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Objective: To identify causal pathophysiological mechanisms for atherosclerosis and incident cardiovascular events using protein measurements. Approach and Results: Carotid artery atherosclerosis was assessed by ultrasound, and 86 cardiovascular-related proteins were measured using the Olink CVD-I panel in 7 Swedish prospective studies (11 754 individuals). The proteins were analyzed in relation to intima-media thickness in the common carotid artery (IMT-CCA), plaque occurrence, and incident cardiovascular events (composite end point of myocardial infarction or ischemic stroke) using a discovery/replication approach in different studies. After adjustments for traditional cardiovascular risk factors, 11 proteins remained significantly associated with IMT-CCA in the replication stage, whereas 9 proteins were replicated for plaque occurrence and 17 proteins for incident cardiovascular events. NT-proBNP (N-terminal pro-B-type natriuretic peptide) and MMP (matrix metalloproteinase)-12 were associated with both IMT-CCA and incident events, but the overlap was considerably larger between plaque occurrence and incident events, including MMP-12, TIM-1 (T-cell immunoglobulin and mucin domain 1), GDF (growth/differentiation factor)-15, IL (interleukin)-6, U-PAR (urokinase plasminogen activator surface receptor), LOX-1 (lectin-like oxidized LDL [low-density lipoprotein] receptor 1), and TRAIL-R2 (TNF [tumor necrosis factor]-related apoptosis-inducing ligand receptor 2). Only MMP-12 was associated with IMT-CCA, plaque, and incident events with a positive and concordant direction of effect. However, a 2-sample Mendelian randomization analysis suggested that increased MMP-12 may be protective against ischemic stroke ( P =5.5×10 −7 ), which is in the opposite direction of the observational analyses. Conclusions: The present meta-analysis discovered several proteins related to carotid atherosclerosis that partly differed in their association with IMT-CCA, plaque, and incident atherosclerotic disease. Mendelian randomization analysis for the top finding, MMP-12, suggests that the increased levels of MMP-12 could be a consequence of atherosclerotic burden rather than the opposite chain of events.

Objective: The pathophysiology of hypertension remains incompletely understood. We investigated associations of circulating metabolites with longitudinal blood pressure (BP) changes in the Prospective Investigation of the Vasculature in Uppsala Seniors cohort and validated the findings in the Uppsala Longitudinal Study of Adult Men cohort. Approach and Results: Circulating metabolite levels were assessed with liquid- and gas-chromatography coupled to mass spectrometry among persons without BP-lowering medication at baseline. We studied associations of baseline levels of metabolites with changes in BP levels and the clinical BP stage between baseline and a follow-up examination 5 years later. In the discovery cohort, we investigated 504 individuals that contributed with 757 observations of paired BP measurements. The mean baseline systolic and diastolic BPs were 144 (19.7)/76 (9.7) mm Hg, and change in systolic and diastolic BPs were 3.7 (15.8)/−0.5 (8.6) mm Hg over 5 years. The metabolites associated with diastolic BP change were ceramide, triacylglycerol, total glycerolipids, oleic acid, and cholesterylester. No associations with longitudinal changes in systolic BP or BP stage were observed. Metabolites with similar structures to the 5 top findings in the discovery cohort were investigated in the validation cohort. Diacylglycerol (36:2) and monoacylglycerol (18:0), 2 glycerolipids, were associated with diastolic BP change in the validation cohort. Conclusions: Circulating baseline levels of ceramide, triacylglycerol, total glycerolipids, and oleic acid were positively associated with longitudinal diastolic BP change, whereas cholesterylester levels were inversely associated with longitudinal diastolic BP change. Two glycerolipids were validated in an independent cohort. These metabolites may point towards pathophysiological pathways of hypertension.

Objective— Revealing patterns of associations between circulating protein and lipid levels could improve biological understanding of cardiovascular disease (CVD). In this study, we investigated the associations between proteins related to CVD and triglyceride (TG), total cholesterol, LDL (low-density lipoprotein), and HDL (high-density lipoprotein) cholesterol levels in individuals from the general population. Approach and Results— We measured plasma protein levels using the Olink ProSeek CVD I or II+III arrays and analyzed 57 proteins available in 3 population-based cohorts: EpiHealth (n=2029; 52% women; median age, 61 years), PIVUS (Prospective Study of the Vasculature in Uppsala Seniors; n=790; 51% women; all aged 70 years), and ULSAM (Uppsala Longitudinal Study of Adult Men; n=551; all men aged 77 years). A discovery analysis was performed in EpiHealth in a regression framework (adjusted for sex, age, body mass index, smoking, glucose levels, systolic blood pressure, blood pressure medication, diabetes mellitus medication, and CVD history), and associations with false discovery rate P value of 0.05 was considered a successful replication (validation false discovery rate of 0.1%). We used summary statistics from a genome-wide association study on each protein biomarker (meta-analysis of EpiHealth, PIVUS, ULSAM, and IMPROVE [Carotid Intima–Media Thickness and IMT-Progression as Predictors of Vascular Events in a High-Risk European Population]) and publicly available data from Global Lipids Genetics Consortium to perform Mendelian randomization analyses to address possible causality of protein levels. Of 57 tested proteins, 42 demonstrated an association with at least 1 lipid fraction; 35 were associated with TG, 15 with total cholesterol, 9 with LDL cholesterol, and 24 with HDL cholesterol. Among these associations, we found KIM-1 (kidney injury molecule-1), TNFR (TNF [tumor necrosis factor] receptor) 1 and 2, TRAIL-R2 (TRAIL [TNF-related apoptosis-inducing ligand] receptor 2), and RETN (resistin) to be associated with all 4 lipid fractions. Further, 15 proteins were related to both TG and HDL cholesterol in a consistent and biologically expected manner, that is, higher TG and lower HDL cholesterol or vice versa. Another common pattern of associations was concomitantly higher TG, total cholesterol, and LDL cholesterol, which is associated with higher CVD risk. We did not find evidence of causal links for protein levels. Conclusions— Our comprehensive analysis of plasma proteins and lipid fractions of 3370 individuals from the general population provides new information about lipid metabolism.

Objective— Current guidelines do not support the use of genetic profiles in risk assessment of coronary heart disease (CHD). However, new single nucleotide polymorphisms associated with CHD and intermediate cardiovascular traits have recently been discovered. We aimed to compare several multilocus genetic risk score (MGRS) in terms of association with CHD and to evaluate clinical use. Approach and Results— We investigated 6 Swedish prospective cohort studies with 10 612 participants free of CHD at baseline. We developed 1 overall MGRS based on 395 single nucleotide polymorphisms reported as being associated with cardiovascular traits, 1 CHD-specific MGRS, including 46 single nucleotide polymorphisms, and 6 trait-specific MGRS for each established CHD risk factors. Both the overall and the CHD-specific MGRS were significantly associated with CHD risk (781 incident events; hazard ratios for fourth versus first quartile, 1.54 and 1.52; P P =0.006 and 0.017). Discrimination improvement was modest (C-index improvement, 0.004). A polygene MGRS performed worse than the CHD-specific MGRS. We estimate that 1 additional CHD event for every 318 people screened at intermediate risk could be saved by measuring the CHD-specific genetic score in addition to the established risk factors. Conclusions— Our results indicate that genetic information could be of some clinical value for prediction of CHD, although further studies are needed to address aspects, such as feasibility, ethics, and cost efficiency of genetic profiling in the primary prevention setting.

Background: We used a proteomics array to simultaneously measure 92 proteins that have been suggested to be associated with atherosclerosis and related them to plaque prevalence and echogenicity in carotid arteries in a human population-based study. Methods: In the Prospective Study of the Vasculature in Uppsala Seniors (PIVUS; n=931, 50% women, all aged 70 years), the number of carotid arteries with plaques was recorded by ultrasound and plaque echogenicity was determined. Levels of 92 proteins were assessed in plasma by a proximity extension assay (Proseek Multiplex CVD, Olink Bioscience, Uppsala, Sweden) and related to carotid measures in a regression framework. Results: Following adjustment for multiple testing, six of the proteins were significantly related to the number of carotid arteries affected by plaques in sex-adjusted models (osteoprotegrin, T-cell immunoglobulin and mucin domain-1, renin, growth hormone, matrix metalloprotease-12 and lecitin-like oxidized LDL receptor 1). When these six proteins were included jointly in a model adjusting for traditional cardiovascular risk factors, renin (odds ratio [OR], 1.30; 95% confidence interval [CI], 1.13-1.50 per standard deviation increase) and growth hormone (OR, 1.26; 95% CI, 1.10-1.45) were related to plaque prevalence independently of each other and known risk factors for atherosclerosis. Thirty-one proteins were related to plaque echogenicity after adjustment for known risk factors. Of these, interleukin-27 subunit alpha (beta, 5.20; P=0.00032), vascular endothelial growth factor-delta (beta, 4.73; P=0.0013) and matrix metalloprotease-1 (beta, 3.93; P=0.0034) were associated with plaque echogenicity independently of each other. Conclusion: A novel targeted proteomics approach using the proximity extension technique discovered several new associations of candidate proteins with plaque prevalence and echogenicity in the carotid arteries in a large human sample.

Objective— Cardiovascular risk factors have different impact on different arterial territories. Diseases with elevated circulating parathyroid hormone (PTH) such as primary hyperparathyroidism and chronic renal failure have been shown to be associated with an increased risk of cardiovascular disease, predominantly heart or cerebrovascular diseases. However, data on the associations between circulating PTH and peripheral atherosclerosis are limited. Approach and Results— Two prospective, community-based studies were used. In 306 men and women, who were 70 years old, from the Prospective investigation of the vasculature in Uppsala seniors (PIVUS) study, cross-sectional relations between PTH and atherosclerotic burden assessed by whole-body magnetic resonance angiography were investigated. In 998 men, who were 71 years old, from the Uppsala longitudinal study of adult men (ULSAM) study, the association between PTH concentration and risk of subsequent nonfatal atherosclerotic disease (excluding coronary or cerebrovascular disease) was investigated. Adjusting for established vascular risk factors, PTH was associated with burden of atherosclerosis (increase in total atherosclerotic score per SD PTH increase: 0.04, 0.003–0.08; P =0.03) in the PIVUS study. During follow-up in the ULSAM study (median 16.7 years), 89 men were diagnosed with nonfatal atherosclerotic disease. In Cox-regression analyses adjusting for established vascular risk factors and mineral metabolism, higher PTH was associated with an increased risk of nonfatal atherosclerotic disease (hazard ratio for 1 SD increase of PTH: 1.55, 1.33–1.88; P Conclusions— In 2 independent community-based cohorts, PTH was associated to the degree of atherosclerosis and risk of clinically overt atherosclerotic disease, respectively. Our data confirm and extend previous studies supporting a role for PTH in the development of atherosclerotic disease.

Objective— Experimental data imply that endostatin, a proteolytically cleaved fragment of collagen XVIII, could be involved in the development of cardiovascular disease and cancer. Prospective data concerning the relation between circulating endostatin and mortality are lacking. Accordingly, we aimed to study associations between circulating endostatin and mortality risk. Approach and Results— Serum endostatin was analyzed in 2 community-based cohorts: the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS; women 50%, n=931; mean age, 70 years; median follow-up, 7.9 years) and the Uppsala Longitudinal Study of Adult Men (ULSAM; n=748; mean age, 77 years; median follow-up, 9.7 years). During follow-up, 90 participants died in PIVUS (1.28/100 person-years at risk), and 417 participants died in ULSAM (6.7/100 person-years at risk). In multivariable Cox regression models adjusted for age and established cardiovascular risk factors, 1 SD higher ln(serum endostatin level) was associated with a hazard ratio of mortality of 1.39 and 95% confidence interval, 1.26 to 1.53, on average in both cohorts. In the ULSAM cohort, serum endostatin was also associated with cardiovascular mortality (177 deaths; hazard ratio per SD of ln[endostatin] 1.45, 95% confidence interval [1.25–1.71]) and cancer mortality (115 deaths; hazard ratio per SD of ln[endostatin] 1.35, 95% confidence interval [1.10–1.66]). Conclusions— High serum endostatin was associated with increased mortality risk in 2 independent community-based cohorts of the elderly. Our observational data support the importance of extracellular matrix remodeling in the underlying pathophysiology of cardiovascular disease and cancer.

Objective— Although obesity without metabolic disturbances has been regarded as harmless, we have recently shown that obese subjects without the metabolic syndrome (MetS) has an increased risk of cardiovascular (CV) disorders and mortality during long-term follow-up. To investigate the basis for that increased risk, we studied the impact of obesity without MetS on multiple markers of subclinical CV disease. Methods and Results— At age 70, 1016 subjects were investigated in the Prospective Investigation of the Vasculature in Uppsala Seniors study. According to body mass index (BMI)/MetS status, they were categorized as normal weight (BMI 2 ) without MetS (National Cholesterol Education Program criteria, n=319), normal weight with MetS (n=19), overweight (BMI 25 to 29.9 kg/m 2 ) without MetS (n=333), overweight with MetS (n=94), obese (BMI ≥30 kg/m 2 ) without MetS (n=102), and obese with MetS (n=118). Several different measurements of endothelial reactivity, arterial compliance (plethysmography and ultrasound), carotid artery atherosclerosis, and echocardiography were performed, and 7 markers of coagulation/fibrinolysis were measured. Subjects with obesity without MetS showed impaired vasoreactivity, a more echolucent carotid artery wall, increased left ventricular mass and function together with impaired coagulation/fibrinolysis compared with normal-weight subjects without the MetS ( P Conclusion— In contrast to some previous studies, our data do not support that obesity without MetS is a benign condition, because obesity without MetS was associated with impairments in multiple markers of subclinical CV disease. This was also the case for overweight subjects without the MetS.

Objective— Hyperphosphatemia is a cardiovascular risk factor in patients with chronic kidney disease. Relations of circulating calcium (Ca) and phosphorus (Pi) to long-term mortality risk in the community require further investigation. Methods and Results— Associations of serum Ca and Pi to mortality were evaluated in a community-based cohort of 2176 men (mean age, 50.1 years). During follow-up (median, 29.8 years), 1009 men died, and 466 of these deaths resulted from cardiovascular causes. In Cox proportional hazards models, serum Pi and [Ca×Pi] were independent predictors of total mortality (hazard ratio per SD, 1.06; 95% CI, 1.01–1.12; P =0.03; 1.07; 95% CI, 1.01–1.12; P =0.01) and cardiovascular mortality (1.10; 95% CI, 1.02–1.18; P =0.01; 1.10; 95% CI, 1.03–1.19; P =0.008). Serum Ca was associated with risk of total mortality (1.08; 95% CI, 1.01–1.16; P =0.02) and noncardiovascular mortality (1.10; 95% CI, 1.01–1.21; P =0.04). Results were consistent after multivariate adjustments in subsamples of individuals with estimated glomerular filtration rate >90 mL/min and low-to-normal serum Ca and Pi. Conclusion— Circulating Ca and Pi levels are associated with risks of total, cardiovascular, and noncardiovascular mortality in the community, and their conjoint effects are additive. Additional studies are warranted to evaluate whether Ca and Pi are modifiable risk factors in the general population.