@article {9255, title = {Plasma proteomic signature of decline in gait speed and grip strength.}, journal = {Aging Cell}, volume = {21}, year = {2022}, month = {2022 Dec}, pages = {e13736}, abstract = {

The biological mechanisms underlying decline in physical function with age remain unclear. We examined the plasma proteomic profile associated with longitudinal changes in physical function measured by gait speed and grip strength in community-dwelling adults. We applied an aptamer-based platform to assay 1154 plasma proteins on 2854 participants (60\% women, aged 76 years) in the Cardiovascular Health Study (CHS) in 1992-1993 and 1130 participants (55\% women, aged 54 years) in the Framingham Offspring Study (FOS) in 1991-1995. Gait speed and grip strength were measured annually for 7 years in CHS and at cycles 7 (1998-2001) and 8 (2005-2008) in FOS. The associations of individual protein levels (log-transformed and standardized) with longitudinal changes in gait speed and grip strength in two populations were examined separately by linear mixed-effects models. Meta-analyses were implemented using random-effects models and corrected for multiple testing. We found that plasma levels of 14 and 18 proteins were associated with changes in gait speed and grip strength, respectively (corrected p~< 0.05). The proteins most strongly associated with gait speed decline were GDF-15 (Meta-analytic p~= 1.58 {\texttimes} 10 ), pleiotrophin (1.23 {\texttimes} 10 ), and TIMP-1 (5.97 {\texttimes} 10 ). For grip strength decline, the strongest associations were for carbonic anhydrase III (1.09 {\texttimes} 10 ), CDON (2.38 {\texttimes} 10 ), and SMOC1 (7.47 {\texttimes} 10 ). Several statistically significant proteins are involved in the inflammatory responses or antagonism of activin by follistatin pathway. These novel proteomic biomarkers and pathways should be further explored as future mechanisms and targets for age-related functional decline.

}, keywords = {Adult, Female, Gait, Hand Strength, Humans, Independent Living, Male, Proteomics, Walking Speed}, issn = {1474-9726}, doi = {10.1111/acel.13736}, author = {Liu, Xiaojuan and Pan, Stephanie and Xanthakis, Vanessa and Vasan, Ramachandran S and Psaty, Bruce M and Austin, Thomas R and Newman, Anne B and Sanders, Jason L and Wu, Chenkai and Tracy, Russell P and Gerszten, Robert E and Odden, Michelle C} } @article {9086, title = {Proteomics and Population Biology in the Cardiovascular Health Study (CHS): design of a study with mentored access and active data sharing.}, journal = {Eur J Epidemiol}, year = {2022}, month = {2022 Jul 05}, abstract = {

BACKGROUND: In the last decade, genomic studies have identified and replicated thousands of genetic associations with measures of health and disease and contributed to the understanding of the etiology of a variety of health conditions. Proteins are key biomarkers in clinical medicine and often drug-therapy targets. Like genomics, proteomics can advance our understanding of biology.

METHODS AND RESULTS: In the setting of the Cardiovascular Health Study (CHS), a cohort study of older adults, an aptamer-based method that has high sensitivity for low-abundance proteins was used to assay 4979 proteins in frozen, stored plasma from 3188 participants (61\% women, mean age 74~years). CHS provides active support, including central analysis, for seven phenotype-specific working groups (WGs). Each CHS WG is led by one or two senior investigators and includes 10 to 20 early or mid-career scientists. In this setting of mentored access, the proteomic data and analytic methods are widely shared with the WGs and investigators so that they may evaluate associations between baseline levels of circulating proteins and the incidence of a variety of health outcomes in prospective cohort analyses. We describe the design of CHS, the CHS Proteomics Study, characteristics of participants, quality control measures, and structural characteristics of the data provided to CHS WGs. We additionally highlight plans for validation and replication of novel proteomic associations.

CONCLUSION: The CHS Proteomics Study offers an opportunity for collaborative data sharing to improve our understanding of the etiology of a variety of health conditions in older adults.

}, issn = {1573-7284}, doi = {10.1007/s10654-022-00888-z}, author = {Austin, Thomas R and McHugh, Caitlin P and Brody, Jennifer A and Bis, Joshua C and Sitlani, Colleen M and Bartz, Traci M and Biggs, Mary L and Bansal, Nisha and B{\r u}zkov{\'a}, Petra and Carr, Steven A and deFilippi, Christopher R and Elkind, Mitchell S V and Fink, Howard A and Floyd, James S and Fohner, Alison E and Gerszten, Robert E and Heckbert, Susan R and Katz, Daniel H and Kizer, Jorge R and Lemaitre, Rozenn N and Longstreth, W T and McKnight, Barbara and Mei, Hao and Mukamal, Kenneth J and Newman, Anne B and Ngo, Debby and Odden, Michelle C and Vasan, Ramachandran S and Shojaie, Ali and Simon, Noah and Smith, George Davey and Davies, Neil M and Siscovick, David S and Sotoodehnia, Nona and Tracy, Russell P and Wiggins, Kerri L and Zheng, Jie and Psaty, Bruce M} } @article {9331, title = {Plasma Proteomic Associations With Incident Ischemic Stroke in Older Adults: The Cardiovascular Health Study.}, journal = {Neurology}, year = {2023}, month = {2023 Apr 04}, abstract = {

BACKGROUND: Plasma proteomics may elucidate novel insights into the pathophysiology of ischemic stroke (IS), identify biomarkers of IS risk, and guide development of nascent prevention strategies. We evaluated the relationship between the plasma proteome and IS risk in the population-based Cardiovascular Health Study (CHS).

METHODS: Eligible CHS participants were free of prevalent stroke and underwent quantification of 1298 plasma proteins using the aptamer-based SOMAScan assay platform from the 1992-1993 study visit. Multivariable Cox proportional hazards regression was used to evaluate associations between a 1-standard deviation increase in the log-2 transformed estimated plasma protein concentrations and incident IS, adjusting for demographics, IS risk factors, and estimated glomerular filtration rate. For proteins independently associated with incident IS, a secondary stratified analysis evaluated associations in subgroups defined by sex and race. Exploratory analyses evaluated plasma proteomic associations with cardioembolic and non-cardioembolic IS as well as proteins associated with IS risk in participants with left atrial dysfunction but without atrial fibrillation.

RESULTS: Of 2983 eligible participants, the mean age was 74.3 ({\textpm} 4.8) years, 61.2\% were women, and 15.4\% were Black. Over a median follow-up of 12.6 years, 450 participants experienced an incident IS. N-terminal pro-brain natriuretic peptide (NTproBNP, adjusted HR 1.37, 95\% CI 1.23-1.53, P=2.08x10) and macrophage metalloelastase (MMP12, adjusted HR 1.30, 95\% CI 1.16-1.45, P=4.55x10) were independently associated with IS risk. These two associations were similar in men and women and in Black and non-Black participants. In exploratory analyses, NTproBNP was independently associated with incident cardioembolic IS, E-selectin with incident non-cardioembolic IS, and secreted frizzled-related protein 1 with IS risk in participants with left atrial dysfunction.

CONCLUSIONS: In a cohort of older adults, NTproBNP and MMP12 were independently associated with IS risk. We identified plasma proteomic determinants of incident cardioembolic and non-cardioembolic IS and found a novel protein associated with IS risk in those with left atrial dysfunction.

}, issn = {1526-632X}, doi = {10.1212/WNL.0000000000207242}, author = {Kalani, Rizwan and Bartz, Traci M and Psaty, Bruce M and Elkind, Mitchell S V and Floyd, James S and Gerszten, Robert E and Shojaie, Ali and Heckbert, Susan R and Bis, Joshua C and Austin, Thomas R and Tirschwell, David L and Delaney, Joseph A C and Longstreth, W T} } @article {9539, title = {A proteomic analysis of atrial fibrillation in a prospective longitudinal cohort (AGES-Reykjavik study).}, journal = {Europace}, volume = {25}, year = {2023}, month = {2023 Nov 02}, abstract = {

AIMS: Atrial fibrillation (AF) is associated with high risk of comorbidities and mortality. Our aim was to examine causal and predictive relationships between 4137 serum proteins and incident AF in the prospective population-based Age, Gene/Environment Susceptibility-Reykjavik (AGES-Reykjavik) study.

METHODS AND RESULTS: The study included 4765 participants, of whom 1172 developed AF. Cox proportional hazards regression models were fitted for 4137 baseline protein measurements adjusting for known risk factors. Protein associations were tested for replication in the Cardiovascular Health Study (CHS). Causal relationships were examined in a bidirectional, two-sample Mendelian randomization analysis. The time-dependent area under the receiver operating characteristic curve (AUC)-statistic was examined as protein levels and an AF-polygenic risk score (PRS) were added to clinical risk models. The proteomic signature of incident AF consisted of 76 proteins, of which 63 (83\%) were novel and 29 (38\%) were replicated in CHS. The signature included both N-terminal prohormone of brain natriuretic peptide (NT-proBNP)-dependent (e.g. CHST15, ATP1B1, and SVEP1) and independent components (e.g. ASPN, AKR1B, and LAMA1/LAMB1/LAMC1). Nine causal candidates were identified (TAGLN, WARS, CHST15, CHMP3, COL15A1, DUSP13, MANBA, QSOX2, and SRL). The reverse causal analysis suggested that most AF-associated proteins were affected by the genetic liability to AF. N-terminal prohormone of brain natriuretic peptide improved the prediction of incident AF events close to baseline with further improvements gained by the AF-PRS at all time points.

CONCLUSION: The AF proteomic signature includes biologically relevant proteins, some of which may be causal. It mainly reflects an NT-proBNP-dependent consequence of the genetic liability to AF. N-terminal prohormone of brain natriuretic peptide is a promising marker for incident AF in the short term, but risk assessment incorporating a PRS may improve long-term risk assessment.

}, keywords = {Atrial Fibrillation, Biomarkers, Endosomal Sorting Complexes Required for Transport, Humans, Natriuretic Peptide, Brain, Oxidoreductases Acting on Sulfur Group Donors, Peptide Fragments, Prognosis, Prospective Studies, Proteomics, Risk Factors}, issn = {1532-2092}, doi = {10.1093/europace/euad320}, author = {Jonmundsson, Thorarinn and Steindorsdottir, Anna E and Austin, Thomas R and Frick, Elisabet A and Axelsson, Gisli T and Launer, Lenore and Psaty, Bruce M and Loureiro, Joseph and Orth, Anthony P and Aspelund, Thor and Emilsson, Valur and Floyd, James S and Jennings, Lori and Gudnason, Vilmundur and Gudmundsdottir, Valborg} } @article {9536, title = {Proteomic prediction of incident heart failure and its main subtypes.}, journal = {Eur J Heart Fail}, year = {2023}, month = {2023 Nov 08}, abstract = {

AIM: To examine the ability of serum proteins in predicting future heart failure (HF) events, including HF with reduced or preserved ejection fraction (HFrEF or HFpEF), in relation to event time, and with or without considering established HF-associated clinical variables.

METHODS AND RESULTS: In the prospective population-based Age, Gene/Environment Susceptibility Reykjavik Study (AGES-RS), 440 individuals developed HF after their first visit with a median follow-up of 5.45 years. Among them, 167 were diagnosed with HFrEF and 188 with HFpEF. A least absolute shrinkage and selection operator regression model with nonparametric bootstrap were used to select predictors from an analysis of 4782 serum proteins, and several pre-established clinical parameters linked to HF. A subset of 8-10 distinct or overlapping serum proteins predicted different future HF outcomes, and C-statistics were used to assess discrimination, revealing proteins combined with a C-index of 0.80 for all incident HF, 0.78 and 0.80 for incident HFpEF or HFrEF, respectively. In the AGES-RS, protein panels alone encompassed the risk contained in the clinical information and improved the performance characteristics of prediction models based on NT-proBNP and clinical risk factors. Finally, the protein predictors performed particularly well close to the time of an HF event, an outcome that was replicated in the Cardiovascular Health Study (CHS).

CONCLUSION: A small number of circulating proteins accurately predicted future HF in the AGES-RS cohort of older adults, and they alone encompass the risk information found in a collection of clinical data. Incident HF events were predicted up to eight years, with predictor performance significantly improving for events occurring less than one year ahead, a finding replicated in an external cohort study. This article is protected by copyright. All rights reserved.

}, issn = {1879-0844}, doi = {10.1002/ejhf.3086}, author = {Emilsson, Valur and Jonsson, Brynjolfur G and Austin, Thomas R and Gudmundsdottir, Valborg and Axelsson, Gisli T and Frick, Elisabet A and Jonmundsson, Thorarinn and Steindorsdottir, Anna E and Loureiro, Joseph and Brody, Jennifer A and Aspelund, Thor and Launer, Lenore J and Thorgeirsson, Gudmundur and Kortekaas, Kirsten A and Lindeman, Jan H and Orth, Anthony P and Lamb, John R and Psaty, Bruce M and Kizer, Jorge R and Jennings, Lori L and Gudnason, Vilmundur} } @article {9700, title = {A plasma protein-based risk score to predict hip fractures.}, journal = {Nat Aging}, year = {2024}, month = {2024 May 27}, abstract = {

As there are effective treatments to reduce hip fractures, identification of patients at high risk of hip fracture is important to inform efficient intervention strategies. To obtain a new tool for hip fracture prediction, we developed a protein-based risk score in the Cardiovascular Health Study using an aptamer-based proteomic platform. The proteomic risk score predicted incident hip fractures and improved hip fracture discrimination in two Tr{\o}ndelag Health Study validation cohorts using the same aptamer-based platform. When transferred to an antibody-based proteomic platform in a UK Biobank validation cohort, the proteomic risk score was strongly associated with hip fractures (hazard ratio per s.d. increase, 1.64; 95\% confidence interval 1.53-1.77). The proteomic risk score, but not available polygenic risk scores for fractures or bone mineral density, improved the C-index beyond the fracture risk assessment tool (FRAX), which integrates information from clinical risk factors (C-index, FRAX 0.735 versus FRAX + proteomic risk score 0.776). The developed proteomic risk score constitutes a new tool for stratifying patients according to hip fracture risk; however, its improvement in hip fracture discrimination is modest and its clinical utility beyond FRAX with information on femoral neck bone mineral density remains to be determined.

}, issn = {2662-8465}, doi = {10.1038/s43587-024-00639-7}, author = {Austin, Thomas R and Nethander, Maria and Fink, Howard A and T{\"o}rnqvist, Anna E and Jalal, Diana I and B{\r u}zkov{\'a}, Petra and Barzilay, Joshua I and Carbone, Laura and Gabrielsen, Maiken E and Grahnemo, Louise and Lu, Tianyuan and Hveem, Kristian and Jonasson, Christian and Kizer, Jorge R and Langhammer, Arnulf and Mukamal, Kenneth J and Gerszten, Robert E and Psaty, Bruce M and Robbins, John A and Sun, Yan V and Skogholt, Anne Heidi and Kanis, John A and Johansson, Helena and {\r A}svold, Bj{\o}rn Olav and Valderr{\'a}bano, Rodrigo J and Zheng, Jie and Richards, J Brent and Coward, Eivind and Ohlsson, Claes} } @article {9640, title = {Plasma proteomic signature of human longevity.}, journal = {Aging Cell}, year = {2024}, month = {2024 Mar 05}, pages = {e14136}, abstract = {

The identification of protein targets that exhibit anti-aging clinical potential could inform interventions to lengthen the human health span. Most previous proteomics research has been focused on chronological age instead of longevity. We leveraged two large population-based prospective cohorts with long follow-ups to evaluate the proteomic signature of longevity defined by survival to 90 years of age. Plasma proteomics was measured using a SOMAscan assay in 3067 participants from the Cardiovascular Health Study (discovery cohort) and 4690 participants from the Age Gene/Environment Susceptibility-Reykjavik Study (replication cohort). Logistic regression identified 211 significant proteins in the CHS cohort using a Bonferroni-adjusted threshold, of which 168 were available in the replication cohort and 105 were replicated (corrected p value <0.05). The most significant proteins were GDF-15 and N-terminal pro-BNP in both cohorts. A parsimonious protein-based prediction model was built using 33 proteins selected by LASSO with 10-fold cross-validation and validated using 27 available proteins in the validation cohort. This protein model outperformed a basic model using traditional factors (demographics, height, weight, and smoking) by improving the AUC from 0.658 to 0.748 in the discovery cohort and from 0.755 to 0.802 in the validation cohort. We also found that the associations of 169 out of 211 proteins were partially mediated by physical and/or cognitive function. These findings could contribute to the identification of biomarkers and pathways of aging and potential therapeutic targets to delay aging and age-related diseases.

}, issn = {1474-9726}, doi = {10.1111/acel.14136}, author = {Liu, Xiaojuan and Axelsson, Gisli Thor and Newman, Anne B and Psaty, Bruce M and Boudreau, Robert M and Wu, Chenkai and Arnold, Alice M and Aspelund, Thor and Austin, Thomas R and Gardin, Julius M and Siggeirsdottir, Kristin and Tracy, Russell P and Gerszten, Robert E and Launer, Lenore J and Jennings, Lori L and Gudnason, Vilmundur and Sanders, Jason L and Odden, Michelle C} } @article {9906, title = {Plasma Proteomic Assessment of Calcific Aortic Valve Disease in Older Adults.}, journal = {J Am Heart Assoc}, volume = {14}, year = {2025}, month = {2025 Mar 04}, pages = {e036336}, abstract = {

BACKGROUND: Calcific aortic valve disease (CAVD), and ensuing severe aortic stenosis (AS), is the foremost valvular disorder of aging, yet preventive therapies are lacking. A better understanding of the molecular underpinnings of aortic valve calcification (AVC) is necessary to develop pharmacologic interventions.

METHODS AND RESULTS: We undertook large-scale plasma proteomics in a cohort study of adults >=65 years old, the CHS (Cardiovascular Health Study), to identify individual proteins associated with echocardiographic AVC and incident moderate/severe AS. Proteomics measurements were performed with the aptamer-based SomaLogic platform of ~5000 proteins. Significant proteins were validated in a second cohort, the AGES-RS (Age, Gene/Environment Susceptibility-Reykjavik Study), which assessed AVC and AS by computed tomography. The potential causal associations of replicated proteins were tested in 2-sample Mendelian randomization using identified cis protein quantitative trait loci in consortia having computed tomography-quantified AVC or AS as outcomes. Six proteins showed Bonferroni-corrected significant relationships with AVC in CHS. Three of these, CXCL-12 (C-X-C chemokine ligand 12), KLKB1 (kallikrein), and leptin, replicated in AGES-RS, of which the former 2 are novel. Only 1 protein, CXCL6, which showed a near-significant association with AS in the replication cohort, was significantly (positively) associated with incident AS. Mendelian randomization analysis was conducted for KLKB1, CXCL12, and CXCL6, which supported a causal relationship for higher KLKB1 with lower AVC (beta=-0.25, =0.009).

CONCLUSIONS: This study of older adults newly identified and largely replicated associations of 3 circulating proteins with calcific aortic valve disease, of which the relationship of plasma KLKB1 may have a causal basis. Additional investigation is necessary to determine if KLKB1 could be harnessed for calcific aortic valve disease therapeutics.

}, keywords = {Age Factors, Aged, Aged, 80 and over, Aortic Valve, Aortic Valve Stenosis, Biomarkers, Blood Proteins, Calcinosis, Chemokine CXCL12, Echocardiography, Female, Humans, Male, Mendelian Randomization Analysis, Proteomics, Severity of Illness Index}, issn = {2047-9980}, doi = {10.1161/JAHA.124.036336}, author = {Bortnick, Anna E and Austin, Thomas R and Hamerton, Emily and Gudmundsdottir, Valborg and Emilsson, Valur and Jennings, Lori L and Gudnason, Vilmundur and Owens, David S and Massera, Daniele and Dufresne, Line and Yang, Ta-Yu and Engert, James C and Thanassoulis, George and Tracy, Russell P and Gerszten, Robert E and Psaty, Bruce M and Kizer, Jorge R} }