Gender, a significant factor in the cross talk between genes, environment, and health

Advances in Nutrigenomics and Applications in Public Health: A Recent Update

Nutrition research is achieving new paradigms through recent advances in the field of Nutrigenomics. The application of genomic principles for the identification of relationships between certain specific nutrients with genetic factors is termed “Nutrigenomics”. This knowledge is essential to understanding the risk factors behind diet-related chronic degenerative diseases, which further helps resolve the underlying mechanism of genetic predisposition. Advances in Sciences associated with the study of genes have assisted in developing a deep insight into genetic variants, and gene expression patterns to work out therapeutic responses toward chronic degenerative diseases associated with Public Health. To appraise recent advances in Nutrigenomics with its application in Public health several databases including Pub Med, Google Scholar, Medline etc were investigated in detail. A total of 72 relevant peer-reviewed journal articles were included in this review paper. Nutrigenomics has an important role in comprehending how homeostatic control is maintained and the way metabolic pathways are influenced by nutrient intake. The knowledge of Nutrigenomics helps in working out personalized nutrition strategies for both prevention and management of the diseased situation. The present review article aims to investigate and present a piece of in-depth information about the latest Advances in Nutrigenomics and its application in public health.

Sex-Dependent Mediation of Leptin in the Association of Perilipin Polymorphisms with BMI and Plasma Lipid Levels in Children

Variations in the perilipin (PLIN) gene have been suggested to be associated with obesity and its related alterations, but a different nutritional status seems to contribute to differences in these associations. In our study, we examined the association of several polymorphisms at the PLIN locus with obesity and lipid profile in children, and then analyzed the mediation of plasma leptin levels on these associations. The single-nucleotide polymorphisms (SNPs) rs894160, rs1052700, and rs2304795 in PLIN1, and rs35568725 in PLIN2, were analyzed by RT-PCR in 1264 children aged 6–8 years. Our results showed a contrasting association of PLIN1 rs1052700 with apolipoprotein (Apo) A-I levels in boys and girls, with genotype TT carriers showing significantly higher Apo A-I levels in boys and significantly lower Apo A-I levels in girls. Significant associations of the SNP PLIN2 rs35568725 with high-density lipoprotein cholesterol (HDL-cholesterol), Apo A-I, and non-esterified fatty acids (NEFA) were observed in boys but not in girls. The associations of the SNPs studied with body mass index (BMI), NEFA, and Apo A-I in boys and girls were different depending on leptin concentration. In conclusion, we describe the mediation of plasma leptin levels in the association of SNPs in PLIN1 and PLIN2 with BMI, Apo A-I, and NEFA. Different leptin levels by sex may contribute to explain the sex-dependent association of the PLIN SNPs with these variables.

Genetic test for the prescription of diets in support of physical activity

Owing to the fields of nutrigenetics and nutrigenomics today we can think of devising approaches to optimize health, delay onset of diseases and reduce its severity according to our genetic blue print. However this requires a deep understanding of nutritional impact on expression of genes that may result in a specific phenotype. The extensive research and observational studies during last two decades reporting interactions between genes, diet and physical activity suggest a cross talk between various genetic and environmental factors and lifestyle interventions. Although considerable efforts have been made in unraveling the mechanisms of gene-diet interactions the scientific evidences behind developing commercial genetic tests for providing personalized nutrition recommendations are still scarce. In this scenario the current mini-review aims to provide useful insights into salient feature of nutrition based genetic research and its commercial application and the ethical issue and concerns related to its outcome.

Study of the association of 17 lipid-related gene polymorphisms with coronary heart disease

Objective

Blood lipids are well-known risk factors for coronary heart disease (CHD). The aim of this study was to explore the association between 17 lipid-related gene polymorphisms and CHD.

Methods

The current study examined with 784 CHD cases and 739 non-CHD controls. Genotyping was performed on the MassARRAY iPLEX^® assay platform.

Results

Our analyses revealed a significant association of APOE rs7259620 with CHD (genotype: χ²=6.353, df=2, p=0.042; allele: χ²=5.05, df=1, p=0.025; recessive model: χ²=5.57, df=1, p=0.018). A further gender-based subgroup analysis revealed significant associations of APOE rs7259620 and PPAP2B rs72664392 with CHD in males (genotype: χ²=8.379, df=2, p=0.015; allele: χ²=5.190, df=1, p=0.023; recessive model: χ²=19.3, df=1, p<0.0001) and females (genotype: χ²=9.878, df=2, p=0.007), respectively. Subsequent breakdown analysis by age showed that CETP rs4783961, MLXIPL rs35493868, and PON2 rs12704796 were significantly associated with CHD among individuals younger than 55 years of age (CETP rs4783961: χ²=8.966, df=1, p=0.011 by genotype; MLXIPL rs35493868: χ²=4.87, df=1, p=0.027 by allele; χ²=4.88, df=1, p=0.027 by dominant model; PON2 rs12704796: χ²=6.511, df=2, p=0.039 by genotype; χ²=6.210, df=1, p=0.013 by allele; χ²=5.03, df=1, p=0.025 by dominant model). Significant allelic association was observed between LEPR rs656451 and CHD among individuals older than 65 years of age (χ²=4.410, df=1, p=0.036).

Conclusion

Our study revealed significant associations of APOE, PPAP2B, CETP, MLXIPL, PON2, and LEPR gene polymorphisms with CHD among the Han Chinese.

A Guide to Applying the Sex-Gender Perspective to Nutritional Genomics

Precision nutrition aims to make dietary recommendations of a more personalized nature possible, to optimize the prevention or delay of a disease and to improve health. Therefore, the characteristics (including sex) of an individual have to be taken into account as well as a series of omics markers. The results of nutritional genomics studies are crucial to generate the evidence needed so that precision nutrition can be applied. Although sex is one of the fundamental variables for making recommendations, at present, the nutritional genomics studies undertaken have not analyzed, systematically and with a gender perspective, the heterogeneity/homogeneity in gene-diet interactions on the different phenotypes studied, thus there is little information available on this issue and needs to be improved. Here we argue for the need to incorporate the gender perspective in nutritional genomics studies, present the general context, analyze the differences between sex and gender, as well as the limitations to measuring them and to detecting specific sex-gene or sex-phenotype associations, both at the specific gene level or in genome-wide-association studies. We analyzed the main sex-specific gene-diet interactions published to date and their main limitations and present guidelines with recommendations to be followed when undertaking new nutritional genomics studies incorporating the gender perspective.

Proposed guidelines to evaluate scientific validity and evidence for genotype-based dietary advice

Nutrigenetic research examines the effects of inter-individual differences in genotype on responses to nutrients and other food components, in the context of health and of nutrient requirements. A practical application of nutrigenetics is the use of personal genetic information to guide recommendations for dietary choices that are more efficacious at the individual or genetic subgroup level relative to generic dietary advice. Nutrigenetics is unregulated, with no defined standards, beyond some commercially adopted codes of practice. Only a few official nutrition-related professional bodies have embraced the subject, and, consequently, there is a lack of educational resources or guidance for implementation of the outcomes of nutrigenetic research. To avoid misuse and to protect the public, personalised nutrigenetic advice and information should be based on clear evidence of validity grounded in a careful and defensible interpretation of outcomes from nutrigenetic research studies. Evidence requirements are clearly stated and assessed within the context of state-of-the-art 'evidence-based nutrition'. We have developed and present here a draft framework that can be used to assess the strength of the evidence for scientific validity of nutrigenetic knowledge and whether 'actionable'. In addition, we propose that this framework be used as the basis for developing transparent and scientifically sound advice to the public based on nutrigenetic tests. We feel that although this area is still in its infancy, minimal guidelines are required. Though these guidelines are based on semi-quantitative data, they should stimulate debate on their utility. This framework will be revised biennially, as knowledge on the subject increases.

Myocardial infarction in the Wisconsin Longitudinal Study: the interaction among environmental, health, social, behavioural and genetic factors

OBJECTIVES

This study examined how environmental, health, social, behavioural and genetic factors interact to contribute to myocardial infarction (MI) risk.

DESIGN

Survey data collected by Wisconsin Longitudinal Study (WLS), USA, from 1957 to 2011, including 235 environmental, health, social and behavioural factors, and 77 single- nucleotide polymorphisms were analysed for association with MI. To identify associations with MI we utilized recursive partitioning and random forest prior to logistic regression and chi-squared analyses.

PARTICIPANTS

6198 WLS participants (2938 men; 3260 women) who (1) had a MI before 72 years and (2) had a MI between 65 and 72 years.

RESULTS

In men, stroke (LR OR: 5.01, 95% CI 3.36 to 7.48), high cholesterol (3.29, 2.59 to 4.18), diabetes (3.24, 2.53 to 4.15) and high blood pressure (2.39, 1.92 to 2.96) were significantly associated with MI up to 72 years of age. For those with high cholesterol, the interaction of smoking and lower alcohol consumption increased prevalence from 23% to 41%, with exposure to dangerous working conditions, a factor not previously linked with MI, further increasing prevalence to 50%. Conversely, MI was reported in <2.5% of men with normal cholesterol and no history of diabetes or depression. Only stroke (4.08, 2.17 to 7.65) and diabetes (2.71, 1.81 to 4.04) by 65 remained significantly associated with MI for men after age 65. For women, diabetes (5.62, 4.08 to 7.75), high blood pressure (3.21, 2.34 to 4.39), high cholesterol (2.03, 1.38 to 3.00) and dissatisfaction with their financial situation (4.00, 1.94 to 8.27) were significantly associated with MI up to 72 years of age. Conversely, often engaging in physical activity alone (0.53, 0.32 to 0.89) or with others (0.34, 0.21 to 0.57) was associated with the largest reduction in odds of MI. Being non-diabetic with normal blood pressure and engaging in physical activity often lowered prevalence of MI to 0.2%. Only diabetes by 65 (4.25, 2.50 to 7.24) and being exposed to dangerous work conditions at 54 (2.24, 1.36 to 3.69) remained significantly associated with MI for women after age 65, while still menstruating at 54 (0.46, 0.23 to 0.91) was associated with reduced odds of MI.

CONCLUSIONS

Together these results indicate important differences in factors associated with MI between the sexes, that combinations of factors greatly influence the likelihood of MI, that MI-associated factors change and associations weaken after 65 years of age in both sexes, and that the limited genotypes assessed were secondary to environmental, health, social and behavioral factors.

Associations of the MCM6-rs3754686 proxy for milk intake in Mediterranean and American populations with cardiovascular biomarkers, disease and mortality: Mendelian randomization

Controversy persists on the association between dairy products, especially milk, and cardiovascular diseases (CVD). Genetic proxies may improve dairy intake estimations, and clarify diet-disease relationships through Mendelian randomization. We meta-analytically (n ≤ 20,089) evaluated associations between a lactase persistence (LP) SNP, the minichromosome maintenance complex component 6 (MCM6)-rs3754686C>T (nonpersistence>persistence), dairy intake, and CVD biomarkers in American (Hispanics, African-American and Whites) and Mediterranean populations. Moreover, we analyzed longitudinal associations with milk, CVD and mortality in PREDIMED), a randomized Mediterranean diet (MedDiet) intervention trial (n = 7185). The MCM6-rs3754686/MCM6-rs309180 (as proxy), LP-allele (T) was strongly associated with higher milk intake, but inconsistently associated with glucose and lipids, and not associated with CVD or total mortality in the whole population. Heterogeneity analyses suggested some sex-specific associations. The T-allele was associated with higher CVD and mortality risk in women but not in men (P-sex interaction:0.005 and 0.032, respectively), mainly in the MedDiet group. However, milk intake was not associated with CVD biomarkers, CVD or mortality either generally or in sub-groups. Although MCM6-rs3754686 is a good milk intake proxy in these populations, attributing its associations with CVD and mortality in Mediterranean women to milk is unwarranted, as other factors limiting the assumption of causality in Mendelian randomization may exist.

Sex hormones and macronutrient metabolism

The biological differences between males and females are determined by a different set of genes and by a different reactivity to environmental stimuli, including the diet, in general. These differences are further emphasized and driven by the exposure to a different hormone flux throughout the life.

These differences have not been taken into appropriate consideration by the scientific community. Nutritional sciences are not immune from this “bias” and when nutritional needs are concerned, females are considered only when pregnant, lactating or when their hormonal profile is returning back to “normal,” i.e., to the male-like profile.

The authors highlight some of the most evident differences in aspects of biology that are associated with nutrition.

This review presents and describes available data addressing differences and similarities of the “reference man” vs. the “reference woman” in term of metabolic activity and nutritional needs. According to this assumption, available evidences of sex-associated differences of specific biochemical pathways involved in substrate metabolism are reported and discussed. The modulation by sexual hormones affecting glucose, amino acid and protein metabolism and the metabolization of nutritional fats and the distribution of fat depots, is considered targeting a tentative starting up background for a gender concerned nutritional science.

The idiopathic preterm delivery methylation profile in umbilical cord blood DNA

BACKGROUND

Preterm delivery is the leading cause of neonatal morbidity and mortality. Two-thirds of preterm deliveries are idiopathic. The initiating molecular mechanisms behind spontaneous preterm delivery are unclear. Umbilical cord blood DNA samples are an easy source of material to study the neonatal state at birth. DNA methylation changes can be exploited as markers to identify spontaneous preterm delivery. To identify methylation differences specific to idiopathic preterm delivery, we assessed genome-wide DNA methylation changes in 24 umbilical cord blood samples (UCB) using the 450 K Illumina methylation array. After quality control, conclusions were based on 11 term and 11 idiopathic preterm born neonates. The differentially methylated positions (DMPs) specific for preterm/term delivery, neonatal sex, use of oxytocin and mode of initiation of labor were calculated by controlling the FDR p value at 0.05.

RESULTS

The analysis identifies 1855 statistically significant DMPs between preterm and term deliveries of which 508 DMPs are also attributable to clinical variables other than preterm versus term delivery. 1347 DMPs are unique to term vs preterm delivery, of which 196 DMPs do not relate to gestational age as such. Pathway analysis indicated enrichment of genes involved in calcium signalling, myometrial contraction and relaxation pathways. The 1151 DMPs that correlate with advancing gestational age (p < 0.05) include 161 DMPs that match with two previously reported studies on UCB methylation. Additionally, 123 neonatal sex specific DMPs, 97 DMPs specific to the induction of labour and 42 DMPs specific to the mode of initiation of labor were also identified.

CONCLUSION

This study identifies 196 DMPs in UCB DNA of neonates which do not relate to gestational age or any other clinical variable recorded and are specific to idiopathic preterm delivery. Furthermore, 161 DMPs from our study overlap with previously reported studies of which a subset is also reported to be differentially methylated at 18 years of age. A DMP on MYL4, encoding myosin light chain 4, is a robust candidate for the identification of idiopathic preterm labour as it is identified by all 3 independent studies.

Birth Cohort, Age, and Sex Strongly Modulate Effects of Lipid Risk Alleles Identified in Genome-Wide Association Studies

Insights into genetic origin of diseases and related traits could substantially impact strategies for improving human health. The results of genome-wide association studies (GWAS) are often positioned as discoveries of unconditional risk alleles of complex health traits. We re-analyzed the associations of single nucleotide polymorphisms (SNPs) associated with total cholesterol (TC) in a large-scale GWAS meta-analysis. We focused on three generations of genotyped participants of the Framingham Heart Study (FHS). We show that the effects of all ten directly-genotyped SNPs were clustered in different FHS generations and/or birth cohorts in a sex-specific or sex-unspecific manner. The sample size and procedure-therapeutic issues play, at most, a minor role in this clustering. An important result was clustering of significant associations with the strongest effects in the youngest, or 3rd Generation, cohort. These results imply that an assumption of unconditional connections of these SNPs with TC is generally implausible and that a demographic perspective can substantially improve GWAS efficiency. The analyses of genetic effects in age-matched samples suggest a role of environmental and age-related mechanisms in the associations of different SNPs with TC. Analysis of the literature supports systemic roles for genes for these SNPs beyond those related to lipid metabolism. Our analyses reveal strong antagonistic effects of rs2479409 (the PCSK9 gene) that cautions strategies aimed at targeting this gene in the next generation of lipid drugs. Our results suggest that standard GWAS strategies need to be advanced in order to appropriately address the problem of genetic susceptibility to complex traits that is imperative for translation to health care.

Polymorphisms in the glucocorticoid receptor gene and in the glucocorticoid-induced transcript 1 gene are associated with disease activity and response to glucocorticoid bridging therapy in rheumatoid arthritis

Glucocorticoids (GC) are widely used in rheumatoid arthritis (RA). Ongoing active disease due to GC resistance may unfavorably influence long-term disease outcome in RA. We studied the association between the presence of glucocorticoid receptor (GR) and glucocorticoid-induced transcript 1 (GLCCI1) gene polymorphisms, which modulate GC sensitivity, and baseline disease activity score (DAS) and efficacy of GC bridging therapy in RA. We prospectively studied in vivo GC sensitivity in 138 patients with recent-onset or longstanding RA. In vivo GC sensitivity was expressed as the relative decrease in DAS following 2 weeks of standardized GC therapy. All patients were genotyped for the GR polymorphisms BclI (rs41423247), N363S (rs6195), 9β (rs6198), ER22/23EK (rs6189 + rs6190), and the GLCCI1 variant rs37972 and subsequently divided in groups carrying a polymorphism associated with increased GC sensitivity (BclI-G allele, N363S-G allele, GLCCI1-C allele) or decreased GC sensitivity (9β-G allele, ER22/23EK-A/A allele, GLCCI1-T allele). Differences in baseline DAS and relative decrease in DAS in the different genotype groups were analyzed using analysis of covariance and linear regression. Baseline DAS was higher in patients who carried polymorphisms of the GR and GLCCI1 genes associated with decreased GC sensitivity. GLCCI1 genotype, but not GR genotypes, was associated with improvement in DAS in male patients with RA. The GLCCI1 gene minor allele (rs37972) may be associated with less efficient GC bridging therapy in male RA patients. Carriers of the BclI-G, N363S-G, or GLCCI1-C alleles had lower levels of baseline disease activity, suggesting a role for the GLCCI1 and GR gene in regulation of GC sensitivity to endogenously produced cortisol.

The role of NOD2 in murine and human melioidosis

Nucleotide-binding oligomerization domain 2 (NOD2) is a cytosolic pathogen recognition receptor that regulates susceptibility to a variety of infections and chronic diseases. Burkholderia pseudomallei, a facultative intracellular bacterium, causes the tropical infection melioidosis. We hypothesized that NOD2 may participate in host defense in melioidosis. We performed a series of in vitro assays and in vivo experiments and analyzed the association of human genetic variation with infection to delineate the contribution of NOD2 to the host response to B. pseudomallei. We found that transfection with NOD2 mediated NF-κB activation induced by B. pseudomallei stimulation of HEK293 cells. After low-dose inoculation with aerosolized B. pseudomallei, Nod2-deficient mice showed impaired clinical responses and permitted greater bacterial replication in the lung and dissemination to the spleen compared with wild-type mice. IL-6 and KC levels were higher in the lungs of Nod2-deficient mice. In a cohort of 1562 Thai subjects, a common genetic polymorphism in the NOD2 region, rs7194886, was associated with melioidosis, and this effect was most pronounced in women. rs7194886 was not associated with differences in cytokine production induced by whole-blood stimulation with the NOD2 ligand, muramyl dipeptide, or B. pseudomallei. To our knowledge, these findings are the first to characterize the role of NOD2 in host defense in mammalian melioidosis.

Sex, gender, genetics, and health

This article addresses 2 questions. First, to what extent are sex and gender incorporated into research on genetics and health? Second, how might social science understandings of sex and gender, and gender differences in health, become more integrated into scholarship in this area? We review articles on genetics and health published in selected peer-reviewed journals. Although sex is included frequently as a control or stratifying variable, few articles articulate a conceptual frame or methodological justification for conducting research in this way, and most are not motivated by sex or gender differences in health. Gender differences in health are persistent, unexplained, and shaped by multilevel social factors. Future scholarship on genetics and health needs to incorporate more systematic attention to sex and gender, gender as an environment, and the intertwining of social and biological variation over the life course. Such integration will advance understandings of gender differences in health, and may yield insight regarding the processes and circumstances that make genomic variation relevant for health and well-being.

Trade-off in the effect of the APOE gene on the ages at onset of cardiocascular disease and cancer across ages, gender, and human generations

Decades of studies of candidate genes show their complex role in aging-related traits. We focus on apolipoprotein E e2/3/4 polymorphism and ages at onset of cardiovascular diseases (CVD) and cancer in the parental and offspring generations of the Framingham Heart Study participants to gain insights on the role of age and gender across generations in genetic trade-offs. The analyses show that the apolipoprotein E e4 allele carriers live longer lives without cancer than the non-e4 allele carriers in each generation. The role of the e4 allele in onset of CVD is age- and generation-specific, constituting two modes of sexually dimorphic genetic trade-offs. In offspring, the e4 allele confers risk of CVD primarily in women and can protect against cancer primarily in men of the same age. In the parental generation, genetic trade-off is seen in different age groups, with a protective role of the e4 allele against cancer in older men and its detrimental role in CVD in younger women. The puzzling complexity of genetic mechanisms working in different genders, ages, and environments calls for more detail and systemic analyses beyond those adapted in current large-scale genetic association studies.

The role of lipid-related genes, aging-related processes, and environment in healthspan

The inherent complexity of aging-related traits can temper progress in unraveling the genetic origins of healthspan. We focus on two generations in the Framingham Heart Study, the original (FHS) and offspring (FHSO) cohorts, to determine whether aging-related processes in changing environments can substantially impact the role of lipid-related genes discovered in candidate gene (the apolipoprotein E (APOE) e2/3/4 polymorphism) and genome-wide (the APOB rs1042034 (C/T)) studies, in regulation of total cholesterol (TC) and onset of cardiovascular disease (CVD). We demonstrate that the APOE e4 allele and APOB CC genotype can play detrimental, neutral, and protective sex-specific roles in the etiology of CVD at different ages and in different environments. We document antagonistic roles for the e4 allele in the onset of CVD characterized by detrimental effects at younger ages (RR≤ 75 years = 1.49, P = 7.5 × 10(-4) ) and protective effects at older ages (RR76+years = 0.77, P = 0.044) for FHS participants. We found that disregarding the role of aging erroneously nullifies the significant effects of the e4 allele in this sample (RR = 0.92, P = 0.387). The leading biogenetic pathways mediating genetic effects on CVD may be more relevant to lipid metabolism for APOB than APOE. Aging-related processes can modulate the strength of genetic associations with TC in the same individuals at different chronological ages. We found substantial differences in the effects of the same APOE and APOB alleles on CVD and TC across generations. The results suggest that aging-related processes in changing environments may play key roles in the genetics of healthspan. Detailed systemic integrative analyses may substantially advance the progress.

Personalized medicine in women's obesity prevention and treatment: implications for research, policy and practice

The prevalence of obesity in America has reached epidemic proportions, and obesity among women is particularly concerning. Severe obesity (body mass index ≥35 kg m(-2) ) is more prevalent in women than men. Further, women have sex-specific risk factors that must be considered when developing preventive and therapeutic interventions. This review presents personalized medicine as a dynamic approach to obesity prevention, management and treatment for women. First, we review obesity as a complex health issue, with contributing sex-specific, demographic, psychosocial, behavioural, environmental, epigenetic and genetic/genomic risk factors. Second, we present personalized medicine as a rapidly advancing field of health care that seeks to quantify these complex risk factors to develop more targeted and effective strategies that can improve disease management and/or better minimize an individual's likelihood of developing obesity. Third, we discuss how personalized medicine can be applied in a clinical setting with current and emerging tools, including health risk assessments, personalized health plans, and strategies for increasing patient engagement. Finally, we discuss the need for additional research, training and policy that can enhance the practice of personalized medicine in women's obesity, including further advancements in the '-omics' sciences, physician training in personalized medicine, and additional development and standardization of innovative targeted therapies and clinical tools.

Update on perilipin polymorphisms and obesity

Perilipin proteins were discovered in the adipocyte, where they regulate lipid storage and lipolysis. Animal knockout models provided initial evidence of the critical role of perilipin 1, the most abundant of the adipocyte proteins, in energy and glucose metabolism. During a decade of study, genetic variation in perilipin 1 has been consistently but not invariably associated with body weight and obesity-related complications. Related phenotypes such as postprandial lipid metabolism and aerobic fitness are also modulated by perilipin 1 genotype, consistent with earlier metabolic studies. Investigations of gene-diet interactions, together with gene expression studies, have yielded increased understanding, but important questions about causal variants and mechanisms remain. The newest work examines perilipin 4, an adipocyte regulator of triglyceride synthesis and packaging. The novel discovery that a perilipin 4 variant creates a binding site for regulation of the perilipin gene (PLIN) by microRNA suggests intriguing new possibilities for additional mechanistic investigations of other perilipin proteins.

Mainstreaming sex and gender analysis in public health genomics

BACKGROUND

The integration of genome-based knowledge into public health or public health genomics (PHG) aims to contribute to disease prevention, health promotion, and risk reduction associated with genetic disease susceptibility. Men and women differ, for instance, in susceptibilities for heart disease, obesity, or depression due to biologic (sex) and sociocultural (gender) factors and their interaction. Genome-based knowledge is rapidly increasing, but sex and gender issues are often not explored.

OBJECTIVE

To explore the implications of a sex and gender analysis for PHG.

METHODS

We explore genome-based knowledge in relation to sex and gender aspects using depression as an example, gender equality, and the intersection of sex and gender with other social stratifiers such as ethnic background or socioeconomic status.

RESULTS

We advocate a sex- and gender-sensitive genomics research agenda alongside studies that provide sex-disaggregated data rather than controls based on sex. Such a research agenda is needed to guide research on how genomics is understood and perceived by men and women across groups, and for the equitable and responsible translation of such knowledge into the public health domain.

CONCLUSIONS

Including sex and gender analysis in PHG research will not only shed more light on phenomena such as diseases with a higher prevalence in either men or women, but will ultimately lead to gendered innovations by way of exploring how gendered and cultural environments increase or safeguard genetic predispositions.

Interaction of apolipoprotein E genotype with smoking and physical inactivity on coronary heart disease risk in men and women

OBJECTIVE

Apolipoprotein E genotype (APOE) polymorphism affects lipid levels and coronary heart disease (CHD) risk. However, these associations may be modified by lifestyle factors. Therefore, we studied whether smoking, physical inactivity or overweight interact with APOE on cholesterol levels and CHD risk.

METHODS

Combining two Swedish case-control studies yielded 1735 CHD cases and 4654 population controls (3747 men, 2642 women). Self-reported questionnaire lifestyle data included smoking (ever [current or former regular] or never) and physical inactivity (mainly sitting leisure time). We obtained LDL cholesterol levels and APOE genotypes. CHD risk was modelled using logistic regression to obtain odds ratios (ORs) and 95% confidence intervals (CIs), adjusted for relevant covariates.

RESULTS

Smoking interacted with APOE on CHD risk; adjusted ORs for ever versus never smoking were 1.45 (95% CI 1.00-2.10) in ɛ2 carriers, 2.25 (95% CI 1.90-2.68) in ɛ3 homozygotes and 2.37 (95% CI 1.85-3.04) in ɛ4 carriers. Female ɛ4 carriers had OR 3.62 (95% CI 2.32-5.63). The adjusted ORs for physical inactivity were 1.09 (95% CI 0.73-1.61), 1.34 (95% CI 1.12-1.61), and 1.79 (95% CI 1.38-2.30) in ɛ2, ɛ3ɛ3 and ɛ4 groups, respectively. No interaction was seen between overweight and APOE for CHD risk, or between any lifestyle factor and APOE for LDL cholesterol levels.

CONCLUSION

The APOE ɛ2 allele counteracted CHD risk from smoking in both genders, while the ɛ4 allele was seen to potentiate this risk mainly in women. Similar ɛ2 protection and ɛ4 potentiation was suggested for CHD risk from physical inactivity.

Different associations of apolipoprotein E polymorphism with metabolic syndrome by sex in an elderly Chinese population

The metabolic syndrome (MetS) is characterized by a cluster of metabolic disorders including abnormal lipid and lipoprotein metabolism. Apolipoprotein E (ApoE) is involved in the regulation of the metabolism of cholesterol, lipoproteins, and triglycerides. The common ApoE polymorphism has been found to be associated with cardiovascular disease and diabetes. This study evaluated the ApoE genetic polymorphism and its relation to MetS defined by the modified National Cholesterol Education Program and International Diabetes Federation criteria in a population-based cross-sectional survey of an elderly Chinese population in Beijing, China. Genotypes of 937 men and 1385 women were included in the study. All participants were measured for blood pressure, anthropometric measurements, and fasting concentrations of glucose, triglycerides, cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol. We applied a logistic regression model to derive adjusted odds ratios (ORs) and their 95% confidence intervals. In this Chinese population, the ɛ2, ɛ3, and ɛ4 allele frequencies were 8.3%, 83.4%, and 8.3% for men and 8.7%, 82.9%, and 8.4% for women, respectively. In men, concentrations of fasting triglycerides were higher among the APOE2 and E4 subjects; and a lower level of high-density lipoprotein cholesterol was observed in the APOE4 group. There were approximately linear associations of low-density lipoprotein cholesterol levels with APOE genotype groups in both men and women. We observed that the ɛ4 allele was associated with a significantly increased OR of MetS defined by the modified National Cholesterol Education Program criteria in men (OR, 1.75; 95% confidence interval, 1.17-2.63). In summary, our data show that common polymorphism of ApoE gene is associated with the presence of MetS in an elderly Chinese population.

Association of mtDNA haplogroup F with healthy longevity in the female Chuang population, China

Human longevity is a complex heritable genetic trait. Based on substantial evidence from model organisms, it is clear that mitochondria play a pivotal role in aging and lifespan. However, the effects that mitochondrial genome variations have upon longevity and longevity-related phenotypes in Chuang people in China have yet to be established. By genotyping 15 variants for 10 haplogroups in 738 Chuang subjects, including 367 long-lived individuals and 371 controls, we found that haplogroup F was significantly associated with longevity in females of Zhuang population of China (p=0.003, OR: 2.01, 95%CI: 1.263-3.197). Additionally, haplogroup F was related to higher HDL levels (p<0.05) in long-lived individuals. Further analysis suggests that the non-synonymous variant m.13928G>C in haplogroup F was also associated with longevity in female Zhuang Chinese which might account for the beneficial effect of F.

The influence of the S19W SNP of the APOA5 gene on triglyceride levels in southern Brazil: interactions with the APOE gene, sex and menopause status

BACKGROUND AND AIMS

Hypertriglyceridemia is an important independent risk factor for coronary artery diseases and is determined by a wide range of factors, both genetic and exogenous. The A5 apolipoprotein, which is associated with the synthesis and removal of triglycerides (TG), is encoded by the APOA5 gene. One of the polymorphisms of this gene that has been the focus of a large number of studies, and which appears to be associated with increased TG, is S19W (rs 3135506). In this study, we examined the influence of this single nucleotide polymorphism (SNP) on TG levels of a sample of southern Brazilians.

METHODS AND RESULTS

Samples obtained from 567 people of European descent were genotyped; interactions between this variant and anthropometric variables were analyzed, and the effects of lifestyle, sex, menopause, and variations of the APOE gene were evaluated. We found that the 19W allele is associated with increased TG (p = 0.025) and that this influence was modulated by sex (p = 0.003), menopause (p = 0.022) and the presence of the E*4 allele (p = 0.027).

CONCLUSION

Our data showed, for the first time, the importance and magnitude of the influence of the S19W variant in a southern Brazilian population.

The challenges for molecular nutrition research 1: linking genotype to healthy nutrition

Nutrition science finds itself at a major crossroad. On the one hand we can continue the current path, which has resulted in some substantial advances, but also many conflicting messages which impair the trust of the general population, especially those who are motivated to improve their health through diet. The other road is uncharted and is being built over the many exciting new developments in life sciences. This new era of nutrition recognizes the complex relation between the health of the individual, its genome, and the life-long dietary exposure, and has lead to the realisation that nutrition is essentially a gene-environment interaction science. This review on the relation between genotype, diet and health is the first of a series dealing with the major challenges in molecular nutrition, analyzing the foundations of nutrition research. With the unravelling of the human genome and the linking of its variability to a multitude of phenotypes from "healthy" to an enormously complex range of predispositions, the dietary modulation of these propensities has become an area of active research. Classical genetic approaches applied so far in medical genetics have steered away from incorporating dietary effects in their models and paradoxically, most genetic studies analyzing diet-associated phenotypes and diseases simply ignore diet. Yet, a modest but increasing number of studies are accounting for diet as a modulator of genetic associations. These range from observational cohorts to intervention studies with prospectively selected genotypes. New statistical and bioinformatics approaches are becoming available to aid in design and evaluation of these studies. This review discusses the various approaches used and provides concrete recommendations for future research.

Nutrigenetics and nutrigenomics: viewpoints on the current status and applications in nutrition research and practice

Nutrigenetics and nutrigenomics hold much promise for providing better nutritional advice to the public generally, genetic subgroups and individuals. Because nutrigenetics and nutrigenomics require a deep understanding of nutrition, genetics and biochemistry and ever new 'omic' technologies, it is often difficult, even for educated professionals, to appreciate their relevance to the practice of preventive approaches for optimising health, delaying onset of disease and diminishing its severity. This review discusses (i) the basic concepts, technical terms and technology involved in nutrigenetics and nutrigenomics; (ii) how this emerging knowledge can be applied to optimise health, prevent and treat diseases; (iii) how to read, understand and interpret nutrigenetic and nutrigenomic research results, and (iv) how this knowledge may potentially transform nutrition and dietetic practice, and the implications of such a transformation. This is in effect an up-to-date overview of the various aspects of nutrigenetics and nutrigenomics relevant to health practitioners who are seeking a better understanding of this new frontier in nutrition research and its potential application to dietetic practice.

Strenuous resistance to natural HIV-1 disease progression: viral controllers and long-term nonprogressors

HIV-1 infection leads to AIDS and death within 8–10 years for most individuals in the absence of antiretroviral therapy (ART). However, a minority of infected individuals show the unusual capacity to spontaneously control disease progression after infection in the absence of any ART. So-called ‘long-term nonprogressors’ are defined by maintenance of peripheral CD4+ T-cell counts >500 cells/µl and good health without ART for >7 years since infection. More recently, ART-naive individuals who spontaneously control their viremia levels at either <50 or <2000 copies of RNA/ml for at least 12 months in the absence of ART have been named ‘elite controllers’ and ‘HIV controllers’, respectively. The overlap between long-term nonprogressors and elite controllers/HIV controllers is partial, and both groups collectively account for <5% of all infected individuals. Unraveling the nature of their relative resistance to HIV-1 disease progression would be of great value for HIV-prevention strategies.

Loci from a genome-wide analysis of bilirubin levels are associated with gallstone risk and composition

BACKGROUND & AIMS

Genome-wide association studies have mapped loci that are associated with serum levels of bilirubin. Bilirubin is a major component of gallstones so we investigated whether these variants predict gallstone bilirubin content and overall risk for gallstones.

METHODS

Loci that were identified in a meta-analysis to attain a genome-wide significance level of a P value less than 1.0×10(-7) (UGT1A1, SLCO1B1, LST-3TM12, SLCO1A2) were analyzed in 1018 individuals with known gallstone composition. Gallstone risk was analyzed in 2606 German choleystecomized individuals and 1121 controls and was replicated in 210 cases and 496 controls from South America.

RESULTS

By using the presence of bilirubin as a phenotype, variants rs6742078 (UGT1A1; P = .003), rs4149056 (SLCO1B1; P = .003), and rs4149000 (SLCO1A2; P = .015) were associated with gallstone composition. In regression analyses, only UGT1A1 and SLCO1B1 were independently retained in the model. UGT1A1 (rs6742078; P = .018) was associated with overall gallstone risk. In a sex-stratified analysis, only male carriers of rs6742078 had an increased risk for gallstone disease (P = 2.1×10(-7); odds ratio(recessive), 2.34; P(women) = .47). The sex-specific association of rs6742078 was confirmed in samples from South America (P(men) = .046; odds ratio(recessive), 2.19; P(women) = .96).

CONCLUSIONS

The UGT1A1 Gilbert syndrome variant rs6742078 is associated with gallstone disease in men; further studies are required regarding the sex-specific physiology of bilirubin and bile acid metabolism. Variants of ABCG8 and UGT1A1 are the 2 major risk factors for overall gallstone disease, they contribute a population attributable risk of 21.2% among men.

Long-term effects of intrauterine growth restriction on cardiac metabolism and susceptibility to ischaemia/reperfusion

AIMS

Adult offspring who are born intrauterine growth restricted (IUGR) are at risk of developing cardiovascular diseases during adulthood. Additionally, several cardiac diseases are associated with changes in myocardial energy metabolism. However, the potential long-term effects of being born IUGR on cardiac energetics are unknown. The aim of this study was to assess the long-term effect of IUGR on cardiac performance and energy metabolism under aerobic conditions and after ischaemia/reperfusion (IR) injury.

METHODS AND RESULTS

To induce IUGR, pregnant Sprague-Dawley rats were randomly assigned to hypoxic (11.5% O(2)) or control (21% O(2)) environments from day 15 to 21 of pregnancy. Cardiac susceptibility to IR was evaluated in male and female offspring at 4 (young-adult) or 12 (ageing) months of age using isolated working hearts. Cardiac production of energy was evaluated using radiolabelled substrates. Both male and female IUGR offspring exhibited an increased susceptibility to IR injury compared with controls (P< 0.05) as well as an increased post-ischaemic production of protons (P< 0.001) secondary to a mismatch between myocardial glycolysis and glucose oxidation rates. Moreover, offspring born IUGR exhibited an increased myocardial production of acetyl-CoA during reperfusion. The mismatch between energy production and cardiac performance indicates that in IUGR offspring, cardiac efficiency during reperfusion was decreased relative to controls.

CONCLUSION

Our results suggest that hypoxia-induced IUGR has long-term effects on cardiac susceptibility to IR injury that are independent of sex and age. Moreover, we identified a mismatch in glucose metabolism, leading to proton accumulation in the post-ischaemic myocardium of offspring born IUGR as a potential mechanism involved.

AKT1 G205T genotype influences obesity-related metabolic phenotypes and their responses to aerobic exercise training in older Caucasians

As part of the insulin signalling pathway, Akt influences growth and metabolism. The AKT1 gene G205T (rs1130214) polymorphism has potential functional effects. Thus, we determined whether the G205T polymorphism influences metabolic variables and their responses to aerobic exercise training. Following dietary stabilization, healthy, sedentary, 50- to 75-year-old Caucasian men (n = 51) and women (n = 58) underwent 6 months of aerobic exercise training. Before and after completing the intervention, dual-energy X-ray absorptiometry was used to measure percentage body fat, computed tomography to measure visceral and subcutaneous fat, and oral glucose tolerance testing to measure glucose total area under the curve (AUC), insulin AUC and insulin sensitivity. Taqman assay was used to determine AKT1 G205T genotypes. At baseline, men with the GG genotype (n = 29) had lower maximal oxygen consumption (VO2 max) values (P = 0.026) and higher percentage body fat (P = 0.046), subcutaneous fat (P = 0.021) and insulin AUC (P = 0.003) values than T allele carriers (n = 22). Despite their rather disadvantageous starting values, men with the GG genotype seemed to respond to exercise training more robustly than men with the T allele, highlighted by significantly greater fold change improvements in insulin AUC (P = 0.012) and glucose AUC (P = 0.035). Although the GG group also significantly improved VO2 max with training, the change in VO2 max was not as great as that of the T allele carriers (P = 0.037). In contrast, after accounting for hormone replacement therapy use, none of the variables differed in the women at baseline. As a result of exercise training, women with the T allele (n = 20) had greater fold change improvements in fasting glucose (P = 0.011), glucose AUC (P = 0.017) and insulin sensitivity (P = 0.044) than GG genotype women (n = 38). Our results suggest that the AKT1 G205T polymorphism influences metabolic variables and their responses to aerobic exercise training in older, previously sedentary individuals.

Influence of genetic variants in the apolipoprotein A5 and C3 gene on lipids, lipoproteins, and its association with coronary artery disease in Indians

Indians worldwide demonstrate a triad of elevated triglyceride (TG) with high low-density lipoprotein cholesterol and low high-density lipoprotein cholesterol levels. In the present study, we aim to investigate the effect of -1131T > C, -3A > G, c.56 C > G, and c.553 G > T SNPs in the apolipoprotein A5 (APOA5) gene and 1100C > T and 3238C > G in the apolipoprotein C3 (APOC3) on plasma lipid and lipoprotein levels and risk of coronary artery disease (CAD) in Indians. Genotyping and lipid assays were carried out using standard protocols in a study population that included 150 controls and 90 cases with CAD. Significant associations between minor alleles and higher TG levels were seen for -1131T > C (P < 0.001), -3A > G (P < 0.001), c.56C > G (P = 0.026), and c.553G > T (P = 0.003) SNPs in the APOA5 gene and 1100C > T (P = 0.001) and 3238C > G (P = 0.009) in the APOC3 gene. The haplotypes 11211, 22111, 11112, and 22112 were significantly associated with TG levels (P = 0.025, P = 0.017, P = 0.027, and P < 0.001, respectively) and very-low-density lipoprotein cholesterol levels (P = 0.025, P = 0.017, P < 0.001, and P = 0.002) in males. The 22111, 11112, and 22112 were associated with elevated TG (P = 0.030, P = 0.036, and P = 0.024) but not VLDL-C levels in females. No association with other lipid parameters was seen. In the logistic regression model, the rare S2 allele was a significant risk factor (P = 0.030, 95% CI 1.186-31.432) along with smoking (P < 0.0001, 95% CI 2.018-10.397) for CAD. The APOA5 and APOC3 locus is a strong determinant of plasma TG levels in Indians. The APOC3 3238G is a risk factor for CAD and a higher frequency was also seen with type 2 diabetes mellitus.

Association of lifestyle factors, polymorphisms in adiponectin, perilipin and hormone sensitive lipase, and clinical markers in Japanese males

According to recent genome-wide association studies, a number of single nucleotide polymorphisms is reported to be associated with diseases or several clinical markers. Among them, adiponectin (ADIPOQ) and perilipin (PLIN) polymorphisms are major factors of obesity. However, the association between lifestyle factor, these polymorphisms and obesity-related clinical markers in Japanese is not well researched. Therefore, the aim of present study is to investigate the association between lifestyle factor, polymorphisms of lipid metabolic genes, and clinical markers in 148 middle-aged Japanese males. The study revealed that ADIPOQ 45 T>G and ADIPOQ 276 G>T genotypes were significantly associated with triglyceride, total cholesterol, hemoglobin A1c (HbA1c) in blood and body mass index (BMI). PLIN4 11482 G>A and hormone sensitive lipase (LIPE)-60 C>G genotypes were respectively associated with BMI and serum triglyceride. Not only genetic factors but also lifestyle factors influence several clinical markers. The BMI of subjects who like sweets and have the GG allele in ADIPOQ 276 G>T was higher than that of subjects who don't like sweets. The habit of eating fruits and fish affected low-density lipoprotein-cholesterol of the GT allele and HbA1c of the TT allele in ADIPOQ 276 G>T. Those findings indicate improvement and conservation of lifestyle depending on genetic predisposition in ADIPOQ, PLIN and LIPE should be encouraged.

Saturated fats: a perspective from lactation and milk composition

For recommendations of specific targets for the absolute amount of saturated fat intake, we need to know what dietary intake is most appropriate? Changing agricultural production and processing to lower the relative quantities of macronutrients requires years to accomplish. Changes can have unintended consequences on diets and the health of subsets of the population. Hence, what are the appropriate absolute amounts of saturated fat in our diets? Is the scientific evidence consistent with an optimal intake of zero? If not, is it also possible that a finite intake of saturated fats is beneficial to overall health, at least to a subset of the population? Conclusive evidence from prospective human trials is not available, hence other sources of information must be considered. One approach is to examine the evolution of lactation, and the composition of milks that developed through millennia of natural selective pressure and natural selection processes. Mammalian milks, including human milk, contain 50% of their total fatty acids as saturated fatty acids. The biochemical formation of a single double bond converting a saturated to a monounsaturated fatty acid is a pathway that exists in all eukaryotic organisms and is active within the mammary gland. In the face of selective pressure, mammary lipid synthesis in all mammals continues to release a significant content of saturated fatty acids into milk. Is it possible that evolution of the mammary gland reveals benefits to saturated fatty acids that current recommendations do not consider?

Sex-specific genetic dissection of diabetes in a rodent model identifies Ica1 and Ndufa4 as major candidate genes

The aim of the study was to initiate a sex-specific investigation of the molecular basis of diabetes, using a genomic approach in the Cohen Diabetic rat model of diet-induced Type 2 diabetes. We used an F2 population resulting from a cross between Cohen Diabetic susceptible (CDs) and resistant (CDr) and consisting of 132 males and 159 females to detect relevant QTLs by linkage and cosegregation analyses. To confirm the functional relevance of the QTL, we applied the "chromosome substitution" strategy. We identified candidate genes within the quantitative trait locus (QTL) and studied their differential expression. We sequenced the differentially expressed candidate genes to account for differences in their expression. We confirmed in this new cross in males a previously detected major QTL on rat chromosome 4 (RNO4); we identified in females this major QTL as well. We found three additional diabetes-related QTLs on RNO11, 13, and 20 in females only. We pursued the investigation of the QTL on RNO4 and generated a CDs.4(CDr) consomic strain, which provided us with functional confirmation for the contribution of the QTL to the diabetic phenotype in both sexes. We successfully narrowed the QTL span to 2.6 cM and identified within it six candidate genes, but only two of which, Ica1 (islet cell autoantigen 1) and Ndufa4 (NADH dehydrogenase ubiquinone) were differentially expressed between CDs and CDr. We sequenced the exons and promoter regions of Ica1 and Ndufa4 but did not identify sequence variations between the strains. The detection of the QTL on RNO4 in both sexes suggests involvement of Ica1, Ndufa4, the Golgi apparatus, the mitochondria and genetic susceptibility to dietary-environmental factors in the pathophysiology of diabetes in our model. The additional sex-specific QTLs are likely to account for differences in the diabetic phenotype between the sexes.

Sociodemographic status and self-reported BMI-related morbidity in Koreans

PURPOSE

This study examined whether the relationship between body mass index (BMI) and the morbidity of chronic diseases differs by marital status, education, and income level.

MATERIALS AND METHODS

From a nationally representative sample of 5,526 adults from the third Korean National Health and Nutrition Examination Survey (2005), data regarding measured height and weight to classify BMI category (< 23, 23-24.9, > or = 25), self-reported sociodemographics (marital status, education, income, age, sex, and residence area), health behaviors (smoking, alcohol use, exercise, sleep, stress perception, and depression), and morbidity from at least one chronic disease were collected.

RESULTS

Education, income, and marital status were significantly associated with morbidity regardless of adjustment for BMI and health behaviors. After adjusting for BMI, other sociodemographic factors, and health behaviors, the odds ratio (95% confidence interval) of morbidity was 2.9 (2.4-3.7) for those in the married group and 2.9 (2.1-4.0) for those in the separated/divorced/widowed group, 2.0 (1.6-2.5) for those in the lowest education group, and 1.3 (1.2-1.6) for those in the lowest income group. When the BMI category and sociodemographic factors were combined, the odds ratios were elevated for those in the combination group with higher BMI and lower sociodemographic position.

CONCLUSION

Korean subjects who were married, in the lowest education group, or in the lowest income level had a higher risk of morbidity in relation to BMI.

The influence of nutrigenetics on the lipid profile: interaction between genes and dietary habits

Nutrigenetics is a new field with few studies in Latin America. Our aim is to investigate the way in which different genes related to the lipid profile influence the response to specific dietary habits. Eight polymorphisms on seven genes were investigated in a sample (n = 567) from Porto Alegre, RS, Brazil. All the volunteers completed a food diary that was then assessed and classified into nine food groups. A number of nutrigenetic interactions were detected primarily related to the apolipoprotein E (apoE) gene. For example, frequent consumption of foods rich in polyunsaturated fat resulted in the beneficial effect of increasing HDL-C only in individuals who were not carriers of the E*4 allele of the APOE gene, whereas variations in eating habits of E*4 carriers did not affect their HDL-C (P = 0.018). Our data demonstrate for the first time nutrigenetic interactions in a Brazilian population.

Commonly studied polymorphisms in inflammatory cytokine genes show only minor effects on mortality and related risk factors in nonagenarians

Systemic low-grade inflammation is consistently associated with functional status, cognitive functioning, multimorbidity, and survival in oldest olds. If inflammation is either a cause or a consequence of age-related pathology, genetic determinants of late-life survival can reside in cytokine genes polymorphisms, regulating inflammatory responses. The aim of this study was to test associations between commonly studied polymorphisms in interleukin (IL)6, IL10, IL15, and IL18, and tumor necrosis factor-alpha genes and late-life survival in a longitudinal cohort of nonagenarians: the Danish 1905 cohort. Additionally, associations were investigated between inflammatory markers and major predictors of mortality as cognitive and functional status. Modest sex-specific associations were found with survival, cognitive functioning, and handgrip strength. Evaluation of combined genotypes indicated that, in nonagenarian men, the balance of pro- and anti-inflammatory activity at IL18 and IL10 loci is protective against cognitive decline. In conclusion, in this large study with virtually complete follow-up, commonly studied polymorphisms in cytokine genes do not have a major impact on late-life survival or associated risk phenotypes.

Cardiac health in women with metabolic syndrome: clinical aspects and pathophysiology

Although the classical cardiovascular risk factors (e.g., smoking and hypertension) are becoming more effectively managed, a continuous increase of the so-called "cardiometabolic risk" is noted. Starting from this century, the nomenclature "metabolic syndrome" has become more popular to identify a cluster of disorders including obesity, dyslipidemia, hypertension, and insulin resistance. It is a primary risk factor for diabetes and cardiovascular disease in both genders. Interestingly, the metabolic diseases display a distinct gender disparity with an apparent "female advantage" in the premenopausal women compared with age-matched men. However, women usually lose such "sex protection" following menopause or affliction of metabolic syndrome especially insulin resistance. A controversy exists in the medical literature concerning whether metabolic syndrome is a real syndrome or simply a cluster of risk factors. Several scenarios are speculated to contribute to the gender dimorphism in the cardiovascular sequelae in patients with metabolic syndrome including sex hormones, intrinsic organ function, and the risk factor profile (e.g., hypertension, dyslipidemia, obesity, sedentary lifestyle, and atherogenic diet). With the alarming rise of obesity prevalence, heart problems in metabolic syndrome continue to rise with a distinct gender dimorphism. Although female hearts seem to better tolerate the stress insults compared with the male counterparts, the female sex hormones such as estrogen can interact with certain risk factors to precipitate myopathic changes in the hearts. This synthetic review of recent literature suggests a role of gender disparity in myopathic factors and risk attributable to each metabolic component in the different prevalence of metabolic syndrome.

Better science with sex and gender: Facilitating the use of a sex and gender-based analysis in health research

Much work has been done to promote sex and gender-based analyses in health research and to think critically about the influence of sex and gender on health behaviours and outcomes. However, despite this increased attention on sex and gender, there remain obstacles to effectively applying and measuring these concepts in health research. Some health researchers continue to ignore the concepts of sex and gender or incorrectly conflate their meanings. We report on a primer that was developed by the authors to help researchers understand and use the concepts of sex and gender in their work. We provide detailed definitions of sex and gender, discuss a sex and gender-based analysis (SGBA), and suggest three approaches for incorporating sex and gender in health research at various stages of the research process. We discuss our knowledge translation process and share some of the challenges we faced in disseminating our primer with key stakeholders. In conclusion, we stress the need for continued attention to sex and gender in health research.

PAT proteins, an ancient family of lipid droplet proteins that regulate cellular lipid stores

The PAT family of lipid droplet proteins includes 5 members in mammals: perilipin, adipose differentiation-related protein (ADRP), tail-interacting protein of 47 kDa (TIP47), S3-12, and OXPAT. Members of this family are also present in evolutionarily distant organisms, including insects, slime molds and fungi. All PAT proteins share sequence similarity and the ability to bind intracellular lipid droplets, either constitutively or in response to metabolic stimuli, such as increased lipid flux into or out of lipid droplets. Positioned at the lipid droplet surface, PAT proteins manage access of other proteins (lipases) to the lipid esters within the lipid droplet core and can interact with cellular machinery important for lipid droplet biogenesis. Genetic variations in the gene for the best-characterized of the mammalian PAT proteins, perilipin, have been associated with metabolic phenotypes, including type 2 diabetes mellitus and obesity. In this review, we discuss how the PAT proteins regulate cellular lipid metabolism both in mammals and in model organisms.

Genomewide association study of an AIDS-nonprogression cohort emphasizes the role played by HLA genes (ANRS Genomewide Association Study 02)

To elucidate the genetic factors predisposing to AIDS progression, we analyzed a unique cohort of 275 human immunodeficiency virus (HIV) type 1-seropositive nonprogressor patients in relation to a control group of 1352 seronegative individuals in a genomewide association study (GWAS). The strongest association was obtained for HCP5 rs2395029 (P=6.79x10(-10); odds ratio, 3.47) and was possibly linked to an effect of sex. Interestingly, this single-nucleotide polymorphism (SNP) was in high linkage disequilibrium with HLA-B, MICB, TNF, and several other HLA locus SNPs and haplotypes. A meta-analysis of our genomic data combined with data from the previously conducted Euro-CHAVI (Center for HIV/AIDS Vaccine Immunology) GWAS confirmed the HCP5 signal (P=3.02x10(-19)) and identified several new associations, all of them involving HLA genes: MICB, TNF, RDBP, BAT1-5, PSORS1C1, and HLA-C. Finally, stratification by HCP5 rs2395029 genotypes emphasized an independent role for ZNRD1, also in the HLA locus, and this finding was confirmed by experimental data. The present study, the first GWAS of HIV-1 nonprogressors, underscores the potential for some HLA genes to control disease progression soon after infection.

Nutrigenetics and personalised nutrition: how far have we progressed and are we likely to get there?

Nutrigenetics and personalised nutrition are components of the concept that in the future genotyping will be used as a means of defining dietary recommendations to suit the individual. Over the last two decades there has been an explosion of research in this area, with often conflicting findings reported in the literature. Reviews of the literature in the area of apoE genotype and cardiovascular health, apoA5 genotype and postprandial lipaemia and perilipin and adiposity are used to demonstrate the complexities of genotype–phenotype associations and the aetiology of apparent between-study inconsistencies in the significance and size of effects. Furthermore, genetic research currently often takes a very reductionist approach, examining the interactions between individual genotypes and individual disease biomarkers and how they are modified by isolated dietary components or foods. Each individual possesses potentially hundreds of ‘at-risk’ gene variants and consumes a highly-complex diet. In order for nutrigenetics to become a useful public health tool, there is a great need to use mathematical and bioinformatic tools to develop strategies to examine the combined impact of multiple gene variants on a range of health outcomes and establish how these associations can be modified using combined dietary strategies.