@article {7002, title = {Incident Atrial Fibrillation and Disability-Free Survival in the Cardiovascular Health Study.}, journal = {J Am Geriatr Soc}, volume = {64}, year = {2016}, month = {2016 Apr}, pages = {838-43}, abstract = {

OBJECTIVES: To assess the associations between incident atrial fibrillation (AF) and disability-free survival and risk of disability.

DESIGN: Prospective cohort study.

SETTING: Cardiovascular Health Study.

PARTICIPANTS: Individuals aged 65 and older and enrolled in fee-for-service Medicare followed between 1991 and 2009 (MN = 4,046). Individuals with prevalent AF, activity of daily living (ADL) disability, or a history of stroke or heart failure at baseline were excluded.

MEASUREMENTS: Incident AF was identified according to annual study electrocardiogram, hospital discharge diagnosis, or Medicare claims. Disability-free survival was defined as survival free of ADL disability (any difficulty or inability in bathing, dressing, eating, using the toilet, walking around the home, or getting out of a bed or chair). ADLs were assessed at annual study visits or in a telephone interview. Association between incident AF and disability-free survival or risk of disability was estimated using Cox proportional hazards models.

RESULTS: Over an average of 7.0 years of follow-up, 660 individuals (16.3\%) developed incident AF, and 3,112 (77\%) became disabled or died. Incident AF was associated with shorter disability-free survival (hazard ratio (HR) for death or ADL disability = 1.71, 95\% confidence interval (CI) = 1.55-1.90) and a higher risk of ADL disability (HR = 1.36, 95\% CI = 1.18-1.58) than in individuals with no history of AF. This association persisted after adjustment for interim stroke and heart failure.

CONCLUSION: These results suggest that AF is a risk factor for shorter functional longevity in older adults, independent of other risk factors and comorbid conditions.

}, keywords = {Activities of Daily Living, Aged, Aged, 80 and over, Atrial Fibrillation, Disability Evaluation, Electrocardiography, Female, Geriatric Assessment, Humans, Incidence, Longevity, Longitudinal Studies, Male, Medicare, Prevalence, Prospective Studies, Survival Rate, United States}, issn = {1532-5415}, doi = {10.1111/jgs.14037}, author = {Wallace, Erin R and Siscovick, David S and Sitlani, Colleen M and Dublin, Sascha and Mitchell, Pamela H and Odden, Michelle C and Hirsch, Calvin H and Thielke, Stephen and Heckbert, Susan R} } @article {8405, title = {Incorporating sampling weights into robust estimation of Cox proportional hazards regression model, with illustration in the Multi-Ethnic Study of Atherosclerosis.}, journal = {BMC Med Res Methodol}, volume = {20}, year = {2020}, month = {2020 03 14}, pages = {62}, abstract = {

BACKGROUND: Cox proportional hazards regression models are used to evaluate associations between exposures of interest and time-to-event outcomes in observational data. When exposures are measured on only a sample of participants, as they are in a case-cohort design, the sampling weights must be incorporated into the regression model to obtain unbiased estimating equations.

METHODS: Robust Cox methods have been developed to better estimate associations when there are influential outliers in the exposure of interest, but these robust methods do not incorporate sampling weights. In this paper, we extend these robust methods, which already incorporate influence weights, so that they also accommodate sampling weights.

RESULTS: Simulations illustrate that in the presence of influential outliers, the association estimate from the weighted robust method is closer to the true value than the estimate from traditional weighted Cox regression. As expected, in the absence of outliers, the use of robust methods yields a small loss of efficiency. Using data from a case-cohort study that is nested within the Multi-Ethnic Study of Atherosclerosis (MESA) longitudinal cohort study, we illustrate differences between traditional and robust weighted Cox association estimates for the relationships between immune cell traits and risk of stroke.

CONCLUSIONS: Robust weighted Cox regression methods are a new tool to analyze time-to-event data with sampling, e.g. case-cohort data, when exposures of interest contain outliers.

}, issn = {1471-2288}, doi = {10.1186/s12874-020-00945-9}, author = {Sitlani, Colleen M and Lumley, Thomas and McKnight, Barbara and Rice, Kenneth M and Olson, Nels C and Doyle, Margaret F and Huber, Sally A and Tracy, Russell P and Psaty, Bruce M and C Delaney, Joseph A} } @article {8403, title = {Innate and adaptive immune cell subsets as risk factors for coronary heart disease in two population-based cohorts.}, journal = {Atherosclerosis}, volume = {300}, year = {2020}, month = {2020 05}, pages = {47-53}, abstract = {

BACKGROUND AND AIMS: Cell-mediated immunity is implicated in atherosclerosis. We evaluated whether innate and adaptive immune cell subsets in peripheral blood are risk factors for coronary heart disease.

METHODS: A nested case-cohort study (n~=~2155) was performed within the Multi-Ethnic Study of Atherosclerosis (MESA) and the Cardiovascular Health Study (CHS). Cases of incident myocardial infarction (MI) and incident angina (n~=~880 total cases) were compared with a cohort random sample (n~=~1275). Immune cell phenotypes (n~=~34, including CD14 monocytes, natural killer cells, γδ T cells, CD4, CD8 and CD19 lymphocyte subsets) were measured from cryopreserved cells by flow cytometry. Cox proportional hazards models with adjustment for cardiovascular disease risk factors were used to evaluate associations of cell phenotypes with incident MI and a composite phenotype of incident MI or incident angina (MI-angina) over a median 9.3 years of follow-up. Th1, Th2, Th17, T regulatory (CD4CD25CD127), naive (CD4CD45RA), memory (CD4CD45RO), and CD4CD28 cells were specified as primary hypotheses. In secondary analyses, 27 additional cell phenotypes were investigated.

RESULTS: After correction for multiple testing, there were no statistically significant associations of CD4 naive, memory, CD28, or T helper cell subsets with MI or MI-angina in MESA, CHS, or combined-cohort meta analyses. Null associations were also observed for monocyte subsets, natural killer cells, γδ T cells, CD19 B cell and differentiated CD4 and CD8 cell subsets.

CONCLUSIONS: The proportions of peripheral blood monocyte and lymphocyte subsets are not strongly related to the future occurrence of MI or angina in adults free of autoimmune disease.

}, issn = {1879-1484}, doi = {10.1016/j.atherosclerosis.2020.03.011}, author = {Olson, Nels C and Sitlani, Colleen M and Doyle, Margaret F and Huber, Sally A and Landay, Alan L and Tracy, Russell P and Psaty, Bruce M and Delaney, Joseph A} } @article {9247, title = {Immune cell subpopulations as risk factors for atrial fibrillation: The Cardiovascular Health Study and Multi-Ethnic Study of Atherosclerosis.}, journal = {Heart Rhythm}, year = {2022}, month = {2022 Oct 18}, issn = {1556-3871}, doi = {10.1016/j.hrthm.2022.10.012}, author = {Floyd, James S and Sitlani, Colleen M and Doyle, Margaret F and Feinstein, Matthew J and Olson, Nels C and Heckbert, Susan R and Huber, Sally A and Tracy, Russell P and Psaty, Bruce M and Delaney, Joseph A C} } @article {9094, title = {Integrative analysis of clinical and epigenetic biomarkers of mortality.}, journal = {Aging Cell}, volume = {21}, year = {2022}, month = {2022 Jun}, pages = {e13608}, abstract = {

DNA methylation (DNAm) has been reported to be associated with many diseases and with mortality. We hypothesized that the integration of DNAm with clinical risk factors would improve mortality prediction. We performed an epigenome-wide association study of whole blood DNAm in relation to mortality in 15 cohorts (n~=~15,013). During a mean follow-up of 10~years, there were 4314 deaths from all causes including 1235 cardiovascular disease (CVD) deaths and 868 cancer deaths. Ancestry-stratified meta-analysis of all-cause mortality identified 163 CpGs in European ancestry (EA) and 17 in African ancestry (AA) participants at p~<~1~{\texttimes}~10 , of which 41 (EA) and 16 (AA) were also associated with CVD death, and 15 (EA) and 9 (AA) with cancer death. We built DNAm-based prediction models for all-cause mortality that predicted mortality risk after adjusting for clinical risk factors. The mortality prediction model trained by integrating DNAm with clinical risk factors showed an improvement in prediction of cancer death with 5\% increase in the C-index in a replication cohort, compared with the model including clinical risk factors alone. Mendelian randomization identified 15 putatively causal CpGs in relation to longevity, CVD, or cancer risk. For example, cg06885782 (in KCNQ4) was positively associated with risk for prostate cancer (Beta~=~1.2, P ~=~4.1~{\texttimes}~10 ) and negatively associated with longevity (Beta~=~-1.9, P ~=~0.02). Pathway analysis revealed that genes associated with mortality-related CpGs are enriched for immune- and cancer-related pathways. We identified replicable DNAm signatures of mortality and demonstrated the potential utility of CpGs as informative biomarkers for prediction of mortality risk.

}, keywords = {Biomarkers, Cardiovascular Diseases, DNA Methylation, Epigenesis, Genetic, Epigenomics, Humans, Male, Neoplasms}, issn = {1474-9726}, doi = {10.1111/acel.13608}, author = {Huan, Tianxiao and Nguyen, Steve and Colicino, Elena and Ochoa-Rosales, Carolina and Hill, W David and Brody, Jennifer A and Soerensen, Mette and Zhang, Yan and Baldassari, Antoine and Elhadad, Mohamed Ahmed and Toshiko, Tanaka and Zheng, Yinan and Domingo-Relloso, Arce and Lee, Dong Heon and Ma, Jiantao and Yao, Chen and Liu, Chunyu and Hwang, Shih-Jen and Joehanes, Roby and Fornage, Myriam and Bressler, Jan and van Meurs, Joyce B J and Debrabant, Birgit and Mengel-From, Jonas and Hjelmborg, Jacob and Christensen, Kaare and Vokonas, Pantel and Schwartz, Joel and Gahrib, Sina A and Sotoodehnia, Nona and Sitlani, Colleen M and Kunze, Sonja and Gieger, Christian and Peters, Annette and Waldenberger, Melanie and Deary, Ian J and Ferrucci, Luigi and Qu, Yishu and Greenland, Philip and Lloyd-Jones, Donald M and Hou, Lifang and Bandinelli, Stefania and Voortman, Trudy and Hermann, Brenner and Baccarelli, Andrea and Whitsel, Eric and Pankow, James S and Levy, Daniel} }