Emerging biomarkers in cardiometabolic disease

AbstractThe epidemiological association between diabetes and heart failure is well-established and the two entities areemerging as global threats, both individually and synergistically, to an aging population. The exploration of multipleproteins can shed light on pathophysiological pathways in both diabetes and cardiovascular disease. This canpossibly provide novel diagnostic, prognostic and hopefully therapeutic implications.The overall aim of this dissertation was to explore novel biomarkers in cardiometabolic disease especially in heartfailure.This thesis was based on epidemiological data from the Malmö Preventive Project Re-Examination (MPP-RES)study and the Heart and brain failure investigation trial (HARVEST-Malmö). In Paper 1 we used a multiplexproteomic panel consisting of 92 proteins with known or alleged associations with cardiovascular disease,metabolism and inflammation to explore novel biomarkers for incident diabetes in the population-based cohortMPP-RES (n=1026). We were able to identify seven proteins associated with incident diabetes, of which four notpreviously described. Two of these (Galectin-4 and Paraoxonase-3) were associated with diabetes independentlyof fasting plasma glucose implying an glucose-independent association with diabetes.In Paper 2, we built upon the results from Paper 1, since one of our ultimate aims with this thesis was to explorecommon pathophysiological pathways between diabetes and cardiovascular disease. Using the seven proteinsidentified in Paper 1 we investigated whether these were associated with pertinent cardiovascular outcomes suchas all-cause and cardiovascular mortality, incident coronary events and incident heart failure. We found that twoproteins (Galectin-4 and Cathepsin D) were associated with all investigated outcomes in multivariable Coxregression analyses and represented novel findings. Galectin-4 may possibly exert its effect on cardiometabolicdisease through the incretin system and Cathepsin-D has previously been described to reduce the antioxidativeeffects of high-density lipoprotein.In Paper 3, we switched from the population-based MPP-RES cohort to the HARVEST-Malmö study whichconsists of heart failure patients admitted to the cardiology and internal medicine wards at Skånes UniversityHospital in Malmö, Sweden. We assessed the predictive ability in terms of mortality and re-hospitalization, of fivedifferent proteins (midregional pro-adrenomedullin, copeptin, NT-proBNP, CT-pro-endothelin-1 and cystatin C).The investigated proteins represent different pathophysiological mechanisms involved in heart failure such as theneuroendocrine response, cardiovascular stress and renal function. Higher plasma levels of all proteins but CTpro-endothelin-1 were associated with increased risk of post-discharge mortality but only NT-proBNP, which inmany ways is the gold standard for biomarkers in heart failure, was associated with increased risk of rehospitalization.Finally, in Paper 4, which was a collaboration with an Italian heart failure study (GREAT Rome Network) weinvestigated the effects of two emerging biomarkers in heart failure; bioactive adrenomedullin (bio-ADM) which isconsidered a marker for congestion, and proenkephalin A (penKid), which is a marker for renal dysfunction. WhileNT-proBNP has many uses, it has not been shown to adequately assess residual congestion in heart failurepatients. We were able to show that increased levels of bio-ADM were associated with increased congestionmeasured through a clinical congestion score where peripheral edema was the strongest and driving association.Furthermore, we showed that bio-ADM was predictive of 1-year mortality, increased risk of re-hospitalization andlength of hospital stay. PenKid levels responded approximately 48 hours prior to creatinine in the setting of acutekidney injury and we showed that penKid was associated with worsening renal function as well as with in-hospitaland 1-year mortality

Selenoprotein P deficiency is associated with higher risk of incident heart failure

AbstractIntroductionSelenium deficiency has been associated with mortality, cardiovascular disease and worsened prognosis in heart failure (HF). In a recent population-based study, high selenium levels were shown to be associated with reduced mortality and reduced incidence of HF, but only in non-smokers. Here, we aimed to examine if selenoprotein P (SELENOP), a main selenium carrier protein, is associated with incident HF.Materials and methodsSELENOP concentrations were measured in plasma of 5060 randomly selected subjects from the population-based prospective cohort “Malmö Preventive Project” (n = 18240) using an ELISA approach. Exclusion of subjects with prevalent HF (n = 230) and subjects with missing data on co-variates included in the regression analysis (n = 27) resulted in complete data for 4803 subjects (29.1% women, mean age 69.6 ± 6.2 years, 19.7% smokers). Cox regression models adjusted for traditional risk factors were used to analyse SELENOP's association with incident HF. Further, subjects within the quintile with the lowest SELENOP concentrations were compared to subjects in the remaining quintiles.ResultsEach 1 standard deviation increment in SELENOP levels was associated with lower risk of incident HF (n = 436) during a median follow-up period of 14.7 years (hazard ratio (HR) 0.90; CI95% 0.82–0.99; p = 0.043). Further analyses showed that subjects in the lowest SELENOP quintile were at the highest risk of incident HF when compared to quintiles 2–5 (HR 1.52; CI95% 1.21–1.89; p = 2.5 × 10−4).ConclusionLow selenoprotein P levels are associated with a higher risk of incident HF in a general population. Further studies are warranted

Cystatin C and Risk of Diabetes and the Metabolic Syndrome - Biomarker and Genotype Association Analyses.

BACKGROUND:We recently reported a relationship between plasma levels of cystatin C and incidence of the metabolic syndrome (MetS) among the first 2,369 subjects who participated in the re-examination study of the population-based Malmö and Diet Cancer Cardiovascular cohort (MDC-CC-re-exam). In this study we aimed to replicate these results and also investigate if cystatin C was causally associated with MetS and diabetes. METHODS:We estimated the effect size of the strongest GWAS derived cystatin C SNP (major allele of rs13038305) on plasma cystatin C in the now completed MDC-CC-re-exam (n = 3,734) and thereafter examined the association between plasma cystatin C (403 cases of diabetes and 2665 controls) as well as rs13038305 (235 cases and 2425 controls) with incident diabetes. The association of rs13038305 and incident MetS (511 cases of MetS and 1980 controls) was similarly investigated in the whole MDC-CC-re-exam. We also attempted to replicate our previously shown association of cystatin C with incident MetS in subjects from the MDC-CC-re-exam (147 cases and 711 controls) that were not included in our previous report. RESULTS:In the entire MDC-CC-re-exam, each copy of the major allele of rs13038305 was associated with approximately 0.30 standard deviation (SD) higher plasma concentration of cystatin C (β = 0.33, p = 4.2E-28) in age and sex adjusted analysis. Cystatin C in plasma was not associated with incident diabetes after adjustment for known diabetes risk factors (OR per 1 SD increment 0.99 (0.86-1.13), p = 0.842). In the replication cohort of MDC-CC-re-exam, the OR (95% CI) for incident MetS in subjects belonging to quartiles 1, 2, 3 and 4 of plasma cystatin C levels was 1.00 (reference), 1.21 (0.70-2.07), 1.62 (0.95-2.78) and 1.72 (1.01-2.93) (ptrend = 0.026) in age and sex adjusted analysis. In the entire MDC-CC-re-exam the odds ratio for incident MetS and diabetes per copy of the major rs13038305 allele was 1.13, (0.95-1.34), p = 0.160 and 1.07, 95% CI 0.89-1.30, p = 0.478, respectively. CONCLUSION:We were able to replicate our previously shown association between high levels of cystatin C and increased risk of future development of MetS. However, a causal involvement of cystatin C in the etiology of MetS or diabetes seems unlikely since genetic elevation of plasma cystatin C was not significantly related to incidence of these diseases

The shrunken pore syndrome is associated with declined right ventricular systolic function in a heart failure population – the HARVEST study

The close relationship between heart and kidney diseases was studied with respect to the ‘Shrunken pore syndrome’ that is characterized by a difference in renal filtration between cystatin C and creatinine. Patients were retrieved from the HeARt and brain failure inVESTigation trail (HARVEST) which is an ongoing study undertaken in individuals hospitalized for the diagnosis of heart failure. Ninety-five of 116 patients who underwent transthoracic echocardiograms (TTE) were eligible for this study. We used four different formulas for estimated glomerular filtration rate (eGFR); CKD-EPIcreatinine, CKD-EPIcystatin C, LMrev and CAPA. Presence of the syndrome was defined as eGFR cystatin C ≤ 60% of eGFR creatinine and absence of the syndrome as eGFR cystatin C >90% and <110% of eGFR creatinine. In a linear regression model, adjusted for age and sex, and the ‘Shrunken pore syndrome’ defined by the equation pair CAPA and LMrev and the equation pair CKD-EPIcystatin C and CKD-EPIcreatinine, echocardiographic parameters were studied. The ‘Shrunken pore syndrome’ showed statistically significant associations with measurements of right ventricular (RV) systolic function; (TAPSE and RV S’) (according to the equation pair CKD-EPIcystatin C and CKD-EPIcreatinine). In conclusion, heart failure patients with the ‘Shrunken pore syndrome’ are at increased risk of having RV systolic dysfunction whilst heart failure patients without ‘Shrunken pore syndrome’ seem protected. These findings may indicate common pathophysiological events in the kidneys and the heart explaining the observed increased risk of mortality in subjects with the ‘Shrunken pore syndrome’

Cardiovascular biomarkers predict post‐discharge re‐hospitalization risk and mortality among Swedish heart failure patients

AIM: The aim of this study was to assess the predictive role of biomarkers, associated with cardiovascular stress and its neuroendocrine response as well as renal function, in relation to mortality and risk of re-hospitalization among consecutive patients admitted because of heart failure (HF).METHODS AND RESULTS: A total of 286 patients (mean age, 75 years; 29% women) hospitalized for newly diagnosed or exacerbated HF were analysed. Associations between circulating levels of mid-regional pro-adrenomedullin (MR-proADM), copeptin, C-terminal pro-endothelin-1, N-terminal pro-brain natriuretic peptide (NT-proBNP), cystatin C, and all-cause mortality as well as risk of re-hospitalization due to cardiac causes were assessed using multivariable Cox regression models. A two-sided Bonferroni-corrected P-value of 0.05/5 = 0.010 was considered statistically significant. All biomarkers were related to echocardiographic measurements of cardiac dimensions and function. A total of 57 patients died (median follow-up time, 17 months). In the multivariable-adjusted Cox regression analyses, all biomarkers, except C-terminal pro-endothelin-1, were significantly associated with increased mortality: NT-proBNP [hazard ratio (HR) 1.85, 95% confidence interval (CI) 1.17-2.17; P = 4.0 × 10-4 ], MR-proADM (HR 1.94, 95% CI 1.36-2.75; P = 2.2 × 10-4 ), copeptin (HR 1.70, 95% CI 1.22-2.36; P = 0.002), and cystatin C (HR 2.11, 95% CI 1.56-2.86; P = 1.0 × 10-6 ). A total of 90 patients were re-hospitalized (median time to re-hospitalization, 5 months). In multivariable Cox regression analyses, NT-proBNP was the only biomarker that showed significant association with risk of re-hospitalization due to cardiac causes (HR 1.43, 95% CI 1.10-1.87; P = 0.009).CONCLUSIONS: Among patients hospitalized for HF, elevated plasma levels of NT-proBNP, MR-proADM, copeptin, and cystatin C are associated with higher mortality after discharge, whereas NT-proBNP is the only biomarker that predicts the risk of re-hospitalization due to cardiac causes

Physical Inactivity Is Associated With Post-discharge Mortality and Re-hospitalization Risk Among Swedish Heart Failure Patients-The HARVEST-Malmö Study

BackgroundSeveral studies have examined the role of physical activity as a predictor of heart failure (HF) mortality and morbidity. Here, we aimed to evaluate the role of self-reported physical activity as an independent risk factor of post-discharge mortality and re-hospitalization in patients hospitalized for HF, as well as study the association between physical activity and 92 plasma proteins associated with cardiovascular disease (CVD). MethodsFour-hundred-and-thirty-four patients hospitalized for HF (mean age 75 years; 32% women) were screened for physical activity derived from questionnaires in the Swedish national public health survey. The median follow-up time to death and re-hospitalization was 835 (interquartile range, 390-1,432) and 157 (43-583) days, respectively. Associations between baseline reported physical activity, mortality and re-hospitalization risk were analyzed using multivariable Cox regression analysis. Plasma samples from 295 study participants were analyzed with a proximity extension assay consisting of 92 proteins. Associations between proteins and physical activity were explored using a false discovery rate of &lt;5%, and significant associations were taken forward to multivariate analyses. ResultsIn the multivariate Cox regression model, physical inactivity, defined as physical activity time &lt;1 h throughout the week was associated with increased risk of all-cause mortality (HR 1.71; CI95% 1.26-2.31; p = 5.9 x 10(-4)) as well as all-cause re-hospitalization (HR 1.27; CI95% 1.01-1.60; p = 0.038). Further, physical inactivity was associated with elevated plasma levels of Metalloproteinase inhibitor 4, Soluble interleukin 1 receptor-like 1, Elafin and Transferrin receptor protein 1, which are implicated in myocardial fibrosis, migration and apoptosis. ConclusionsSelf-reported low weekly physical activity is associated with increased risk of mortality and re-hospitalization in patients hospitalized for HF independent of traditional risk factors. Furthermore, physical inactivity was associated with elevated levels of 4 proteins linked to cardiovascular disease

Impaired cerebral oxygenation in heart failure patients at rest and during head-up tilt testing

AIMS: Heart failure (HF) confers potentially negative effects on the brain and autonomic nervous system. The measurement cerebral tissue oxygen saturation (SctO2 ) may aid in understanding such effects. We aimed to investigate if compensated HF affects SctO2 at rest and during orthostatic challenge.METHODS AND RESULTS: Non-invasive haemodynamic monitoring and near-infrared spectroscopy were applied during head-up tilt (HUT) in 61 HF patients [mean (SD) 71 (11) years, 82% male, New York Heart Association (NYHA) class I-III] and 60 controls [60 (12) years, 42% male). Group differences in continuous variables were compared using Student's t-test. Associations between HF and SctO2 were studied using multivariable linear regression models adjusted for age, sex, diabetes, smoking, systolic blood pressure (SBP), and heart rate in supine position and after 10 min of HUT. Mean SctO2 was lower in HF patients compared with controls both in the supine position (67 vs. 71%; P < 0.001) and after 10 min of HUT (64 vs. 69%; P < 0.001). The HUT-induced SctO2 decrease was greater in HF patients compared with controls (P = 0.026). SBP did not change in neither HF patients nor controls during HUT, whereas diastolic blood pressure and heart rate increased in both groups. HF was associated with lower SctO2 in supine (B = -2.5%, P = 0.023) and after 10 min of HUT (B = -2.6%, P = 0.007) after multivariable adjustments.CONCLUSIONS: Cerebral tissue oxygenation is lower in HF patients both at rest and during orthostasis compared with subjects without HF. Future studies should test if the lower cerebral oxygenation associates with negative prognosis and with impaired cognitive function

Autonomic dysfunction is associated with cardiac remodelling in heart failure patients

AIMS: Orthostatic hypotension (OH) is a cardinal sign of autonomic dysfunction and a common co-morbidity in heart failure (HF). The role of autonomic dysfunction in the development of structural cardiac anomalies in HF patients has not been sufficiently explored. We aimed to assess relations between orthostatic blood pressure (BP) responses during active standing and echocardiographic changes in a series of patients admitted for HF.METHODS AND RESULTS: One hundred and forty-nine patients hospitalized for HF [mean age: 74 years; 30% women; ejection fraction (LVEF) 40 ± 16%] were examined with conventional echocardiograms and active-standing test. Associations of cardiac remodelling parameters with the difference between supine and standing (after 3 min) systolic/diastolic BP were examined. Systolic BP decreased (-1.1 ± 15 mmHg), whereas diastolic BP increased (+1.0 ± 9.5 mmHg) after 3 min of active standing. A total of 34 patients (23%) met conventional OH criteria; i.e. systolic/diastolic BP decreases by ≥20/10 mmHg. In the multivariable linear regression analysis, adjusted for traditional cardiovascular risk factors and LVEF, a decrease in systolic BP upon standing was associated with greater left atrial volume [β per -10 mmHg: 2.37, standard error (SE) = 1.16, P = 0.043], and greater left ventricular mass (β per -10 mmHg: 5.67, SE = 2.24, P = 0.012), but not with other echocardiographic parameters. No significant associations were observed between signs of cardiac remodelling and decrease in diastolic BP.CONCLUSIONS: Orthostatic decrease in systolic BP among older HF patients is associated with structural cardiac changes such as increased left atrial volume and left ventricular mass, independently of traditional risk factors and left ventricular dysfunction

Proteins linked to atherosclerosis and cell proliferation are associated with the shrunken pore syndrome in heart failure patients

PURPOSE: The "Shrunken pore syndrome" (SPS) is characterized by a difference in renal filtration between cystatin C and creatinine, resulting in a low eGFRcystatinC /eGFRcreatinine -ratio. Studies have demonstrated a high risk for cardiovascular morbidity and mortality for patients with SPS. In this discovery study, we explored associations between SPS and proteins implicated in cardiovascular disease and inflammation in patients with heart failure.EXPERIMENTAL DESIGN: Plasma samples from 300 individuals in HARVEST-Malmö trial hospitalized for the diagnosis of heart failure (mean age 74.9±11.5 years; 30.0% female), were analyzed with a proximity extension assay consisting of 92 proteins. A Bonferroni-corrected p-value of 0.05/92 = 5.4 × 10-4 was considered significant in the initial age and sex-adjusted analyses. Presence of SPS was defined as eGFRcystatinC ≤60% of eGFRcreatinine .RESULTS: SPS presented with significant associations (p < 5.4 × 10-4 ) in age and sex-adjusted logistic regressions with elevated levels of six proteins; scavenger receptor cysteine rich type 1 protein M130, tumor necrosis factor receptor 1, tumor necrosis factor receptor 2, osteoprotegerin, interleukin-2 receptor subunit alpha, and tyrosine-protein kinase receptor UFO. All proteins remained associated (p < 0.05) with SPS after multivariate adjustments.CONCLUSIONS AND CLINICAL RELEVANCE: In heart failure patients, SPS was associated with proteins linked to atherosclerosis and cell proliferation. This article is protected by copyright. All rights reserved