Multilocus family-based association analysis of seven candidate polymorphisms with essential hypertension in an african-derived semi-isolated brazilian population. Int J Hypertens. 2012;2012:859219. [PMID: 23056922 PMCID: PMC3463917 DOI: 10.1155/2012/859219]

G protein-coupled receptor kinases in hypertension: physiology, pathogenesis, and therapeutic targets

G protein-coupled receptors (GPCRs) mediate cellular responses to a myriad of hormones and neurotransmitters that play vital roles in the regulation of physiological processes such as blood pressure. In organs such as the artery and kidney, hormones or neurotransmitters, such as angiotensin II (Ang II), dopamine, epinephrine, and norepinephrine exert their functions via their receptors, with the ultimate effect of keeping normal vascular reactivity, normal body sodium, and normal blood pressure. GPCR kinases (GRKs) exert their biological functions, by mediating the regulation of agonist-occupied GPCRs, non-GPCRs, or non-receptor substrates. In particular, increasing number of studies show that aberrant expression and activity of GRKs in the cardiovascular system and kidney inhibit or stimulate GPCRs (e.g., dopamine receptors, Ang II receptors, and α- and β-adrenergic receptors), resulting in hypertension. Current studies focus on the effect of selective GRK inhibitors in cardiovascular diseases, including hypertension. Moreover, genetic studies show that GRK gene variants are associated with essential hypertension, blood pressure response to antihypertensive medicines, and adverse cardiovascular outcomes of antihypertensive treatment. In this review, we present a comprehensive overview of GRK-mediated regulation of blood pressure, role of GRKs in the pathogenesis of hypertension, and highlight potential strategies for the treatment of hypertension. Schematic representation of GPCR desensitization process. Activation of GPCRs begins with the binding of an agonist to its corresponding receptor. Then G proteins activate downstream effectors that are mediated by various signaling pathways. GPCR signaling is halted by GRK-mediated receptor phosphorylation, which causes receptor internalization through β-arrestin.

G Protein Subunit Beta 3 (GNB3) Variant Is Associated with Biochemical Changes in Brazilian Patients with Hypertension

BACKGROUND

Central Illustration : G Protein Subunit Beta 3 (GNB3) Variant Is Associated with Biochemical Changes in Brazilian Patients with Hypertension.

BACKGROUND

Genes and their variants associated with environmental factors contribute to the development of the hypertensive phenotype. The G protein beta 3 subunit gene (GNB3) is involved in the intracellular signaling process, and its variants have been related to susceptibility to arterial hypertension.

OBJECTIVE

To determine the association of the GNB3 variant (rs5443:C>T) with arterial hypertension, biochemical parameters, age, and obesity in hypertensive and normotensive individuals from Ouro Preto, Minas Gerais, Brazil.

METHOD

The identification of variants was performed by real-time PCR, using the TaqMan® system, in 310 samples (155 hypertensive and 155 normotensive). Biochemical analyses (renal function, lipid profile and glycemia) were performed from the serum using UV/Vis spectrophotometry and ion-selective electrode. A multiple logistic regression model was used to identify factors associated with arterial hypertension. The analysis of continuous variables with normal distribution was performed using the unpaired Student's t test; non-normal data were analyzed using Mann-Whitney. P < 0.05 was considered significant.

RESULTS

The rs5443:C>T variant was not associated with arterial hypertension in the evaluated population (p = 0.88). Regarding biochemical measures, the T allele was associated with high levels of triglycerides, glucose and uric acid in hypertensive individuals (p < 0.05).

CONCLUSION

These results show the importance of genetic diagnosis to prevent the causes and consequences of diseases and imply that the GNB3 rs5443:C>T variant may be associated with changes in the biochemical profile in hypertensive individuals.

Ancestry, diversity, and genetics of health-related traits in African-derived communities (quilombos) from Brazil

Brazilian quilombos are communities formed by enslaved Africans and their descendants all over the country during slavery and shortly after its abolition. Quilombos harbor a great fraction of the largely unknown genetic diversity of the African diaspora in Brazil. Thus, genetic studies in quilombos have the potential to provide important insights not only into the African roots of the Brazilian population but also into the genetic bases of complex traits and human adaptation to diverse environments. This review summarizes the main results of genetic studies performed on quilombos so far. Here, we analyzed the patterns of African, Amerindian, European, and subcontinental ancestry (within Africa) of quilombos from the five different geographic regions of Brazil. In addition, uniparental markers (from the mtDNA and the Y chromosome) studies are analyzed together to reveal demographic processes and sex-biased admixture that occurred during the formation of these unique populations. Lastly, the prevalence of known malaria-adaptive African mutations and other African-specific variants discovered in quilombos, as well as the genetic bases of health-related traits, are discussed here, together with their implication for the health of populations of African descent.

A review of ancestrality and admixture in Latin America and the caribbean focusing on native American and African descendant populations

Genomics can reveal essential features about the demographic evolution of a population that may not be apparent from historical elements. In recent years, there has been a significant increase in the number of studies applying genomic epidemiological approaches to understand the genetic structure and diversity of human populations in the context of demographic history and for implementing precision medicine. These efforts have traditionally been applied predominantly to populations of European origin. More recently, initiatives in the United States and Africa are including more diverse populations, establishing new horizons for research in human populations with African and/or Native ancestries. Still, even in the most recent projects, the under-representation of genomic data from Latin America and the Caribbean (LAC) is remarkable. In addition, because the region presents the most recent global miscegenation, genomics data from LAC may add relevant information to understand population admixture better. Admixture in LAC started during the colonial period, in the 15th century, with intense miscegenation between European settlers, mainly from Portugal and Spain, with local indigenous and sub-Saharan Africans brought through the slave trade. Since, there are descendants of formerly enslaved and Native American populations in the LAC territory; they are considered vulnerable populations because of their history and current living conditions. In this context, studying LAC Native American and African descendant populations is important for several reasons. First, studying human populations from different origins makes it possible to understand the diversity of the human genome better. Second, it also has an immediate application to these populations, such as empowering communities with the knowledge of their ancestral origins. Furthermore, because knowledge of the population genomic structure is an essential requirement for implementing genomic medicine and precision health practices, population genomics studies may ensure that these communities have access to genomic information for risk assessment, prevention, and the delivery of optimized treatment; thus, helping to reduce inequalities in the Western Hemisphere. Hoping to set the stage for future studies, we review different aspects related to genetic and genomic research in vulnerable populations from LAC countries.

Cardiovascular risk factors across different levels of urbanization in Brazilian Afro‐derived communities ( quilombos )

OBJECTIVES

The frequency of cardiovascular diseases has increased throughout the world. People of African descent have been disproportionately affected, particularly if they reside in urban settings. In this work, we evaluate risk factors associated with cardiovascular diseases (CVD) and other chronic diseases in rural and urban Afro-derived communities (quilombo) in Central Brazil. We also determine if there are associations between the frequency of CVD risk factors, sex, and proximity to urban environments.

METHODS

Through a cross-sectional study of participants (n = 347) within three Brazilian Afro-derived communities: Kalunga (a semi-isolated rural community; n = 214), Cocalinho (a non-isolated rural village; n = 70), and Pé do Morro (an urban community; n = 63), we collected data regarding chronic disease (i.e., CVD, diabetes, and hypertension) risk through questionnaires, anthropometrics, blood pressure, and blood samples using standard protocols. Differences between variables were tested by the Chi-square test of Pearson and Fisher's Exact Test, independent sample t-tests, analysis of variances, and Kruskal-Wallis tests (p ≤ .05).

RESULTS

The prevalence of hypertension, overweight, obesity, and other cardiovascular risk factors were higher in the non-isolated rural and urban communities than in the semi-isolated rural community. We found significant sex differences in the distribution of the CVD risk factors, with all occurring at a higher frequency among females.

CONCLUSIONS

Our findings indicate that Brazilian Afro-derived communities are currently going through an epidemiological transition. The urban lifestyle and its environmental factors are likely contributing to an escalation in cardio-metabolic disease risk. However, the magnitude of this transition differentially impacts the sexes, as females suffer a higher frequency of risk factors compared to males.

Hypertension is associated with a variant in the RARRES2 gene in populations of Ouro Preto, Minas Gerais, Brazil: a cross-sectional study

BACKGROUND

Arterial hypertension (AH) is implicated in vascular health and contributes significantly to cardiovascular morbidity and mortality. In addition to the contribution of usual risk factors for AH, elucidating the influence of genetic factors is a promising area of investigation. Therefore, we evaluated the association between AH and cardiovascular risk factors (CVRFs) and genetic polymorphisms in communities in Southeast Brazil.

METHODS

A total of 515 adults aged 18-91 years, who were cross-sectionally assessed between 2015-2016, were included. Demographic, clinical, behavioral, anthropometric characteristics, and laboratory parameters and 12 single nucleotide polymorphisms in seven candidate genes involved in cardiovascular risk (RARRES2, AGT, NOS3, GNB3, APOE, APOB, APOC3, LDLR, and PPARG) were evaluated, with AH as the outcome. Sex, age, and laboratory parameters were considered the main confounding factors.

RESULTS

There was a significant association between age >60 years (odds ratio [OR] =6.74), alcohol dependence (OR=3.84), smoking (OR=1.74), overweight (OR=1.74), high plasma triglyceride (TG) levels (OR=1.98) and low high-density lipoprotein (HDL-c) (OR=6.22), diabetes (OR=3.68), and insulin resistance (OR=2.40) and AH. A significant association was observed between rs4721 in RARRES2 and AH. The T allele in homozygosis was a potent chance modifier for AH. The highest chance gradients for AH were characterized by the presence of the TT genotype and DMT2 (OR=9.70), high TG (OR=6.26), low HDL-c (OR=8.20), and age more than 60 years (OR=9.96).

CONCLUSION

The interaction of the T allele of the rs4721 polymorphism in RARRES2 with CVRFs may predispose carriers to a higher cardiovascular risk.

Lipid Rafts and Dopamine Receptor Signaling

The renal dopaminergic system has been identified as a modulator of sodium balance and blood pressure. According to the Centers for Disease Control and Prevention, in 2018 in the United States, almost half a million deaths included hypertension as a primary or contributing cause. Renal dopamine receptors, members of the G protein-coupled receptor family, are divided in two groups: D1-like receptors that act to keep the blood pressure in the normal range, and D2-like receptors with a variable effect on blood pressure, depending on volume status. The renal dopamine receptor function is regulated, in part, by its expression in microdomains in the plasma membrane. Lipid rafts form platforms within the plasma membrane for the organization and dynamic contact of molecules involved in numerous cellular processes such as ligand binding, membrane sorting, effector specificity, and signal transduction. Understanding all the components of lipid rafts, their interaction with renal dopamine receptors, and their signaling process offers an opportunity to unravel potential treatment targets that could halt the progression of hypertension, chronic kidney disease (CKD), and their complications.

High levels of chemerin associated with variants in the NOS3 and APOB genes in rural populations of Ouro Preto, Minas Gerais, Brazil

Chemerin is an adipokine that has been associated with components of metabolic syndrome. It has been described to affect adipocyte metabolism and inflammatory responses in adipose tissue, as well as the systemic metabolism of lipids and glucose. Few epidemiological studies have evaluated classical and genetics cardiovascular risk factors (CVRFs) in the mixed adult rural population in Brazil. Therefore, the present study explored possible associations between CVRFs and chemerin. This cross-sectional study included 508 adults from the rural localities of Lavras Novas, Chapada, and Santo Antônio do Salto in Ouro Preto, Minas Gerais, Southeast Brazil. Demographic, behavioral, clinical, biochemical, anthropometric variables, and 12 single nucleotide polymorphisms (SNPs) linked with metabolic syndrome phenotypes were evaluated for associations with chemerin level. There was a significant association of high triglyceride levels [odds ratio (OR)=1.91, 95%CI: 1.23-2.98], insulin resistance (OR=1.82, 95%CI: 1.03-3.22), age (OR=1.64, 95%CI: 1.08-2.49), and sex (OR=1.99, 95%CI: 1.35-2.95) with high levels of chemerin. High chemerin levels were significantly associated with the genetic polymorphisms rs693 in the APOB gene (OR=1.50, 95%CI: 1.03-2.19) and rs1799983 in the NOS3 gene (OR=1.46, 95%CI: 1.01-2.12) for the AA and GT+TT genotypes, respectively. In the concomitant presence of genotypes AA of rs693 and GT+TT of rs1799983, the chance of presenting high levels of chemerin showed a 2.21-fold increase (95%CI: 1.25-3.88) compared to the reference genotype. The development of classical CVRFs in this population may be influenced by chemerin and by two risk genotypes characteristic of variants in well-studied genes for hypertension and dyslipidemia.

Prevalence of Systemic Arterial Hypertension in Quilombola Communities, State of Sergipe, Brazil

Background

The quilombolas are groups formed by black ancestry individuals, living in a context of social vulnerability due to low socioeconomic level, which influences health care and the development of chronic diseases.

Objective

To assess the prevalence of systemic arterial hypertension and its association with cardiovascular risk factors in the quilombola population in the State of Sergipe, Brazil.

Methods

Study design was cross sectional, involving the administration of a questionnaire to individuals aged ≥ 18 years, in 15 quilombola communities of the State of Sergipe, Brazil. A value of two-sided p < 0.05 was considered statistically significant.

Results

sA total of 390 individuals were evaluated, 72.3% of whom were women, with a mean age of 44.7 years. The prevalence of hypertension was 26% (with a confidence interval of 95% [95% CI]: 22-30), with no significant sex-related differences. The age was associated with arterial hypertension (95% CI: 1.03-1.06), systolic (95% CI: 1.04-1.07) and diastolic (IC 95%: 1.01-1.04) arterial hypertension. The level of body mass index was associated with arterial hypertension (95% CI: 1.00-1.11) and diastolic arterial hypertension (95% CI: 1.03-1.17). Economic class was associated with diastolic arterial hypertension (95% CI: 1.22-5.03).

Conclusion

The prevalence of arterial hypertension in the quilombola communities was high. Its association with cardiovascular risk factors indicates the need to improve access to healthcare services.

[Arterial prehypertension in slave-descendant communities in southeast Bahia State, Brazil]

Arterial prehypertension is a precursor of arterial hypertension and a risk factor for cardiovascular diseases. Vulnerable populations are more prone to this condition due to difficulties in access to health services. A previous study in quilombola communities (descendants of African slaves) reported a high prevalence of arterial hypertension. The current study aimed to estimate the prevalence of arterial prehypertension in quilombolas and to assess associated factors. This was a cross-sectional population-based study in individuals 18 years and older. Prehypertension was defined as arterial systolic pressure ≥ 121mmHg and < 140mmHg and/or diastolic ≥ 81mmHg and < 90mmHg. Multivariate Poisson regression with robust variance was used. Population-attributable fractions (PAF) were also calculated for the modifiable associated factors. Prevalence of prehypertension was 55% (95%CI: 50.2-59.7). Male gender (PR = 1.54), 1 to 4 complete years of schooling (PR = 1.44), and BMI classified as overweight (PR = 1.39) and obesity (PR = 1.87) showed positive association with prehypertension. Higher attributable fractions were observed in individuals with 1 to 4 years of schooling (13.7%) and those classified as overweight (9.35%) and obese (4.6%). Prevalence of prehypertension in quilombola communities was high, and its identification may allow screening and awareness-raising in a group with increased risk of cardiovascular disease and progression to full-blown hypertension. The study highlights the need for broad access to health services and specific measures for orientation, prevention, and health promotion in this population.

Detecting multi-way epistasis in family-based association studies

The era of genome-wide association studies (GWAS) has led to the discovery of numerous genetic variants associated with disease. Better understanding of whether these or other variants interact leading to differential risk compared with individual marker effects will increase our understanding of the genetic architecture of disease, which may be investigated using the family-based study design. We present M-TDT (the multi-locus transmission disequilibrium test), a tool for detecting family-based multi-locus multi-allelic effects for qualitative or quantitative traits, extended from the original transmission disequilibrium test (TDT). Tests to handle the comparison between additive and epistatic models, lack of independence between markers and multiple offspring are described. Performance of M-TDT is compared with a multifactor dimensionality reduction (MDR) approach designed for investigating families in the hypothesis-free genome-wide setting (the multifactor dimensionality reduction pedigree disequilibrium test, MDR-PDT). Other methods derived from the TDT or MDR to investigate genetic interaction in the family-based design are also discussed. The case of three independent biallelic loci is illustrated using simulations for one- to three-locus alternative hypotheses. M-TDT identified joint-locus effects and distinguished effectively between additive and epistatic models. We showed a practical example of M-TDT based on three genes already known to be implicated in malaria susceptibility. Our findings demonstrate the value of M-TDT in a hypothesis-driven context to test for multi-way epistasis underlying common disease etiology, whereas MDR-PDT-based methods are more appropriate in a hypothesis-free genome-wide setting.

Estimation of inbreeding and substructure levels in African-derived Brazilian quilombo populations

This article deals with the estimation of inbreeding and substructure levels in a set of 10 (later regrouped as eight) African-derived quilombo communities from the Ribeira River Valley in the southern portion of the state of São Paulo, Brazil. Inbreeding levels were assessed through F-values estimated from the direct analysis of genealogical data and from the statistical analysis of a large set of 30 molecular markers. The levels of population substructure found were modest, as was the degree of inbreeding: in the set of all communities considered together, F-values were 0.00136 and 0.00248 when using raw and corrected data from their complete genealogical structures, respectively, and 0.022 and 0.036 when using the information taken from the statistical analysis of all 30 loci and of 14 single-nucleotide polymorphic loci, respectively. The overall frequency of consanguineous marriages in the set of all communities considered together was ∼ 2%. Although modest, the values of the estimated parameters are much larger than those obtained for the overall Brazilian population and in general much smaller than the ones recorded for other Brazilian isolates. To circumvent problems related to heterogeneous sampling and virtual absence of reliable records of biological relationships, we had to develop or adapt several methods for making valid estimates of the prescribed parameters.

Association between GRK4 and DRD1 gene polymorphisms and hypertension: a meta-analysis

The role of GRK4 and DRD1 genes in hypertension remains controversial. We performed a meta-analysis to determine whether GRK4 and DRD1 polymorphisms influence the risk of hypertension and examined the relationship between the genetic variances and the etiology of hypertension. Relevant case-control studies were retrieved by database searches and selected according to established inclusion criteria. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to evaluate the strength of the associations. Meta-regression, subgroup analysis, and sensitivity analysis were performed. A total of 15 articles containing 29 studies were finally included. In the dominant model, rs4532 locus of DRD1 gene was related to hypertension with a pooled OR of 1.353 (95% CI =1.016-1.802, P=0.038). Subgroup analysis for ethnicity showed that rs1024323 locus of GRK4 gene was associated with hypertension in Caucasians (OR =1.826, 95% CI =1.215-2.745, P=0.004) but not in East Asians and Africans. Rs4532 locus was associated with hypertension in East Asians (OR =1.833, 95% CI =1.415-2.376, P,0.001) but not in Caucasians. These data provide possible references for future case-control studies in hypertension.

Association study of NOS3 gene polymorphisms and hypertension in the Han Chinese population

BACKGROUND

Recent studies have reported that NOS3 plays an important role in cardiovascular pathology, whereas the association of NOS3 and hypertension (HT) has been controversial between African Americans and European whites. Here, we aimed to further investigate the genetic effect of unexplored loci at NOS3 on the susceptibility of HT in the Han Chinese population.

METHODS AND RESULTS

The association of three polymorphisms; rs4496877, rs1808593 and rs3918186 to HT was tested in a case control study that included 2012 HT cases and 2210 controls. Association analysis showed that there was no significant association between rs4496877, rs1808593 and rs3918186 of NOS3 and HT in the whole study population. Stratification analysis indicated that rs3918186 was significantly associated with HT in the ≥55-year-old population (OR = 1.245, 95% CI = 1.010-1.534, P = 0.04). The rs4496877 and rs1808593 were significantly associated with HT in the male population (P = 0.015) and <55-year-old population (P = 0.025), respectively (OR = 3.254, 95% CI = 1.257-8.425 and OR = 1.683, 95% CI = 1.066-2.657, respectively). Quantitative trait analysis showed that there were significant differences in systolic blood pressure (SBP) among the genotypes (AA, AT and TT) of rs3918186 in the non-intervention populations (P = 0.016). GMDR analysis showed that drinking and rs3918186 had significant interaction effects for risk of HT.

CONCLUSIONS

The findings of this study indicated that the rs4496877, rs1808593 and rs3918186 polymorphisms of NOS3 contribute to the genetic susceptibility of HT and that rs3918186 was associated with SBP in the Chinese population. Age and gender might modify the genetic effect of NOS3 on HT, and drinking significantly interacts with rs3918186.

Common variants of the G protein-coupled receptor type 4 are associated with human essential hypertension and predict the blood pressure response to angiotensin receptor blockade

Non-synonymous GRK4 variants, R65L, A142V and A486V, are associated with essential hypertension in diverse populations. This study replicated the association of GRK4 variants, including GRK4(142V), with human essential hypertension in a Japanese population (n=588; hypertensive, n=486 normotensive controls) and determined whether the presence of GRK4 variants predicted the blood pressure (BP) response to angiotensin receptor blockers (ARBs) in patients with essential hypertension. We analyzed 829 patients and compared the response to ARBs between individuals with no GRK4 variants (n=136) and those with variants at one or any of the three loci (n=693). Carriers of hGRK4(142V) had a greater decrease in systolic BP in response to ARBs than non-carrier hypertensive patients. By contrast, those with variants only at GRK4(486V) were less likely to achieve the BP goal in response to an ARB than those with no variants. These studies showed for the first time the association between GRK4(142V) and a larger decrease in BP with ARBs in hypertensive patients.

Overweight in Goiás'quilombola students and food insecurity in their families

Objective: To characterize the nutritional status of quilombola students and determine the food security status of their households. Methods: This is a cross-sectional study with students aged six to nineteen years from quilombola communities in twelve municipalities of Goiás categorized by age, gender, school location (urban/rural), and nutritional status based on the World Health Organization's height-for-age and body mass index for-age charts. The Brazilian Food Insecurity Scale was used for measuring food (in)security in their families. Descriptive and association analyses were conducted using the Chi-square test at a significance level of 5% (p<0.05). Results: In a sample of 226 students, overweight (17.2%) was more common than malnutrition (1.3%), especially in students attending urban schools (28.2%) (p<0.05). Most (75.2%) quilombola families experienced food insecurity, especially mild. Conclusion: The apparent contradiction of excess weight and food insecurity occurring simultaneously indicates the need of revising the study instruments and the causal network that identify poverty.

Elevated blood pressure: Our family's fault? The genetics of essential hypertension

AIM

To provide an updated review on current genetic aspects possibly affecting essential hypertension (EH), and to further elucidate their role in EH.

METHODS

We searched for genetic and epigenetic factors in major studies associated with EH between Jan 2008-Oct 2013 using PubMed. We limited our search to reviews that discussed mostly human studies, and were accessible through the university online resource. We found 11 genome wide association studies (GWAS), as well as five methylation and three miRNA studies that fit our search criteria. A distinction was not made between genes with protective effects or negative effects, as this article is only meant to be a summary of genes associated with any aspect of EH.

RESULTS

We found 130 genes from the studies that met our inclusion/exclusion criteria. Of note, genes with multiple study references include: STK39, CYP17A1, MTHFR-NPPA, MTHFR-NPPB, ATP2B1, CSK, ZNF652, UMOD, CACNB2, PLEKHA7, SH2B3, TBX3-TBX5, ULK4, CSK-ULK3, CYP1A2, NT5C2, CYP171A, PLCD3, SH2B3, ATXN2, CACNB2, PLEKHA7, SH2B3, TBX3-TBX5, ULK4, and HFE. The following genes overlapped between the genetic studies and epigenetic studies: WNK4 and BDKRB2. Several of the identified genes were found to have functions associated with EH. Many epigenetic factors were also correlated with EH. Of the epigenetic factors, there were no articles discussing siRNA and its effects on EH that met the search criteria, thus the topic was not included in this review. Among the miRNA targets found to be associated with EH, many of the genes involved were also identified in the GWAS studies.

CONCLUSION

Genetic hypertension risk algorithms could be developed in the future but may be of limited benefit due to the multi-factorial nature of EH. With emerging technologies, like next-generation sequencing, more direct causal relationships between genetic and epigenetic factors affecting EH will likely be discovered creating a tremendous potential for personalized medicine using pharmacogenomics.

Multivariate meta-analysis of the association of G-protein beta 3 gene (GNB3) haplotypes with cardiovascular phenotypes

The objective of the present study was to review previous investigations on the association of haplotypes in the G-protein β3 subunit (GNB3) gene with representative cardiovascular risk factors/phenotypes: hypertension, overweight, and variation in the systolic and diastolic blood pressures (SBP and DBP, respectively) and as well as body mass index (BMI). A comprehensive literature search was undertaken in Pubmed, Web of Science, EMBASE, Biological Abstracts, LILACS and Google Scholar to identify potentially relevant articles published up to April 2011. Six genetic association studies encompassing 16,068 participants were identified. Individual participant data were obtained for all studies. The three most investigated GNB3 polymorphisms (G-350A, C825T and C1429T) were considered. Expectation-maximization and generalized linear models were employed to estimate haplotypic effects from data with uncertain phase while adjusting for covariates. Study-specific results were combined through a random-effects multivariate meta-analysis. After carefully adjustments for relevant confounding factors, our analysis failed to support a role for GNB3 haplotypes in any of the investigated phenotypes. Sensitivity analyses excluding studies violating Hardy-Weinberg expectations, considering gender-specific effects or more extreme phenotypes (e.g. obesity only) as well as a fixed-effects "pooled" analysis also did not disclose a significant influence of GNB3 haplotypes on cardiovascular phenotypes. We conclude that the previous cumulative evidence does not support the proposal that haplotypes formed by common GNB3 polymorphisms might contribute either to the development of hypertension and obesity, or to the variation in the SBP, DBP and BMI.