Life expectancy associated with different ages at diagnosis of type 2 diabetes in high-income countries: 23 million person-years of observation

BACKGROUND

The prevalence of type 2 diabetes is increasing rapidly, particularly among younger age groups. Estimates suggest that people with diabetes die, on average, 6 years earlier than people without diabetes. We aimed to provide reliable estimates of the associations between age at diagnosis of diabetes and all-cause mortality, cause-specific mortality, and reductions in life expectancy.

METHODS

For this observational study, we conducted a combined analysis of individual-participant data from 19 high-income countries using two large-scale data sources: the Emerging Risk Factors Collaboration (96 cohorts, median baseline years 1961-2007, median latest follow-up years 1980-2013) and the UK Biobank (median baseline year 2006, median latest follow-up year 2020). We calculated age-adjusted and sex-adjusted hazard ratios (HRs) for all-cause mortality according to age at diagnosis of diabetes using data from 1 515 718 participants, in whom deaths were recorded during 23·1 million person-years of follow-up. We estimated cumulative survival by applying age-specific HRs to age-specific death rates from 2015 for the USA and the EU.

FINDINGS

For participants with diabetes, we observed a linear dose-response association between earlier age at diagnosis and higher risk of all-cause mortality compared with participants without diabetes. HRs were 2·69 (95% CI 2·43-2·97) when diagnosed at 30-39 years, 2·26 (2·08-2·45) at 40-49 years, 1·84 (1·72-1·97) at 50-59 years, 1·57 (1·47-1·67) at 60-69 years, and 1·39 (1·29-1·51) at 70 years and older. HRs per decade of earlier diagnosis were similar for men and women. Using death rates from the USA, a 50-year-old individual with diabetes died on average 14 years earlier when diagnosed aged 30 years, 10 years earlier when diagnosed aged 40 years, or 6 years earlier when diagnosed aged 50 years than an individual without diabetes. Using EU death rates, the corresponding estimates were 13, 9, or 5 years earlier.

INTERPRETATION

Every decade of earlier diagnosis of diabetes was associated with about 3-4 years of lower life expectancy, highlighting the need to develop and implement interventions that prevent or delay the onset of diabetes and to intensify the treatment of risk factors among young adults diagnosed with diabetes.

FUNDING

British Heart Foundation, Medical Research Council, National Institute for Health and Care Research, and Health Data Research UK.

C-reactive protein as a possible modifier of Lipoprotein(a)-related risk for coronary heart disease in Europe: results from the BiomarCARE project

Background

Lipoprotein(a) (Lp(a)) represents a unique proatherogenic lipoprotein with potent pro-thrombotic and pro-inflammatory properties. Recent studies demonstrated that Lp(a)-associated risk for cardiovascular disease (CVD) was significantly increased only in individuals with a high inflammatory burden (i.e. hsCRP levels >2 mg/L). However, these results have been either based on a post-hoc analysis in a highly selected study population with a high/very high CVD risk, or conducted within a multi-ethnic population with significant variation in Lp(a) levels.

Purpose

The main aim was to investigate whether hsCRP concentration modulates the predictive value of Lp(a) for coronary heart disease (CHD) events in the general population across Europe.

Methods

Data of 87,760 participants from 10 European prospective population-based cohorts, participating in the Biomarkers for Cardiovascular Risk Assessment in Europe (BiomarCaRE)-project, were used for the present analysis (79,958 subjects without and 7,189 individuals with established CHD at baseline (primary/secondary prevention cohorts, respectively)). All Lp(a) measurements were performed in the central BiomarCaRE laboratory. Fine and Gray competing risk-adjusted models stratified by study cohort were calculated to assess the association between Lp(a) levels and future CHD events stratified according to hsCRP levels (<1 mg/l, ≥1–<2 mg/l and ≥2 mg/l).

Results

During a median follow-up of 11.3 years, 4,928 events occurred in the CHD-free subpopulation and 1,772 events occurred in the CHD subpopulation. In the primary prevention cohort, increased Lp(a) was significantly associated with future CHD events irrespective of hsCRP: Hazard ratios (HRs) for future CHD events (top vs bottom quintile (Q) of Lp(a) distribution) were 1.46 (95% CI: 1.21–1.78; p<0.001) in those having a hsCRP concentration <1 mg/l; 1.32 (95% CI: 1.09–1.61; p=0.0052) for a hsCRP group of ≥1-<2 mg/l and 1.40 (95% CI: 1.22–1.61; p<0.001) in subjects with a hsCRP concentration ≥2 mg/l, after multivariable adjustment for traditional CV risk factors including LDL-Ccorr and lipid-lowering medication. In contrast, in the secondary prevention, we found no association between increased Lp(a) levels and CHD events in individuals with a very low inflammatory burden (HR for hsCRP <1 mg/l 0.92 (95% CI 0.63–1.34), p=0.66, Q5 vs Q1)), whereas the association was significant among subjects with a hsCRP concentration ≥1 mg/l (HRs: 1.43 (95% CI: 1.01–2.03; p=0.045) for hsCRP group ≥1-<2 mg/l and 1.35 (95% CI: 1.07–1.71; p=0.013) for hsCRP group ≥2 mg/l (both for Q5 vs Q1)).

Conclusion

In a primary prevention setting, Lp(a) was associated with incident CHD irrespective of the inflammatory burden. In contrast, among subjects with known CHD, the association of Lp(a) and future CHD events was only present in those with hsCRP levels >1 mg/l. These findings might guide target population selection for upcoming Lp(a)-targeting compounds.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): This work was supported by the 7th Framework Programme Collaborative Project (grant agreement no. HEALTH-F2-2011-278913). The MORGAM Project has received funding from EU projects MORGAM (Biomed, BMH4-CT98-3183), GenomEUtwin (Fifth Framework Programme FP5, QLG2-CT-2002-01254), ENGAGE (FP7, HEALTH-F4-2007-201413), CHANCES (FP7, HEALTH-F3-2010-242244), BiomarCaRE (FP7, HEALTH-F2-2011-278913), euCanSHare (Horizon 2020, No. 825903) and AFFECT-EU (Horizon 2020, No. 847770); and Medical Research Council, London (G0601463, No. 80983: Biomarkers in the MORGAM Populations).

Exploring circulating biomarkers for risk prediction of incident atrial fibrillation – insights from the BiomarCaRE project

Background

Atrial fibrillation (AF) remains a major health issue in Europe and worldwide. Risk prediction is crucial to identify at-risk individuals and prevent subsequent complications of AF such as stroke and heart failure. Biomarker-enriched, personalized risk prediction offers great potential for population-wide prevention beyond traditional cardiovascular risk factors.

Purpose

We aimed to identify robust predictors for incident AF using classical regressions and machine learning (ML) techniques within a broad spectrum of candidate variables.

Methods

Three European community cohorts from the Biomarkers for Cardiovascular Risk Assessment in Europe (BiomarCaRE) consortium were included to explore the predictive utility of 14 biomarkers mirroring distinct pathophysiological pathways of AF including lipids, inflammation (C-reactive protein [CRP]), renal, and myocardium-specific markers (N-terminal pro B-type natriuretic peptide [NT-proBNP], high-sensitivity troponin I [hsTnI]) within a population-based sample of 42,280 individuals free of AF at baseline. Investigated biomarkers were examined in relation to incident AF using Cox regressions adjusted for multiple cardiovascular risk factors, and additionally by C-indices and net reclassification improvement (NRI) when compared to a reference model incorporating clinical variables. Their predictive utility for incident AF was further analyzed using different ML methods, including Least Absolute Shrinkage and Selection Operator (LASSO) and Random Survival Forest (RSF).

Results

Of 42,280 individuals (21,843 women [51.7%]; median [interquartile range, IQR] age, 52.2 [42.6, 62.0] years), 1496 (3.5%) developed AF during a median follow-up time of 5.7 years. In multivariable-adjusted Cox regression analysis, NT-proBNP was the strongest circulating predictor of incident AF (hazard ratio [HR] per standard deviation [SD] 1.93, 95% CI 1.82–2.04; P<0.001). Further, hsTnI (HR per SD 1.18, 95% CI 1.13–1.22; P<0.001), cystatin C (HR per SD 1.16, 95% CI 1.10–1.23; P<0.001) and CRP (HR per SD 1.08, 95% CI 1.02–1.14, P=0.012) correlated positively with new-onset AF. NT-proBNP enhanced model discrimination (ΔC-index 0.037, 95% CI 0.029–0.044) markedly and yielded the best reclassification improvement (NRI 0.237, 95% CI 0.187–0.287) when compared to the clinical model. Neither the addition of hsTnI to NT-proBNP, nor a model comprising all investigated biomarkers further increased discrimination or reclassification substantially. In different ML models, NT-proBNP and age were the strongest predictors of incident AF.

Conclusions

Using a dual approach with both classical regressions and modern ML methods, NT-proBNP consistently remained the strongest blood-based predictor of incident AF with relevant discriminative ability and reclassification yield beyond classical cardiovascular risk factors. The clinical benefit of these findings for AF risk prediction needs to be tested prospectively.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): BiomarCaRE (FP7, HEALTH-F2-2011-278913)European Union's Horizon 2020 research and innovation programme (grant agreement number 847770, AFFECT-EU)

VEGF beta is a candidate biomarker for cardiovascular risk stratification

Background

The blood-based transcriptome changes in relation to body weight but longitudinal data on specific transcripts are rare. Monocytes play a crucial role in the development of atherosclerosis and coronary artery disease. Monitoring monocytic gene expression patterns could aid to identify biomarkers for improved cardiovascular risk stratification. BMI and diabetes mellitus (T2DM) are associated with coronary artery disease (CAD). There are mRNAs associated with the development of atherosclerosis and CAD, which can be detected in circulating cells. The exact pathways and direct targets have not been explored.

Objective

To apply transcriptome screening and validation analysis to identify novel biomarker candidates associated with longitudinal changes of BMI as cardiovascular risk factors and test association with clinical endpoints.

Methods

Transcriptome-wide monocytic gene expression changes were screened in relation to changes in BMI over a time period of 5 years in 1,092 participants of the Gutenberg Health Study with available transcriptomics data at baseline investigation and at 5-years follow-up. Functional enrichment of BMI-related genes (FDR <0.01) was tested based on pathway databases and selected gene sets. Serum VEGFB levels were quantified and validated in serum from n=1,895 individuals from an independent cohort study (FinRisk). In-vitro, THP1 cells were stimulated with recombinant VEGFB.

Results

143 transcripts showed a significant association with change in BMI over 5 years. Decreased VEGFB mRNA levels strongly associated with increased BMI (p=2.8x10–9). Lower levels of VEGFB mRNA were associated with increased mortality (HRperSD=0.757, 95% CI: 0.647–0.885, p=0.0005) following adjustment for age and sex and incident diabetes (p=0.01). Circulating VEGFB levels inversely correlated with VEGFB mRNA (r=−0.2, p=0.0024) and positively correlated with an increase in BMI (beta=0.226, p=8.4x10–6), type 2 diabetes mellitus risk (HRperSD=1.279, 95% CI: 1.148–1.425, p=7.8x10–6) and all-cause mortality (HRperSD=1.184, 95% CI: 1.045–1.342, p=0.008). Further exploration in n=1,895 individuals from FinRisk revealed an association of increased VEGFB levels with increased risk for heart failure (HRperSD=1.373, 95% CI: 1.210–1.560, p=1.0x10–6) and coronary artery disease (HR=1.018, 95% CI: 1.003–1.034, p=0.019), even after adjustment for BMI. In THP-1 culture, stimulation with VEGFB resulted in downregulation of VEGFB mRNA levels.

Conclusion

Decreased monocytic gene expression of VEGFB is related to increased BMI, increased risk of T2DM and all-cause mortality. Vice versa,circulating VEGFB levels associates positively with BMI, diabetes, mortality as well as heart failure and coronary heart disease. We hypothesize that monocytes regulate VEGFB expression by a negative feed-back mechanism based. Circulating VEGFB is a potential novel biomarker candidate for weight-related diabetes risk and cardiovascular risk evaluation.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): DZHK

Biomarker-based prediction of fatal and non-fatal cardiovascular outcomes in individuals of the general population with and without diabetes mellitus

Introduction

Cardiovascular biomarkers may reflect different aspects of cardiovascular disease, including myocardial tissue damage (high-sensitive cardiac troponin [hs-cTn]), hemodynamic stress (N-terminal prohormone of brain natriuretic peptide [NT-proBNP)), or inflammation (high-sensitivity C-reactive protein [hs-CRP]).

Purpose

To determine the risk for fatal and non-fatal cardiovascular events in patients with diabetes mellitus (DM), a high-risk group for cardiovascular complications, after accounting for these biomarkers and to determine the risk associated with these biomarkers.

Methods

Harmonized data of population-based studies from the Biomarkers for Cardiovascular Risk Assessment in Europe (BiomaCaRE) and MOnica Risk, Genetics, Archiving and Monograph (MORGAM) consortia were used to calculate hazard ratios (HRs, 95% confidence intervals [CI] per standard deviation) for these biomarkers adjusted for diabetes, patient characteristics and biomarkers for their association with the primary endpoint of fatal and non-fatal cardiovascular events during a median follow-up of 9.6 years (maximum 28 years). Additionally, a years-of-life-lost analysis was conducted stratified by prevalent diabetes and specific biomarker cut-offs known to be associated with increased risk for events (hs-cTnI >5 ng/L, NTproBNP >125 ng/L, hs-CRP >5mg/L).

Results

We included 95,302 individuals, of whom 6,501 had DM (6.8%). Cox-regression analysis revealed DM to be independently associated with the primary endpoint (2.1 [95% CI 1.9, 2.3], p<0.001) despite adjustment for clinical characteristics and biomarkers. Also, all three biomarkers were independent predictors themselves: log-transformed NT-proBNP 1.3 [95% CI 1.3, 1.4] p<0.001; log-transformed hs-CRP 1.2 [95% CI 1.1, 1.2] p<0.001; third-root-transformed hs-cTnI 1.1 [95% CI 1.0, 1.1] p=0.0038). The sex-, age- and cohort-adjusted HR for the primary endpoint according to absolute biomarker concentrations derived by cox-regression models using cubic splines is provided for the three biomarkers in Figure 1. Upon dichotomization of biomarkers, individuals with diabetes and at least one elevated biomarker lost a median of 15.5 healthy years because of the primary endpoint (Kaplan-Meier plot in Figure 2, with age on the x-axis).

Conclusion

Our findings confirm that diabetes confers a residual cardiovascular risk beyond adjustment for clinical characteristics and cardiovascular biomarker. Furthermore, biomarkers may aid in the identification of patients at highest risk, which should be considered in future models of risk prediction.

Funding Acknowledgement

Type of funding sources: None.

Risk factors, subsequent disease onset and prognostic impact of myocardial infarction and atrial fibrillation

Background

Myocardial infarction (MI) is a known risk factor for incident atrial fibrillation (AF), while AF frequently complicates acute MI. Although both diseases share common cardiovascular risk factors, the direction and strength of the association of the risk factors with disease onset, subsequent disease incidence and mortality are not completely understood.

Purpose

Our goal was to define the temporal relationship of MI and AF and the association of cardiovascular risk factors with disease incidence in order to determine whether common clinical risk factors show different associations with incident MI or AF. We further aimed to investigate predictors of subsequent disease onset and the impact of subsequent disease diagnosis on mortality.

Methods

In pooled multivariable Cox regression analyses we examined temporal relations of disease onset and identified predictors of MI, AF and subsequent all-cause mortality in 108,363 individuals (median age 46.0 years, 48.2% men) free of MI and AF at baseline from six European population-based cohorts.

Results

Over a maximum follow-up of 10.0 years 3558 (3.3%) individuals were diagnosed exclusively with MI, 1922 (1.8%) with AF but no MI, and 491 (0.5%) individuals developed both MI and AF. Association of male sex, systolic blood pressure, antihypertensive treatment and diabetes mellitus appeared to be stronger with incident MI than with AF, whereas increasing age and body mass index showed a higher risk for incident AF. Total cholesterol and daily smoking were significantly related to incident MI but not AF. The combined population attributable fraction of the cardiovascular risk factors was over 70% for incident MI, whereas it was only about one quarter for incident AF. Subsequent MI after incident AF (hazard ratio1.68, 95% CI 1.03–2.74) and subsequent AF after MI (hazard ratio 1.75, 95% CI 1.31–2.34) both significantly increased overall mortality risk.

Conclusions

Subsequent diagnosis of MI and AF was associated with a significant increase in mortality, irrespective of the first event. We found different associations of common cardiovascular risk factors with incident MI and AF indicating distinct pathophysiological pathways in disease development.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): European Union's Horizon 2020 research and innovation programme (grant agreement No 847770, AFFECT-EU) European Union's Horizon 2020 research and innovation programme (grant agreement No 648131)

Risk prediction of atrial fibrillation and its complications in the community using high-sensitivity cardiac troponin I: results from the BiomarCaRE Consortium

Aims

Atrial fibrillation (AF) is becoming increasingly common and is associated with serious complications. Traditional cardiovascular risk factors (CVRF) do not explain all AF cases. Blood-based biomarkers reflecting cardiac injury may help close this gap. High-sensitivity troponin I (hsTnI) has emerged as a potential predictor.

Methods

We investigated the predictive ability of hsTnI for incident AF in 29,227 participants (median age 52.6 years, 51.2% men) across four different European community cohorts of the Biomarkers for Cardiovascular Risk Assessment in Europe (BiomarCaRE) consortium in comparison to CVRF and established biomarkers (high-sensitive C-reactive protein (hsCRP), N-terminal pro B-type natriuretic peptide (NT-proBNP)).

Results

During a median follow-up of 13.8 (lower and upper quartiles 4.5, 21.3) years, 1,509 (5.2%) participants developed AF. Those in the highest fourth of hsTnI values at baseline (≥5.1 ng/L) had a 2.71-fold (95% confidence interval (CI) 2.31, 3.17; P<0.01) risk for developing AF compared to those in the lowest fourth (≤2.1 ng/L). In multivariable-adjusted Cox proportional hazard models no statistically significant association was seen between hsTnI and AF, whereas NT-proBNP (hazard ratio (HR) per two-fold increase in NT-proBNP 1.64; 95% CI 1.56, 1.72; P<0.001) as well as hsCRP (HR ratio per two-fold increase in hsCRP 1.05; 95% CI 1.01, 1.10; P=0.01) were statistically significantly related to incident AF. Inclusion of hsTnI did not improve model discrimination over CVRFs (C-index CVRF 0.7914 vs. C-index CVRF, hsTnI 0.7927; 95% CI −0.0004, 0.0031; P=0.130). Higher hsTnI concentrations were associated with AF complications such as stroke (HR 1.25; 95% CI 1.03, 1.51; P=0.02), heart failure (HR 1.27; 95% CI 1.12, 1.44; P<0.001) and cardiovascular events (HR 1.24; 95% CI 1.08, 1.42; P<0.001) as well as overall mortality (HR 1.15; 95% CI 1.05, 1.25; P<0.001) in those who were diagnosed with AF.

Conclusion

hsTnI as a biomarker of myocardial injury does not improve prediction of AF incidence beyond classical CVRFs. However, it is associated with AF complications and mortality after AF onset probably reflecting underlying subclinical cardiovascular impairment.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): European Union Seventh Framework Programme (FP7/2007-2013

Chronic kidney disease and risk of atrial fibrillation and heart failure in general population-based cohorts – the BiomarCaRE project

Background

Chronic kidney disease (CKD) has a complicated relationship with the heart, leading to many adverse outcomes.

Purpose

The aim of the study was to evaluate the relationship between CKD and the incidence of atrial fibrillation (AF) and heart failure (HF) along with mortality as a competing risk in general population cohorts.

Methods

This study was conducted as part of the BiomarCaRE project using harmonised data from 12 population-based cohorts (n=40,212) from Europe. Cox proportional hazards models were used to determine hazard ratios (HRs) for the incidence of AF and HF in CKD and with competing mortality risk after adjusting for covariates.

Results

Mean age at baseline was 51.1 (standard deviation 11.9) years, and 49.3% were men. Overall, 3.5% had CKD at baseline. The rate for incident AF was 3.9 per 1000 person-years during follow-up. The HR for AF for those with CKD compared with those without was 1.23 (95% CI 1.00–1.52, p=0.0465) after adjustment for covariates. The rate for incident HF was 3.9 per 1000 person-years and the associated risk in the presence of CKD was HR 1.67 (95% CI 1.39–2.01). In subjects with CKD, N-terminal pro-B-type natriuretic peptide (NT-proBNP) showed an association with AF, while NT-proBNP and C-reactive protein (CRP) showed an association with HF.

Conclusion

CKD is an independent risk factor for subsequent AF and even more so for HF. In patients with CKD, NT-proBNP was clearly associated with subsequent risk of AF. In addition to this marker, hs-CRP was also associated with risk of subsequent HF.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): 7th framework programme collaborative project, grant agreement no. HEALTH-F2-2011_278913. Atrial Fibrillation and HF in CKD

Cardiac troponin I and incident stroke in European cohorts – insights from the BiomarCaRE project

Background

Stroke is a common cause of death and a leading cause of disability and morbidity. Stroke risk assessment remains a challenge but circulating biomarkers may improve risk prediction. Controversial evidence is available on the predictive ability of troponin concentrations and the risk of stroke in the community. Furthermore, reports on the predictive value of troponin concentrations for different stroke subtypes (ischemic and hemorrhagic) are scarce.

Methods

High-sensitivity cardiac troponin I (hsTnI) concentrations were assessed in 82,881 individuals (median age 50.7 years, 49.7% men) free of stroke or myocardial infarction at baseline from nine prospective European community cohorts. Multiple imputations were used to handle missing data. We used Cox proportional hazards regression to determine relative risks, followed by measures of discrimination and reclassification using 10-fold cross-validation to control for over-optimism. Follow-up was based upon linkage with national hospitalization registries and causes of death registries.

Results

Over a median follow-up of 12.7 years, 3,033 individuals were diagnosed with incident non-fatal or fatal stroke (N=1,654 ischemic strokes, N=612 hemorrhagic strokes, N=767 indeterminate strokes). In multivariable regression models hsTnI concentrations were associated with overall stroke (hazard ratio (HR) per one standard deviation increase 1.16, 95% confidence interval (CI) 1.10–1.21), ischemic stroke (HR 1.15, 95% CI 1.09–1.21) and hemorrhagic stroke (HR 1.10, 95% CI 1.01–1.21). Adding hsTnI concentrations to classical cardiovascular risk factors (C-indices 0.808, 0.840 and 0.735 for overall, ischemic and hemorrhagic stroke, respectively) increased the C-index significantly, but modestly. In individuals with an intermediate ten-year risk (5–20%) the net reclassification improvement for overall stroke was 0.039 (p=0.010).

Conclusions

Elevated hsTnI concentrations are associated with an increased risk of incident stroke in the community, irrespective of stroke subtype. Adding hsTnI concentrations to classical risk factors only modestly improved estimation of 10-year risk of stroke in the overall cohort, but might be of some value in individuals at an intermediate risk.

Funding Acknowledgement

Type of funding source: Public grant(s) – EU funding. Main funding source(s): The BiomarCaRE Project is funded by the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no.HEALTH-F2-2011-278913. This project has received further funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No 648131).

Atrial fibrillation risk factor burden and disease onset across age decades

Background

Although a number of risk factors have been associated with the progression of atrial fibrillation (AF), there is limited knowledge of their relevance for AF in relation to age.

Purpose

We examined whether the association between modifiable risk factors and AF differed between age decades.

Methods

Data were derived from five European cohorts from Denmark, Finland, Italy, Sweden, and Norway. In total, 66 951 individuals (49.1% men) aged ≥40 years (mean baseline age 53.5 years) and without prevalent AF were followed for incident AF, with the follow-up truncated at 10 years. Data on risk factors (body mass index [BMI], hypertension [systolic blood pressure ≥140 mmHg and/or use of antihypertensive medication], diabetes mellitus, myocardial infarction [MI] event before baseline examinations, daily smoking, and alcohol consumption) were available from the baseline examinations. Stratification into age decades was based on age at baseline examination. Furthermore, the participants were followed for events of stroke or mortality after AF diagnosis. Mortality, stroke, and AF outcomes were derived from national registers and hospital discharge registers. All analyses were adjusted for AF risk factors.

Results

The incidence of AF increased from 0.9 per 1000 person-years at the age of 40 to <50, to 17.7 at the age of ≥70 years. Multivariable-adjusted Cox models showed that BMI, hypertension, alcohol consumption, and history of MI were associated with increased risk of AF across age decades (p<0.05). Of these, the risk of AF associated with BMI and an MI event before baseline examinations differed across age decades. For each 5 units increase in BMI, risk of AF increased with 40% (95% confidence interval 17–68%) at the age of 40 to <50, falling to 17% (6–29%) at the age of ≥70 years (p=0.08 for difference between age decades 40 to <50 and ≥70). Participants with a history of MI showed decreased risk of AF with ageing, from a hazard ratio (HR) of 5.53 (2.85–10.73) in the 40 to <50 age group to a HR of 1.41 (1.11–1.79) at the age of ≥70 (p<0.001). Daily smoking and prevalent diabetes mellitus were in general not associated with AF. The multivariable-adjusted associations between new-onset AF and the succeeding risk of stroke and mortality increased with age, showing a 1.6 to 2.6-fold increase in risk of death at ages ≥60 years and two-fold increased risk of stroke in participants aged ≥70 years (p≤0.001).

Conclusion

The relative importance of modifiable risk factors on incident AF do not vary across age decades, with a few exceptions; BMI and a history of MI were stronger risk factors for AF at younger ages. Thus, preventive measures should target risk factors rigorously, in particular obesity. New-onset AF was associated with increased risk of stroke and mortality only at older ages, emphasizing the importance of adequate patient management in the older and oldest old.

Funding Acknowledgement

Type of funding source: None

Simple cardiovascular risk stratification using anthropometric measures instead of serum cholesterol. The MORGAM Prospective Cohort Project

Background

Body composition predicts cardiovascular outcomes, but it is uncertain whether anthropometric measures can replace the more expensive serum total cholesterol for cardiovascular risk stratification in low resource settings.

Purpose

The purpose of the study was to compare the additive prognostic ability of serum total cholesterol with that of body mass index (BMI), waist/hip ratio (WHR), and estimated fat mass (EFM, calculated using a validated prediction equation), individually and combined.

Methods

We used data from the MORGAM (MONICA, Risk, Genetics, Archiving, and Monograph) Prospective Cohort Project, an international pooling of cardiovascular cohorts, to determine the relationship between anthropometric measures, serum cholesterol, and cardiovascular events, using multivariable Cox proportional-hazards regression analysis. We further investigated the ability of these measures to enhance prognostication beyond a simpler prediction model, consisting of age, sex, smoking status, systolic blood pressures, and country, using comparison of area under the receiver operating characteristics curve (AUCROC) derived from binary logistic regression models. The primary endpoint was major adverse cardiovascular events (MACE), defined as a composite of death from coronary heart disease, myocardial infarction, or stroke.

Results

The study population consisted of 52,188 apparently healthy subjects (56.3% men) aged 47±12 years ranging from 20 to 84, derived from 37 European cohorts, with baseline between 1982–2002 all followed for 10 years during which MACE occurred in 2465 (4.7%) subjects. All anthropometric measures (BMI: hazard ratio (HR) 1.04 [95% confidence interval (CI): 1.03–1.05] per kg/m2; WHR: HR 7.5 [4.0–14.0] per unit; EFM: HR 1.02 [1.01–1.02] per kg) as well as serum total cholesterol (HR 1.20 [1.16–1.24] per mmol/l) were significantly associated with MACE (P<0.001 for all), independently of age, sex, smoking status, systolic blood pressures, and country. The addition of serum cholesterol significantly improved the predictive ability of the simple model (AUCROC 0.818 vs. 0.814, P<0.001), as did the combination of WHR, BMI, and EFM (AUCROC 0.817 vs. 0.814, P=0.004). When assessed individually, BMI (AUCROC 0.816 vs. 0.814, P=0.004) and WHR (AUCROC 0.815 vs. 0.814, P=0.02) improved model performance, while EFM narrowly missed significance (AUCROC 0.815 vs. 0.814, P=0.06). There was no significant difference in the predictive ability of a model including serum cholesterol versus that including all three anthropometric measures (AUCROC 0.818 vs. 0.817, P=0.13). The figure shows the pertinent areas under the ROC curve in predicting MACE.

Conclusion

In this large population-based cohort study, the addition of a combination of anthropometric measures, i.e. BMI, WHR, and EFM, raised the predictive ability of a simple prognostic model comparable to that obtained by the addition of serum total cholesterol.

Figure 1

Funding Acknowledgement

Type of funding source: None

Assessment of causality of natriuretic peptides and atrial fibrillation and heart failure – a Mendelian randomization study in the FINRISK cohort

Background

Natriuretic peptides are extensively studied biomarkers for atrial fibrillation (AF) and heart failure (HF). Their role in the pathogenesis of both diseases is not entirely understood and in previous studies several single nucleotide polymorphisms (SNPs) at the NPPA-NPPB locus associated with natriuretic peptides have been identified.

Purpose

We investigated whether a causal relationship exists between natriuretic peptides and AF as well as HF using a Mendelian randomization approach.

Methods

N-terminal pro B-type natriuretic peptide (NT-proBNP) (N=6669), B-type natriuretic peptide (BNP) (N=6674) and mid-regional pro atrial natriuretic peptide (MR-proANP) (N=6813) were measured in the FINRISK 1997 cohort. Thirty common SNPs related to NT-proBNP, BNP and MR-proANP were selected from prior studies. We performed six Mendelian randomizations for all three natriuretic peptide biomarkers and for both outcomes, AF and HF separately. Polygenic risk scores (PRS) based on multiple SNPs were used as the genetic instrumental variable in Mendelian randomizations.

Results

PRS were significantly associated with the three natriuretic peptides. PRS were not significantly associated with incident AF nor HF. Most cardiovascular risk factors showed significant confounding percentages, but no association with PRS. A causal relation, other than a weak one, is unlikely.

Conclusion

In our Mendelian randomization approach, based on common genetic variation at the NPPA-NPPB locus, associations of the common polymorphisms with natriuretic peptides and the protein biomarkers themselves with incident disease could be confirmed. A strong causal relationship between natriuretic peptides and incidence of AF as well as HF was ruled out. Therapeutic approaches targeting natriuretic peptides will therefore very likely work through indirect mechanisms.

Comparison of hazard ratios

Funding Acknowledgement

Type of funding source: Public grant(s) – EU funding. Main funding source(s): European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme, German Ministry of Research and Education

P6226Association of functional iron deficiency with incident cardiovascular diseases and mortality in the general population

Background

Functional iron deficiency (FID) has been established as a risk factor in patients with cardiovascular diseases (CVD). As opposed to absolute iron deficiency, it reflects stored iron as well as utilized iron and allows for a more accurate evaluation of individual iron status. However, evidence is scant on the relevance of FID to the incidence of CVD in the general population.

Aim

This study aimed to evaluate the association of FID with incident cardiovascular diseases and mortality endpoints in a large population-based cohort.

Methods

FID was defined as either ferritin below 100 μg/L or ferritin between 100 and 299 μg/L and transferrin saturation below 20%. Only individuals free of CVD at baseline from three population-based European cohorts were included. Multivariable-adjusted sex- and cohort-stratified Cox regression analyses were performed to evaluate the association of functional iron deficiency with incident cardiovascular diseases (coronary heart disease, cerebral infarction, heart failure and atrial fibrillation) as well as with all-cause and cardiovascular mortality. Adjustments were performed for sex (as strata), age (as time scale), smoking, total cholesterol, systolic blood pressure, diabetes, body mass index and high-sensitive C-reactive protein.

Results

In total, N=12146 individuals were included in the analysis with a median age of 59.0 years (25thpercentile 45.0, 75thpercentile 68.0), and 45.2% men. Incidence of FID was 64.3%. Median follow-up times were 12.3 to 21.8 years, with an all-cause mortality rate of 18.2% and a cardiovascular mortality rate of 6.2%. Incident coronary heart disease, cerebral infarction, heart failure and atrial fibrillation were observed in 8.7%, 6.5%, 5.9% and 11.7%, respectively.

FID was significantly associated with all-cause mortality (hazard ratio (HR) 1.12, 95% confidence interval (CI) 1.01–1.24, p=0.034), cardiovascular death (HR 1.26, 95% CI 1.03–1.54, p=0.027) and incident coronary heart disease (HR 1.23, 95% CI 1.06–1.43, p<0.01). There was no significant association with the other tested endpoints.

Conclusion

In our analysis of population-based cohorts, FID showed a significant positive association with all-cause as well as cardiovascular mortality and incident coronary heart disease. Further research is needed to validate the role of FID as a cardiovascular risk factor in the general population and to evaluate the impact of iron supplementation on gender and outcome.

P3820Differential associations of common risk factors and biomarkers with atrial fibrillation and heart failure and their ability to predict sequential disease onset and mortality

Background

Although atrial fibrillation (AF) and heart failure (HF) have a similar cardiovascular risk profile, the differential associations of the risk factors with both disease are incompletely understood.

Aim

The aim of this study was to understand whether common clinical risk factors and cardiovascular biomarkers show different associations with incident AF and HF, and to investigate predictors of sequential disease onset and mortality.

Methods

In 58693 individuals free of AF and HF from European population-based cohorts, pooled multivariable Cox regression analysis was used to find predictors for AF, HF and all-cause mortality. P-values for differences between Hazard Ratios (HR) of risk factors for AF and HF were estimated using bootstrapping with 5,000 replications. When AF and/or HF were used in Cox regressions as explanatory variables, they were included as time-dependent variables.

Results

Median age was 50.5 years, 49.3% were men. Median follow-up time was 13.8 years with an all-cause mortality rate of 15.7%. Incident AF and HF was present in 5.0% and 5.4% of the participants, with 1.8% showing a sequential disease onset.

In multivariable-adjusted models we observed stronger associations of body mass index (HR of 1.32 (95% CI 1.25–1.39) vs. 1.42 (95% CI 1.36–1.49), p=0.02), smoking (HR of 1.21 (95% CI 1.08–1.33) vs. 2.11 (95% CI 1.90–2.32), p<0.01) and antihypertensive medication (HR of 1.21 (95% CI 1.10–1.35) vs. 1.43 (95% CI 1.27–1.59), p<0.01) with incident HF than with incident AF.

Total serum cholesterol (HR of 1.10 (95% CI 1.06–1.15), prevalent diabetes (HR of 3.46 (95% CI 2.60–4.32), high-sensitive C-reactive protein (HR of 1.12 (95% CI 1.08–1.16)) and glomerular filtration rate (HR of 0.92 (95% CI 0.85–1.00) were significantly related to incident HF but not AF.

Age (HR of 1.54 (95% CI 1.47–1.61) vs. 1.54 (95% CI 1.47–1.62), p=0.95), male sex (HR of 2.87 (95% CI 2.42–3.33), p=0.13), prevalent myocardial infarction (HR of 1.65 (95% CI 1.26–2.04) vs. 1.75 (95% CI 1.36–2.11), p=0.73) and NT-proBNP (HR of 1.59 (95% CI 1.50–1.68) vs. 1.60 (95% CI 1.51–1.69), p=0.86) showed comparable associations with both diseases.

Age, male sex, body mass index, total serum cholesterol, prevalent diabetes and NT-proBNP were all predictors of sequential disease onset after multivariable adjustment.

In models including cardiovascular risk factors and NT-proBNP, the time-varying covariates incident AF and HF showed a strong association with all-cause mortality, with HR of 2.2 (95% CI 1.9–2.5) and 10.7 (95% CI 9.1–12.6), respectively. Sequential disease onset further increased the hazard ratio to 15.1 (95% CI 11.6–19.5).

Conclusion

In our pooled analysis of population-based cohorts, new-onset AF and HF showed different associations with common cardiovascular risk factors and biomarkers. Although both diseases significantly increased mortality, the highest risk was observed in individuals with sequential disease onset.

P1642High-sensitivity cardiac troponin I and NT-proBNP and their relationship to heart failure in the European BiomarCaRE population

Aims

Heart failure (HF) is an increasingly important contributor to the overall burden of cardiovascular disease in the population. We aimed to determine the distribution of the cardiac biomarkers high-sensitivity cardiac troponin I (hs-cTnI) and N-terminal prohormone of brain natriuretic peptide (NT-proBNP) concentrations across the European population to characterize the association with incident HF.

Methods and results

Based on the Biomarkers for Cardiovascular Risk Assessment in Europe (BiomarCaRE)-project, we analysed data of 48,455 individuals from four prospective population-based cohort studies (DanMONICA, FINRISK, Moli-Sani, Northern Sweden MONICA study) across Europe with a maximum follow-up of 27 years. The median age of the participants was 50.7 years (25th percentile: 40.0 years, 75th percentile: 61.7 years) and 49.1% (25,146) were men. Considered endpoints were incident HF and all-cause mortality. The median follow-up time for occurrence of HF was 6.61 (6.55; 6.66) years. We found that cardiovascular risk factors (CVRFs), especially diabetes with HR of 2.11 (95% CI 1.8, 2.5) and smoking status with HR of 1.79 (95% CI 1.59, 2.1) (Figure 1) were associated with incident HF. Furthermore, beyond the CVRFs, elevated hs-cTnI and NT-proBNP concentrations contributed to risk of HF in the general population with HR of 1.49 (95% CI 1.21, 1.9) and HR of 2.37 (95% CI 1.97, 3.0) respectively. As a cut-off value to select individuals, who would benefit most from preventive strategies, a hs-cTnI concentration of 2.8 ng/L was calculated using the optimal cut-off methodology by Contal and O'Quigley in CSDA 1999.

Hazard ratio for incident HF

Conclusion

In our large population-based cohort, hs-cTnI and NT-proBNP were independently associated with incident HF. Use of biomarkers for HF screening thus may help to select those individuals in the general population who would benefit most from preventive strategies. Based on the cut-off value future studies are needed to evaluate therapeutic options.

P4796Risk prediction of atrial fibrillation in the community combining biomarkers and genetics

Background

Classical cardiovascular risk factors (CVRF), biomarkers and genetic variation have been suggested for risk assessment of atrial fibrillation (AF).

Purpose

To evaluate their clinical potential, we analysed their individual and combined effectiveness in AF prediction.

Methods

In N=6945 individuals of the FINRISK 1997 cohort, we assessed the predictive value of CVRF, N-terminal pro B-type natriuretic peptide (NT-proBNP) and 145 recently identified single nucleotide polymorphisms (SNPs) for incident AF.

Results

Over a median follow-up of 17.8 years, N=551 participants (7.9%) developed AF. In multivariable-adjusted Cox proportional hazard models, NT-proBNP (hazard ratio (HR) per standard deviation (SD) 1.90, 95% confidence interval (CI): 1.71–2.11, P<0.001) and the polygenic risk score (PRS) (HR per SD 1.66, 95% CI: 1.51–1.84, P<0.001) were significantly related to incident AF. The discriminatory ability improved asymptotically with increasing numbers of SNPs. Compared to a clinical model, AF risk prediction was significantly improved by addition of NT-proBNP and the PRS. The C-statistic for the combination of all CVRF, NT-proBNP and the PRS reached 0.82 compared to 0.77 for CVRF only (P<0.001). Comparing the highest versus lowest quartile, age remained the strongest risk factor with a 15-fold increased risk of AF. The highest quartiles of NT-proBNP and the PRS both showed an approximately 3-fold increased AF risk compared to the lowest quartiles.

C-Index for AF prediction

Conclusions

The PRS and the established biomarker NT-proBNP predicted incident AF comparably. Both provided incremental predictive value over standard clinical variables. Further improvements for the PRS are likely with the discovery of additional SNPs.

Acknowledgement/Funding

European Research Council, German Ministry of Research and Education, DZHK, European Union Seventh Framework Programme, CHANCES, THL

P3398Cystatin C based eGFR estimation compared to crea-based estimation equation for assessing risk of cardiovascular and total mortality in population-based studies and patients with manifest CVD

Introduction

Chronic kidney disease (CKD) represents a global public health problem and affects a large proportion of the adult population worldwide. Early detection, adequate risk stratification and specific treatment can prevent or delay the adverse effects of CKD.

Purpose

To assess cardiovascular risk and total mortality of subjects with CKD using cystatin C based and Crea-based estimated glomerular filtration rate (eGFR) equations (CKDEpi) in the general population, in diseased cohorts, and in specific subgroups.

Methods

The present study has been conducted within the BiomarCaRE project, with harmonized data from 21 population-based cohorts from 6 European countries and 3 cardiovascular disease (CVD) cohorts from Germany. Cox proportional hazards models were used to assess hazard ratios (HRs) for the various CKD definitions with adverse outcomes and mortality after adjustment for age, sex, cohort, smoking status, body mass index, history of diabetes, history of hypertension, and total cholesterol.

Results

21 population-based cohorts (n=76,954, median age 51 years, 52.2% men, 4.4% diabetic) and 3 diseased cohorts (n=4,982, median age 63 years, 75.6% men, 18.7% diabetic) with an average follow-up between 2.8 and 23.5 years and between 0.5 and 9.4 years, respectively, were included in the analysis. Prevalence of CKD-stage 3–5 by CKD-EPIcrea and CKD-EPIcys eGFR respectively, was 3.4% and 7.3% in the population-based cohorts and 13.9% and 14.4% in the diseased cohorts. In the population-based cohorts the incidence (per 1000 person years) of a non-fatal or fatal CVD event and total mortality respectively, was 10.0 and 11.8, whereas it was 21.2 and 17.8 in the diseased cohorts. In the population-based cohorts the HR for a CVD-event was 1.32 (95% CI 1.21–1.44) for the population with CKD-EPIcrea stage 3–5 and it was 1.47 (95% CI 1.35–1.60) based on CKD-EPIcys after adjustment for covariates. The HR for total mortality for those with CKD-EPIcrea stage 3–5 was 1.31 (1.21–1.41) and for CKD-EPIcys it was 1.86 (95% CI 1.73–2.00). Discrepancies between CKD-EPIcrea and CKD-EPIcys were even more striking across subgroups with and without diabetes or across specific age groups.

Conclusion

CKD is an important risk factor for subsequent CVD events and total mortality. However, point estimates of CKD-EPIcrea and CKD-EPIcys eGFR differ considerably between specific risk groups. Therefore, the clinical utility of both equations in different risk groups has to be considered and should be evaluated further.

Acknowledgement/Funding

7th framework programme collaborative project, grant agreement no. HEALTH-F2-2011-278913

Predictive value of low testosterone concentrations regarding coronary heart disease and mortality in men and women - evidence from the FINRISK97 study

INTRODUCTION

The relevance of low testosterone concentrations for incident coronary heart disease (CHD) and mortality has been discussed in various studies. Here, we evaluate the predictive value of low baseline testosterone levels in a large population-based cohort.

METHODS

We measured the serum levels of testosterone in 7671 subjects (3710 male, 3961 female) of the population-based FINRISK97 study.

RESULTS

The median follow-up (FU) was 13.8 years. During the FU, a total of 779 deaths from any cause, and 395 incident CHD events were recorded. The age-adjusted baseline testosterone levels were similar in subjects suffering incident events during FU and those without incident events during FU (men: 15.80 vs. 17.01 nmol L-1 ; P = 0.69, women: 1.14 vs. 1.15 nmol L-1 ; P = 0.92). Weak correlations of testosterone levels were found with smoking (R = 0.09; P < 0.001), HDL cholesterol levels (R = 0.22, P < 0.001), systolic blood pressure (R = -0.05; P = 0.011), BMI (R = -0.23; P < 0.001) and waist-hip-ratio (R = -0.21; P < 0.001) in men, and with eGFR (R = -0.05; P = 0.009) in women. Kaplan-Meier analyses did not reveal a positive association of testosterone levels with incident CHD or mortality. Accordingly, also in Cox regression analyses, testosterone levels were not predictive for incident CHD or mortality - neither in men (HR 1.02 [95%CI: 0.70-1.51]; P = 0.79 for lowest versus highest quarter regarding CHD and HR 1.06 [95%CI: 0.80-1.39]; P = 0.67 regarding mortality), nor in women (HR 1.13 [95%CI: 0.69-1.85]; P = 0.56 for lowest versus highest quarter regarding CHD and HR 0.99 [95%CI: 0.71-1.39]; P = 0.80 regarding mortality).

CONCLUSIONS

Low levels of testosterone are not predictive regarding future CHD or mortality - neither in men, nor in women.

Genome-wide analysis of nuclear magnetic resonance metabolites revealed parent-of-origin effect on triglycerides in medium very low-density lipoprotein in PTPRD gene

Aim: The aim of the study was to explore the parent-of-origin effects (POEs) on a range of human nuclear magnetic resonance metabolites. Materials & methods: We search for POEs in 14,815 unrelated individuals from Estonian and Finnish cohorts using POE method for the genotype data imputed with 1000 G reference panel and 82 nuclear magnetic resonance metabolites. Results: Meta-analysis revealed the evidence of POE for the variant rs1412727 in PTPRD gene for the metabolite: triglycerides in medium very low-density lipoprotein. No POEs were detected for genetic variants that were previously known to have main effect on circulating metabolites. Conclusion: We demonstrated possibility to detect POEs for human metabolites, but the POEs are weak, and therefore it is hard to detect those using currently available sample sizes.

Pharmacogenomics study of thiazide diuretics and QT interval in multi-ethnic populations: the cohorts for heart and aging research in genomic epidemiology

Thiazide diuretics, commonly used antihypertensives, may cause QT interval (QT) prolongation, a risk factor for highly fatal and difficult to predict ventricular arrhythmias. We examined whether common single-nucleotide polymorphisms (SNPs) modified the association between thiazide use and QT or its component parts (QRS interval, JT interval) by performing ancestry-specific, trans-ethnic and cross-phenotype genome-wide analyses of European (66%), African American (15%) and Hispanic (19%) populations (N=78 199), leveraging longitudinal data, incorporating corrected standard errors to account for underestimation of interaction estimate variances and evaluating evidence for pathway enrichment. Although no loci achieved genome-wide significance (P<5 × 10-8), we found suggestive evidence (P<5 × 10-6) for SNPs modifying the thiazide-QT association at 22 loci, including ion transport loci (for example, NELL1, KCNQ3). The biologic plausibility of our suggestive results and simulations demonstrating modest power to detect interaction effects at genome-wide significant levels indicate that larger studies and innovative statistical methods are warranted in future efforts evaluating thiazide-SNP interactions.

Increased Mortality Despite Successful Multifactorial Cardiovascular Risk Reduction in Healthy Men: 40-Year Follow-Up of the Helsinki Businessmen Study Intervention Trial

OBJECTIVES

In a 5-year multifactorial risk reduction intervention for healthy men with at least one cardiovascular disease (CVD) risk factor, mortality was unexpectedly higher in the intervention than the control group during the first 15-year follow-up. In order to find explanations for the adverse outcome, we have extended mortality follow-up and examined in greater detail baseline characteristics that contributed to total mortality.

DESIGN

Long-term follow-up of a controlled intervention trial.

SETTING

The Helsinki Businessmen Study Intervention Trial.

PARTICIPANTS AND INTERVENTION

The prevention trial between 1974-1980 included 1,222 initially healthy men (born 1919-1934) at high CVD risk, who were randomly allocated into intervention (n=612) and control groups (n=610). The 5-year multifactorial intervention consisted of personal health education and contemporary drug treatments for dyslipidemia and hypertension. In the present analysis we used previously unpublished data on baseline risk factors and lifestyle characteristics.

MAIN OUTCOME MEASURES

40-year total and cause-specific mortality through linkage to nation-wide death registers.

RESULTS

The study groups were practically identical at baseline in 1974, and the 5-year intervention significantly improved risk factors (body mass index, blood pressure, serum lipids and glucose), and total CVD risk by 46% in the intervention group. Despite this, total mortality has been consistently higher up to 25 years post-trial in the intervention group than the control group, and converging thereafter. Increased mortality risk was driven by CVD and accidental deaths. Of the newly-analysed baseline factors, there was a significant interaction for mortality between intervention group and yearly vacation time (P=0.027): shorter vacation was associated with excess 30-year mortality in the intervention (hazard ratio 1.37, 95% CI 1.03-1.83, P=0.03), but not in the control group (P=0.5). This finding was robust to multivariable adjustments.

CONCLUSION

After a multifactorial intervention for healthy men with at least one CVD risk factor, there has been an unexpectedly increased mortality in the intervention group. This increase was especially observed in a subgroup characterised by shorter vacation time at baseline. Although this adverse response to personal preventive measures in vulnerable individuals may be characteristic to men of high social status with subclinical CVD, it clearly deserves further investigation.

Genetic predisposition to obesity, restrained eating and changes in body weight: a population-based prospective study

OBJECTIVES

There is no consensus on whether cognitive control over food intake (that is, restrained eating) is helpful, merely ineffective or actually harmful in weight management. We examined the interplay between genetic risk of obesity, restrained eating and changes in body weight and size.

METHODS

Participants were Finnish aged 25-74 years who attended the DIetary, Lifestyle and Genetic determinants of Obesity and Metabolic syndrome study at baseline in 2007 and follow-up in 2014. At baseline (n=5024), height, weight and waist circumference (WC) were measured in a health examination and participants self-reported their weight at age 20 years. At follow-up (n=3735), height, weight and WC were based on measured or self-reported information. We calculated 7-year change in body mass index (BMI) and WC and annual weight change from age 20 years to baseline. Three-Factor Eating Questionnaire-R18 was used to assess restrained eating. Genetic risk of obesity was assessed by calculating a polygenic risk score of 97 known BMI-related loci.

RESULTS

Cross-lagged autoregressive models indicated that baseline restrained eating was unrelated to 7-year change in BMI (β=0.00; 95% confidence interval (CI)=-0.01, 0.02). Instead, higher baseline BMI predicted greater 7-year increases in restrained eating (β=0.08; 95% CI=0.05, 0.11). Similar results were obtained with WC. Polygenic risk score correlated positively with restrained eating and obesity indicators in both study phases, but it did not predict 7-year change in BMI or WC. However, individuals with higher genetic risk of obesity tended to gain more weight from age 20 years to baseline, and this association was more pronounced in unrestrained eaters than in restrained eaters (P=0.038 for interaction).

CONCLUSIONS

Our results suggest that restrained eating is a marker for previous weight gain rather than a factor that leads to future weight gain in middle-aged adults. Genetic influences on weight gain from early to middle adulthood may vary according to restrained eating, but this finding needs to be replicated in future studies.

Plasma levels of hepatocyte growth factor and placental growth factor predict mortality in a general population: a prospective cohort study

BACKGROUND

Circulating levels of growth factors involved in leucocyte production and angiogenesis could be indicative of underlying aberrations of tissue homeostasis and therefore be utilized as predictors of risk for all-cause cardiovascular disease (CVD) or cancer mortality.

METHODS

Baseline plasma levels of a range of growth factors were measured in two cohorts of the population-based FINRISK study (1997 Discovery cohort, N = 8444, aged 25-74; 2002 Replication cohort, N = 2951, aged 51-74 years) using a multiplexed bead array methodology and ELISA. Participants were followed up by linking them to registry data.

RESULTS

In the Discovery cohort (653 deaths; 216 CVD-related, 231 cancer-related), fully adjusted Cox proportional hazard regression models showed that increased plasma hepatocyte growth factor (HGF) and placental growth factor (PlGF) were associated with higher risk of 10-year mortality (HR, 1.29 [95% confidence interval (CI), 1.18-1.41] and HR, 1.23 [95% CI, 1.14-1.32], respectively). In the Replication cohort (259 deaths; 83 CVD-related, 90 cancer-related), baseline HGF levels also predicted all-cause mortality (HR, 1.2 [95% CI, 1.08-1.32]; PlGF data not available). By including HGF levels in a CVD mortality model, 9% of all CVD deaths were correctly reclassified in the Discovery cohort (categorical net reclassification improvement [NRI] for events, P = 4.0 × 10^-4 ). Moreover, adding HGF to all-cause and CVD mortality models resulted in an overall clinical NRI of 0.10-0.18 in the Discovery cohort and meta-analyses (P < 0.05 for all tests).

CONCLUSION

Blood levels of HGF and PlGF may serve as new biomarkers for predicting increased risk of death in the general population.

Neuregulin signaling pathway in smoking behavior

Understanding molecular processes that link comorbid traits such as addictions and mental disorders can provide novel therapeutic targets. Neuregulin signaling pathway (NSP) has previously been implicated in schizophrenia, a neurodevelopmental disorder with high comorbidity to smoking. Using a Finnish twin family sample, we have previously detected association between nicotine dependence and ERBB4 (a neuregulin receptor), and linkage for smoking initiation at the ERBB4 locus on 2q33. Further, Neuregulin3 has recently been shown to associate with nicotine withdrawal in a behavioral mouse model. In this study, we scrutinized association and linkage between 15 036 common, low frequency and rare genetic variants in 10 NSP genes and phenotypes encompassing smoking and alcohol use. Using the Finnish twin family sample (N=1998 from 740 families), we detected 66 variants (representing 23 LD blocks) significantly associated (false discovery rate P<0.05) with smoking initiation, nicotine dependence and nicotine withdrawal. We comprehensively annotated the associated variants using expression (eQTL) and methylation quantitative trait loci (meQTL) analyses in a Finnish population sample. Among the 66 variants, we identified 25 eQTLs (in NRG1 and ERBB4), 22 meQTLs (in NRG3, ERBB4 and PSENEN), a missense variant in NRG1 (rs113317778) and a splicing disruption variant in ERBB4 (rs13385826). Majority of the QTLs in blood were replicated in silico using publicly available databases, with additional QTLs observed in brain. In conclusion, our results support the involvement of NSP in smoking behavior but not in alcohol use and abuse, and disclose functional potential for 56 of the 66 associated single-nucleotide polymorphism.

Somatic, positive and negative domains of the Center for Epidemiological Studies Depression (CES-D) scale: a meta-analysis of genome-wide association studies

BACKGROUND

Major depressive disorder (MDD) is moderately heritable, however genome-wide association studies (GWAS) for MDD, as well as for related continuous outcomes, have not shown consistent results. Attempts to elucidate the genetic basis of MDD may be hindered by heterogeneity in diagnosis. The Center for Epidemiological Studies Depression (CES-D) scale provides a widely used tool for measuring depressive symptoms clustered in four different domains which can be combined together into a total score but also can be analysed as separate symptom domains.

METHOD

We performed a meta-analysis of GWAS of the CES-D symptom clusters. We recruited 12 cohorts with the 20- or 10-item CES-D scale (32 528 persons).

RESULTS

One single nucleotide polymorphism (SNP), rs713224, located near the brain-expressed melatonin receptor (MTNR1A) gene, was associated with the somatic complaints domain of depression symptoms, with borderline genome-wide significance (p discovery = 3.82 × 10-8). The SNP was analysed in an additional five cohorts comprising the replication sample (6813 persons). However, the association was not consistent among the replication sample (p discovery+replication = 1.10 × 10-6) with evidence of heterogeneity.

CONCLUSIONS

Despite the effort to harmonize the phenotypes across cohorts and participants, our study is still underpowered to detect consistent association for depression, even by means of symptom classification. On the contrary, the SNP-based heritability and co-heritability estimation results suggest that a very minor part of the variation could be captured by GWAS, explaining the reason of sparse findings.

Missing Teeth Predict Incident Cardiovascular Events, Diabetes, and Death

Periodontitis, the main cause of tooth loss in the middle-aged and elderly, associates with the risk of atherosclerotic vascular disease. The objective was to study the capability of the number of missing teeth in predicting incident cardiovascular diseases (CVDs), diabetes, and all-cause death. The National FINRISK 1997 Study is a Finnish population–based survey of 8,446 subjects with 13 y of follow-up. Dental status was recorded at baseline in a clinical examination by a trained nurse, and information on incident CVD events, diabetes, and death was obtained via national registers. The registered CVD events included coronary heart disease events, acute myocardial infarction, and stroke. In Cox regression analyses, having ≥5 teeth missing was associated with 60% to 140% increased hazard for incident coronary heart disease events ( P < 0.020) and acute myocardial infarction ( P < 0.010). Incident CVD ( P < 0.043), diabetes ( P < 0.040), and death of any cause ( P < 0.019) were associated with ≥9 missing teeth. No association with stroke was observed. Adding information on missing teeth to established risk factors improved risk discrimination of death ( P = 0.0128) and provided a statistically significant net reclassification improvement for all studied end points. Even a few missing teeth may indicate an increased risk of CVD, diabetes, or all-cause mortality. When individual risk factors for chronic diseases are assessed, the number of missing teeth could be a useful additional indicator for general medical practitioners.

Systemic exposure to a common periodontal pathogen and missing teeth are associated with metabolic syndrome

Periodontitis is a common chronic infection of tooth-supporting tissues leading to tooth loss. Two of the major periodontal pathogens are Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis. Clinically diagnosed periodontitis has been associated with metabolic syndrome (MetS). The aim of the study was to investigate the association of serum antibody levels against A. actinomycetemcomitans and P. gingivalis and the number of missing teeth with MetS. The population was the PAIS subcohort of the FINRISK '97 study (n = 1,354). The subjects were men aged 45-74 years, and they participated in this cardiovascular risk factor survey in Finland. A total of 534 (39 %) subjects had MetS defined according to the guidelines of the International Diabetes Federation. Serum antibody levels against the pathogens were measured by multiserotype ELISA. A. actinomycetemcomitans antibody levels and the number of missing teeth were significantly higher in subjects with a large waist circumference or with low serum high-density lipoprotein cholesterol. The number of missing teeth was also higher among subjects with a high serum triglyceride concentration or high plasma glucose concentration. Seropositivity for A. actinomycetemcomitans was significantly associated with MetS with an odds ratio (OR) 1.42 (95 % confidence interval 1.09-1.85, p = 0.009). More than four missing teeth and complete edentulousness were also significantly associated with MetS with ORs 1.69 (1.26-2.27, p < 0.001) and 1.93 (1.30-2.86, p = 0.001), respectively. Missing teeth and systemic exposure to A. actinomycetemcomitans were associated with several components of Mets. Infection with this common pathogen or the host response against it is associated with the presence of MetS.

Drug-gene interactions and the search for missing heritability: a cross-sectional pharmacogenomics study of the QT interval

Variability in response to drug use is common and heritable, suggesting that genome-wide pharmacogenomics studies may help explain the 'missing heritability' of complex traits. Here, we describe four independent analyses in 33 781 participants of European ancestry from 10 cohorts that were designed to identify genetic variants modifying the effects of drugs on QT interval duration (QT). Each analysis cross-sectionally examined four therapeutic classes: thiazide diuretics (prevalence of use=13.0%), tri/tetracyclic antidepressants (2.6%), sulfonylurea hypoglycemic agents (2.9%) and QT-prolonging drugs as classified by the University of Arizona Center for Education and Research on Therapeutics (4.4%). Drug-gene interactions were estimated using covariable-adjusted linear regression and results were combined with fixed-effects meta-analysis. Although drug-single-nucleotide polymorphism (SNP) interactions were biologically plausible and variables were well-measured, findings from the four cross-sectional meta-analyses were null (Pinteraction>5.0 × 10(-8)). Simulations suggested that additional efforts, including longitudinal modeling to increase statistical power, are likely needed to identify potentially important pharmacogenomic effects.

The return of unexpected research results in a biobank study and referral to health care for heritable long QT syndrome

BACKGROUND

In this study, we examined how biobank study participants, who were found to have long QT syndrome (LQTS), a potentially life-threatening but treatable cardiac arrhythmia condition, experienced the process of disclosure of unexpected results and referral to health care.

METHODS

All 27 subjects with a LQTS mutation finding were asked to complete a questionnaire. Four participants did not uptake the re-testing and 5 others did not respond to the questionnaire. We received 17 questionnaires from 6 males and 11 females, aged 46-82; 5 of them were also willing to participate in qualitative interviews.

RESULTS

Of the respondents, 16/17 had experienced the process of receiving the results as positive and useful, especially if they had had symptoms. One respondent experienced the process negatively due to concerns related to informing her children. All respondents felt that genetic results should be reported back to the participants, while 2 indicated that this should occur only in the case of treatable conditions. Respondents had informed all of their children about the genetic condition, except 2 minors.

CONCLUSIONS

The respondents from a population biobank study who were informed about an unexpected genetic finding evaluated this process as mainly positive. They considered that delivering genetic information about a life-threatening but actionable condition has more beneficial than adverse consequences. The feedback policy for biobanks should include how and who is informed, advise treatment or care pathways for actionable findings, and it should also include suitable options for those who do not want to know about such findings.

Trends in population attributable fraction of acute coronary syndrome and ischaemic stroke due to diabetes in Finland

AIMS/HYPOTHESIS

Cardiovascular disease (CVD) event rates are decreasing, but the prevalence of diabetes is increasing. The effect of these developments on the population attributable fraction (PAF) of CVD events due to diabetes is not known.

METHODS

We used country-wide healthcare registers to identify all persons aged 25-80 years treated for diabetes in Finland during 1992-2002. These data were further linked to the National Cardiovascular Disease Register to identify the first CVD events (acute coronary syndrome and ischaemic stroke) among the individuals with and without diabetes. We calculated the annual PAF of the first CVD events due to diabetes separately for men and women.

RESULTS

The number of men treated for diabetes each year almost doubled during the study period from 37,073 to 69,158 between 1992 and 2002. Among women, the number increased from 42,485 to 57,372. The annual number of first CVD events in the country declined among men with diabetes from 13,436 to 12,678 and among women with diabetes from 8,658 to 7,521 between 1992 and 2002. During the same period, the PAF due to diabetes of the first CVD events increased among men from 11.4% (95% CI 10.8, 12.0%) to 13.8% (95% CI 13.2, 14.5%) and decreased among women from 20.1% (95% CI 19.2, 21.0%) to 16.9% (95% CI 15.9, 17.8%). The trends in PAF were different between the sexes (p < 0.001 for the interaction year × sex).

CONCLUSIONS/INTERPRETATION

Despite the very large increase in the prevalence of diabetes, the PAF of the first CVD events due to diabetes decreased in women and increased only slightly in men.

Associations between interleukin-1 (IL-1) gene variations or IL-1 receptor antagonist levels and the development of type 2 diabetes

OBJECTIVES

To examine whether interleukin-1 receptor antagonist (IL-1Ra) is a predictor for clinically incident diabetes in subjects with metabolic syndrome (MetS) and whether its predictive power is independent of C-reactive protein (CRP), an established marker of inflammation. We further examined whether genetic variants at the interleukin-1 (IL-1) locus would predict clinically incident diabetes.

DESIGN

Two observational prospective cohort studies.

SETTING

Two separate cohorts, Health 2000 and FINRISK 1997, followed up for an average of 7.1 and 10.8 years, respectively.

SUBJECTS

Random population samples consisting of 5511 subjects aged 30-74 years in Health 2000 and 7374 subjects aged 25-74 years in FINRISK 1997.

RESULTS

During follow-up, 141 cases of clinically incident diabetes were observed amongst subjects with MetS at baseline in Health 2000 and 248 cases in FINRISK 97. After adjustment for multiple traditional risk factors of diabetes, including age and body mass index, IL-1Ra was a significant (P < 0.01) predictor of incident diabetes amongst men in both cohorts and amongst women in FINRISK 1997. Further adjustment for CRP reduced the hazard ratios only slightly. Genetic analyses produced nominally significant associations for three single-nucleotide polymorphisms: rs3213448 in IL-1 receptor antagonist (IL1RN), rs1143634 in IL-1 beta (IL1B) and rs1800587 in IL-1 alpha (IL1A). The two latter variants had an interaction with gender (P = 0.023 and 0.002, respectively) suggesting the presence of gender-specific associations with the risk of clinically incident diabetes.

CONCLUSIONS

IL-1Ra predicted the progression of MetS to clinically incident diabetes independently of CRP and other risk factors. Genetic variation in the IL-1 locus may have gender-specific associations with the risk of type 2 diabetes.

Prior antiplatelet therapy and outcome following intracerebral hemorrhage: a systematic review

OBJECTIVES

Antiplatelet therapy (APT) promotes bleeding; therefore, APT might worsen outcome in patients with intracerebral hemorrhage (ICH). We performed a systematic review and meta-analysis to address the hypothesis that pre-ICH APT use is associated with mortality and poor functional outcome following ICH.

METHODS

The Medline and Embase databases were searched in February 2008 using relevant key words, limited to human studies in the English language. Cohort studies of consecutive patients with ICH reporting mortality or functional outcome according to pre-ICH APT use were identified. Of 2,873 studies screened, 10 were judged to meet inclusion criteria by consensus of 2 authors. Additionally, we solicited unpublished data from all authors of cohort studies with >100 patients published within the last 10 years, and received data from 15 more studies. Univariate and multivariable-adjusted odds ratios (ORs) for mortality and poor functional outcome were abstracted as available and pooled using a random effects model.

RESULTS

We obtained mortality data from 25 cohorts (15 unpublished) and functional outcome data from 21 cohorts (14 unpublished). Pre-ICH APT users had increased mortality in both univariate (OR 1.41, 95% confidence interval [CI] 1.21 to 1.64) and multivariable-adjusted (OR 1.27, 95% CI 1.10 to 1.47) pooled analyses. By contrast, the pooled OR for poor functional outcome was no longer significant when using multivariable-adjusted estimates (univariate OR 1.29, 95% CI 1.09 to 1.53; multivariable-adjusted OR 1.10, 95% CI 0.93 to 1.29).

CONCLUSIONS

In cohort studies, APT use at the time of ICH compared to no APT use was independently associated with increased mortality but not with poor functional outcome.