Uppsala Longitudinal Study Of Adult Men Research Articles

The use of class imbalanced learning methods on ULSAM data to predict the case–control status in genome-wide association studies

Machine learning (ML) methods for uncovering single nucleotide polymorphisms (SNPs) in genome-wide association study (GWAS) data that can be used to predict disease outcomes are becoming increasingly used in genetic research. Two issues with the use of ML models are finding the correct method for dealing with imbalanced data and data training. This article compares three ML models to identify SNPs that predict type 2 diabetes (T2D) status using the Support vector machine SMOTE (SVM SMOTE), The Adaptive Synthetic Sampling Approach (ADASYN), Random under sampling (RUS) on GWAS data from elderly male participants (165 cases and 951 controls) from the Uppsala Longitudinal Study of Adult Men (ULSAM). It was also applied to SNPs selected by the SMOTE, SVM SMOTE, ADASYN, and RUS clumping method. The analysis was performed using three different ML models: (i) support vector machine (SVM), (ii) multilayer perceptron (MLP) and (iii) random forests (RF). The accuracy of the case–control classification was compared between these three methods. The best classification algorithm was a combination of MLP and SMOTE (97% accuracy). Both RF and SVM achieved good accuracy results of over 90%. Overall, methods used against unbalanced data, all three ML algorithms were found to improve prediction accuracy.

Plasma Protein Profiling of Incident Cardiovascular Diseases: A Multisample Evaluation.

Proteomic profiling could potentially disclose new pathophysiological pathways for cardiovascular diseases (CVD) and improve prediction at the individual level. We therefore aimed to study the plasma protein profile associated with the incidence of different CVDs. Plasma levels of 245 proteins suspected to be linked to CVD or metabolism were measured in 4 Swedish prospective population-based cohorts (SIMPLER [Swedish Infrastructure for Medical Population-Based Life-Course and Environmental Research], ULSAM (Uppsala Longitudinal Study of Adult Men), EpiHealth, and POEM [Prospective Investigation of Obesity, Energy Production, and Metabolism]) comprising 11 869 individuals, free of CVD diagnoses at baseline. Our primary CVD outcome was defined by a combined end point that included either incident myocardial infarction, stroke, or heart failure. Using a discovery/validation approach, 42 proteins were associated with our primary composite end point occurring in 1163 subjects. In separate meta-analyses for each of the 3 CVD outcomes, 49 proteins were related to myocardial infarction, 34 to ischemic stroke, and 109 to heart failure. Thirteen proteins were related to all 3 outcomes. Of those, urokinase plasminogen activator surface receptor, adrenomedullin, and KIM-1 (kidney injury molecule 1) were also related to several markers of subclinical CVD in Prospective Investigation of Obesity, Energy production and Metabolism, reflecting myocardial or arterial pathologies. In prediction analysis, a lasso selection of 11 proteins in ULSAM improved the discrimination of CVD by 3.3% (P<0.0001) in SIMPLER when added to traditional risk factors. Protein profiling in multiple samples disclosed several new proteins to be associated with subsequent myocardial infarction, stroke, and heart failure, suggesting common pathophysiological pathways for these diseases. KIM-1, urokinase plasminogen activator surface receptor, and adrenomedullin were novel early markers of CVD. A selection of 11 proteins improved the discrimination of CVD.

Plasma proteomic signatures of a direct measure of insulin sensitivity in two population cohorts.

The euglycaemic-hyperinsulinaemic clamp (EIC) is the reference standard for the measurement of whole-body insulin sensitivity but is laborious and expensive to perform. We aimed to assess the incremental value of high-throughput plasma proteomic profiling in developing signatures correlating with the M value derived from the EIC. We measured 828 proteins in the fasting plasma of 966 participants from the Relationship between Insulin Sensitivity and Cardiovascular disease (RISC) study and 745 participants from the Uppsala Longitudinal Study of Adult Men (ULSAM) using a high-throughput proximity extension assay. We used the least absolute shrinkage and selection operator (LASSO) approach using clinical variables and protein measures as features. Models were tested within and across cohorts. Our primary model performance metric was the proportion of the M value variance explained (R2). A standard LASSO model incorporating 53 proteins in addition to routinely available clinical variables increased the M value R2 from 0.237 (95% CI 0.178, 0.303) to 0.456 (0.372, 0.536) in RISC. A similar pattern was observed in ULSAM, in which the M value R2 increased from 0.443 (0.360, 0.530) to 0.632 (0.569, 0.698) with the addition of 61 proteins. Models trained in one cohort and tested in the other also demonstrated significant improvements in R2 despite differences in baseline cohort characteristics and clamp methodology (RISC to ULSAM: 0.491 [0.433, 0.539] for 51 proteins; ULSAM to RISC: 0.369 [0.331, 0.416] for 67 proteins). A randomised LASSO and stability selection algorithm selected only two proteins per cohort (three unique proteins), which improved R2 but to a lesser degree than in standard LASSO models: 0.352 (0.266, 0.439) in RISC and 0.495 (0.404, 0.585) in ULSAM. Reductions in improvements of R2 with randomised LASSO and stability selection were less marked in cross-cohort analyses (RISC to ULSAM R2 0.444 [0.391, 0.497]; ULSAM to RISC R2 0.348 [0.300, 0.396]). Models of proteins alone were as effective as models that included both clinical variables and proteins using either standard or randomised LASSO. The single most consistently selected protein across all analyses and models was IGF-binding protein 2. A plasma proteomic signature identified using a standard LASSO approach improves the cross-sectional estimation of the M value over routine clinical variables. However, a small subset of these proteins identified using a stability selection algorithm affords much of this improvement, especially when considering cross-cohort analyses. Our approach provides opportunities to improve the identification of insulin-resistant individuals at risk of insulin resistance-related adverse health consequences.

Large-Scale Plasma Protein Profiling of Incident Myocardial Infarction, Ischemic Stroke, and Heart Failure.

BackgroundWe recently reported a link between plasma levels of 2 of 84 cardiovascular disease (CVD)–related proteins and the 3 major CVDs, myocardial infarction, ischemic stroke, and heart failure. The present study investigated whether measurement of almost 10 times the number of proteins could lead to discovery of additional risk markers for CVD.Methods and ResultsWe measured 742 proteins using the proximity extension assay in 826 male participants of ULSAM (Uppsala Longitudinal Study of Adult Men) who were free from CVD at the age of 70 years. Cox proportional hazards models were adjusted for age only, as well as all traditional risk factors. During a 12.5‐year median follow‐up (maximal, 22.0 years), 283 incident CVDs occurred. Forty‐one proteins were significantly (false discovery rate <0.05) related to the combined end point of incident CVD, with N‐terminal pro–brain natriuretic peptide as the top finding, while 53 proteins were related to incident myocardial infarction. A total of 13 and 16 proteins were significantly related to incident ischemic stroke and heart failure, respectively. Growth differentiation factor 15, 4‐disulfide core domain protein 2, and kidney injury molecule were related to all of the 3 major CVD outcomes. A lasso selection of 11 proteins improved discrimination of incident CVD by 5.0% (P=0.0038).ConclusionsLarge‐scale proteomics seem useful for the discovery of new risk markers for CVD and to improve risk prediction in an elderly population of men. Further studies are needed to replicate the findings in independent samples of both men and women of different ages.

Strong Associations between Plasma Osteopontin and Several Inflammatory Chemokines, Cytokines, and Growth Factors.

Osteopontin is a member of the proinflammatory cytokine network, a complex system that involves many chemokines, cytokines, and growth factors. The aim of the present study was to study the associations between osteopontin and a large number of chemokines, cytokines, and growth factors. We analyzed plasma and urine osteopontin in 652 men from the Uppsala Longitudinal Study of Adult Men (ULSAM) study cohort and compared the levels with the levels of eighty-five chemokines, cytokines, and growth factors. We found significant associations between plasma osteopontin and 37 plasma biomarkers in a model adjusted for age, and 28 of those plasma biomarkers were significant in a model also adjusting for cardiovascular risk factors. There were no significant associations after Bonferroni adjustment between urine osteopontin and any of the studied plasma cytokine biomarkers. This study shows that circulating osteopontin participates in a protein–protein interaction network of chemokines, cytokines, and growth factors. The network contains responses, pathways, and receptor binding interactions relating to cytokines, regulation of the immune system, and also regulation of apoptosis and intracellular signal transduction.

Plasma Protein Profile of Incident Myocardial Infarction, Ischemic Stroke, and Heart Failure in 2 Cohorts.

BackgroundThe aim is to study common etiological pathways for 3 major cardiovascular diseases (CVD), as reflected in multiple proteins.Methods and ResultsEighty‐four proteins were measured using the proximity extension technique in 870 participants in the PIVUS (Prospective Investigation of Uppsala Seniors Study) cohort on 3 occasions (age 70, 75, and 80 years). The sample was followed for incident myocardial infarction, ischemic stroke or heart failure. The same proteins were measured in an independent validation sample, the ULSAM (Uppsala Longitudinal Study of Adult Men) cohort in 595 participants at age 77. During a follow‐up of up to 15 years in PIVUS and 9 years in ULSAM, 222 and 167 individuals experienced a CVD. Examining associations with the 3 outcomes separately in a meta‐analysis of the 2 cohorts, 6 proteins were related to incident myocardial infarction, 25 to heart failure, and 8 proteins to ischemic stroke following adjustment for traditional risk factors. Growth differentiation factor 15 and tumor necrosis factor‐related apoptosis‐inducing ligand receptor 2 were related to all 3 CVDs. Including estimated glomerular filtration rate in the models attenuated some of these relationships. Fifteen proteins were related to a composite of all 3 CVDs using a discovery/validation approach when adjusting for traditional risk factors. A selection of 7 proteins by lasso in PIVUS improved discrimination of incident CVD by 7.3% compared with traditional risk factors in ULSAM.ConclusionsWe discovered and validated associations of multiple proteins with incident CVD. Only a few proteins were associated with all 3 diseases: myocardial infarction, ischemic stroke, and heart failure.

Life-Time Covariation of Major Cardiovascular Diseases: A 40-Year Longitudinal Study and Genetic Studies.

It is known that certain cardiovascular diseases (CVD) are associated, like atrial fibrillation and stroke. However, for other CVDs, the links and temporal trends are less studied. In this longitudinal study, we have investigated temporal epidemiological and genetic associations between different CVDs. The ULSAM (Uppsala Longitudinal Study of Adult Men; 2322 men aged 50 years) has been followed for 40 years regarding 4 major CVDs (incident myocardial infarction, ischemic stroke, heart failure, and atrial fibrillation). For the genetic analyses, publicly available data were used. Using multistate modeling, significant relationships were seen between pairs of all of the 4 investigated CVDs. However, the risk of obtaining one additional CVD differed substantially both between different CVDs and between their temporal order. The relationship between heart failure and atrial fibrillation showed a high risk ratio (risk ratios, 24-26) regardless of the temporal order. A consistent association was seen also for myocardial infarction and atrial fibrillation but with a lower relative risk (risk ratios, 4-5). In contrast, the risk of receiving a diagnosis of heart failure following a myocardial infarction was almost twice as high as for the reverse temporal order (risk ratios, 16 versus 9). Genetic loci linked to traditional risk factors could partly explain the observed associations between the CVDs, but pathway analyses disclosed also other pathophysiological links. During 40 years, all of the 4 investigated CVDs were pairwise associated with each other regardless of the temporal order of occurrence, but the risk magnitude differed between different CVDs and their temporal order. Genetic analyses disclosed new pathophysiological links between CVDs.

Sarcopenic obesity and associations with mortality in older women and men \u2013 a prospective observational study

BackgroundThe combined effect of sarcopenia and obesity, i.e., sarcopenic obesity, has been associated with disability and worse outcomes in older adults, but results are conflicting. The objectives of this study were to describe the prevalence of sarcopenic obesity (SO) in older adults, and to examine how the risk of mortality is associated with SO and its various components.MethodsData were obtained from two Swedish population studies, the Gothenburg H70 Birth Cohort Studies of 521 women and men at the age of 75, and the Uppsala Longitudinal Study of Adult Men (ULSAM), which included 288 men aged 87 years. Sarcopenia was defined using the recently updated EWGSOP2 definition. Obesity was defined by any of three established definitions: body mass index ≥30 kg/m2, fat mass > 30%/ > 42% or waist circumference ≥ 88 cm/≥102 cm for women and men, respectively. The Kaplan-Meier survival curve and the Cox proportional hazard model were used for 10-year and 4-year survival analyses in the H70 and ULSAM cohorts, respectively.ResultsSO was observed in 4% of the women and 11% of the men in the H70 cohort, and in 10% of the ULSAM male cohort. The 75-year-old women with SO had a higher risk (HR 3.25, 95% confidence interval (1.2–8.9)) of dying within 10 years compared to those with a “normal” phenotype. A potential similar association with mortality among the 75-year-old men was not statistically significant. In the older men aged 87 years, obesity was associated with increased survival.ConclusionsSO was observed in 4–11% of community-dwelling older adults. In 75-year-old women SO appeared to associate with an increased risk of dying within 10 years. In 87-year-old men, the results indicated that obesity without sarcopenia was related to a survival benefit over a four-year period.

0836 Self-Reported Difficulty Initiating Sleep and Early Morning Awakenings are Associated With Nocturnal Diastolic Non-Dipping in Older Men

Abstract Introduction Aging increases the risk of insomnia and elevated blood pressure (BP). Here, we examined in older men whether reports of difficulty falling asleep (DIS) and early morning awakenings (EMA) are associated with 24-h BP and heart rate. Methods We utilized variables from 995 men (mean age: 71 years) who participated in the Uppsala Longitudinal Study of Adult Men (ULSAM). BP and heart rate were measured over 24 hours. Results Non-dippers (night-to-day BP ratio &amp;gt; 0.90) had a higher risk of hypertension than dippers (systolic non-dippers vs. systolic dippers, OR [95%CI]: 1.64 [1.21, 2.21], P=0.001; diastolic non-dippers vs. diastolic dippers, 1.50 [1.10, 2.04], P=0.01). Compared to men without DIS, men who reported DIS (10% of the cohort) had a higher risk of diastolic non-dipping (1.85 [1.19, 2.87], P=0.006). Similarly, men who reported EMA (19% of the cohort) had a higher risk of diastolic non-dipping than those without EMA (1.59 [1.12, 2.24], P=0.009). Despite a slightly higher nocturnal diastolic BP among men with EMA vs. those without EMA (+1.4 mmHg, P=0.035), no other differences in BP and heart rate were found between men with and those without insomnia complaints. Conclusion Our findings uncover a link between disruption in nocturnal dipping of diastolic BP and insomnia symptoms related to difficulty initiating sleep and early morning awakening in older men. Support Authors’ work is funded by the Novo Nordisk Foundation (C.B., NNF19OC0056777), Swedish Brain Research Foundation (C.B., FO2019-0028), Swedish Research Council (C.B., 2015-03100), Åke Wiberg Foundation (X.T., M18-0169, M19-0266), Fredrik and Ingrid Thuring Foundation (X.T., 2018-00365), and the Swedish Medical Research Society (X.T., P18-0084).

Sarcopenia prevalence and associations with mortality and hospitalisation by various sarcopenia definitions in 85\u201389\u2009year old community-dwelling men: a report from the ULSAM study

BackgroundOperational definitions of sarcopenia, i.e. loss of muscle function and mass, have been proposed by the European Working Group on Sarcopenia in Older People (EWGSOP) and the Foundation for the National Institutes of Health Sarcopenia Project (FNIH). The aim of this study was to analyse the prevalence and outcome, i.e. all-cause mortality and hospitalisation, of sarcopenia and its diagnostic components in octogenarian community-dwelling men.MethodsIn total 287 men, aged 85–89 y, participating in the Uppsala Longitudinal Study of Adult Men (ULSAM) underwent Dual X-ray Absorptiometry (DXA), measurement of hand grip strength (HGS), gait speed (GS), and a five-times chair stand test (CS). Sarcopenia and probable sarcopenia were defined according to EWGSOP (2010), EWGSOP2 (2018), and FNIH (2014). All-cause mortality and hospitalisations over 3 years were registered.ResultsSarcopenia according to EWGSOP, EWGSOP2 and FNIH was observed in 21%, 20%, and 8% of the men, respectively, while probable sarcopenia (EWGSOP2; eq. reduced muscle strength only) was seen in 73%. “Sarcopenia (EWGSOP)” and “probable sarcopenia (EWGSOP2)” were associated with increased mortality (HR 1.95, 95% CI 1.12–3.40 and HR 3.26, 95% CI 1.38–7.70, respectively). “Probable sarcopenia (EWGSOP2)” was associated with days of hospitalisation (RR 2.12, 95% CI 1.36–3.30), whereas sarcopenia according to FNIH showed an association with the number of hospitalisations (RR 1.75, 95% CI 1.10–2.81).ConclusionsIn very old men, reduced muscle strength, i.e. probable sarcopenia, was common and associated with mortality and length of stay during hospitalisation. When combined with low muscle mass (according to DXA), i.e. sarcopenia, the various definitions were associated more weakly with the adverse outcomes. The findings support the emphasis on reduced muscle strength as the major determinant of sarcopenia.

Proteomic Analysis of Longitudinal Changes in Blood Pressure.

Hypertension is the leading risk factor for premature death worldwide. The identification of modifiable causes of hypertension remains an imperative task. We aimed to investigate associations between 79 proteins implicated in cardiovascular disease and longitudinal blood pressure (BP) changes in three Swedish prospective cohorts. In a discovery phase, we investigated associations between baseline circulating protein levels assessed with a proximity extension assay and BP stage progression at follow-up 5 years later among persons without BP-lowering drugs at baseline in two independent community-based cohorts from the Prospective Investigation of the Vasculature in Uppsala Seniors study (PIVUS) and the Uppsala Longitudinal Study of Adult Men (ULSAM). We used an independent cohort, the Malmö Diet and Cancer Study (MDC), for replication. The primary outcome of BP stage progression was defined as per the 2017 AHA/ACC (American Heart Association/ American College of Cardiology) Guideline BP categories. We also investigated associations of protein levels with changes in BP on a continuous scale, and meta-analyzed all three cohorts. Levels of renin were associated with BP stage progression with a 5% false discovery rate (FDR) in the ULSAM (n = 238) and PIVUS (n = 566) cohorts, but we could not replicate this association in the MDC cohort (n = 2659). The association in the discovery cohorts was modest, with an odds ratio for BP stage progression over 5 years of 1.33 (95% confidence interval 1.14 to 1.56) per standard deviation of baseline renin. In conclusion, we could not find any novel robust associations with longitudinal BP increase in a proximity extension assay-based proteomics investigation in three cohorts.

The metabolites urobilin and sphingomyelin (30:1) are associated with incident heart failure in the general population.

AimsWe aimed to investigate whether metabolomic profiling of blood can lead to novel insights into heart failure pathogenesis or improved risk prediction.Methods and resultsMass spectrometry‐based metabolomic profiling was performed in plasma or serum samples from three community‐based cohorts without heart failure at baseline (total n = 3924; 341 incident heart failure events; median follow‐up ranging from 4.6 to 13.9 years). Cox proportional hazard models were applied to assess the association of each of the 206 identified metabolites with incident heart failure in the discovery cohorts Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) (n = 920) and Uppsala Longitudinal Study of Adult Men (ULSAM) (n = 1121). Replication was undertaken in the independent cohort TwinGene (n = 1797). We also assessed whether metabolites could improve the prediction of heart failure beyond established risk factors (age, sex, body mass index, low‐density and high‐density lipoprotein cholesterol, triglycerides, lipid medication, diabetes, systolic and diastolic blood pressure, blood pressure medication, glomerular filtration rate, smoking status, and myocardial infarction prior to or during follow‐up). Higher circulating urobilin and lower sphingomyelin (30:1) were associated with incident heart failure in age‐adjusted and sex‐adjusted models in the discovery and replication sample. The hazard ratio for urobilin in the replication cohort was estimated to 1.29 per standard deviation unit, 95% confidence interval (CI 1.03–1.63), and for sphingomyelin (30:1) to 0.72 (95% CI 0.58–0.89). Results remained similar after further adjustment for established heart failure risk factors in meta‐analyses of all three cohorts. Urobilin concentrations were inversely associated with left ventricular ejection fraction at baseline in the PIVUS cohort (β = −0.70, 95% CI −1.03 to −0.38). No major improvement in risk prediction was observed when adding the top 2 metabolites (C‐index 0.787, 95% CI 0.752–0.823) or nine Lasso‐selected metabolites (0.790, 95% CI 0.754–0.826) to a modified Atherosclerosis Risk in Communities heart failure risk score model (0.780, 95% CI 0.745–0.816).ConclusionsOur metabolomic profiling of three community‐based cohorts study identified associations of circulating levels of the haem breakdown product urobilin, and sphingomyelin (30:1), a cell membrane component involved in signal transduction and apoptosis, with incident heart failure.

Longitudinal Muscle and Myocellular Changes in Community-Dwelling Men Over Two Decades of Successful Aging-The ULSAM Cohort Revisited.

Participants of the population-based Uppsala longitudinal study of adult men (ULSAM) cohort reaching more than 88 years of age (survivors, S) were investigated at age 70, 82, and 88-90 and compared at 70 years with non-survivors (NS) not reaching 82 years. Body composition, muscle mass and muscle histology were remarkably stable over 18 years of advanced aging in S. Analysis of genes involved in muscle remodeling showed that S had higher mRNA levels of myogenic differentiation factors (Myogenin, MyoD), embryonic myosin (eMyHC), enzymes involved in regulated breakdown of myofibrillar proteins (Smad2, Trim32, MuRF1,) and NCAM compared with healthy adult men (n = 8). S also had higher mRNA levels of eMyHC, Smad 2, MuRF1 compared with NS. At 88 years, S expressed decreased levels of Myogenin, MyoD, eMyHC, NCAM and Smad2 towards those seen in NS at 70 years. The gene expression pattern of S at 70 years was likely beneficial since they maintained muscle fiber histology and appendicular lean body mass until advanced age. The expression pattern at 88 years may indicate a diminished muscle remodeling coherent with a decline of reinnervation capacity and/or plasticity at advanced age.

Associations of Circulating Protein Levels With Lipid Fractions in the General Population.

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 <0.05 were further tested in PIVUS and ULSAM, where a 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.

Cognitive function in very old men does not correlate to biomarkers of Alzheimer\u2019s disease

BackgroundThe Alzheimer’s disease (AD) brain displays atrophy with amyloid-β (Aβ) and tau deposition, whereas decreased Aβ42 and increased tau are measured in cerebrospinal fluid (CSF). The aim of this study was to relate cognitive performance to the degree of brain atrophy, CSF biomarker levels and neuropathology in a cohort of aged men.MethodsFifty-eight 86–92-year-old men from the Uppsala Longitudinal Study of Adult Men (ULSAM) cohort underwent cognitive testing, brain computed tomography and lumbar puncture. Atrophy was graded with established scales. Concentrations of CSF Aβ42, t-tau and p-tau were measured by ELISA. Thirteen brains were examined post mortem.ResultsForty-six of the individuals were considered non-demented, whereas twelve were diagnosed with dementia, either at baseline (n = 4) or during follow-up (n = 8). When comparing subjects with and without dementia, there were no differences in the degree of atrophy, although the mini mental state examination (MMSE) scoring correlated weakly with the degree of medial temporal atrophy (MTA) (p = 0.04). Moreover, the CSF biomarker levels did not differ significantly between healthy (n = 27) and demented (n = 8) subjects (median values 715 vs 472 pg/ml for Aβ42, 414 vs 427 pg/ml for t-tau and 63 vs 60 pg/ml for p-tau). Similarly, there were no differences in the biomarker levels between individuals with mild (n = 24) and severe (n = 11) MTA (median values 643 vs 715 pg/ml for Aβ42, 441 vs 401 pg/ml for t-tau and 64 vs 53 pg/ml for p-tau). Finally, the neuropathological changes did not correlate with any of the other measures.ConclusionIn this cohort of aged men only a weak correlation could be seen between cognitive performance and MTA, whereas the various neuroradiological, biochemical and neuropathological measures did not correlate with each other. Thus, AD biomarkers seem to be less informative in subjects of an advanced age.

The association between serum cathepsin L and mortality in older adults

Background and aimsResearch suggests that the protease cathepsin L is causally involved in atherosclerosis. However, data on cathepsin L as a risk marker are lacking. Therefore, we investigated associations between circulating cathepsin L and cardiovascular mortality. MethodsTwo independent community-based cohorts were used: Uppsala Longitudinal Study of Adult Men (ULSAM); n = 776; mean age 77 years; baseline 1997–2001; 185 cardiovascular deaths during 9.7 years follow-up, and Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS); n = 993; 50% women; mean age 70 years; baseline 2001–2004; 42 cardiovascular deaths during 10.0 years follow-up. ResultsHigher serum cathepsin L was associated with an increased risk for cardiovascular mortality in age- and sex-adjusted models in both cohorts (ULSAM: hazard ratio (HR) for 1-standard deviation (SD) increase, 1.17 [95% CI, 1.01–1.34], p = 0.032 PIVUS: HR 1.35 [95% CI, 1.07–1.72], p = 0.013). When merging the cohorts, these associations were independent of inflammatory markers and cardiovascular risk factors, but non-significant adjusting for kidney function. Individuals with a combination of elevated cathepsin L and increased inflammation, kidney dysfunction, or prevalent cardiovascular disease had a markedly increased risk, while no increased risk was associated with elevated cathepsin L, in the absence of these disease states. ConclusionsAn association between higher serum cathepsin L and increased risk of cardiovascular mortality was found in two independent cohorts. Impaired kidney function appears to be an important moderator or mediator of these associations. Further studies are needed to delineate the underlying mechanisms and to evaluate whether the measurement of cathepsin L might have clinical utility.

Discovery of new biomarkers for atrial fibrillation using a custom-made proteomics chip

BackgroundApart from several established clinical risk factors for atrial fibrillation (AF), a number of biomarkers have also been identified as potential risk factors for AF. None of these have so...

NT-proBNP is a powerful predictor for incident atrial fibrillation — Validation of a multimarker approach

BackgroundBiomarkers may be of value to identify individuals at risk of developing atrial fibrillation (AF). Using a multimarker approach, this study investigated if the biomarkers; NT-proBNP, high-sensitivity cardiac troponin (hs-cTn), growth differentiation factor-15 (GDF-15), cystatin C and high-sensitivity C-reactive protein (CRP) are independent predictors for incident AF. MethodsBlood samples were collected from 883 individuals in the Uppsala Longitudinal Study of Adult Men (ULSAM) and 978 individuals in the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study. Participants were followed for 10–13years with n=113 incident AF cases in ULSAM and n=148 in PIVUS. The associations between biomarkers and incident AF were analysed in Cox proportional hazards regression models. ResultsThe hazard ratio (HR) for incident AF was significant for all five biomarkers in unadjusted analyses in both cohorts. Only NT-proBNP remained significant when adjusting for cardiovascular risk factors and the other biomarkers (HR (1SD) 2.05 (1.62–2.59) (ULSAM) and 1.56 (1.30–1.86) (PIVUS), both p<0.001). The C-index improved from 0.64 to 0.69 in ULSAM and from 0.62 to 0.68 in PIVUS, by adding NT-proBNP to cardiovascular risk factors (both p<0.001). The C-index of the CHARGE-AF risk score increased from 0.62 to 0.68 (ULSAM) and 0.60 to 0.66 (PIVUS) by addition of NT-proBNP (p<0.001). ConclusionsUsing a multimarker approach NT-proBNP was the strongest predictor of incident AF in two cohorts, and improved risk prediction when added to traditional risk factors. NT-proBNP significantly improved the predictive ability of the novel CHARGE-AF risk score, although the predictive value remained modest.

The Discovery of Two Novel Biomarkers in a High-Fat Diet C56bl6 Obese Mouse Model for Non-Adipose Tissue: A Comprehensive LCMS Study at Hind Limb, Heart, Carcass Muscle, Liver, Brain, Blood Plasma and Food Composition Following a Lipidomics LCMS-Based Approach

Aim/Objective: This study was designed to find via a highfat (HF) diet induced insulin resistant (IR) and/or type-2 diabetes (T2DM) C57Bl/6 mouse model potential novel biomarkers. Major aiming is to find following this lipidomics based approach novel safe biomarkers applicable for humans with IR/T2DM that can be used in the assessment of diagnosis, intensive treatment, clinical use and new drug development. In addition, the biomarker has to be found in blood-plasma simultaneously while is not a component of the HF-diet. Methods: Reversed phase liquid chromatography coupled to mass spectrometry (LC-MS) were used to quantify and qualify the rearrangement and repartitioning of fat stores in the heart-, hind limb-, carcass-muscle, liver, brain, and blood plasma of this mice model following a systems biology lipidomics based approach. Results: Two potential biomarkers were found for this HFdiet mouse model. The first biomarker was a 20:3 cholesteryl-ester (20:3-ChE) which significantly increased (P ≤ 0.016) in the fatty heart with 1317% while it rose very significantly (P ≤ 0.00001) in blood plasma with 1013% in the HF diet group in comparison to the control-group. (Co). The second biomarker was a 36:1 phosphatidylcholine (36:1-PC), which rose significantly (P ≤ 0.025) mainly in heart muscle with 400% while concentrations increased significantly strongly (P ≤ 0.002) in blood plasma with 1493% in the high-fat diet vs. Co. As an earlier defined prerequisite, both compounds were not found in the food. Conclusion: The 20:3-ChE biomarker (dihomo-γ-linolenic; 20:3 n-6) has been classified as a potential type 2 diabetes biomarker (T2DM) biomarker in a human cohort of the uppsala longitudinal study of adult men (ULSAM). In addition, we give a biochemical explanation for the 36:1- PC as hypoxic biomarker for cardiovascular diseases (CVD) diagnosis and therapy. Both biomarkers are interesting candidates for further validation in human cohorts.

Kidney function, β-cell function and glucose tolerance in older men.

Kidney dysfunction induces insulin resistance, but it is unknown if β cell function is affected. To investigate insulin release (β cell function) and glucose tolerance following a standardized oral glucose tolerance test (OGTT) across kidney function strata. Community-based cohort study from the Uppsala Longitudinal Study of Adult Men (ULSAM). PARTICIPANTS AND MAIN OUTCOME MEASURE: Included were 1015 nondiabetic Swedish men aged 70-71 years. All participants underwent OGTT and euglycaemic hyperinsulinaemic clamp (HEGC) tests, allowing determination of insulin sensitivity, β cell function, and glucose tolerance. Kidney function was estimated by cystatin C-algorithms. Mixed models were used to identify determinants of insulin secretion after the hyperglycemic load. As many as 466 (46%) of participants presented moderate-advanced kidney disease. Insulin sensitivity (by HEGC) decreased across decreasing kidney function quartiles. After the OGTT challenge, however, β cell function indices (area under the curve for insulin release, the estimated first phase insulin release, and the insulinogenic index) were incrementally higher. Neither the oral disposition index nor the 2-h postload glucose tolerance differed across the kidney function strata. Mixed models showed that dynamic insulin release during the OGTT was inversely associated with kidney function, despite the correction for each individual's insulin sensitivity or its risk factors. In older men, β cell function after a hyperglycemic load appropriately compensated the loss in insulin sensitivity that accompanies kidney dysfunction. As a result, the net balance between insulin sensitivity and β cell function was preserved.