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Aims: Plasminogen activator inhibitor-1 (PAI-1) is the main inhibitor of the fibrinolytic system and is mainly secreted from adipose tissue. It is associated with cardiovascular disease and has also been considered a possible early risk marker for type 2 diabetes. Here, we present the results of a large prospective study investigating PAI-1 levels in relation to incident type 2 diabetes mellitus.

Methods: We conducted a prospective incident case-referent study within the Västerbotten Intervention Programme (VIP). Data on cardiovascular risk factors, fasting plasma glucose (FPG) and 2-hour plasma glucose (2-hPG) were collected at baseline health examination 1990–2005. Blood samples were collected and stored for future analyses. Participants were followed and 484 cases developed type 2 diabetes. Referents without type 2 diabetes were matched for sex, age, and year of participation, n = 484. Baseline plasma samples were analysed for PAI-1. Subgroup analysis was performed for 201 cases and 201 matched referents with normal baseline glucose levels (FPG < 6.1 and 2hPG < 8.9 mmol/L).

Results: Elevated baseline levels of PAI-1 were associated with incident type 2 diabetes after adjustments for BMI, family history of diabetes, smoking status, hypertension, FPG and 2hPG (PAI-1; OR = 1.87, 95% CI: 1.06–3.29). A similar result was shown in the subgroup analysis with 201 participants who had normal glucose levels at time of the health examination (PAI-1; OR = 2.68, 95% CI: 1.03–6.95).

Conclusions: Elevated PAI-1 levels in non-diabetic persons precede the manifestation of type 2 diabetes and can be detected before an elevation of FPG or 2-hPG is observed.

Patients at a high risk for sudden cardiac death (SCD) without previous history of cardiovascular disease remain a challenge to identify. Atherosclerosis and prothrombotic states involve inflammation and non-cardiac tissue damage that may play active roles in SCD development. Therefore, we hypothesized that circulating proteins implicated in inflammation and tissue damage are linked to the future risk of SCD. We conducted a prospective nested case–control study of SCD cases with verified myocardial infarction (N = 224) and matched controls without myocardial infarction (N = 224), aged 60 ± 10 years time and median time to event was 8 years. Protein concentrations (N = 122) were measured using a proximity extension immunoassay. The analyses revealed 14 proteins significantly associated with an increased risk of SCD, from which two remained significant after adjusting for smoking status, systolic blood pressure, BMI, cholesterol, and glucose levels. We identified leukotriene A4 hydrolase (LTA4H, odds ratio 1.80, corrected confidence interval (CI_corr) 1.02–3.17) and hepatocyte growth factor (HGF; odds ratio 1.81, CI_corr 1.06–3.11) as independent risk markers of SCD. Elevated LTA4H may reflect increased systemic and pulmonary neutrophilic inflammatory processes that can contribute to atherosclerotic plaque instability. Increased HGF levels are linked to obesity-related metabolic disturbances that are more prevalent in SCD cases than the controls.

The present study explored patterns of circulating metabolites and proteins that can predict future risk for ST-elevation myocardial infarction (STEMI) and non-ST-elevation myocardial infarction (NSTEMI). We conducted a prospective nested case-control study in northern Sweden in individuals who developed STEMI (N = 50) and NSTEMI (N = 50) within 5 years and individually matched controls (N = 100). Fasted plasma samples were subjected to multiplatform mass spectrometry-based metabolomics and multiplex protein analyses. Multivariate analyses were used to elucidate infarction-specific metabolite and protein risk profiles associated with future incident STEMI and NSTEMI. We found that altered lysophosphatidylcholine (LPC) to lysophosphatidylethanolamine (LPE) ratio predicted STEMI and NSTEMI events in different ways. In STEMI, lysophospholipids (mainly LPEs) were lower, whereas in NSTEMI, lysophospholipids (mainly LPEs) were higher. We found a similar response for all detected lysophospholipids but significant alterations only for those containing linoleic acid (C18:2, p < 0.05). Patients with STEMI had higher secretoglobin family 3A member 2 and tartrate-resistant acid phosphate type 5 and lower platelet-derived growth factor subunit A, which are proteins associated with atherosclerosis severity and plaque development mediated via altered phospholipid metabolism. In contrast, patients with NSTEMI had higher levels of proteins associated with inflammation and macrophage activation, including interleukin 6, C-reactive protein, chemerin, and cathepsin X and D. The STEMI risk marker profile includes factors closely related to the development of unstable plaque, including a higher LPC:LPE ratio, whereas NSTEMI is characterized by a lower LPC:LPE ratio and increased inflammation.

The role of dairy products in cancer is unclear. We assessed consumption of fermented milk, non-fermented milk, cheese, and butter, estimated from semi-quantitative food frequency questionnaires, in relation to prospective risk of breast, prostate, colorectal, smoking-, and obesity-related cancers in 101,235 subjects, including 12,552 cancer cases, in the population-based Northern Sweden Health and Disease Study. Most analyses (n = 20) rendered null results. In men, we observed an increased prostate cancer risk among high-consumers of cheese (hazard ratio (HR) for highest vs. lowest quintile (Q5-Q1), 1.11; 95% CI, 0.97-1.27; P^trend = 0.013). In women, high-consumers of cheese had a decreased risk of overall cancer (HR Q5-Q1, 0.95; 95% CI, 0.88-1.04; P^trend = 0.039), smoking-related (HR Q5-Q1, 0.84; 95% CI, 0.72-0.97; P^trend ≤ 0.001), and colorectal cancers (HR Q5-Q1, 0.82; 95% CI, 0.63-1.07; P^trend = 0.048). Butter yielded a weak decreased obesity-related cancer risk in women (HR Q5-Q1, 0.91; 95% CI, 0.81-1.02; P^trend = 0.049). Fermented milk yielded HRs below zero in women, but with no clear linear associations. In conclusion, this study does not support any major adverse or beneficial effects of fermented milk, non-fermented milk, cheese, and butter in the diet from a cancer risk perspective.

Aims: Preventing sudden cardiac death (SCD) due to acute myocardial infarction (MI) in previously healthy patients is challenging. Proteomic analysis may lead to an understanding of biological mechanisms and provide predictive biomarkers.

Methods: In this prospective, nested case-control study from northern Sweden, 87 candidate cardiovascular protein biomarkers were studied in 244 individuals who later died within 24 h from an incident MI and 244 referents without MI and individually matched for age, sex and date of health examination and alive at the date of event in the index person. Association analysis was conducted using conditional logistic regression. Bonferroni correction was applied to avoid false positive findings.

Results: Ten proteins were associated with future SCD due to acute MI in the non-adjusted analysis. The strongest association were found for growth differentiation factor 15 (GDF-15) with an odds ratio (OR) of 1.79 (95% confidence interval [CI] 1.41, 2.25) per standard deviation increase in protein, and urokinase-type plasminogen activator receptor with an OR of 1.66 (95% CI 1.34, 2.06). In models adjusted for lipid levels, body mass index, education, smoking, hypertension and C-reactive protein, only association with GDF-15 remained (OR 1.47 (95% 1.11, 1.95)).

Conclusion: Elevated levels of GDF-15 are associated with increased risk of SCD within 24 h of incident MI. Further research may enable the use of GDF-15 together with other clinical and biological markers to guide primary preventive interventions for individuals at high risk for SCD.

Trinucleotide (CAG) repeat expansions longer than 39 in the huntingtin (HTT) gene cause Huntington's disease (HD). The frequency of intermediate alleles (IA) with a length of 27-35 in the general population is not fully known, but studied in specific materials connected to the incidence of HD. The Swedish Huntingtin Alleles and Phenotype (SHAPE) study aims to assess the frequency of trinucleotide repeat expansions in the HTT gene in north Sweden. 8260 individuals unselected for HD from the counties of Norr- and Vasterbotten in the north of Sweden were included. DNA samples were obtained and analysis of the HTT gene was performed, yielding data on HTT gene expansion length in 7379 individuals. A high frequency of intermediate alleles, 6.8%, was seen. Also, individuals with repeat numbers lower than ever previously reported (<5) were found. These results suggest a high frequency of HD in the norther parts of Sweden. Subsequent analyses may elucidate the influence of IA:s on traits other than HD.

Leptin, an adipocyte-derived hormone, is involved in the regulation of body weight and is associated with obesity-related complications, notably cardiovascular disease (CVD). A putative link between obesity and CVD could be induction of plasminogen activator inhibitor-1 (PAI-1) synthesis by leptin. In this study, we hypothesized that the beneficial effect of the angiotensin-converting enzyme inhibitor (ACE(i)) enalapril on PAI-1 levels is mediated by effects on leptin levels. The association between leptin and components of the fibrinolytic system was evaluated in a non-prespecified post hoc analysis of a placebo-controlled randomized, double-blind trial where the effect of the ACE(i) enalapril on fibrinolysis was tested. A total of 46 men and 37 women were randomized to treatment with enalapril or placebo after (median 12 months) an uncomplicated myocardial infarction. At baseline, the participants were stable and had no signs of congestive heart failure. Leptin and fibrinolytic variables (mass concentrations of PAI-1, tissue plasminogen activator (tPA) and tPA-PAI complex) were measured at baseline, and after 10 days, 6 months and 12 months. Enalapril treatment did not change leptin levels, which increased significantly during 1 year of follow-up (p = .007). Changes in leptin levels were strongly associated with changes of tPA mass (p = .001), tPA-PAI complex (p = .003) and of PAI-1 (p = .006) in men, but not in women. Leptin levels are not influenced by treatment with an ACE(i). In contrast, leptin associates strongly with changes in fibrinolytic variables notably with a sex difference, which could be of importance for obesity-related CVD.

Smoking is a major heritable and modifiable risk factor for many diseases, including cancer, common respiratory disorders and cardiovascular diseases. Fourteen genetic loci have previously been associated with smoking behaviour-related traits. We tested up to 235,116 single nucleotide variants (SNVs) on the exome-array for association with smoking initiation, cigarettes per day, pack-years, and smoking cessation in a fixed effects meta-analysis of up to 61 studies (up to 346,813 participants). In a subset of 112,811 participants, a further one million SNVs were also genotyped and tested for association with the four smoking behaviour traits. SNV-trait associations with P < 5 × 10^-8 in either analysis were taken forward for replication in up to 275,596 independent participants from UK Biobank. Lastly, a meta-analysis of the discovery and replication studies was performed. Sixteen SNVs were associated with at least one of the smoking behaviour traits (P < 5 × 10^-8) in the discovery samples. Ten novel SNVs, including rs12616219 near TMEM182, were followed-up and five of them (rs462779 in REV3L, rs12780116 in CNNM2, rs1190736 in GPR101, rs11539157 in PJA1, and rs12616219 near TMEM182) replicated at a Bonferroni significance threshold (P < 4.5 × 10^-3) with consistent direction of effect. A further 35 SNVs were associated with smoking behaviour traits in the discovery plus replication meta-analysis (up to 622,409 participants) including a rare SNV, rs150493199, in CCDC141 and two low-frequency SNVs in CEP350 and HDGFRP2. Functional follow-up implied that decreased expression of REV3L may lower the probability of smoking initiation. The novel loci will facilitate understanding the genetic aetiology of smoking behaviour and may lead to the identification of potential drug targets for smoking prevention and/or cessation.

Background and Purpose: Previous observational studies have shown a moderately increased risk of intracerebral hemorrhage (ICH) with high self-reported alcohol consumption. However, self-reported data tend to underestimate alcohol consumption. Phosphatidylethanol is a specific biomarker reflecting alcohol intake during the last month and correlates with the amount of alcohol consumed. The present study aimed to investigate the association between phosphatidylethanol levels and the risk of future ICH.

Methods: This population-based nested case-referent study was conducted within the Northern Sweden Health and Disease Cohort. At baseline, all participants underwent a health examination, including a questionnaire with questions about alcohol consumption. A blood sample was collected and stored at −80°C, and phosphatidylethanol 16:0/18:1 levels were measured in packed erythrocytes. Cases (n=97) were diagnosed with a first-ever ICH between 1985 and 2007. Two referents (n=180) were matched to each case.

Results: The mean age at baseline was 55 years, 39% of participants were women, and the mean time from blood sampling to ICH was 7.3 years. Only phosphatidylethanol and hypertension remained independently associated with ICH in a multivariable model. Participants with phosphatidylethanol >0.30 μmol/L had an increased risk of ICH compared with those with phosphatidylethanol <0.01 μmol/L (odds ratio, 4.64 [95% CI, 1.49–14.40]).

Conclusions: High blood concentrations of phosphatidylethanol were associated with an increased risk of future ICH. This association was independent of hypertension and other risk factors for ICH. Our findings suggest that phosphatidylethanol, as a marker of alcohol consumption, may be used as a risk marker of future ICH.

BACKGROUND: The health consequences of the use of Swedish snus, including its relationship with mortality, have not been fully established. We investigated the relationship between snus use and all-cause and cause-specific mortality (death due to cardiovascular diseases, cancer diseases and all other reasons, respectively) in a nationwide collaborative pooling project.

METHODS: We followed 169 103 never-smoking men from eight Swedish cohort studies, recruited in 1978-2010. Shared frailty models with random effects at the study level were used in order to estimate adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) of mortality associated with snus use.

RESULTS: Exclusive current snus users had an increased risk of all-cause mortality (aHR 1.28, 95% CI 1.20-1.35), cardiovascular mortality (aHR 1.27, 95% CI 1.15-1.41) and other cause mortality (aHR 1.37, 95% CI 1.24-1.52) compared with never-users of tobacco. The risk of cancer mortality was also increased (aHR 1.12, 95% CI 1.00-1.26). These mortality risks increased with duration of snus use, but not with weekly amount.

CONCLUSIONS: Snus use among men is associated with increased all-cause mortality, cardiovascular mortality, with death from other causes and possibly with increased cancer mortality.