Genome-wide association studies have identified variants associated with obesity-related traits, such as the body mass index (BMI). We sought to determine how the combination of 31 validated, BMI-associated loci contributes to obesity- and diabetes-related traits in a French population sample. The MONA LISA Lille study (1578 participants, aged 35–74) constitutes a representative sample of the population living in Lille (northern France). Genetic variants were considered both individually and combined into a genetic predisposition score (GPS).
Individually, 25 of 31 SNPs showed directionally consistent effects on BMI. Four loci (FTO, FANCL, MTIF3 and NUDT3) reached nominal significance (p ≤ 0.05) for their association with anthropometric traits. When considering the combined effect of the 31 SNPs, each additional risk allele of the GPS was significantly associated with an increment in the mean [95% CI] BMI of 0.13 [0.07-0.20] kg/m2 (p = 6.3x10-5) and a 3% increase in the risk of obesity (p = 0.047). The GPS explained 1% of the variance in the BMI. Furthermore, the GPS was associated with higher fasting glycaemia (p = 0.04), insulinaemia (p = 0.008), HbA1c levels (p = 0.01) and HOMA-IR scores (p = 0.0003) and a greater risk of type 2 diabetes (OR [95% CI] = 1.06 [1.00-1.11], p = 0.03). However, these associations were no longer statistically significant after adjustment for BMI.
Our results show that the GPS was associated with a higher BMI and an insulin-resistant state (mediated by BMI) in a population in northern France.
Genetic predisposition score; Polymorphism; BMI; Obesity; General population
Genome-wide association studies have shown that the rs340874 single nucleotide polymorphism (SNP) in PROX1 is a genetic susceptibility factor for type 2 diabetes. We conducted genetic and molecular studies to better understand the role of PROX1 in type 2 diabetes. We assessed the impact of the whole common genetic variability of PROX1 (80 SNPs) on type 2 diabetes–related biochemical traits in the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study (n = 1,155). Three SNPs (rs340838, rs340837, and rs340836) were significantly associated with fasting plasma insulin levels (P ≤ 0.00295). We evaluated the impact of nine PROX1 SNPs (the three insulin-associated SNPs plus six SNPs in strong linkage disequilibrium) on luciferase reporter gene expression. The insulin-lowering alleles of rs340874, rs340873, and rs340835 were associated with lower luciferase activity in MIN6 and HepG2 cells (except for rs340874, which was in HepG2 cells only). Electrophoretic mobility shift assays indicated that specific nuclear protein bindings occur at the three SNPs in HepG2 cells, with allele-binding differences for rs340874. We also showed that the knockdown of Prox1 expression by small interfering RNAs in INS-1E cells resulted in a 1.7-fold reduction in glucose-stimulated insulin secretion. All together, we propose that reduced expression of PROX1 by cis-regulatory variants results in altered β-cell insulin secretion and thereby confers susceptibility to type 2 diabetes.
Guidelines for management of patients with type 2 diabetes mellitus recommend the use of hypoglycaemic drugs when lifestyle interventions remain insufficient for glycaemic control. Recent trials have provided worrying safety data on certain hypoglycaemic drugs. The aim of this study was to assess 14-year risk of all-cause mortality according to hypoglycaemic drug exposure at baseline, in a general population.
Our analysis was based on the observational Third French MONICA survey on cardiovascular risk factors (1995–1997). Vital status was obtained 14 years after inclusion, and assessment of determinants of mortality was based on multivariable Cox modelling.
There were 3336 participants and 248 deaths over the 14-year period. At baseline, there were 3162 (95%) non-diabetic, 46 (1%) untreated type 2 diabetic and 128 (4%) type 2 diabetic subjects with hypoglycaemic drug treatment (metformin alone (31%), sulfonylureas alone or in combination (49%), insulin alone or in combination (10%), or other treatments (9%)). After adjustment for duration of diabetes, history of diabetes complications, area of residence (centre), age, gender, educational level, alcohol consumption, smoking, blood pressure, LDL and HDL cholesterol, which all were significant and independent determinants of mortality, the hazard ratio for all-cause mortality was 3.22 [95% confidence interval: 0.87–11.9] for untreated diabetic subjects, 2.28 [0.98–5.26] for diabetics treated with metformin alone, 1.70 [0.92–3.16] for diabetics with sulfonylureas and 4.92 [1.70–14.3] for diabetic with insulin versus non-diabetic subjects.
Our results support the conclusion that until more evidence is provided from randomized trials, a prudent approach should be to restrain use of insulin to situations in which combinations of non-insulin agents have failed to appropriately achieve glycemic control, as it is recommended in the current guidelines for the management of type 2 diabetes.
Elevated C-reactive protein (CRP) levels are associated with high cardiovascular risk, and might identify patients who could benefit from more carefully adapted risk factor management. We have assessed the prevalence of elevated CRP levels in patients with one or more traditional cardiovascular risk factors.
Data were analysed from the European Study on Cardiovascular Risk Prevention and Management in Usual Daily Practice (EURIKA, ClinicalTrials.gov Identifier: NCT00882336), which included patients (aged ≥50 years) from 12 European countries with at least one traditional cardiovascular risk factor but no history of cardiovascular disease. Analysis was also carried out on the subset of patients without diabetes mellitus who were not receiving statin therapy.
In the overall population, CRP levels were positively correlated with body mass index and glycated haemoglobin levels, and were negatively correlated with high-density lipoprotein cholesterol levels. CRP levels were also higher in women, those at higher traditionally estimated cardiovascular risk and those with greater numbers of metabolic syndrome markers. Among patients without diabetes mellitus who were not receiving statin therapy, approximately 30% had CRP levels ≥3 mg/L, and approximately 50% had CRP levels ≥2 mg/L, including those at intermediate levels of traditionally estimated cardiovascular risk.
CRP levels are elevated in a large proportion of patients with at least one cardiovascular risk factor, without diabetes mellitus who are not receiving statin therapy, suggesting a higher level of cardiovascular risk than predicted according to conventional risk estimation systems.
ClinicalTrials.gov Identifier: NCT00882336
C-reactive protein; Cardiovascular disease; Epidemiology; Risk factors/global assessment
Birth weight within the normal range is associated with a variety of adult-onset diseases, but the mechanisms behind these associations are poorly understood1. Previous genome-wide association studies identified a variant in the ADCY5 gene associated both with birth weight and type 2 diabetes, and a second variant, near CCNL1, with no obvious link to adult traits2. In an expanded genome-wide association meta-analysis and follow-up study (up to 69,308 individuals of European descent from 43 studies), we have now extended the number of genome-wide significant loci to seven, accounting for a similar proportion of variance to maternal smoking. Five of the loci are known to be associated with other phenotypes: ADCY5 and CDKAL1 with type 2 diabetes; ADRB1 with adult blood pressure; and HMGA2 and LCORL with adult height. Our findings highlight genetic links between fetal growth and postnatal growth and metabolism.
Multiple genetic variants have been associated with adult obesity and a few with severe obesity in childhood; however, less progress has been made to establish genetic influences on common early-onset obesity. We performed a North American-Australian-European collaborative meta-analysis of fourteen studies consisting of 5,530 cases (≥95th percentile of body mass index (BMI)) and 8,318 controls (<50th percentile of BMI) of European ancestry. Taking forward the eight novel signals yielding association with P < 5×10−6 in to nine independent datasets (n = 2,818 cases and 4,083 controls) we observed two loci that yielded a genome wide significant combined P-value, namely near OLFM4 on 13q14 (rs9568856; P=1.82×10−9; OR=1.22) and within HOXB5 on 17q21 (rs9299; P=3.54×10−9; OR=1.14). Both loci continued to show association when including two extreme childhood obesity cohorts (n = 2,214 cases and 2,674 controls). Finally, these two loci yielded directionally consistent associations in the GIANT meta-analysis of adult BMI1.
Participation rate and response rate are key issues in a cross sectional large-scale epidemiological study. The objective of this paper is to describe the study population and to evaluate participation and response rate as well as the key nutritional status variables in male and female adolescents involved in the HELENA study.
A multi-stage random cluster sampling with a target sample of 3000 adolescents aged [12.5 to 17.5] years, stratified for geographical location and age, was carried out. Information for participants and non-participants (NP) was compared, and participation and response rates to specific questionnaires were discussed.
3,865 adolescents aged [12.5 to 17.5] years (1,845 females) participated in the HELENA study, of whom 1,076 (568 females) participated in the blood sampling. 3,528 (1,845 females) adolescents were finally kept for statistical analysis. Participation rates for the schools and classes differed importantly between countries. The participation rate of pupils within the participating classes also differed importantly between countries. Sex ratio, mean age and BMI were similar between NP and participating adolescents within each centre, and in the overall sample. For all the questionnaires included in the database, the response rate of questionnaires was high (more than 80% of questions were completed).
From this study it could be concluded that participation rate differed importantly between countries, though no bias could be identified when comparing the key study variables between participants and non-participants. Response rate for questionnaires was very high. Future studies investigating lifestyle and health in adolescents can optimize their methods when considering the opportunities and barriers observed in the HELENA study.
Physicians involved in primary prevention are key players in CVD risk control strategies, but the expected reduction in CVD risk that would be obtained if all patients attending primary care had their risk factors controlled according to current guidelines is unknown. The objective of this study was to estimate the excess risk attributable, firstly, to the presence of CVD risk factors and, secondly, to the lack of control of these risk factors in primary prevention care across Europe.
Cross-sectional study using data from the European Study on Cardiovascular Risk Prevention and Management in Daily Practice (EURIKA), which involved primary care and outpatient clinics involved in primary prevention from 12 European countries between May 2009 and January 2010. We enrolled 7,434 patients over 50 years old with at least one cardiovascular risk factor but without CVD and calculated their 10-year risk of CVD death according to the SCORE equation, modified to take diabetes risk into account.
The average 10-year risk of CVD death in study participants (N = 7,434) was 8.2%. Hypertension, hyperlipidemia, smoking, and diabetes were responsible for 32.7 (95% confidence interval 32.0-33.4), 15.1 (14.8-15.4), 10.4 (9.9-11.0), and 16.4% (15.6-17.2) of CVD risk, respectively. The four risk factors accounted for 57.7% (57.0-58.4) of CVD risk, representing a 10-year excess risk of CVD death of 5.66% (5.47-5.85). Lack of control of hypertension, hyperlipidemia, smoking, and diabetes were responsible for 8.8 (8.3-9.3), 10.6 (10.3-10.9), 10.4 (9.9-11.0), and 3.1% (2.8-3.4) of CVD risk, respectively. Lack of control of the four risk factors accounted for 29.2% (28.5-29.8) of CVD risk, representing a 10-year excess risk of CVD death of 3.12% (2.97-3.27).
Lack of control of CVD risk factors was responsible for almost 30% of the risk of CVD death among patients participating in the EURIKA Study.
cardiovascular disease; mortality; risk factors; control; SCORE
Evidence suggests possible synergetic effects of multiple lifestyle behaviors on health risks like obesity and other health outcomes. A better insight in the clustering of those behaviors, could help to identify groups who are at risk in developing chronic diseases. This study examines the prevalence and clustering of physical activity, sedentary and dietary patterns among European adolescents and investigates if the identified clusters could be characterized by socio-demographic factors.
The study comprised a total of 2084 adolescents (45.6% male), from eight European cities participating in the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study. Physical activity and sedentary behavior were measured using self-reported questionnaires and diet quality was assessed based on dietary recall. Based on the results of those three indices, cluster analyses were performed. To identify gender differences and associations with socio-demographic variables, chi-square tests were executed.
Five stable and meaningful clusters were found. Only 18% of the adolescents showed healthy and 21% unhealthy scores on all three included indices. Males were highly presented in the cluster with high levels of moderate to vigorous physical activity (MVPA) and low quality diets. The clusters with low levels of MVPA and high quality diets comprised more female adolescents. Adolescents with low educated parents had diets of lower quality and spent more time in sedentary activities. In addition, the clusters with high levels of MVPA comprised more adolescents of the younger age category.
In order to develop effective primary prevention strategies, it would be important to consider multiple health indices when identifying high risk groups.
Aß peptides are often considered as catabolic by-products of the amyloid ß protein precursor (APP), with unknown physiological functions. However, several biological properties have been tentatively attributed to these peptides, including a role in vasomotion.
We assess whether plasma Aß peptide levels might be associated with systolic and diastolic blood pressure values (SBP and DBP, respectively).
Plasma Aß1-40 and Aß1-42 levels were measured using an xMAP-based assay in 1,972 individuals (none of whom were taking antihypertensive drugs) from 3 independent studies: the French population-based 3C and MONA-LISA (Lille) studies (n = 627 and n = 769, respectively) and the Australian, longitudinal AIBL study (n = 576). In the combined sample, the Aß1-42/ Aß1-40 ratio was significantly and inversely associated with SBP (p = 0.03) and a similar trend was observed for DBP (p = 0.06). Using the median age (69) as a cut-off, the Aß1-42/Aß1-40 ratio was strongly associated with both SBP and DBP in elderly individuals (p = 0.002 and p = 0.03, respectively). Consistently, a high Aß1-42/ Aß1-40 ratio was associated with a lower risk of hypertension in both the combined whole sample (odds ratio [OR], 0.71; 95% confidence interval [CI], 0.56-0.90) and (to an even greater extent) in the elderly subjects (OR, 0.53; 95% CI, 0.37–0.75). Lastly, all these associations appeared to be primarily driven by the level of plasma Aß1-40.
The plasma Aß1-42/Aß1-40 ratio is inversely associated with SBP, DBP and the risk of hypertension in elderly subjects, suggesting that Aß peptides affect blood pressure in vivo. These results may be particularly relevant in Alzheimer's disease, in which a high Aß1-42/Aß1-40 plasma ratio is reportedly associated with a decreased risk of incident disease.
Most studies on the primary prevention of cardiovascular disease (CVD) have been limited to patients at high CVD risk. We assessed the achievement of treatment goals for CVD risk factors among patients with a substantial variation in CVD risk.
Methods and results
This study was conducted with 7641 outpatients aged ≥50 years, free of clinical CVD and with at least one major CVD risk factor, selected from 12 European countries in 2009. Risk factor definition and treatment goals were based on the 2007 European guidelines on CVD prevention. Cholesterol fractions and glycated haemoglobin (HbA1c) were measured in a central laboratory. Cardiovascular disease risk was estimated with the SCORE equation. Patients' mean age was 63 years (48% men), and 40.1% had a high CVD risk. Among treated hypertensives (94.2%), only 38.8% achieved the blood pressure target of <140/90 mmHg [between-country range (BCR): 32.1–47.5%]. Among treated dyslipidaemic patients (74.4%), 41.2% attained both the total- and LDL-cholesterol target of <5 and <3 mmol/L, respectively (BCR: 24.3–68.4%). Among treated type 2 diabetic patients (87.2%), 36.7% achieved the <6.5% HbA1c target (BCR: 23.4–48.4%). Among obese patients on non-pharmacological treatment (92.2%), 24.7% reached the body mass index target of <30 kg/m2 (BCR: 12.7–37.1%). About one-third of controlled patients on treatment were still at high remaining CVD risk. Although most patients were advised to reduce excess weight and to follow a low-calorie diet, less than half received written recommendations.
In Europe, a large proportion of patients in primary prevention have CVD risk factors that remain uncontrolled, and lifestyle counselling is not well implemented; moreover, there is substantial between-country variation, which indicates additional room for improvement. Raised residual CVD risk is relatively frequent among patients despite control of their primary risk factors and should be addressed.
Cardiovascular disease; Prevention; Hypertension; Dyslipidaemia; Diabetes; Obesity; Europe
The peroxisome proliferator–activated receptor-γ2 (PPARG2) Pro12Ala polymorphism has been associated with a higher BMI and a lower risk of type 2 diabetes in adulthood. The association between adiposity and PPARG variants can be influenced by environmental factors such as early growth, dietary fat, and (as recently shown) breast-feeding. The objectives of this study were to assess 1) the influence of the PPARG2 Pro12Ala polymorphism on adiposity markers in adolescents and 2) a possible modulating effect of breast-feeding on these associations.
RESEARCH DESIGN AND METHODS
Data on breast-feeding duration, BMI, and genotypes for the Pro12Ala polymorphism were available for 945 adolescents (mean age 14.7 years). The breast-feeding duration was obtained from parental records. We measured weight, height, waist circumference, and six skinfold thicknesses.
No significant associations between the Pro12Ala polymorphism and any of the above-mentioned anthropometric parameters were found. There were significant interactions between the PPARG2 Pro12Ala polymorphism and breast-feeding with regard to adiposity measurements (all adjusted P < 0.05). Indeed, in children who had not been breast-fed, Ala12 allele carriers had higher adiposity parameters (e.g., Δ BMI +1.88 kg/m2, adjusted for age, sex, and center, P = 0.007) than Pro12Pro adolescents. In contrast, in breast-fed subjects, there was no significant difference between Ala12 allele carriers and Pro12Pro children in terms of adiposity measurements, whatever the duration of breast-feeding.
Breast-feeding appears to counter the deleterious effect of the PPARG2 Pro12Ala polymorphism on anthropometric parameters in adolescents.
The liver X receptors (LXR) α and β regulate lipid and carbohydrate homeostasis and inflammation. Lxrβ-/- mice are glucose intolerant and at the same time lean. We aimed to assess the associations between single nucleotide polymorphisms (SNPs) in LXRβ and risk of type 2 diabetes mellitus (T2DM), obesity and related traits in 3 separate cohort studies.
Twenty LXRβ SNPs were identified by sequencing and genotyped in the HUNT2 adult nested case-control study for T2DM (n = 835 cases/1986 controls). Five tag-SNPs (rs17373080, rs2695121, rs56151148, rs2303044 and rs3219281), covering 99.3% of the entire common genetic variability of the LXRβ gene were identified and genotyped in the French MONICA adult study (n = 2318) and the European adolescent HELENA cross-sectional study (n = 1144). In silico and in vitro functionality studies were performed.
We identified suggestive or significant associations between rs17373080 and the risk of (i) T2DM in HUNT2 (OR = 0.82, p = 0.03), (ii) obesity in MONICA (OR = 1.26, p = 0.05) and (iii) overweight/obesity in HELENA (OR = 1.59, p = 0.002). An intron 4 SNP (rs28514894, a perfect proxy for rs17373080) could potentially create binding sites for hepatic nuclear factor 4 alpha (HNF4α) and nuclear factor 1 (NF1). The C allele of rs28514894 was associated with ~1.25-fold higher human LXRβ basal promoter activity in vitro. However, no differences between alleles in terms of DNA binding and reporter gene transactivation by HNF4α or NF1 were observed.
Our results suggest that rs17373080 in LXRβ is associated with T2DM and obesity, maybe via altered LXRβ expression.
To analyse the relation between various food groups and the frequency of insulin resistance syndrome (IRS).
A sample of 912 men aged 45–64 years was randomly selected. Questionnaires on risk factors and a three consecutive day food diary were completed. Height, weight, waist circumference, and blood pressure were measured. A fasting blood sample was analysed for lipid and glucose measurements. The NCEP‐ATP‐III definition was used to assess IRS. Data were analysed according to quintiles of food groups and medians of dairy products, fish, or cereal grains.
The prevalence of IRS was 23.5%. It reached 29.0%, 28.1% and 28.1% when the intake was below the median for fish, dairy products, and grain, respectively. When consumptions of all three types of food were higher than the median, the prevalence reached 13.1%, and when they were lower, the prevalence was 37.9% (p<0.001). In logistic regression adjusted for confounders (centre, age, physical activities, education level, smoking, dieting, alcohol intake, treatments for hypertension and dyslipidaemia, energy intake, and diet quality index) the odds ratios for IRS (above median value v below) were 0.51 (95% confidence interval, 0.36 to 0.71) for fish, 0.67 (0.47 to 0.94) for dairy products, and 0.69 (0.47 to 1.01) for grain. When intakes of all three kinds of food were high, the OR was 0.22 (0.10 to 0.44).
A high consumption of dairy products, fish, or cereal grains is associated with a lower probability of IRS. The probability decreases when intakes of all three types of food were high.
diet; fish; dairy products; grain; insulin resistance syndrome
The EURIKA study aims to assess the status of primary prevention of cardiovascular disease (CVD) across Europe. Specifically, it will determine the degree of control of cardiovascular risk factors in current clinical practice in relation to the European guidelines on cardiovascular prevention. It will also assess physicians' knowledge and attitudes about CVD prevention as well as the barriers impeding effective risk factor management in clinical practice.
Cross-sectional study conducted simultaneously in 12 countries across Europe. The study has two components: firstly at the physician level, assessing eight hundred and nine primary care and specialist physicians with a daily practice in CVD prevention. A physician specific questionnaire captures information regarding physician demographics, practice settings, cardiovascular prevention beliefs and management. Secondly at the patient level, including 7641 patients aged 50 years or older, free of clinical CVD and with at least one classical risk factor, enrolled by the participating physicians. A patient-specific questionnaire captures information from clinical records and patient interview regarding sociodemographic data, CVD risk factors, and current medications. Finally, each patient provides a fasting blood sample, which is sent to a central laboratory for measuring serum lipids, apolipoproteins, hemoglobin-A1c, and inflammatory biomarkers.
Primary prevention of CVD is an extremely important clinical issue, with preventable circulatory diseases remaining the leading cause of major disease burden. The EURIKA study will provide key information to assess effectiveness of and attitudes toward primary prevention of CVD in Europe. A transnational study creates opportunities for benchmarking good clinical practice across countries and improving outcomes. (ClinicalTrials.gov number, NCT00882336.)
Single nucleotide polymorphisms (SNPs) in the peroxisome proliferator-activated receptor γ (PPARG) gene have been associated with cardiovascular risk factors, particularly obesity and diabetes. We assessed the relationship between 4 PPARG SNPs (C-681G, C-689T, Pro12Ala, and C1431T) and coronary heart disease (CHD) in the PRIME (249 cases/494 controls, only men) and ADVANCE (1,076 cases/805 controls, men or women) studies. In PRIME, homozygote individuals for the minor allele of the PPARG C-689T, Pro12Ala, and C1431T SNPs tended to have a higher risk of CHD than homozygote individuals for the frequent allele (adjusted OR [95% CI] = 3.43 [0.96–12.27], P = .058, 3.41 [0.95–12.22], P = .060 and 5.10 [0.99–26.37], P = .050, resp.). No such association could be detected in ADVANCE. Haplotype distributions were similar in cases and control in both studies. A meta-analysis on the Pro12Ala SNP, based on our data and 11 other published association studies (6,898 CHD cases/11,287 controls), revealed that there was no evidence for a significant association under the dominant model (OR = 0.99
[0.92–1.07], P = .82). However, there was a borderline association under the recessive model (OR = 1.29 [0.99–1.67], P = .06) that became significant when considering men only (OR = 1.73 [1.20–2.48], P = .003). In conclusion, the PPARG Ala12Ala genotype might be associated with a higher CHD risk in men but further confirmation studies are needed.
The metabolic syndrome (MS) is associated with an increased cardiovascular risk. Patients with the MS have endothelial dysfunction, decreased circulating adiponectin, and a high expression of angiogenic inhibitors such as plasminogen activator inhibitor-1 (PAI-1). We hypothesized that such patients, in the event of a coronary occlusion, might exhibit a less developed collateral circulation.
Methods and results
Three hundred and eighty-seven consecutive patients with at least one coronary occlusion of a major coronary vessel at diagnostic angiography were prospectively enrolled. Collateral development was graded with validated angiographic methods. The MS was defined according to the ATP-III definition. Fasting glucose, adiponectin, insulin concentrations, and PAI-1 were measured at the time of angiography. MS was associated with less developed collateral vessels (P = 0.005). In multivariable analysis adjusting for potential confounding factors including the duration of coronary occlusion (P = 0.0001), fasting glycaemia (P = 0.0007), low adiponectin concentration (P = 0.01), insulin-resistance (HOMA-IR; P = 0.01), high circulating PAI-1 concentration (P = 0.01), and hypertension (P = 0.008) were independently associated with poor coronary collateral vessel development.
This study shows that in patients with coronary occlusion, collateral circulation is impaired in patients with the MS. This association is partly related to fasting glycaemia and to key parameters linked to insulin resistance.
Angiogenesis; Collateral circulation; Coronary disease; Diabetes mellitus; Fibrinolysis; Insulin
The goal of the present study was to assess the effect of genetic variability at the APOA5/A4/C3/A1 cluster locus on the risk of metabolic syndrome.
The APOA5 Ser19Trp, APOA5 -12,238T>C, APOA4 Thr347Ser, APOC3 -482C>T and APOC3 3238C>G (SstI) polymorphisms were analyzed in a representative population sample of 3138 men and women from France, including 932 individuals with metabolic syndrome and 2206 without metabolic syndrome, as defined by the NCEP criteria.
Compared with homozygotes for the common allele, the odds ratio (OR) [95% CI] for metabolic syndrome was 1.30 [1.03–1.66] (p = 0.03) for APOA5 Trp19 carriers, 0.81 [0.69–0.95] (p = 0.01) for APOA5 -12,238C carriers and 0.84 [0.70–0.99] (p = 0.04) for APOA4 Ser347 carriers. Adjustment for plasma triglycerides, (but not for waist girth, HDL, blood pressure or glycemia – the other components of metabolic syndrome) abolished these associations and suggests that triglyceride levels explain the association with metabolic syndrome. There was no association between the APOC3 -482C>T or APOC3 3238C>G polymorphisms and metabolic syndrome. The decreased risk of metabolic syndrome observed in APOA5 -12,238C and APOA4 Ser347 carriers merely reflected the fact that the APOA5 Trp19 allele was in negative linkage disequilibrium with the common alleles of APOA5 -12,238T>C and APOA4 Thr347Ser polymorphisms.
The APOA5 Trp19 allele increased susceptibility to metabolic syndrome via its impact on plasma triglyceride levels.
Experimental studies support an important role for endothelial nitric oxide synthase (eNOS) in the regulation of angiogenesis. In humans, a common polymorphism exists in the eNOS gene that results in the conversion of glutamate to aspartate for codon 298. In vitro and in vivo studies have suggested a decreased NOS activity in patients with the Asp298 variant. We hypothesized that a genetic-mediated decreased eNOS activity may limit collateral development in patients with chronic coronary occlusions.
We selected 291 consecutive patients who underwent coronary angiography and who had at least one chronic (>15 days) total coronary occlusion. Collateral development was graded angiographically using two different methods: the collateral flow grade and the recipient filling grade. Genomic DNA was extracted from white blood cells and genotyping was performed using previously published techniques.
Collateral development was lower in patients carrying the Asp298 variant than in Glu-Glu homozygotes (collateral flow grade: 2.64 ± 0.08 and 2.89 ± 0.08, respectively, p = 0.04; recipient filling grade: 3.00 ± 0.08 and 3.24 ± 0.07, respectively, p = 0.04). By multivariable analysis, three variables were independently associated with the collateral flow grade: female gender, smoking, and the Asp298 variant (p = 0.03) while the Asp298 variant was the sole variable independently associated with the recipient filling grade (p = 0.03).
Collateral development is lower in patients with the Asp298 variant. This may be explained by the decreased NOS activity in patients with the Asp298 variant. Further studies will have to determine whether increasing eNOS activity in humans is associated with coronary collateral development.
Serum levels of HDL are inversely correlated with the risk of coronary heart disease. The anti-atherogenic effect of HDL is partially mediated by its major protein constituent apoA-I. In this study, we identify bile acids that are activators of the nuclear receptor farnesoid X receptor (FXR) as negative regulators of human apoA-I expression. Intrahepatocellular accumulation of bile acids, as seen in patients with progressive familial intrahepatic cholestasis and biliary atresia, was associated with diminished apoA-I serum levels. In human apoA-I transgenic mice, treatment with the FXR agonist taurocholic acid strongly decreased serum concentrations and liver mRNA levels of human apoA-I, which was associated with reduced serum HDL levels. Incubation of human primary hepatocytes and hepatoblastoma HepG2 cells with bile acids resulted in a dose-dependent downregulation of apoA-I expression. Promoter mutation analysis and gel-shift experiments in HepG2 cells demonstrated that bile acid–activated FXR decreases human apoA-I promoter activity by a negative FXR response element mapped to the C site. FXR bound this site and repressed transcription in a manner independent of retinoid X receptor. The nonsteroidal synthetic FXR agonist GW4064 likewise decreased apoA-I mRNA levels and promoter activity in HepG2 cells.
This paper presents a summary of the potential practical and economic barriers to implementation of primary prevention of cardiovascular disease guided by total cardiovascular risk estimations in the general population. It also reviews various possible solutions to overcome these barriers. The report is based on discussion among experts in the area at a special CardioVascular Clinical Trialists workshop organized by the European Society of Cardiology Working Group on Cardiovascular Pharmacology and Drug Therapy that took place in September 2009. It includes a review of the evidence in favour of the ‘treat-to-target’ paradigm, as well as potential difficulties with this approach, including the multiple pathological processes present in high-risk patients that may not be adequately addressed by this strategy. The risk-guided therapy approach requires careful definitions of cardiovascular risk and consideration of clinical endpoints as well as the differences between trial and ‘real-world’ populations. Cost-effectiveness presents another issue in scenarios of finite healthcare resources, as does the difficulty of documenting guideline uptake and effectiveness in the primary care setting, where early modification of risk factors may be more beneficial than later attempts to manage established disease. The key to guideline implementation is to improve the quality of risk assessment and demonstrate the association between risk factors, intervention, and reduced event rates. In the future, this may be made possible by means of automated data entry and various other measures. In conclusion, opportunities exist to increase guideline implementation in the primary care setting, with potential benefits for both the general population and healthcare resources.
Cardiovascular disease; primary prevention; risk-guided therapy