The Gly82Ser polymorphism in the receptor for advanced glycation endproducts increases the risk for coronary events in the general population.

The receptor for advanced glycation endproducts (RAGE) has pro-inflammatory and pro-atherogenic effects. Low plasma levels of soluble RAGE (sRAGE), a decoy receptor for RAGE ligands, have been associated with increased risk for major adverse coronary events (MACE) in the general population. We performed a genome-wide association study to identify genetic determinants of plasma sRAGE in 4338 individuals from the cardiovascular arm of the Malmö Diet and Cancer study (MDC-CV). Further, we explored the associations between these genetic variants, incident first-time MACE and mortality in 24,640 unrelated individuals of European ancestry from the MDC cohort. The minor alleles of four single nucleotide polymorphisms (SNPs): rs2070600, rs204993, rs116653040, and rs7306778 were independently associated with lower plasma sRAGE. The minor T (vs. C) allele of rs2070600 was associated with increased risk for MACE [HR 1.13 95% CI (1.02-1.25), P = 0.016]. Neither SNP was associated with mortality. This is the largest study to demonstrate a link between a genetic sRAGE determinant and CV risk. Only rs2070600, which enhances RAGE function by inducing a Gly82Ser polymorphism in the ligand-binding domain, was associated with MACE. The lack of associations with incident MACE for the other sRAGE-lowering SNPs suggests that this functional RAGE modification is central for the observed relationship.

Clinical Evaluation of the Polygenetic Background of Blood Pressure in the Population-Based Setting.

The clinical value of the polygenetic component of blood pressure (BP) is commonly questioned. We evaluated a genetic risk score for BP (BP-GRS858), based on the most recently published genome-wide association studies variants that were significantly associated with either systolic BP or diastolic BP, for prediction of hypertension and cardiovascular end points. The genotyping was performed in 2 urban-based prospective cohorts: the Malmö Diet and Cancer (n=29 295) and the Malmö Preventive Project (n=9367) and a weighted BP-GRS858 based on 858 SNPs was calculated. At baseline, we found a difference of 9.0 mm Hg (systolic BP) and 4.8 mm Hg (diastolic BP) between the top and the bottom quartile of BP-GRS858. In Malmö Preventive Project, the top versus bottom quartile of BP-GRS858 was associated with a doubled risk of incident hypertension (odds ratio, 2.05 [95% CI, 1.75-2.39], P=1.4×10-21), a risk higher than that of body mass index, as evaluated in quartiles. In Malmö Diet and Cancer, significant association was found between the age and sex-adjusted BP-GRS858 and the incidence of total cardiovascular events, stroke, coronary artery disease, heart failure, atrial fibrillation, and total mortality. Most of these associations remained significant after adjusting for traditional risk factors, including hypertension. BP-GRS858 could contribute predictive information regarding future hypertension, with an effect size comparable to other well-known risk factors such as obesity, and predicts cardiovascular events. Given that the exposure to high polygenetic risk starts at birth, we suggest that the BP-GRS858 might be useful to identify children or adolescents who would benefit from early hypertension screening and treatment.

Polygenetic risk for coronary artery disease increases hospitalization burden and mortality.

BACKGROUND: Coronary artery disease (CAD) is a leading cause of death worldwide and increasing cost for society. Genome wide association studies (GWAS) have identified common variants associated with CAD. Combining single nucleotide polymorphisms (SNPs) into a genetic risk score (GRS) can estimate an individual's genetic burden. OBJECTIVES: To investigate whether GRS for CAD can predict hospitalization and mortality. METHODS: 23,594 individuals without CAD at baseline and with full data for all covariates from the population based prospective study Malmö diet and cancer study were investigated. The association between hospitalizations was calculated by negative binomial regression and risk of mortality was calculated by Cox proportional hazards regression. The GRS was constructed from 50 SNPs. RESULTS: The study population was divided into quintiles according to the value of GRS. During the mean follow-up time of 17.8 years, 17,254 individuals were hospitalized at least once. Individuals in the highest quintile of GRS were hospitalized 10% more often than individuals in the lowest quintile (IRR: 1.10 [95% CI 1.04-1.16], p = 0.001), mainly for cardiovascular reasons (IRR: 1.31 [95% CI 1.20-1.43], p = 5.17 × 10-10). These individuals had highly increased risk of CVD mortality (HR: 1.44 [1.25-1.66], p = 6.56 × 10-7) but not the risk of mortality due to other causes. CONCLUSION: Our results suggest that genetic predisposition for CAD can predict hospitalization burden and mortality, especially due to cardiovascular causes, independently of traditional risk factors. As the risk conferred by the GRS is partially modifiable, our results may help to reduce societal costs, individual suffering and prolong life.

Genetic vasopressin 1b receptor variance in overweight and diabetes mellitus.

OBJECTIVE: Recently, imbalance in the vasopressin (AVP) system, measured as elevated levels of copeptin (the C-terminal part of the AVP pro-hormone) in plasma, was linked to the development of abdominal obesity and diabetes mellitus (DM). Here, we aim to investigate if the genetic variation of the human AVP receptor 1b gene (AVPR1B) is associated with measures of obesity and DM. DESIGN: Malmö Diet and Cancer study (MDC) is a population-based prospective cohort examined 1991-1996. METHODS: Four tag single nucleotide polymorphisms (SNPs: rs35810727, rs28373064, rs35439639, rs35608965) of AVPR1B were genotyped in the cardiovascular cohort (n=6103) of MDC (MDC-CC) and associated with measures of obesity and DM. Significant SNPs were replicated in another 24 344 MDC individuals (MDC replication cohort). RESULTS: In MDC-CC, the major allele of rs35810727 was associated with elevated BMI (ß-coefficient ± s.e.m.; 0.30 ± 0.14, P=0.03) and waist (0.78 ± 0.36, P=0.03) after age and gender adjustment. The association with BMI was replicated in the MDC replication cohort (0.21 ± 0.07, P=0.003), whereas that with waist was not significant. In MDC-CC there was no association between the major allele of rs35810727 and DM, but in the complete MDC cohort (n=30 447) the major allele of rs35810727 was associated with DM (OR (95% CI); 1.10 (1.00-1.20), P=0.04). CONCLUSIONS: Genetic variance of AVPR1B contributes to overweight. Furthermore, our data indicate a link between AVPR1B variance and DM development. Our data point at a relationship between the disturbance of the pharmacologically modifiable AVP system and the body weight regulation.

A genetic risk score for hypertension associates with the risk of ischemic stroke in a Swedish case-control study.

Genetic risk scores (GRS), summing up the total effect of several single-nucleotide polymorphisms (SNPs) in genes associated with either coronary risk or cardiovascular risk factors, have been tested for association with ischemic stroke with conflicting results. Recently an association was found between a GRS based on 29 SNPs discovered by genome-wide association studies and hypertension. The aim of our study was to investigate the possible association of the same GRS with ischemic stroke on top of other 'traditional risk factors', also testing its potential improvement in indices of discrimination and reclassification, in a Swedish case-control study. Twenty-nine SNPs were genotyped in 3677 stroke cases and 2415 controls included in the Lund Stroke Register (LSR), the Malmö Diet and Cancer (MDC) study and the Sahlgrenska Academy Study on Ischemic Stroke (SAHLSIS). The analysis was conducted in the combined sample, and separately for the three studies. After adjustment for hypertension, diabetes mellitus and smoking habits, the GRS was associated with ischemic stroke in the combined sample (OR (95% CI) 1.086 (1.029-1.147) per SD increase in the GRS P=0.003) with similar trends in all three samples: LSR (1.050 (0.967-1.140); P=0.25), MDC (1.168 (1.060-1.288); P=0.002) and SAHLSIS (1.124 (0.997-1.267); P=0.055). Measures of risk discrimination and reclassification improved marginally using the GRS. A blood pressure GRS is independently associated with ischemic stroke risk in three Swedish case-control studies, however, the effect size is low and adds marginally to prediction of stroke on top of traditional risk factors including hypertension.

Twelve-single nucleotide polymorphism genetic risk score identifies individuals at increased risk for future atrial fibrillation and stroke.

BACKGROUND AND PURPOSE: Atrial fibrillation (AF) is prevalent and there is a clinical need for biomarkers to identify individuals at higher risk for AF. Fixed throughout a life course and assayable early in life, genetic biomarkers may meet this need. Here, we investigate whether multiple single nucleotide polymorphisms together as an AF genetic risk score (AF-GRS) can improve prediction of one's risk for AF. METHODS: In 27 471 participants of the Malmö Diet and Cancer Study, a prospective, community-based cohort, we used Cox models that adjusted for established AF risk factors to assess the association of AF-GRS with incident AF and ischemic stroke. Median follow-up was 14.4 years for incident AF and 14.5 years for ischemic stroke. The AF-GRS comprised 12 single nucleotide polymorphisms that had been previously shown to be associated with AF at genome-wide significance. RESULTS: During follow-up, 2160 participants experienced a first AF event and 1495 had a first ischemic stroke event. Participants in the top AF-GRS quintile were at increased risk for incident AF (hazard ratio, 2.00; 95% confidence interval, 1.73-2.31; P=2.7×10(-21)) and ischemic stroke (hazard ratio, 1.23; 95% confidence interval, 1.04-1.46; P=0.02) when compared with the bottom quintile. Addition of the AF-GRS to established AF risk factors modestly improved both discrimination and reclassification (P<0.0001 for both). CONCLUSIONS: An AF-GRS can identify 20% of individuals who are at ≈2-fold increased risk for incident AF and at 23% increased risk for ischemic stroke. Targeting diagnostic or therapeutic interventions to this subset may prove clinically useful.

Cardiovascular consequences of a polygenetic component of blood pressure in an urban-based longitudinal study: the Malmö diet and cancer.

BACKGROUND: A recently published genome wide association study identified 29 single nucleotide polymorphisms (SNPs) influencing blood pressure (BP). Case-control studies suggest that a genetic risk score (GRS) based on these 29 SNPs affect the risk of cardiovascular disease (CVD), but its role for CVD at population level is unknown. Here, we prospectively evaluate the impact of this polygenetic BP component on CVD morbidity and mortality in a large urban-based middle-aged population. METHOD: The 29 previously BP associated SNPs were genotyped in the Swedish Malmö Diet and Cancer Study; (n = 27,003 with at least 24 valid SNPs). The number of BP elevating alleles of each SNPs, weighted by their effect size in the discovery studies, was summed into a BP-GRS. RESULTS: Using regression models, we found significant associations of the BP-GRS, cross-sectionally, with BP and hypertension prevalence, prospectively, with incident cardiovascular morbidity and mortality during 14.2 ± 3.2 years of follow-up. After adjustment for traditional cardiovascular risk factors (TRF), including hypertension, the BP-GRS remained significantly associated only with CVDs [in terms of strokes and coronary artery disease; hazard ratio 1.15; 95% confidence interval (CI) 1.06-1.24 comparing the third vs. first tertile; P = 0.003]. Calibration, discrimination and reclassification analyses did not show a meaningful increment in prediction using the BP-GRS in addition to the model encompassing only the TRF. CONCLUSION: The polygenetic component of BP influences risk of cardiovascular morbidity and mortality. However, the effect size is small and unlikely to be useful for prediction at the population level.

Association of BTG2, CYR61, ZFP36, and SCD gene polymorphisms with Graves' disease and ophthalmopathy.

BACKGROUND: Environmental and genetic factors predispose an individual to the development of Graves' disease (GD). In an expression study of intraorbital tissue, adipocyte-related immediate early genes (IEGs) and immunomodulatory genes were found to be overexpressed in patients with Graves' ophthalmopathy (GO). We hypothesized that genetic variations in these genes could be associated with GD and/or GO. METHODS: A total of 98 single nucleotide polymorphisms (SNPs) in 12 genes were genotyped in 594 GD patients with (n=267) or without (n=327) GO and 1147 sex- and ethnicity-matched controls from Malmö, Sweden. RESULTS: Ten SNPs in four genes (BTG family, member 2 [BTG2], cysteine-rich, angiogenic inducer 61 [CYR61], zinc finger protein 36, C3H type, homolog mouse [ZFP36], and stearoyl-coenzyme A desaturase [SCD]) showed an association with GD and/or GO. SNPs rs12136280 (odds ratio [OR] 1.29, p=0.002), rs6663606 (OR 1.26, p=0.004), and rs17534202 (OR 1.21, p=0.02) in BTG2 and rs3753793 (OR 1.21, p=0.03) in CYR61 were associated with GD. An association with GO was shown for SNPs rs3753793 (OR 1.45, p=0.008), rs6682848 (OR 1.55, p=0.03), rs12756618 (OR 1.77, p=0.049), and rs1378228 (OR 1.29, p=0.049) in CYR61, rs1057745 (OR 1.56, p=0.03) and rs11083522 (OR 1.32, p=0.04) in ZFP36, and rs1393491 (OR 1.38, p=0,048) in SCD. Smoking and CYR61 rs12756618 interacted to increase the risk of GO. CONCLUSIONS: We found associations of SNPs in IEGs and SCD with GD and/or GO; however, confirmation in a different population is required.

Smoking modifies the associated increased risk of future cardiovascular disease by genetic variation on chromosome 9p21.

AIMS: Genetic predisposition for cardiovascular disease (CVD) is likely to be modified by environmental exposures. We tested if the associated risk of CVD and CVD-mortality by the single nucleotide polymorphism rs4977574 on chromosome 9p21 is modified by life-style factors. METHODS AND RESULTS: A total of 24,944 middle-aged subjects (62% females) from the population-based Malmö-Diet-and-Cancer-Cohort were genotyped. Smoking, education and physical activity-levels were recorded. Subjects were followed for 15 years for incidence of coronary artery disease (CAD; N = 2309), ischemic stroke (N = 1253) and CVD-mortality (N = 1156). Multiplicative interactions between rs4977574 and life-style factors on endpoints were tested in Cox-regression-models. We observed an interaction between rs4977574 and smoking on incident CAD (P = 0.035) and CVD-mortality (P = 0.012). The hazard ratios (HR) per risk allele of rs4977574 were highest in never smokers (N = 9642) for CAD (HR = 1.26; 95% CI 1.13-1.40; P<0.001) and for CVD-mortality (HR = 1.40; 95% CI 1.20-1.63; P<0.001), whereas the risk increase by rs4977574 was attenuated in current smokers (N = 7000) for both CAD (HR = 1.05; 95%CI 0.95-1.16; P = 0.326) and CVD-mortality (HR = 1.08; 95%CI 0.94-1.23; P = 0.270). A meta-analysis supported the finding that the associated increased risk of CAD by the risk-allele was attenuated in smokers. Neither education nor physical activity-levels modified the associated risk of CAD, ischemic stroke and CVD mortality conferred by rs4977574. CONCLUSION: Smoking may modify the associated risk of CAD and CVD-mortality conferred by genetic variation on chromosome 9p21. Whether the observed attenuation of the genetic risk reflects a pathophysiological mechanism or is a result of smoking being such a strong risk-factor that it may eliminate the associated genetic effect, requires further investigation.

Genetic variation in NEDD4L, an epithelial sodium channel regulator, is associated with cardiovascular disease and cardiovascular death.

OBJECTIVES: We have previously shown that genetic variance in NEDD4L, a regulating protein of a sodium channel in the distal nephron, has been associated with marginally higher blood pressure and enhanced salt sensitivity. Here, we tested if the genetic NEDD4L variation previously associated with salt sensitivity is related to population blood pressure, incidence of cardiovascular disease (CVD) and mortality. METHOD: We genotyped the rs4149601 A→G and rs2288774 T→C NEDD4L variants in 27,564 participants of the Malmö Diet and Cancer Study. The genotype combination previously shown to be associated with salt sensitivity (rs4149601 GG+rs2288774 CC), which was present in 9.6% of participants, was related to cross sectional blood pressure as well as to CVD incidence and mortality during a median follow-up time of 14 years using Cox regression models. RESULTS: Carriers of the NEDD4L salt sensitivity-associated genotype had (mean ± SEM) higher systolic (142 ± 0.4 vs. 141 ± 0.1 mmHg, P = 0.002) and diastolic (86.0 ± 0.5 vs. 85.6 ± 0.2 mmHg, P = 0.025) blood pressure and multivariate adjusted hazards ratio (95% confidence interval) of CVD 1.13 (1.02-1.25, P = 0.018), coronary events 1.20 (1.06-1.37; P = 0.005) and cardiovascular mortality 1.17 (0.99-1.37; P = 0.055) than noncarriers but there was no significant difference in the incidence of stroke and total mortality. CONCLUSION: The NEDD4L salt sensitivity-associated genotype was associated with higher blood pressure, which may translate into increased risk for CVD morbidity and mortality. Interestingly, there was no association with stroke suggesting that the association is partially blood pressure independent.

Smoking and obesity associated BDNF gene variance predicts total and cardiovascular mortality in smokers.

OBJECTIVE: The brain derived neurotrophic factor (BDNF) locus has been implicated in psychiatric and substance related disorders. Recent genome-wide association studies (GWAS) have shown strong associations between single nucleotide polymorphisms in BDNF, smoking behaviour and high body mass index (BMI). Our aim was to test whether genetic BDNF variation alters the risk of smoking related morbidity and mortality. DESIGN: Cox proportional hazards models were used to relate the BDNF rs4923461(A/G) polymorphisms to all-cause, cancer and cardiovascular mortality and cardiovascular disease (CVD) incidence adjusted for age, sex, BMI, and smoking quantity. SETTING: The Malmö Diet and Cancer Study (MDCS), a population based prospective cohort study (n=30 447). PATIENTS: We obtained complete data on 25 071 subjects, of whom 6507 were current smokers and 18 564 were non-smokers who underwent a baseline examination from 1991-1996. MAIN OUTCOME MEASURES: During a mean follow-up time of 12 years, 1049 deaths (346 cardiovascular deaths and 492 cancer deaths) and 802 incident CVD events occurred among current smokers. RESULTS: The major allele (A) of rs4923461 was significantly associated with ever having smoked (p=0.03) and high BMI (p=0.001). The A-allele was associated with risk of all-cause (HR=1.12, 95% CI 1.00 to 1.25; p<0.05) and CVD (HR=1.23, 95% CI 1.01 to 1.49; p=0.04) mortality. There was no significant association between the rs4923461 and cancer mortality or CVD incidence. CONCLUSIONS: Our data suggest that smoking- and obesity-associated variation of the BDNF gene affects the risk of death, especially due to cardiovascular causes, in smokers. Determination of the BDNF genotype in smokers may guide the need for smoking cessation interventions.

Genetic associations with valvular calcification and aortic stenosis.

BACKGROUND: Limited information is available regarding genetic contributions to valvular calcification, which is an important precursor of clinical valve disease. METHODS: We determined genomewide associations with the presence of aortic-valve calcification (among 6942 participants) and mitral annular calcification (among 3795 participants), as detected by computed tomographic (CT) scanning; the study population for this analysis included persons of white European ancestry from three cohorts participating in the Cohorts for Heart and Aging Research in Genomic Epidemiology consortium (discovery population). Findings were replicated in independent cohorts of persons with either CT-detected valvular calcification or clinical aortic stenosis. RESULTS: One SNP in the lipoprotein(a) (LPA) locus (rs10455872) reached genomewide significance for the presence of aortic-valve calcification (odds ratio per allele, 2.05; P=9.0×10(-10)), a finding that was replicated in additional white European, African-American, and Hispanic-American cohorts (P<0.05 for all comparisons). Genetically determined Lp(a) levels, as predicted by LPA genotype, were also associated with aortic-valve calcification, supporting a causal role for Lp(a). In prospective analyses, LPA genotype was associated with incident aortic stenosis (hazard ratio per allele, 1.68; 95% confidence interval [CI], 1.32 to 2.15) and aortic-valve replacement (hazard ratio, 1.54; 95% CI, 1.05 to 2.27) in a large Swedish cohort; the association with incident aortic stenosis was also replicated in an independent Danish cohort. Two SNPs (rs17659543 and rs13415097) near the proinflammatory gene IL1F9 achieved genomewide significance for mitral annular calcification (P=1.5×10(-8) and P=1.8×10(-8), respectively), but the findings were not replicated consistently. CONCLUSIONS: Genetic variation in the LPA locus, mediated by Lp(a) levels, is associated with aortic-valve calcification across multiple ethnic groups and with incident clinical aortic stenosis. (Funded by the National Heart, Lung, and Blood Institute and others.).

Genetic polymorphisms confer risk of atrial fibrillation in patients with heart failure: a population-based study.

AIMS: Atrial fibrillation (AF) is a frequent co-morbidity in heart failure (HF) associated with increased mortality, but little is known about the mechanisms underlying AF onset in HF patients. We evaluated the association of cardiovascular and genetic risk factors with AF in HF patients. METHODS AND RESULTS: Individuals hospitalized for HF (n = 1040; 500 with AF) were identified from a large, population-based cohort study (n = 30 447; 2339 with AF). Genetic polymorphisms in the chromosomal regions 4q25 (rs2200733) and 16q22 (rs2106261) associated with AF in genome-wide association studies were genotyped. Association of cardiovascular risk factors and polymorphisms with AF was tested in HF patients and the entire cohort using both prospective and non-time-dependent models. Cardiovascular risk factors-hypertension, body mass index, sex, smoking, diabetes, and myocardial infarction-were associated with AF in the entire cohort but not in HF patients. In contrast, polymorphisms on chromosomes 16q22 and 4q25 were associated with AF both in the entire cohort and in HF patients, conferring 75% [95% confidence interval (CI) 35-126, P = 2 × 10(-5)] and 57% (95% CI 18-109, P = 0.002) increased risk of AF per copy in HF patients, respectively. In the entire cohort, AF risk in the presence of HF was multiplicatively magnified by genotype for 16q22 (P for interaction = 7 × 10(-4)) but not 4q25 (P = 0.83). In prospective analyses excluding patients with AF diagnosis prior to or simultaneously with HF diagnosis, 16q22 but not 4q25 remained robustly associated with AF (hazard ratio 1.96, 95% CI 1.40-2.73, P = 8 × 10(-5)). The proportion of AF diagnoses in HF patients attributable to polymorphisms was 19% and 12%, respectively. CONCLUSIONS: A polymorphism in the ZFHX3 gene, encoding a cardiac transcription factor, was associated with increased AF risk in HF patients, and the genetic association with AF was more pronounced in HF patients than in the general population.

The Renalase Asp37Glu polymorphism is not associated with hypertension and cardiovascular events in an urban-based prospective cohort: the Malmö Diet and cancer study.

BACKGROUND: Renalase (gene name RNLS), a recently discovered enzyme with monoamine oxidase activity, is implicated in the degradation of catecholamines. Recent studies delineate a possible role of this enzyme in blood pressure (BP) maintenance and cardiac protection and two single nucleotide polymorphisms, RNLS rs2576178 A > G and rs2296545 C > G have been associated with hypertension. The latter SNP leads to a non synonymous Asp to Glu substitution deleting a flavin adenine dinucleotide (FAD) binding site with possible impaired functionality. We tested the hypothesis that these polymorphisms could affect BP levels, hypertension prevalence, and risk of incident cardiovascular events in middle-aged Swedes. METHODS: The polymorphisms were genotyped in 5696 participants of the population-based Cardiovascular Cohort of the "Malmö Diet and Cancer" (MDC-CC). The incidence of cardiovascular events (coronary events [n = 408], strokes [n = 330], heart failure [n = 190] and atrial fibrillation/flutter [n = 406]) was monitored for an average of approximately 15 years of follow-up. RESULTS: Both before and after adjustment for sex, age and BMI the polymorphisms did not show any effect on BP level and hypertension prevalence. Before and after adjustment for major cardiovascular risk factors, the hazard ratio for cardiac and cerebrovascular events was not significantly different in carriers of different genotypes. A significant interaction was found between the rs2296545 C > G and age with respect to BP/hypertension. CONCLUSIONS: Our data do not support a major role for these RNLS polymorphisms in determining BP level and incident events at population level. The positive interaction with age suggest that the effect of the rs2296545 C > G polymorphism, if any, could vary between different ages.

Genetic variation within the interleukin-1 gene cluster and ischemic stroke.

BACKGROUND AND PURPOSE: Evidence is emerging that inflammation plays a key role in the pathophysiology of ischemic stroke (IS). The aim of this study was to investigate whether genetic variation in the interleukin-1α, interleukin-1ß, and interleukin-1 receptor antagonist genes (IL1A, IL1B, and IL1RN) is associated with IS and/or any etiologic subtype of IS. METHODS: Twelve tagSNPs were analyzed in the Sahlgrenska Academy Study on Ischemic Stroke (SAHLSIS), which comprises 844 patients with IS and 668 control subjects. IS subtypes were defined according to the Trial of Org 10172 in Acute Stroke Treatment criteria in SAHLSIS. The Lund Stroke Register and the Malmö Diet and Cancer study were used as a replication sample for overall IS (in total 3145 patients and 1793 control subjects). RESULTS: The single nucleotide polymorphism rs380092 in IL1RN showed an association with overall IS in SAHLSIS (OR, 1.21; 95% CI, 1.02-1.43; P=0.03), which was replicated in the Lund Stroke Register and the Malmö Diet and Cancer study sample. An association was also detected in all samples combined (OR, 1.12; 95% CI, 1.04-1.21; P=0.03). Three single nucleotide polymorphisms in IL1RN (including rs380092) were nominally associated with the subtype of cryptogenic stroke in SAHLSIS, but the statistical significance did not remain after correction for multiple testing. Furthermore, increased plasma levels of interleukin-1 receptor antagonist were observed in the subtype of cryptogenic stroke compared with controls. CONCLUSIONS: This comprehensive study, based on a tagSNP approach and replication, presents support for the role of IL1RN in overall IS.

The functional variant V433M of the CYP4F2 and the metabolic syndrome in Swedes.

BACKGROUND AND AIM: The genetic basis of Metabolic syndrome (MetS) is largely unknown but a link with salt sensitivity is recognized. The cytochrome P450 isoform 4F2 (CYP4F2) is involved in renal production of 20-hydroxyeicosatethraenoic acid (20-HETE), a natriuretic substance associated with salt sensitivity. The same enzyme is implicated in ω-hydroxylation of very long and medium chain fatty acids in the liver suggesting its possible influence on gluco-metabolic components of MetS. The aim of the present study was to evaluate the effect of CYP4F2 V433M, a functional polymorphism previously associated with hypertension via renal salt reabsorption, on the individual components of MetS and MetS itself. METHODS: The polymorphism was genotyped in the cardiovascular cohort of the Malmö Diet and Cancer (MDC-CVA) study and successively in the Malmö Preventive Project (MPP) cohort. Different definitions of the MetS were applied. RESULTS: In the MDC-CVA, male, but not female, CYP4F2 M433 carriers had significantly higher levels of waist, triglycerides, BP and a composite sum of MetS phenotypes (MetS score) beside lower HDL-cholesterol respect to V-homozygotes. MetS, as defined in the ATPIII and the AHA/NHLBI definitions, was more prevalent in M-carriers with respect to V-homozygotes. In the MPP cohort, significant association was detectable only for triglycerides at baseline and for Diastolic BP at reinvestigation in male M-carriers. CONCLUSION: The initial positive association of the CYP4F2 V433M polymorphism with components of MetS and MetS itself, found in MDC-CVA, was partially denied in another large cohort. The first association either could be due to a false positive result or alternatively, different genetic background or population stratification could have hidden the effect of the polymorphism in the replication cohort.

A large-sample assessment of possible association between ischaemic stroke and rs12188950 in the PDE4D gene.

Previous reports have shown ambiguous findings regarding the possible associations between ischaemic stroke (IS) and single nucleotide polymorphisms (SNPs) in the phosphodiesterase 4D (PDE4D) gene region. The SNP rs12188950 (or SNP45) has often been studied in this context. We performed a multi-centre study involving a large sample of 2599 IS patients and 2093 control subjects from the south and west regions of Sweden to replicate previous studies regarding IS risk and rs12188950. Subjects from Lund Stroke Register (LSR), Malmö Diet and Cancer Study (MDC) and Sahlgrenska Academy Study on Ischemic Stroke (SAHLSIS) were enroled. Subgroups of participants with hypertension and participants <55 years of age, as well as the TOAST subgroups large vessel disease, small vessel disease and cardioembolism, were also assessed. Univariate odds ratios (ORs) and ORs controlling for hypertension, diabetes and current smoking were calculated. We additionally performed a meta-analysis including 10,500 patients and 10,102 control subjects from 17 publications (including the present study). When assessing pooled data from LSR, MDC and SAHLSIS we obtained no association between IS and rs12188950 for all participants (OR=0.93; 95% confidence interval (CI): 0.83-1.05). Significant associations were not found for hypertensive participants or participants with age <55, or when separately evaluating patients from the three different TOAST subgroups. The meta-analysis showed no significant overall estimate (OR=0.96; 95% CI: 0.89-1.04) with significant heterogeneity for random effect (P=0.042). No effect from rs12188950 on IS was found from either our pooled multi-centre data or the performed meta-analysis. We did not find any association between the examined subgroups and rs12188950 either.

A variant upstream of the CDH13 adiponectin receptor gene and metabolic syndrome in Swedes.

Metabolic syndrome (MetS) constitutes a worldwide epidemic burst accounting for billions of cardiovascular disease events and deaths. The genetic basis of MetS is largely unknown. The rs11646213 T → A polymorphism maps at 16q23.3 upstream of the CDH13 gene codifying for cadherin-13 (also known as T-cadherin or H-cadherin), which is considered a vascular adiponectin receptor. This and other single-nucleotide polymorphisms have been associated with hypertension and adiponectin level in separate studies. The aim of the present study was to evaluate the effect of the CDH13 rs11646213 T → A polymorphism on individual components of MetS and on MetS. The polymorphism was genotyped in the cardiovascular cohort of the Malmö Diet and Cancer Study (n = 4,942) and successively in the Malmö Preventive Project (n = 17,675) cohort at baseline and after an average of 23 years of follow-up (reinvestigation). Four different definitions of MetS were applied to these cohorts. In the cardiovascular arm, CDH13 rs11646213 AA homozygotic women showed a trend toward higher triglycerides and lower high-density lipoprotein cholesterol and presented a higher MetS score (composite sum of MetS phenotypes). MetS (Adult Treatment Panel III definition) was more prevalent in AA homozygotic women compared to T-carriers, a result confirmed in the Malmö Preventive Project cohort at baseline and at reinvestigation with an increased risk from 19% to 45% in AA homozygotic women. In conclusion, the CDH13 rs11646213 T > A polymorphism was consistently associated with MetS in Swedish women recruited in 2 large cohorts. In light of the role of cadherin-13 as a vascular receptor for adiponectin, our study supports the genetic basis for the role of adiponectin in MetS pathogenesis.

Serine/threonine kinase 39 is a candidate gene for primary hypertension especially in women: results from two cohort studies in Swedes.

BACKGROUND: As recently pinpointed by a genome-wide association study the serine/threonine kinase 39 (STK39) is a candidate gene for hypertension. This kinase is strongly implicated in sodium reabsorption by the kidney through its modulating effect on furosemide-sensitive and thiazide-sensitive channels. The aim of our study was to test the effects of the STK39 rs35929607A>G polymorphism on blood pressure (BP) levels and the prevalence and incidence of hypertension in middle-aged Swedes participating in two urban-based surveys in Malmö (Sweden). METHODS: The rs35929607A>G polymorphism was genotyped in 5634 participants included in the cardiovascular cohort of the 'Malmö Diet and Cancer-cardiovascular arm' (MDC-CVA) study and successively in 17 894 participants of the 'Malmö Preventive Project' (MPP) both at baseline and at reinvestigation after a mean of 23 years. The effect of the same single nucleotide polymorphism on salt sensitivity was tested in 39 participants of the Salt Reduction to Avoid Hypertension study. RESULTS: Both before and after adjustment for covariates, the functional rs35929607A>G polymorphism was associated with higher SBP and DBP values in the MDC-CVA, but not in the MPP. In both surveys, the polymorphism was associated with hypertension prevalence; after adjustment using the autosomal-dominant model, the odds ratio for hypertension ranged between 1.077 (MPP at baseline) and 1.151 (MDC-CVA) with P-value less than 0.05. After stratification for sex, the results remained statistically significant in women, but not in men. Carriers of the G-allele displayed an increase in salt sensitivity. CONCLUSION: Our results from two large cohort studies support previous evidence about the association of the STK39 rs35929607A>G variant with hypertension, especially in women. If further confirmed in successive studies, owing to its pivotal role in sodium reabsorption at the renal tubule level, STK39 might prove to be a suitable target for antihypertensive therapy. The greater effect of the STK39 rs35929607A>G polymorphism in women with respect to men deserves further investigation.

Genome-wide association study of blood pressure extremes identifies variant near UMOD associated with hypertension.

Hypertension is a heritable and major contributor to the global burden of disease. The sum of rare and common genetic variants robustly identified so far explain only 1%-2% of the population variation in BP and hypertension. This suggests the existence of more undiscovered common variants. We conducted a genome-wide association study in 1,621 hypertensive cases and 1,699 controls and follow-up validation analyses in 19,845 cases and 16,541 controls using an extreme case-control design. We identified a locus on chromosome 16 in the 5' region of Uromodulin (UMOD; rs13333226, combined P value of 3.6 × 10⁻¹¹). The minor G allele is associated with a lower risk of hypertension (OR [95%CI]: 0.87 [0.84-0.91]), reduced urinary uromodulin excretion, better renal function; and each copy of the G allele is associated with a 7.7% reduction in risk of CVD events after adjusting for age, sex, BMI, and smoking status (H.R. = 0.923, 95% CI 0.860-0.991; p = 0.027). In a subset of 13,446 individuals with estimated glomerular filtration rate (eGFR) measurements, we show that rs13333226 is independently associated with hypertension (unadjusted for eGFR: 0.89 [0.83-0.96], p = 0.004; after eGFR adjustment: 0.89 [0.83-0.96], p = 0.003). In clinical functional studies, we also consistently show the minor G allele is associated with lower urinary uromodulin excretion. The exclusive expression of uromodulin in the thick portion of the ascending limb of Henle suggests a putative role of this variant in hypertension through an effect on sodium homeostasis. The newly discovered UMOD locus for hypertension has the potential to give new insights into the role of uromodulin in BP regulation and to identify novel drugable targets for reducing cardiovascular risk.