Göran Hallmans

Prostate cancer (PCa) is the most common cancer form in males in many European and American countries, but there are still open questions regarding its etiology. Untargeted metabolomics can produce an unbiased global metabolic profile, with the opportunity for uncovering new plasma metabolites prospectively associated with risk of PCa, providing insights into disease etiology. We conducted a prospective untargeted liquid chromatography‐mass spectrometry (LC‐MS) metabolomics analysis using prediagnostic fasting plasma samples from 752 PCa case‐control pairs nested within the Northern Sweden Health and Disease Study (NSHDS). The pairs were matched by age, BMI, and sample storage time. Discriminating features were identified by a combination of orthogonal projection to latent structures‐effect projections (OPLS‐EP) and Wilcoxon signed‐rank tests. Their prospective associations with PCa risk were investigated by conditional logistic regression. Subgroup analyses based on stratification by disease aggressiveness and baseline age were also conducted. Various free fatty acids and phospholipids were positively associated with overall risk of PCa and in various stratification subgroups. Aromatic amino acids were positively associated with overall risk of PCa. Uric acid was positively, and glucose negatively, associated with risk of PCa in the older subgroup. This is the largest untargeted LC‐MS based metabolomics study to date on plasma metabolites prospectively associated with risk of developing PCa. Different subgroups of disease aggressiveness and baseline age showed different associations with metabolites. The findings suggest that shifts in plasma concentrations of metabolites in lipid, aromatic amino acid, and glucose metabolism are associated with risk of developing PCa during the following two decades.

The intake of the mainly plant-derived n-3 PUFA α-linolenic acid (ALA) has been reported to be associated with a lower risk of CHD. However, the results have been inconsistent. Therefore, the objective of the present study was to examine the association between the intake of ALA and the risk of CHD. Potential effect modification by the intake of long-chain n-3 PUFA (n-3 LCPUFA) was also investigated. Data from eight American and European prospective cohort studies including 148 675 women and 80 368 men were used. The outcome measure was incident CHD (CHD event and death). During 4–10 years of follow-up, 4493 CHD events and 1751 CHD deaths occurred. Among men, an inverse association (not significant) between the intake of ALA and the risk of CHD events and deaths was observed. For each additional gram of ALA consumed, a 15 % lower risk of CHD events (hazard ratios (HR) 0·85, 95 % CI 0·72, 1·01) and a 23 % lower risk of CHD deaths (HR 0·77, 95 % CI 0·58, 1·01) were observed. No consistent association was observed among women. No effect modification by the intake of n-3 LCPUFA was observed.

Aims: To compare data on cardiovascular risk factor changes in lipids, insulin, proinsulin, fibrinolysis, leptin and C-reactive protein, and on diabetes incidence, in relation to changes in lifestyle. Methods: The study was a randomized lifestyle intervention trial conducted in northern Sweden between 1995 and 2000, in 168 individuals with impaired glucose tolerance (IGT) and body mass index above 27 at start. The intensive intervention group (n = 83) was subjected to a 1-month residential lifestyle programme. The usual care group (n = 85) participated in a health examination ending with a single counselling session. Follow-up was conducted at 1, 3 and 5 years. Results: At 1-year follow-up, an extensive cardio-metabolic risk factor reduction was demonstrated in the intensive intervention group, along with a 70% decrease of progress to type 2 diabetes. At 5-year follow-up, most of these beneficial effects had disappeared. Reported physical activity and fibre intake as well as high-density lipoprotein cholesterol were still increased, and fasting insulin and proinsulin were lower. Conclusions: The intervention affected several important cardio-metabolic risk variables beneficially, and reduced the risk for type 2 diabetes, but the effects persisted only as long as the new lifestyle was maintained. Increased physical activity seemed to be the behaviour that was most easy to preserve.

Background: Chronic infections and associated inflammatory markers are suggested risk factors for cardiovascular diseases (CVD) and stroke. The proinflammatory cytokine interleukin (IL)-1β is suggested to play a role in the regulation of local inflammatory responses in both CVD and periodontitis. The leukotoxin from the periodontal pathogen Actinobacillus actinomycetemcomitans has recently been shown to cause abundant secretion of IL-1β from macrophages. The aim of the present study was to compare the prevalence of systemic antibodies to A. actinomycetemcomitans leukotoxin in stroke cases (n = 273) and matched controls (n = 546) in an incident case-control study nested within the Northern Sweden MONICA and Västerbotten Intervention cohorts. Methods: Antibodies to A. actinomycetemcomitans leukotoxin were analyzed in a bioassay with HL-60 cells (leukocytes), purified A. actinomycetemcomitans leukotoxin, and plasma. Plasma samples which inhibited lactate dehydrogenase release from leukotoxin-lysed cells by ≧50% were classified as antibody positive. Results: Antibodies to A. actinomycetemcomitans leukotoxin were detected in 18.8% of the women and 15.2% of the men. Women with those antibodies had a significantly decreased risk for stroke (OR = 0.28, 95% CI: 0.13–0.59), but not men (OR = 0.88, 95% CI: 0.52–1.51). Conclusion: The immunoreactivity to A. actinomycetemcomitans leukotoxin correlates negatively with a future stroke in woman, but not in men. Further studies are needed to explain the underlying mechanisms, as well as the biological relevance of this finding.

To test whether von Willebrand factor, a new cardiovascular risk factor, belongs to the group of risk factors forming part of the insulin resistance syndrome. A population-based, age-stratified, cross-sectional study. A primary health care centre. All subjects aged 35, 45, 55, and 65 years in Norsjö municipality (n = 265) were invited, and 68% (82 males, 93 females) entered and completed the study. von Willebrand factor did not correlate with any measured lipid, anthropometric, or glucose metabolism variable. The higher levels of cardiovascular risk factors found in the subgroup of patients with electrocardiographical signs of ischaemic heart disease did not confound this result. von Willebrand factor plasma concentration is unrelated to the metabolic factors involved in the insulin resistance syndrome. Thus, it may be difficult to reduce elevated von Willebrand factor levels by conventional non-pharmacological cardiovascular high-risk intervention schemes.

Two groups of adult male rats aged 15 weeks and 49 weeks, 15 rats in each group, were analysed for the concentrations of the trace elements zinc (Zn) and copper (Cu) in serum, liver, kidney, and five parts of the brain (cortex, corpus striatum, hippocampus, midbrain+medulla, and cerebellum). All organs increased in weight from 15 weeks to 49 weeks. In all parts of the brain, except for corpus striatum, there was a significant increase of the weights. The dry weight (% of wet) increased in all parts of the brain. In serum, the Zn and Cu concentrations increased from 15 weeks to 49 weeks. In the liver, both concentrations decreased and in the kidney the concentrations increased with increasing age. The Zn concentrations increased in cortex and corpus striatum and decreased in cerebellum and hippocampus. The Cu levels increased in all parts of the brain with the largest changes in corpus striatum. For rats aged 49 weeks, a significant correlation was found between the Cu concentrations of corpus striatum or midbrain+medulla and the fluid consumption. The findings of the present study reveal a dynamic age-related pattern of changes in the concentrations of Zn and Cu in different organs of the adult rat. This stresses the need of age-matching as an important control in experiment studies.