and Manichaikul, Ani W and Barr, R Graham and Kahali, Bratati and Speliotes, Elizabeth and Yerges-Armstrong, Laura M and Cheng, Ching-Yu and Jonas, Jost B and Wong, Tien Yin and Fogh, Isabella and Lin, Kuang and Powell, John F and Rice, Kenneth and Relton, Caroline L and Martin, Richard M and Davey Smith, George} } @article {7548, title = {Association of Mitochondrial DNA Copy Number With Cardiovascular Disease.}, journal = {JAMA Cardiol}, volume = {2}, year = {2017}, month = {2017 Nov 01}, pages = {1247-1255}, abstract = {

Importance: Mitochondrial dysfunction is a core component of the aging process and may play a key role in atherosclerotic cardiovascular disease. Mitochondrial DNA copy number (mtDNA-CN), which represents the number of mitochondria per cell and number of mitochondrial genomes per mitochondrion, is an indirect biomarker of mitochondrial function.

Objective: To determine whether mtDNA-CN, measured in an easily accessible tissue (buffy coat/circulating leukocytes), can improve risk classification for cardiovascular disease (CVD) and help guide initiation of statin therapy for primary prevention of CVD.

Design, Setting, and Participants: Prospective, population-based cohort analysis including 21 870 participants (20 163 free from CVD at baseline) from 3 studies: Cardiovascular Health Study (CHS), Atherosclerosis Risk in Communities Study (ARIC), and Multiethnic Study of Atherosclerosis (MESA). The mean follow-up was 13.5 years. The study included 11 153 participants from ARIC, 4830 from CHS, and 5887 from MESA. Analysis of the data was conducted from March 10, 2014, to January 29, 2017.

Exposures: Mitochondrial DNA-CN measured from buffy coat/circulating leukocytes.

Main Outcomes and Measures: Incident CVD, which combines coronary heart disease, defined as the first incident myocardial infarction or death owing to coronary heart disease, and stroke, defined as the first nonfatal stroke or death owing to stroke.

Results: Of the 21 870 participants, the mean age was 62.4 years (ARIC, 57.9 years; MESA, 62.4 years; and CHS, 72.5 years), and 54.7\% of participants were women. The hazard ratios for incident coronary heart disease, stroke, and CVD associated with a 1-SD decrease in mtDNA-CN were 1.29 (95\% CI, 1.24-1.33), 1.11 (95\% CI, 1.06-1.16), and 1.23 (95\% CI, 1.19-1.26). The associations persisted after adjustment for traditional CVD risk factors. Addition of mtDNA-CN to the 2013 American College of Cardiology/American Heart Association Pooled Cohorts Equations for estimating 10-year hard atherosclerosis CVD risk was associated with improved risk classification (continuous net reclassification index, 0.194; 95\% CI, 0.130-0.258; P < .001). Mitochondrial DNA-CN further improved sensitivity and specificity for the 2013 American College of Cardiology/American Heart Association recommendations on initiating statin therapy for primary prevention of ASCVD (net 221 individuals appropriately downclassified and net 15 individuals appropriately upclassified).

Conclusions and Relevance: Mitochondrial DNA-CN was independently associated with incident CVD in 3 large prospective studies and may have potential clinical utility in improving CVD risk classification.

}, issn = {2380-6591}, doi = {10.1001/jamacardio.2017.3683}, author = {Ashar, Foram N and Zhang, Yiyi and Longchamps, Ryan J and Lane, John and Moes, Anna and Grove, Megan L and Mychaleckyj, Josyf C and Taylor, Kent D and Coresh, Josef and Rotter, Jerome I and Boerwinkle, Eric and Pankratz, Nathan and Guallar, Eliseo and Arking, Dan E} } @article {7778, title = {A comprehensive evaluation of the genetic architecture of sudden cardiac arrest.}, journal = {Eur Heart J}, year = {2018}, month = {2018 Aug 28}, abstract = {

Aims: Sudden cardiac arrest (SCA) accounts for 10\% of adult mortality in Western populations. We aim to identify potential loci associated with SCA and to identify risk factors causally associated with SCA.

Methods and results: We carried out a large genome-wide association study (GWAS) for SCA (n = 3939 cases, 25~989 non-cases) to examine common variation genome-wide and in candidate arrhythmia genes. We also exploited Mendelian randomization (MR) methods using cross-trait multi-variant genetic risk score associations (GRSA) to assess causal relationships of 18 risk factors with SCA. No variants were associated with SCA at genome-wide significance, nor were common variants in candidate arrhythmia genes associated with SCA at nominal significance. Using cross-trait GRSA, we established genetic correlation between SCA and (i) coronary artery disease (CAD) and traditional CAD risk factors (blood pressure, lipids, and diabetes), (ii) height and BMI, and (iii) electrical instability traits (QT and atrial fibrillation), suggesting aetiologic roles for these traits in SCA risk.

Conclusions: Our findings show that a comprehensive approach to the genetic architecture of SCA can shed light on the determinants of a complex life-threatening condition with multiple influencing factors in the general population. The results of this genetic analysis, both positive and negative findings, have implications for evaluating the genetic architecture of patients with a family history of SCA, and for efforts to prevent SCA in high-risk populations and the general community.

}, issn = {1522-9645}, doi = {10.1093/eurheartj/ehy474}, author = {Ashar, Foram N and Mitchell, Rebecca N and Albert, Christine M and Newton-Cheh, Christopher and Brody, Jennifer A and M{\"u}ller-Nurasyid, Martina and Moes, Anna and Meitinger, Thomas and Mak, Angel and Huikuri, Heikki and Junttila, M Juhani and Goyette, Philippe and Pulit, Sara L and Pazoki, Raha and Tanck, Michael W and Blom, Marieke T and Zhao, XiaoQing and Havulinna, Aki S and Jabbari, Reza and Glinge, Charlotte and Tragante, Vinicius and Escher, Stefan A and Chakravarti, Aravinda and Ehret, Georg and Coresh, Josef and Li, Man and Prineas, Ronald J and Franco, Oscar H and Kwok, Pui-Yan and Lumley, Thomas and Dumas, Florence and McKnight, Barbara and Rotter, Jerome I and Lemaitre, Rozenn N and Heckbert, Susan R and O{\textquoteright}Donnell, Christopher J and Hwang, Shih-Jen and Tardif, Jean-Claude and VanDenburgh, Martin and Uitterlinden, Andr{\'e} G and Hofman, Albert and Stricker, Bruno H C and de Bakker, Paul I W and Franks, Paul W and Jansson, Jan-H{\r a}kan and Asselbergs, Folkert W and Halushka, Marc K and Maleszewski, Joseph J and Tfelt-Hansen, Jacob and Engstr{\o}m, Thomas and Salomaa, Veikko and Virmani, Renu and Kolodgie, Frank and Wilde, Arthur A M and Tan, Hanno L and Bezzina, Connie R and Eijgelsheim, Mark and Rioux, John D and Jouven, Xavier and K{\"a}{\"a}b, Stefan and Psaty, Bruce M and Siscovick, David S and Arking, Dan E and Sotoodehnia, Nona} } @article {7672, title = {Genome-Wide Associations of Global Electrical Heterogeneity ECG Phenotype: The ARIC (Atherosclerosis Risk in Communities) Study and CHS (Cardiovascular Health Study).}, journal = {J Am Heart Assoc}, volume = {7}, year = {2018}, month = {2018 Apr 05}, abstract = {

BACKGROUND: ECG global electrical heterogeneity (GEH) is associated with sudden cardiac death. We hypothesized that a genome-wide association study would identify genetic loci related to GEH.

METHODS AND RESULTS: We tested genotyped and imputed variants in black (N=3057) and white (N=10~769) participants in the ARIC (Atherosclerosis Risk in Communities) study and CHS (Cardiovascular Health Study). GEH (QRS-T angle, sum absolute QRST integral, spatial ventricular gradient magnitude, elevation, azimuth) was measured on 12-lead ECGs. Linear regression models were constructed with each GEH variable as an outcome, adjusted for age, sex, height, body mass index, study site, and principal components to account for ancestry. GWAS identified 10 loci that showed genome-wide significant association with GEH in whites or joint ancestry. The strongest signal (rs7301677, near ) was associated with QRS-T angle (white standardized β+0.16 [95\% CI 0.13-0.19]; =1.5{\texttimes}10), spatial ventricular gradient elevation (+0.11 [0.08-0.14]; =2.1{\texttimes}10), and spatial ventricular gradient magnitude (-0.12 [95\% CI -0.15 to -0.09]; =5.9{\texttimes}10). Altogether, GEH-SNPs explained 1.1\% to 1.6\% of GEH variance. Loci on chromosomes 4 (near ), 5 (), 11 (11p11.2 region cluster), and 7 (near ) are novel ECG phenotype-associated loci. Several loci significantly associated with gene expression in the left ventricle ( locus-with ; locus-with ), and atria ( locus-with expression of a long non-coding RNA and ).

CONCLUSIONS: We identified 10 genetic loci associated with ECG GEH. Replication of GEH GWAS findings in independent cohorts is warranted. Further studies of GEH-loci may uncover mechanisms of arrhythmogenic remodeling in response to cardiovascular risk factors.

}, issn = {2047-9980}, doi = {10.1161/JAHA.117.008160}, author = {Tereshchenko, Larisa G and Sotoodehnia, Nona and Sitlani, Colleen M and Ashar, Foram N and Kabir, Muammar and Biggs, Mary L and Morley, Michael P and Waks, Jonathan W and Soliman, Elsayed Z and Buxton, Alfred E and Biering-S{\o}rensen, Tor and Solomon, Scott D and Post, Wendy S and Cappola, Thomas P and Siscovick, David S and Arking, Dan E} }