Maternal mood disorders and lithium exposure in utero were not associated with poor cognitive development during childhood.

AIM: This study evaluated whether maternal mood disorders (MMD), particularly bipolar disorder, and lithium treatment during pregnancy influenced the neonatal health and cognition of children born from 2006 to 2010. METHODS: Our study at Karolinska University Hospital, Stockholm, Sweden, focused on women with and without mood disorders and their children. Information on pharmacotherapy, mental health, delivery and neonatal complications was retrospectively collected from electronic patient records. Children were tested in a blinded manner at four to five years of age with the Wechsler Preschool and Primary Scale of Intelligence, 3rd edition. Maternal health, child health and social situations were evaluated. RESULTS: Of the 39 children, 20 were exposed to lithium and MMD during pregnancy, eight were exposed to MMD but not lithium and 11 were not exposed to MMD or lithium. The children's full scale intelligence quotient (IQ), performance IQ and verbal IQ results did not differ significantly between the groups. The processing speed quotient was significantly lower in children exposed to mood disorders, but there was a high level of missing data for this subtest. CONCLUSION: This small, clinical cohort showed no significant association between mothers' prenatal exposure to lithium or mood disorders and their offspring's IQ.

The Swedish CArdioPulmonary BioImage Study: objectives and design.

Cardiopulmonary diseases are major causes of death worldwide, but currently recommended strategies for diagnosis and prevention may be outdated because of recent changes in risk factor patterns. The Swedish CArdioPulmonarybioImage Study (SCAPIS) combines the use of new imaging technologies, advances in large-scale 'omics' and epidemiological analyses to extensively characterize a Swedish cohort of 30 000 men and women aged between 50 and 64 years. The information obtained will be used to improve risk prediction of cardiopulmonary diseases and optimize the ability to study disease mechanisms. A comprehensive pilot study in 1111 individuals, which was completed in 2012, demonstrated the feasibility and financial and ethical consequences of SCAPIS. Recruitment to the national, multicentre study has recently started.

Weak associations between human leucocyte antigen genotype and acute myocardial infarction.

OBJECTIVES: Human leucocyte antigens (HLAs) are polymorphic molecules involved in antigen presentation. Associations between HLA type and autoimmune diseases, such as type 1 diabetes and rheumatoid arthritis, are well established but the potential association of genetic variation affecting antigen presentation with cardiovascular disease has not been systematically investigated in large cohorts. The importance of such studies is stressed by recent experimental findings of an involvement of autoimmunity in the atherosclerotic disease process. RESULTS: An SSP-PCR method was used for HLA genotyping to determine associations of HLA-DRB1, -DQA1 and -DQB1 with cardiovascular disease in a population-based cohort of 1188 acute myocardial infarction (AMI) patients and 1191 matched healthy controls. The HLA-DRB1*0101 allele, as well as the HLA-DRB1*0101-DQA1*01-DQB1*05 haplotype, was found to be associated with increased risk for AMI (OR 1.24; 95% CI 1.00-1.54 for both). In contrast, the DRB1*07 and DQA*02 alleles (OR 0.78; 95% CI 0.65-0.95 for both), as well as the DRB1*07-DQA*02-DQB*02 haplotype, conferred protection (OR 0.79; 95% CI 0.63-0.98). An HLA risk score taking each individual's both haplotypes into account was higher amongst cases (2.43 +/- 0.92 vs. 2.29 +/- 0.95, P = 0.001). The association between HLA risk score and AMI was independent of other cardiovascular risk factors assessed. CONCLUSIONS: This study demonstrates that the associations between HLA-DRB1 and DQA1 loci and cardiovascular disease exists but that they are considerably weaker than those previously reported for other diseases with an established autoimmune aetiology such as type 1 diabetes, systemic lupus erythematosus and rheumatoid arthritis.

Linoleic acid, a dietary n-6 polyunsaturated fatty acid, and the aetiology of ulcerative colitis: a nested case-control study within a European prospective cohort study.

OBJECTIVE: Dietary linoleic acid, an n-6 polyunsaturated fatty acid, is metabolised to arachidonic acid, a component of colonocyte membranes. Metabolites of arachidonic acid have pro-inflammatory properties and are increased in the mucosa of patients with ulcerative colitis. The aim of this investigation was to conduct the first prospective cohort study investigating if a high dietary intake of linoleic acid increases the risk of developing incident ulcerative colitis. DESIGN AND SETTING: Dietary data from food frequency questionnaires were available for 203 193 men and women aged 30-74 years, resident in the UK, Sweden, Denmark, Germany or Italy and participating in a prospective cohort study, the European Prospective Investigation into Cancer and Nutrition (EPIC). These participants were followed up for the diagnosis of ulcerative colitis. Each case was matched with four controls and the risk of disease calculated by quartile of intake of linoleic acid adjusted for gender, age, smoking, total energy intake and centre. RESULTS: A total of 126 participants developed ulcerative colitis (47% women) after a median follow-up of 4.0 years (range, 1.7-11.3 years). The highest quartile of intake of linoleic acid was associated with an increased risk of ulcerative colitis (odds ratio (OR) = 2.49, 95% confidence interval (CI) = 1.23 to 5.07, p = 0.01) with a significant trend across quartiles (OR = 1.32 per quartile increase, 95% CI = 1.04 to 1.66, p = 0.02 for trend). CONCLUSIONS: The data support a role for dietary linoleic acid in the aetiology of ulcerative colitis. An estimated 30% of cases could be attributed to having dietary intakes higher than the lowest quartile of linoleic acid intake.

Ability of physical activity measurements to assess health-related risks.

The aim of this study is to evaluate if two different physical activity (PA) questionnaires have similar ability to rank individuals, and to examine associations with cardiovascular-metabolic risk factors, compared to an objective measure. In a random sample (n=369, age: 65+/-6 years) from the population-based 'Malmö Diet and Cancer' (MDC) cohort, PA was measured by a leisure-time comprehensive questionnaire (MDC-score), a simple leisure-time questionnaire and by accelerometer-monitoring (CSA). Moderate correlations were observed between MDC-score and CSA in men and women (r=0.35 and 0.24, respectively). In men, both questionnaires and CSA were inversely associated with waist circumference, insulin resistance and metabolic syndrome. In women, the MDC-score was positively associated with high-density lipoprotein-cholesterol, and the simple questionnaire inversely associated with anthropometric indexes, but no association was seen between PA estimates and cardiovascular components. We conclude that both PA questionnaires distinguish health risks associated with anthropometric-metabolic risk factors, particularly in men.

Quantitative analysis of DNA methylation after whole bisulfitome amplification of a minute amount of DNA from body fluids.

Cell-free circulating DNA isolated from the plasma of individuals with cancer has been shown to harbor cancer-associated changes in DNA methylation, and thus it represents an attractive target for biomarker discovery. However, the reliable detection of DNA methylation changes in body fluids has proven to be technically challenging. Here we describe a novel combination of methods that allows quantitative and sensitive detection of DNA methylation in minute amounts of DNA present in body fluids (quantitative Methylation Analysis of Minute DNA amounts after whole Bisulfitome Amplification, qMAMBA). This method involves genome-wide amplification of bisulphite-modified DNA template followed by quantitative methylation detection using pyrosequencing and allows analysis of multiple genes from a small amount of starting DNA. To validate our method we used qMAMBA assays for four genes and LINE1 repetitive sequences combined with plasma DNA samples as a model system. qMAMBA offered high efficacy in the analysis of methylation levels and patterns in plasma samples with extremely small amounts of DNA and low concentrations of methylated alleles. Therefore, qMAMBA will facilitate methylation studies aiming to discover epigenetic biomarkers, and should prove particularly valuable in profiling a large sample series of body fluids from molecular epidemiology studies as well as in tracking disease in early diagnostics.

Assessing the effect of interaction between an FTO variant (rs9939609) and physical activity on obesity in 15,925 Swedish and 2,511 Finnish adults.

AIMS/HYPOTHESIS: Recent reports have suggested that genotypes at the FTO locus interact with physical activity to modify levels of obesity-related traits. We tested this hypothesis in two non-diabetic population-based cohorts, the first from southern Sweden and the second from the Botnia region of western Finland. METHODS: In total 2,511 Finnish and 15,925 Swedish non-diabetic middle-aged adults were genotyped for the FTO rs9939609 variant. Physical activity was assessed by questionnaires and standard clinical procedures were conducted, including measures of height and weight and glucose regulation. Tests of gene x physical activity interaction were performed using linear interaction effects to determine whether the effect of this variant on BMI is modified by physical activity. RESULTS: The minor A allele at rs9939609 was associated with higher BMI in both cohorts, with the per allele difference in BMI being about 0.13 and 0.43 kg/m(2) in the Swedish and Finnish cohorts, respectively (p < 0.0001). The test of interaction between physical activity and the rs9939609 variant on BMI was not statistically significant after controlling for age and sex in either cohort (Sweden: p = 0.71, Finland: p = 0.18). CONCLUSIONS/INTERPRETATION: The present report does not support the notion that physical activity modifies the effects of the FTO rs9939609 variant on obesity risk in the non-diabetic Swedish or Finnish adults studied here.

Immune responses against fibronectin modified by lipoprotein oxidation and their association with cardiovascular disease.

OBJECTIVES: Accumulation and subsequent oxidation of LDL in the arterial wall are considered as key events in the development of atherosclerosis. We have investigated the possibility that LDL oxidation results in release of aldehydes that modify surrounding matrix proteins and that this may target immune responses against the plaque extracellular matrix and modulate the disease progression. RESULTS: Using custom-made ELISAs we demonstrate that human plasma contains autoantibodies against aldehyde-modified fibronectin (FN) and to a lesser extent also other extracellular matrix proteins including collagen type I, type III, and tenascin-C. Immunohistochemistry and western blot analysis showed that aldehyde-modified FN is present in human atherosclerotic plaques and that aldehydes generated by oxidation of LDL formed adducts with FN in vitro. We also demonstrate that aldehyde-modification of FN results in a loss of its ability to promote basal secretion of cytokines and growth factors from cultured macrophages without affecting the ability of the cells to respond to stimulation with LPS. A prospective clinical study demonstrated that subjects that subsequently developed acute myocardial infarction or sudden cardiac death had lower baseline levels of autoantibodies against aldehyde-modified FN than matched controls. CONCLUSIONS: These observations demonstrate that oxidation of LDL in the arterial wall may lead to aldehyde-modification of surrounding extracellular matrix proteins and that these modifications may affect macrophage function and activate autoimmune responses of pathophysiological importance for the development of atherosclerosis.

Breast feeding, but not use of oral contraceptives, is associated with a reduced risk of rheumatoid arthritis.

OBJECTIVE: To determine whether breast feeding or the use of oral contraceptives (OCs) affects the future risk of rheumatoid arthritis (RA) in a community-based prospective cohort. METHODS: A community-based health survey (18 326 women) was linked to regional and national registers, and incident cases of RA were identified. All women with a diagnosis of RA after inclusion in the health survey (n = 136) and four female controls for every case, who were alive and free from RA when the index person was given a diagnosis of RA, were included in a case-control study. Data on lifestyle factors at baseline were derived from a self-administered questionnaire. Potential predictors were examined in logistic regression models. RESULTS: 136 women with incident RA were compared with 544 age-matched controls. A longer history of breast feeding was associated with a reduced risk of RA (OR 0.46 (95% CI 0.24 to 0.91) for women who had breast fed for >/=13 months and OR 0.74 (95% CI 0.45 to 1.20) for those who had breast fed for 1-12 months, compared with those who had never breast fed). The protective effect of longer breast feeding remained significant after adjustment for smoking and level of education in multivariate models, and point estimates were protective also when the analyses were restricted to parous women. Neither parity nor OC use had any significant effect on the risk of RA. CONCLUSION: In this study, long-term breast feeding, but not OC use, was associated with a significant reduction in the risk of RA.

Health-related quality of life and distress in cancer patients: results from a large randomised study.

To compare the effectiveness of individual support, group rehabilitation and a combination of the two in improving health-related quality of life (HRQOL) and psychological well-being in cancer patients during 24 months after diagnosis, as compared with standard care (SC). Furthermore, to compare the study sample and a random sample of the Swedish population with regard to HRQOL. A total of 481 consecutive patients, newly diagnosed with cancer, were randomly assigned to one of the four alternatives. Data on HRQOL and psychological well-being were collected at baseline and after 3, 6, 12 and 24 months. The interventions did not improve HRQOL or psychological well-being, as compared with SC. At 3 months, the study sample reported an HRQOL comparable with the normal population. Many cancer patients are able to manage their cancer-related concerns with the support available from SC. However, it is reasonable to assume that the findings suffer from a lack of data from especially vulnerable patients and a possible Hawthorne effect. It cannot be concluded that cancer patients have no need for additional psychosocial interventions. Future projects should include screening and target interventions for those at risk for significant and prolonged psychological distress.

The Pro12Ala polymorphism of the PPARG gene is not associated with the metabolic syndrome in an urban population of middle-aged Swedish individuals.

BACKGROUND: To determine if the common Pro12Ala polymorphism (rs1801282) of the peroxisome proliferator-activated receptor (PPARG) gene is associated with the metabolic syndrome (MetS) or with its individual components in middle-aged Swedish individuals. METHODS: MetS was defined according to the National Cholesterol Education Program/Adult Panel III (NCEP/ATP III), the International Diabetes Federation (IDF) and the European Group for the Study of Insulin Resistance (EGIR) criteria in a population-based sample of nearly 5000 subjects participating in the Malmö Diet and Cancer-cardiovascular arm. RESULTS: Of the subjects included in the analysis, 21.8, 29.4 and 20.4% had MetS according to the NCEP/ATP III, IDF and EGIR (only in subjects without diabetes) definitions, respectively. The Pro12Ala was not associated with MetS or with its individual components. These results were similar when patients with diabetes were excluded. Hypertensive and obese ala-carriers had lower fasting glucose and hypertensive ala-carriers also had lower level triglycerides (P < 0.05). CONCLUSIONS: Our data do not support a major role for the Pro12Ala variant of the PPARG gene in MetS and its individual components. The modest difference in triglyceride and glucose levels, restricted to hypertensive and obese subjects in our cohort, suggests that the polymorphism has a minor effect on glucose and lipid metabolism, particularly in individuals at risk for gluco-metabolic disturbances.

The search for putative unifying genetic factors for components of the metabolic syndrome.

AIMS/HYPOTHESIS: The metabolic syndrome is a cluster of factors contributing to increased risk of cardiovascular disease and type 2 diabetes but unifying mechanisms have not been identified. Our aim was to study whether common variations in 17 genes previously associated with type 2 diabetes or components of the metabolic syndrome and variants in nine genes with inconsistent association with at least two components of the metabolic syndrome would also predict future development of components of the metabolic syndrome, individually or in combination. METHODS: Genetic variants were studied in a large prospective study of 16,143 non-diabetic individuals (mean follow-up time 23 years) from the Malmö Preventive Project. In this study, development of at least three of obesity (BMI >or= 30 kg/m(2)), dyslipidaemia (triacylglycerol >or= 1.7 mmol/l and/or lipid-lowering treatment), hypertension (blood pressure >or= 140/90 mmHg and/or antihypertensive medication) and hyperglycaemia (fasting plasma glucose >or= 5.6 mmol/l and/or known diabetes) was defined as development of the metabolic syndrome. The risk of developing at least three components of the metabolic syndrome or the individual components was calculated by logistic regression adjusted for age at baseline, follow-up time and sex. RESULTS: Polymorphisms in TCF7L2 (rs7903146, OR 1.10, 95% CI 1.04-1.17, p = 0.00097), FTO (rs9939609, OR 1.08, 95% CI 1.02-1.14, p = 0.0065), WFS1 (rs10010131, OR 1.07, 95% CI 1.02-1.13, p = 0.0078) and IGF2BP2 (rs4402960, OR 1.07, 95% CI 1.01-1.13, p = 0.021) predicted the development of at least three components of the metabolic syndrome in both univariate and multivariate analysis; in the case of TCF7L2, WFS1 and IGF2BP this was due to their association with hyperglycaemia (p < 0.00001, p = 0.0033 and p = 0.027, respectively) and for FTO it was due to its association with obesity (p = 0.004). A polymorphism in the GCKR gene predicted dyslipidaemia (rs1260326, OR 1.15, 95% CI 1.09-1.22, p < 0.00001) but not the metabolic syndrome. None of the studied polymorphisms was associated with more than two components of the metabolic syndrome. A composite genotype score of the 17 polymorphisms associated with type 2 diabetes predicted the development of at least three components of the metabolic syndrome (OR 1.04, p < 0.00001) and the development of hyperglycaemia (OR 1.06, p < 0.00001). Carriers of >or=19 risk alleles had 51 and 72% increased risk of developing at least three components of the metabolic syndrome and hyperglycaemia, respectively, compared with carriers of

Cytokine gene polymorphisms and the risk of adenocarcinoma of the stomach in the European prospective investigation into cancer and nutrition (EPIC-EURGAST).

BACKGROUND: The relative contribution to gastric cancer (GC) risk of variants in genes that determine the inflammatory response remains mostly unknown and results from genotyping studies are inconsistent. PATIENTS AND METHODS: A nested case-control study within the prospective European Prospective Investigation into Cancer and Nutrition cohort was carried out, including 248 gastric adenocarcinomas and 770 matched controls. Twenty common polymorphisms at cytokine genes [interleukin (IL)1A, IL1B, IL1RN, IL4, IL4R, IL6, IL8, IL10, IL12A, IL12B, lymphotoxin alpha and tumor necrosis factor (TNF)] were analyzed. Antibodies against Helicobacter pylori (Hp) and CagA were measured. RESULTS: IL1RN 2R/2R genotype [odds ratio (OR) 2.43; 95% confidence interval (CI) 1.19-4.96] and allele IL1RN Ex5-35C were associated with an increased risk of Hp(+) non-cardia GC. IL8 -251AA genotype was associated with a decreased risk of Hp(+) non-cardia GC (OR 0.51; 95% CI 0.32-0.81), mainly of the intestinal type. These associations were not modified by CagA status. Carriers of IL1B -580C and TNF -487A alleles did not associate with an increased risk. A moderately increased risk of Hp(+) non-cardia GC for IL4R -29429T variant was observed (OR 1.74; 95% CI 1.15-2.63). CONCLUSION: This prospective study confirms the association of IL1RN polymorphisms with the risk of non-cardia GC and indicates that IL8 -251T>A may modify the risk for GC.

Animal foods, protein, calcium and prostate cancer risk: the European Prospective Investigation into Cancer and Nutrition.

We examined consumption of animal foods, protein and calcium in relation to risk of prostate cancer among 142 251 men in the European Prospective Investigation into Cancer and Nutrition. Associations were examined using Cox regression, stratified by recruitment centre and adjusted for height, weight, education, marital status and energy intake. After an average of 8.7 years of follow-up, there were 2727 incident cases of prostate cancer, of which 1131 were known to be localised and 541 advanced-stage disease. A high intake of dairy protein was associated with an increased risk, with a hazard ratio for the top versus the bottom fifth of intake of 1.22 (95% confidence interval (CI): 1.07-1.41, P(trend)=0.02). After calibration to allow for measurement error, we estimated that a 35-g day(-1) increase in consumption of dairy protein was associated with an increase in the risk of prostate cancer of 32% (95% CI: 1-72%, P(trend)=0.04). Calcium from dairy products was also positively associated with risk, but not calcium from other foods. The results support the hypothesis that a high intake of protein or calcium from dairy products may increase the risk for prostate cancer.

Meat intake and bladder cancer in a prospective study: a role for heterocyclic aromatic amines?

BACKGROUND: The suspect carcinogens, heterocyclic amines (HAAs), found in well-done meat require host-mediated metabolic activation before inducing DNA mutations. The role of SULT1A1 and of NAT2 on the activation of HAAs suggests that NAT2 rapid acetylator genotype and SULT1A1 allele variants can have an effect on HAA carcinogenicity. METHODS: Data were collected as part of a case-control study nested within the EPIC cohort, the Gen Air investigation. EPIC is a prospective study designed to investigate the relationship between nutrition and cancer. Information was collected through a non-dietary questionnaire on lifestyle variables and through a dietary questionnaire. The subjects were restricted to non-smokers. We calculated the matched odds ratio for bladder cancer risk using logistic regression, controlling for potential confounders. RESULTS: There were 227 bladder cases and 612 controls matched 1:3. Meat intake and NAT2 genotype were not independently associated with bladder cancer risk. A significant relationship was observed between bladder cancer risk and consumption of meat only among subjects with the rapid NAT2 genotype (odds ratios [OR] 2.9, 95% CI 1.0-7.9 for the 2nd quartile of meat intake; 3.6, 95% CI 1.3-9.7 for the 3rd quartile; and 3.5, 95% CI 1.2-9.7 for the 4th quartile), and was not present among subjects with the slow genotype. An interaction between NAT2 and meat intake was found in logistic regression (P = 0.034). No association was observed for SULT1A *1/2 genotype (1.0; 95% CI 0.7-1.5) and for SULT1A1 *2/2 genotype (0.9; 95% CI 0.5-1.7). CONCLUSIONS: These results are suggestive of a role of meat intake and NAT2 on bladder cancer risk. They support the hypothesis that among subjects with the rapid NAT2 acetylation genotype higher levels of HAAs exposure are a bladder cancer risk factor. We did not observe an effect of SULT1A1 allele variants on this cancer. The present study adds new information on the possible long-term adverse effects of diets with high meat intake.

Polymorphisms in the gene encoding the voltage-dependent Ca(2+) channel Ca (V)2.3 (CACNA1E) are associated with type 2 diabetes and impaired insulin secretion.

AIMS/HYPOTHESIS: Glucose-stimulated insulin secretion is dependent on the electrical activity of beta cells; hence, genes encoding beta cell ion channels are potential candidate genes for type 2 diabetes. The gene encoding the voltage-dependent Ca(2+) channel Ca(V)2.3 (CACNA1E), telomeric to a region that has shown suggestive linkage to type 2 diabetes (1q21-q25), has been ascribed a role for second-phase insulin secretion. METHODS: Based upon the genotyping of 52 haplotype tagging single nucleotide polymorphisms (SNPs) in a type 2 diabetes case-control sample (n = 1,467), we selected five SNPs that were nominally associated with type 2 diabetes and genotyped them in the following groups (1) a new case-control sample of 6,570 individuals from Sweden; (2) 2,293 individuals from the Botnia prospective cohort; and (3) 935 individuals with insulin secretion data from an IVGTT. RESULTS: The rs679931 TT genotype was associated with (1) an increased risk of type 2 diabetes in the Botnia case-control sample [odds ratio (OR) 1.4, 95% CI 1.0-2.0, p = 0.06] and in the replication sample (OR 1.2, 95% CI 1.0-1.5, p = 0.01 one-tailed), with a combined OR of 1.3 (95% CI 1.1-1.5, p = 0.004 two-tailed); (2) reduced insulin secretion [insulinogenic index at 30 min p = 0.02, disposition index (D (I)) p = 0.03] in control participants during an OGTT; (3) reduced second-phase insulin secretion at 30 min (p = 0.04) and 60 min (p = 0.02) during an IVGTT; and (4) reduced D (I) over time in the Botnia prospective cohort (p = 0.05). CONCLUSIONS/INTERPRETATION: We conclude that genetic variation in the CACNA1E gene contributes to an increased risk of the development of type 2 diabetes by reducing insulin secretion.

Genetic susceptibility according to three metabolic pathways in cancers of the lung and bladder and in myeloid leukemias in nonsmokers.

BACKGROUND: We chose a set of candidate single nucleotide polymorphisms (SNPs) to investigate gene-environment interactions in three types of cancer that have been related to air pollution (lung, bladder and myeloid leukemia). PATIENTS AND METHODS: The study has been conducted as a nested case-control study within the European Prospective Investigation into Cancer and Nutrition cohort (409 cancer cases and 757 matched controls). We included never and ex-smokers. SNPs were in genes involved in oxidative stress, phase I metabolizing genes, phase II metabolizing genes and methylenetetrahydrofolate reductase (MTHFR). RESULTS: The most notable findings are: GSTM1 deletion and bladder cancer risk [odds ratio (OR) = 1.60; 95% confidence interval 1.00-2.56]; CYP1A1 and leukemia (2.22, 1.33-3.70; heterozygotes); CYP1B1 and leukemia (0.47, 0.27-0.84; homozygotes); MnSOD and leukemia (1.91, 1.08-3.38; homozygotes) and NQO1 and lung cancer (8.03, 1.73-37.3; homozygotes). Other statistically significant associations were found in subgroups defined by smoking habits (never or ex-smokers), environmental tobacco smoke or gender, with no obvious pattern. When gene variants were organized according to the three main pathways, the emerging picture was of a strong involvement of combined phase I enzymes in leukemia, with an OR of 5 (1.63-15.4) for those having three or more variant alleles. The association was considerably stronger for leukemias arising before the age of 55.

Association testing of common variants in the insulin receptor substrate-1 gene (IRS1) with type 2 diabetes.

AIMS/HYPOTHESIS: Activation of the insulin receptor substrate-1 (IRS1) is a key initial step in the insulin signalling pathway. Despite several reports of association of the G972R polymorphism in its gene IRS1 with type 2 diabetes, we and others have not observed this association in well-powered samples. However, other nearby variants might account for the putative association signal. SUBJECTS AND METHODS: We characterised the haplotype map of IRS1 and selected 20 markers designed to capture common variations in the region. We genotyped this comprehensive set of markers in several family-based and case-control samples of European descent totalling 12,129 subjects. RESULTS: In an initial sample of 2,235 North American and Polish case-control pairs, the minor allele of the rs934167 polymorphism showed nominal evidence of association with type 2 diabetes (odds ratio [OR] 1.25, 95% CI 1.03-1.51, p = 0.03). This association showed a trend in the same direction in 7,659 Scandinavian samples (OR 1.16, 95% CI 0.96-1.39, p = 0.059). The combined OR was 1.20 (p = 0.008), but statistical correction for the number of variants examined yielded a p value of 0.086. We detected no differences across rs934167 genotypes in insulin-related quantitative traits. CONCLUSIONS/INTERPRETATION: Our data do not support an association of common variants in IRS1 with type 2 diabetes in populations of European descent.

Collaborative meta-analysis of individual participant data from observational studies of Lp-PLA2 and cardiovascular diseases.

BACKGROUND: A large number of observational epidemiological studies have reported generally positive associations between circulating mass and activity levels of lipoprotein-associated phospholipase A2 (Lp-PLA2) and the risk of cardiovascular diseases. Few studies have been large enough to provide reliable estimates in different circumstances, such as in different subgroups (e.g., by age group, sex, or smoking status) or at different Lp-PLA2 levels. Moreover, most published studies have related disease risk only to baseline values of Lp-PLA2 markers (which can lead to substantial underestimation of any risk relationships because of within-person variability over time) and have used different approaches to adjustment for possible confounding factors. OBJECTIVES: By combination of data from individual participants from all relevant observational studies in a systematic 'meta-analysis', with correction for regression dilution (using available data on serial measurements of Lp-PLA2), the Lp-PLA2 Studies Collaboration will aim to characterize more precisely than has previously been possible the strength and shape of the age and sex-specific associations of plasma Lp-PLA2 with coronary heart disease (and, where data are sufficient, with other vascular diseases, such as ischaemic stroke). It will also help to determine to what extent such associations are independent of possible confounding factors and to explore potential sources of heterogeneity among studies, such as those related to assay methods and study design. It is anticipated that the present collaboration will serve as a framework to investigate related questions on Lp-PLA2 and cardiovascular outcomes. METHODS: A central database is being established containing data on circulating Lp-PLA2 values, sex and other potential confounding factors, age at baseline Lp-PLA2 measurement, age at event or at last follow-up, major vascular morbidity and cause-specific mortality. Information about any repeat measurements of Lp-PLA2 and potential confounding factors has been sought to allow adjustment for possible confounding and correction for regression dilution. The analyses will involve age-specific regression models. Synthesis of the available observational studies of Lp-PLA2 will yield information on a total of about 15 000 cardiovascular disease endpoints.

Rosiglitazone and carotid IMT progression rate in a mixed cohort of patients with type 2 diabetes and the insulin resistance syndrome: main results from the Rosiglitazone Atherosclerosis Study.

OBJECTIVE: Insulin resistance is associated with progression of atherosclerosis. We assessed the effect of 12 months of treatment with rosiglitazone (RSG) on the progression of carotid intima-media thickness (IMT) in people with type 2 diabetes mellitus (T2DM) or the insulin resistance syndrome (IRS). DESIGN: Randomized, double-blind, placebo-controlled trial. SETTING: Malmö University Hospital, Malmö, Sweden. SUBJECTS: 555 subjects (200 with T2DM and 355 nondiabetics with IRS according to EGIR criteria), aged 35-80 years. 447 subjects (165 T2DM and 282 IRS) completed the study. INTERVENTION: Participants were allocated to placebo or RSG 4 mg for 2 months and then 8 mg daily. MAIN OUTCOME MEASURE: Change in composite IMT [mean IMT in the common carotid artery (CCA) and maximal IMT in the bulb] was the primary and various other IMT measures were secondary outcome variables. RESULTS: There was no effect of RSG treatment in the mixed population. In T2DM patients there was a reduced progression of the composite IMT (mean change: 0.041 vs. 0.070 mm, P = 0.07), and of the mean IMT CCA (mean change: -0.005 mm vs. 0.021 mm, P = 0.007). RSG treatment led to significant reductions of HOMA-IR, fasting plasma glucose, HbA1c, PAI-1 activity, fibrinogen, C-reactive protein and matrix metalloproteinase-9. CONCLUSIONS: In a mixed study population of patients with T2DM and IRS RSG treatment was not associated with a statistically significant reduction of carotid IMT progression rate. Separate analyses of these two patient groups indicated, however, a significant beneficial effect on CCA IMT in T2DM patients but no similar effect in subjects with IRS.