Gene-nutrient interactions in the metabolic syndrome: single nucleotide polymorphisms in ADIPOQ and ADIPOR1 interact with plasma saturated fatty acids to modulate insulin resistance

Gene-environment interactions that influence CVD, lipid traits, obesity, diabetes, and hypertension appear to be able to influence gene therapy

Most mind boggling diseases are accepted to be impacted by both genetic and environmental elements. As of late, there has been a flood in the improvement of different methodologies, concentrate on plans, and measurable and logical techniques to examine gene-environment cooperations (G × Es) in enormous scope studies including human populaces. The many-sided exchange between genetic elements and environmental openings has long charmed the consideration of clinicians and researchers looking to grasp the complicated starting points of diseases. While single variables can add to disease, the blend of genetic variations and environmental openings frequently decides disease risk. The fundamental point of this paper is to talk about the Gene-Environment Associations That Impact CVD, Lipid Characteristics, Obesity, Diabetes, and Hypertension Have all the earmarks of being Ready to Impact Gene Therapy. This survey paper investigates the meaning of gene-environment collaborations (G × E) in disease advancement. The intricacy of genetic and environmental communications in disease causation is explained, underlining the multifactorial idea of many circumstances. The job of gene-environment cooperations in cardiovascular disease, lipid digestion, diabetes, obesity, and hypertension is investigated. This audit fixates on Gene by Environment (G × E) collaborations, investigating their importance in disease etiology.

Identification of a novel lipid metabolism-related gene signature for predicting colorectal cancer survival

Colorectal cancer (CRC) is a common malignant tumor worldwide. Lipid metabolism is a prerequisite for the growth, proliferation and invasion of cancer cells. However, the lipid metabolism-related gene signature and its underlying molecular mechanisms remain unclear. The aim of this study was to establish a lipid metabolism signature risk model for survival prediction in CRC and to investigate the effect of gene signature on the immune microenvironment. Lipid metabolism-mediated genes (LMGs) were obtained from the Molecular Signatures Database. The consensus molecular subtypes were established using "ConsensusClusterPlus" based on LMGs and the cancer genome atlas (TCGA) data. The risk model was established using univariate and multivariate Cox regression with TCGA database and independently validated in the international cancer genome consortium (ICGC) datasets. Immune infiltration in the risk model was developed using CIBERSORT and xCell analyses. A total of 267 differentially expressed genes (DEGs) were identified between subtype 1 and subtype 2 from consensus molecular subtypes, including 153 upregulated DEGs and 114 downregulated DEGs. 21 DEGs associated with overall survival (OS) were selected using univariate Cox regression analysis. Furthermore, a prognostic risk model was constructed using the risk coefficients and gene expression of eleven-gene signature. Patients with a high-risk score had poorer OS compared with patients in the low-risk score group (p = 3.36e-07) in the TCGA cohort and the validationdatasets (p = 4.03e-05). Analysis of immune infiltration identified multiple T cells were associated with better prognosis in the low-risk group, including Th2 cells (p = 0.0208), regulatory T cells (p = 0.0425), and gammadelta T cells (p = 0.0112). A nomogram integrating the risk model and clinical characteristics was further developed to predict the prognosis of patients with CRC. In conclusion, our study revealed that the expression of lipid-metabolism genes were correlated with the immune microenvironment. The eleven-gene signature might be useful for prediction the prognosis of CRC patients.

Adiponectin gene polymorphisms and posttraumatic stress disorder symptoms among female rape survivors: an exploratory study

Background: Rape is a common traumatic event which may result in the development of posttraumatic stress disorder (PTSD), yet few studies have investigated risk biomarkers in sexually traumatised individuals. Adiponectin is a novel cytokine within inflammatory and cardiometabolic pathways with evidence of involvement in PTSD. Objective: This prospective exploratory study in a sample of female rape survivors investigated the association of single nucleotide polymorphisms (SNPs) in the adiponectin gene (ADIPOQ) and posttraumatic stress symptom (PTSS) severity, and the interaction of these SNPs of interest with childhood trauma in modifying the association with PTSS severity. Method: The study involved 455 rape-exposed black South African women (mean age (SD), 25.3 years (±5.5)) recruited within 20 days of being raped. PTSS was assessed using the Davidson Trauma Scale (DTS) and childhood trauma was assessed using a modified version of the Childhood Trauma Scale-Short Form Questionnaire. Eight ADIPOQ SNPs (rs17300539, rs16861194, rs16861205, rs2241766, rs6444174, rs822395, rs1501299, rs1403697) were genotyped using KASP. Mixed linear regression models were used to test additive associations of ADIPOQ SNPs and PTSS severity at baseline, 3 and 6 months following rape. Results: The mean DTS score post-sexual assault was high (71.3 ± 31.5), with a decrease in PTSS severity shown over time for all genotypes. rs6444174TT genotype was inversely associated with baseline PTSS in the unadjusted model (β = -13.6, 95% CI [-25.1; -2.1], p = .021). However, no genotype was shown to be significantly associated with change in PTSS severity over time and therefore ADIPOQ SNP x childhood trauma interaction was not further investigated. Conclusion: None of the ADIPOQ SNPs selected for investigation in this population were shown to be associated with change in PTSS severity over a 6-month period and therefore their clinical utility as risk biomarkers for rape-related PTSD appears limited. These SNPs should be further investigated in possible gene-gene and gene-environment interactions.

Personalized Nutrition in the Management of Female Infertility: New Insights on Chronic Low-Grade Inflammation

Increasing evidence on the significance of nutrition in reproduction is emerging from both animal and human studies, suggesting a mutual association between nutrition and female fertility. Different “fertile” dietary patterns have been studied; however, in humans, conflicting results or weak correlations are often reported, probably because of the individual variations in genome, proteome, metabolome, and microbiome and the extent of exposure to different environmental conditions. In this scenario, “precision nutrition”, namely personalized dietary patterns based on deep phenotyping and on metabolomics, microbiome, and nutrigenetics of each case, might be more efficient for infertile patients than applying a generic nutritional approach. In this review, we report on new insights into the nutritional management of infertile patients, discussing the main nutrigenetic, nutrigenomic, and microbiomic aspects that should be investigated to achieve effective personalized nutritional interventions. Specifically, we will focus on the management of low-grade chronic inflammation, which is associated with several infertility-related diseases.

Serum concentrations of SFAs and CDKAL1 single-nucleotide polymorphism rs7747752 are related to an increased risk of gestational diabetes mellitus

BACKGROUND

Interactions between genetic and nutritional factors can contribute to the risk of gestational diabetes mellitus (GDM).

OBJECTIVES

We aimed to explore the associations of cyclin-dependent kinase 5 regulatory subunit associated protein 1-like 1 (CDKAL1) single-nucleotide polymorphism (SNP) rs7747752 and serum concentrations of SFAs with the risk of GDM in Chinese women.

METHODS

We conducted a 1:1 case-control study in a prospective cohort of pregnant women in Tianjin, China. Serum SFA data were collected from a total of 243 women with GDM and their controls matched by maternal age (±1 y). Among them, 207 case-control pairs had high-quality sequencing data. P/L and S/P ratios were defined as palmitic acid (16:0)/lauric acid (12:0) and stearic acid (18:0)/palmitic acid, respectively. Conditional logistic regression analysis was performed to estimate associations of CDKAL1 SNP rs7747752 and serum concentrations of SFAs with the risk of GDM. An additive interaction between rs7747752 and palmitic acid was analyzed to test the contribution of their interaction to the risk of GDM.

RESULTS

Among the 5 tested SFAs, palmitic acid was positively whereas lauric acid was negatively associated with the risk of GDM. A P/L ratio ≥12.2 and an S/P ratio ≤0.71 were independently and synergistically associated with an increased risk of GDM. The CDKAL1 rs7747752 G > C variant was significantly associated with an increased risk of GDM (P < 0.05). Furthermore, the presence of the rs7747752 G > C variant increased the OR (95% CI) of high palmitic acid concentration from 1.55 (0.61, 3.97) to 4.34 (2.04, 9.23), with a significant additive interaction.

CONCLUSIONS

The interaction between high serum palmitic acid concentration and the CDKAL1 rs7747752 G > C variant played a critical role in GDM. Given that a hypocaloric low-carbohydrate diet can lower palmitic acid concentrations, it is worthwhile to test whether such a diet is effective in reducing the risk of GDM, especially among women who have both risk factors.

Associations of the Polymorphisms in ADIPOQ with Circulating Levels of Adiponectin and Lipids: A Meta-Analysis

The relationships between the rs266729, rs1501299, and rs2241766 polymorphisms in adiponectin gene (ADIPOQ) and circulating levels of adiponectin and lipids remain to be clarified. Databases including PubMed and Embase were searched for eligible studies. The random-effects model was used, and standardized mean difference (SMD) with 95% confidence interval (CI) was calculated to estimate the differences in circulating levels of adiponectin and lipids between the subjects with different genotypes. A total of 12 810, 17 319, and 21 361 subjects were identified in the analyses for the rs266729, rs1501299, and rs2241766 polymorphisms, respectively. G allele carriers of the rs266729 polymorphism had lower levels of adiponectin (SMD=-0.28, 95% CI=-0.43 to-0.12) and high-density lipoprotein cholesterol (HDL-C) (SMD=-0.10, 95% CI=-0.17 to-0.02) than CC homozygotes; T allele carriers of the rs1501299 polymorphism had higher levels of adiponectin (SMD=0.21, 95% CI=0.05 to 0.36) and HDL-C (SMD=0.09, 95% CI=0.04 to 0.15) and lower levels of triglycerides (SMD=-0.06, 95% CI=-0.12 to-0.01) than GG homozygotes; G allele carriers of the rs2241766 polymorphism had lower levels of adiponectin (SMD=-0.18, 95% CI=-0.31 to-0.05) and HDL-C (SMD=-0.12, 95% CI=-0.20 to-0.04) than TT homozygotes. This meta-analysis suggests that the rs266729, rs1501299, and rs2241766 polymorphisms of ADIPOQ are significantly associated with circulating levels of adiponectin and lipids, which may partly explain the associations between these polymorphisms and coronary artery disease.

Genetically Guided Mediterranean Diet for the Personalized Nutritional Management of Type 2 Diabetes Mellitus

The current consensus for the prevention and management of type 2 diabetes mellitus (T2DM) is that high-quality diets and adherence to a healthy lifestyle provide significant health benefits. Remarkably, however, there is little agreement on the proportions of macronutrients in the diet that should be recommended to people suffering from pre-diabetes or T2DM. We herein discuss emerging evidence that underscores the importance of gene-diet interactions in the improvement of glycemic biomarkers in T2DM. We propose that we can achieve better glycemic control in T2DM patients by coupling Mediterranean diets to genetic information as a predictor for optimal diet macronutrient composition in a personalized manner. We provide evidence to support this concept by presenting a case study of a T2DM patient who achieved rapid glycemic control when adhered to a personalized, genetically-guided Mediterranean Diet.

Adiponectin gene variant rs266729 interacts with different macronutrient distributions of two different hypocaloric diets during nine months

Introduction

Background: the role of ADIPOQ gene variants on metabolic changes after weight loss secondary to different hypocaloric diets remains unclear and poorly investigated. Objective: we evaluated the effect of polymorphism rs266729 of ADIPOQ gene on biochemical changes and weight loss after a high-protein/low-carbohydrate diet vs a standard severe hypocaloric diet during 9 months. Material and methods: a population of 269 obese patients was enrolled in a randomized intervention trial for 9 months with two diets. Diet HP (high protein) was 33 % of carbohydrates (86.1 g/day), 33 % of fat (39.0 g/day), and 34 % of proteins (88.6 g/day). Diet S (standard) was 1093 cal/day, 53 % carbohydrates (144.3 g/day), 27 % fats (32.6 g), and 20 % proteins (55.6 g/day). Before and after the intervention an anthropometric evaluation, an assessment of nutritional intake, and a biochemical analysis were carried out. Results: all patients lost weight regardless of genotype and diet. After the intervention with a high protein hypocaloric diet (diet HP) only subjects with CC genotype showed significant improvement in cholesterol (14.4 ± 1.8 md/dL vs -5.0 ± 1.9 mg/dL; p = 0.02), LDL-cholesterol (14.4 ± 1.9 mg/dL vs -5.1 ± 1.8 mg/dL; p = 0.01), insulin (-4.1 ± 0.3 mU/L vs -2.0 ± 0.6 mU/L; p = 0.02), HOMA-IR (-1.4 ± 0.2 units vs -0.5 ± 0.3 units; p = 0.02) and adiponectin (10.2 ± 1.4 ng/dL vs 3.1 ± 1.1 ng/dL; p = 0.01) levels. After the second dietary strategy with a standard hypocaloric diet (diet S) only subjects with CC genotype showed significant improvement in total cholesterol (CC vs CG + GG) (-17.1 ± 1.9 md/dL vs -5.3 ± 1.3 mg/dL; p = 0.02), LDL-cholesterol (-12.3 ± 1.9 mg/dL vs -8.0 ± 1.2 mg/dL; p = 0.01), insulin (-4.0 ± 0.9 mU/L vs -1.3 ± 0.5 mU/L; p = 0.02), HOMA-IR (-1.2 ± 0.1 units vs -0.6 ± 0.2 units; p = 0.02), and adiponectin (11.1 ± 2.7 ng/dL vs 3.3 ± 1.2 ng/dL; p = 0.02) levels. Conclusion: non G-allele carriers showed a better response of LDL-cholesterol, HOMA-IR, insulin, and adiponectin levels than G-allele carriers before weight loss with both diets.

Genetic markers and continuity of healthy metabolic status: Tehran cardio-metabolic genetic study (TCGS)

Obese individuals can be categorized as “healthy obese” (MHO) and “unhealthy obese” (MUO) based on the presence or absence of metabolic abnormality. This study sets out to assess potential genetic causes behind persistence of healthy metabolic status in individuals categorized as “healthy obese”. This study was conducted in the framework of the Tehran cardio-metabolic genetic study (TCGS). 766 MHO subjects at the start of the study followed up 15 years for occurrence of metabolic unhealthy status. These two groups (persistent MHO, MUO) were compared regarding the presence or absence of 16 single nucleotide polymorphisms (SNPs) identified as being associated with obesity phenotype in previous studies. We used logistic regression model for assessing the association between MHO/MUO with candidate SNPs. By the end of the follow up, 206 (27%) were categorized as the persistent MHO and 560 (73%) as MUO groups. Considering interaction effect between some SNP and sex, a sex stratification analysis was applied. When the analysis was performed by gender, rs1121980 associated with a decrease, and rs7903146 with an increase in the likelihood of persistent MHO individuals. Another analysis was separately performed on postmenopausal women from both groups; it showed that rs13107325 was associated with an increase in the likelihood of persistent MHO status in this subgroup of woman. In all cases, the markers had dominant inheritance. This findings suggest that the expression of some genetic markers are associated with persistence of healthy metabolic status, in female obese individuals.

Inflammation and metabolism: the role of adiposity in sarcopenic obesity

Sarcopenic obesity is characterised by the double burden of diminished skeletal muscle mass and the presence of excess adiposity. From a mechanistic perspective, both obesity and sarcopenia are associated with sub-acute, chronic pro-inflammatory states that impede metabolic processes, disrupting adipose and skeletal functionality, which may potentiate disease. Recent evidence suggests that there is an important cross-talk between metabolism and inflammation, which has shifted focus upon metabolic-inflammation as a key emerging biological interaction. Dietary intake, physical activity and nutritional status are important environmental factors that may modulate metabolic-inflammation. This paradigm will be discussed within the context of sarcopenic obesity risk. There is a paucity of data in relation to the nature and the extent to which nutritional status affects metabolic-inflammation in sarcopenic obesity. Research suggests that there may be scope for the modulation of sarcopenic obesity with alterations in diet. The potential impact of increasing protein consumption and reconfiguration of dietary fat composition in human dietary interventions are evaluated. This review will explore emerging data with respect to if and how different dietary components may modulate metabolic-inflammation, particularly with respect to adiposity, within the context of sarcopenic obesity.

Genetic Variants of the PLCXD3 Gene Are Associated with Risk of Metabolic Syndrome in the Emirati Population

Phosphatidylinositol-specific phospholipase C X domain 3 (PLCXD3) has been shown to influence pancreatic β-cell function by disrupting insulin signaling. Herein, we investigated two genetic variants in the PLCXD3 gene in relation to type 2 diabetes (T2D) or metabolic syndrome (MetS) in the Emirati population. In total, 556 adult Emirati individuals (306 T2D and 256 controls) were genotyped for two PLCXD3 variants (rs319013 and rs9292806) using TaqMan genotyping assays. The frequency distribution of minor homozygous CC genotype of rs9292806 and GG genotype of rs319013 were significantly higher in subjects with MetS compared to Non-MetS (p < 0.01). The minor homozygous rs9292806-CC and rs319013-GG genotypes were significantly associated with increased risk of MetS (adj. OR 2.92; 95% CI 1.61–5.3; p < 0.001) (adj. OR 2.62; 95% CI 1.42–4.83; p = 0.002), respectively. However, no associations were detected with T2D. In healthy participants, the homozygous minor genotypes of both rs9292806 and rs319013 were significantly higher fasting glucose (adj. p < 0.005), HbA1c (adj. p < 0.005) and lower HDL-cholesterol (adj. p < 0.05) levels. Data from T2D Knowledge Portal database disclosed a nominal association of rs319013 and rs9292806 with T2D and components of MetS. Bioinformatics prediction analysis showed a deleterious effect of rs9292806 on the regulatory regions of PLCXD3. In conclusion, this study identifies rs319013 and rs9292806 variants of PLCXD3 as additional risk factors for MetS in the Emirati population.

The interaction between dietary patterns and melanocortin-4 receptor polymorphisms in relation to obesity phenotypes

INTRODUCTION

Data shows that interactions between dietary factors and genetic variants can modulate the association of polymorphisms such as the Melanocortin-4 receptor (MC4R) gene with obesity. Considering the limited data available on this topic we aimed to investigate interactions between dietary patterns (DPs) and MC4R polymorphisms in relation to obesity phenotypes.

METHODS

This cohort study was performed in the framework of Tehran Lipid and Glucose Study; for eligible participants in this study (n=3850), the median follow-up was 4 years. DPs were determined using factor analysis. The genotypes of polymorphisms (17782313rs and 12970134rs) were identified and their interaction with DPs were assessed in relation to incidence of obesity phenotypes including central obesity, general obesity and visceral adiposity dysfunction.

RESULTS

The mean age of participants (62.5% females) were 37.0±13.7 years. Two main DPs (healthy and unhealthy) were extracted. C-allele carriers of rs17782313 in higher quartiles of the healthy DP score had a significant decrease in the incidence of general obesity, compared to those who had the TT genotype (HR=0.61, 95% CI=0.42-0.89, P interaction=0.01). For rs12970134 A-allele carriers, subjects in the second compared to the first quartile of the healthy DP score, had a significant decrease in the incidence of general obesity (HR=0.68, 95% CI=0.46-0.99). There were no significant interaction between DPs and MC4R variants in relation to other obesity phenotypes.

CONCLUSION

Our results indicate that the healthy DP could interact with rs17782313 in relation to incidence of general obesity.

Effect of two different dietary fatty acid profiles and variant rs266729 in ADIPOQ on weight loss and adiponectin concentrations

BACKGROUND

The role of ADIPOQ gene rs266729 variants on weight loss after a dietary intervention are still unclear.

OBJECTIVE

To analyze the effects of the ADIPOQ gene rs266729 variant n weight loss, cardiovascular risk factors, and adiponectin levels after two hypocaloric diets with different dietary fatty profiles.

DESIGN

A population of 362 obese patients was enrolled in a randomized clinical trial with two diets (Diet M, monounsaturated fat-enriched diet, and Diet P, polyunsaturated-fat enriched diet). Anthropometric measurements, an assessment of nutritional intake, and biochemical tests were performed at baseline and after 12 weeks.

RESULTS

Weight loss was similar with both diets. After Diet M, only subjects with CC genotype showed significant improvements in total cholesterol (CC vs. CG±GG) (-9.0±1.1mU/L vs. -4.5±2.4mg/dL, p=0.01), LDL cholesterol (-6.0±1.1mg/dL vs. -3.0±0.9mg/dL, p=0.03), glucose (-4.7±1.1mg/dL vs. -0.6±0.5mg/dL, p=0.01), and insulin levels (-2.6±1.0mU/L vs. -0.7±0.3mU/L, p=0.02) and in HOMA-IR (-0.5±0.2 units vs. -0.2±0.4 units, p=0.03). The same improvement was reported after Diet P in all parameters, including total cholesterol (CC vs. CG±GG) (-8.0±1.2mU/L vs. -2.1±1.4mg/dL, p=0.02), LDL cholesterol (-7.3±1.2mg/dL vs. -2.1±0.8mg/dL, p=0.02), glucose (-3.2±0.1mg/dL vs. -0.2±0.5mg/dL, p=0.01), and insulin levels (-2.5±1.0mU/L vs. -1±0.6mU/L, p=0.02) and HOMA-IR (-0.5±0.1 units vs. -0.3±0.4 units, p=0.02). Only subjects with CC genotype showed significant increases in adiponectin levels after both diets: (Diet M: 10.3±2.0ng/dL vs. Diet P: 9.3±2.9ng/dL, p=0.43).

CONCLUSION

The CC genotype of ADIPOQ gene rs266729 variant is associated to increased adiponectin levels and decreases in LDL cholesterol, glucose, insulin, and HOMA-IR levels after weight loss.

Adiponectin Gene Variant rs266729 Interacts with Different Macronutrient Distribution of Two Different Hypocaloric Diets

BACKGROUND

The role of ADIPOQ gene variants in weight loss after different dietary fat amounts remains unclear.

OBJECTIVE

Our aim was to analyze the effects of ADIPOQ gene polymorphism rs266729 on metabolic changes after two different amounts of dietary fat in two hypocaloric diets.

DESIGN

A population of 283 obese patients was recruited in a randomized clinical trial with two diets: Diet HF (high-fat diet: 38% carbohydrates, 24% proteins, and 38% fats) versus Diet LF (low-fat diet: 53% carbohydrates, 20% proteins, and 27% fats). Before and after 3 months, an anthropometric evaluation, an assessment of nutritional intake, and a biochemical analysis were carried out. The variant of the ADIPOQgene was assessed by real-time PCR.

RESULTS

Weight loss was similar with both diets in both genotypes (CC vs. CG+GG). After dietary intervention with Diet HF, only subjects with CC genotype showed a significant improvement in insulin levels (-3.3 ± 0.6 vs. -1.8 ± 0.9 mU/L; p = 0.03) and the homeostasis model assessment for insulin resistance (HOMA-IR) (-1.3 ± 0.1 vs. -0.8 ± 0.2 units; p = 0.02). After Diet LF, subjects with CC genotype showed a significant improvement in total cholesterol levels (CC vs. CG+GG) (-15.3 ± 1.4 vs. -6.4 ± 1.3 mg/dL; p = 0.01), LDL cholesterol (-14.6 ± 1.8 vs. -6.4 ± 1.3 mg/dL; p = 0.01), insulin levels (-4.6 ± 1.0 vs. -1.6 ± 0.5 mU/L; p = 0.01), and HOMA-IR (-1.6 ± 0.1 vs. -1.0 ± 0.2 units; p = 0.02). Only subjects with CC genotype showed a significant increase of adiponectin levels after both diets (CC vs. CG+GG): Diet HF (10.6 ± 2.0 vs. 1.8 ± 1.0 ng/dL; p = 0.01) and Diet LF (16.1 ± 2.8 vs. 1.3 ± 1.0 ng/dL: p = 0.03).

CONCLUSION

CC genotype of ADIPOQgene variantrs266729 was associated with a better metabolic response after both diets. Additionally, Diet LF produced a significant improvement in lipid profile in noncarriers of allele G.

Associations of SNPs of the ADIPOQ Gene with Serum Adiponectin Levels, Unstable Angina, and Coronary Artery Disease

Adiponectin is encoded by the ADIPOQ gene and participates in the pathogenesis of cardiovascular and metabolic diseases. The goal of the study was to assess associations of rs17300539, rs266729, rs182052, rs2241766, and rs17366743 single nucleotide polymorphisms (SNPs) of the ADIPOQ gene with concentrations of serum adiponectin and with coronary atherosclerosis and type 2 diabetes mellitus in 447 patients (316 men and 131 women) subjected to coronary angiography. SNPs of the ADIPOQ gene of the study participants were genotyped using real-time PCR. Multivariate linear regression adjusted for covariates revealed significant association between rs182052 SNP and serum adiponectin concentration (β= -0.11; 95% confidence interval (95%CI): -0.19, -0.03; p = 0.016). Regression analysis revealed an increase in prevalence of unstable angina (OR (odds ratio) = 2.55; 95%CI 1.4-4.82; p = 0.018) and coronary artery disease (OR = 1.55; 95%CI 1.15-2.09; p = 0.021) per copy of the rs182052 A allele. Prevalence of type 2 diabetes mellitus was higher in subjects with the rs182052 A allele (OR = 2.29; 95%CI 1.29-4.21; p = 0.024). Regression analysis of rs266729 showed that prevalence of unstable angina was increased (OR = 3.59; 95%CI 1.17-10.01; p = 0.045) in the subjects with the GG genotype and prevalence of coronary artery disease (CAD) was significantly increased (OR = 1.48; 95%CI 1.09-2.03; p = 0.045) per copy of the G allele. Haplotype analysis revealed that the subjects with the GCATT haplotype have lower adiponectin levels (β= -0.15; p = 0.042) and higher prevalence of unstable angina (OR = 3.597; p = 0.007) compared with reference haplotype carriers. Thus, the results indicate that minor A allele of rs182052 of the ADIPOQ gene is significantly associated with a decrease in serum adiponectin levels, and two SNPs (rs182052 and rs266729) of the ADIPOQ gene are significantly associated with cardiovascular and metabolic diseases.

ADIPOQ + 45T≥G Polymorphism, Food Ingestion, and Metabolic Syndrome in Elderly Persons

INTRODUCTION

The current nutritional transition process contributes further to accelerate the onset of metabolic disorders, as do a number of environmental factors that lead to the diagnosis of chronic diseases, as a diet of low nutritional value, is possibly related to the incidence of metabolic syndrome. In addition to these factors, metabolic syndrome may also be related to genetic factors, the ADIPOQ + 45T> G polymorphism has been associated with serum adiponectin levels, insulin sensitivity, and obesity, which affects adiponectin levels act as protective factor for cardiovascular disease. In this way, the present study aimed to analyze the possible association between the ADIPOQ + 45T> G gene polymorphism, usual diet and metabolic syndrome in the elderly.

METHODS

We evaluated inflammatory and biochemical markers compared with older age groups (age 60 years) with and without metabolic syndrome. In addition to the anthropometric measurements of weight, height and waist circumference, the ADIPOQ + 45T> G gene polymorphism was determined by PCR- RFLP, and food consumption was investigated using a food frequency questionnaire.

RESULTS

The study included 111 elderly individuals. Our main results show that there was a significant relationship between the habitual consumption of milk for the group that had metabolic syndrome (p < 0.05). HDL-c levels, glucose, triglycerides, diastolic blood pressure and weight, height and waist circumference had to be altered in patients with metabolic syndrome. There was an association between habitual dietary intake of white meat with haplotypes TG and GG.

CONCLUSION

We conclude that the relationship between the habitual consumption of certain food groups and ADIPOQ indicates the need for further studies to develop a better understanding of this relationship; however, there was no association between the ADIPOQ + 45T> G gene polymorphism and metabolic syndrome in the group of elderly studied.

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.

Clustering high-dimensional mixed data to uncover sub-phenotypes: joint analysis of phenotypic and genotypic data

The LIPGENE-SU.VI.MAX study, like many others, recorded high-dimensional continuous phenotypic data and categorical genotypic data. LIPGENE-SU.VI.MAX focuses on the need to account for both phenotypic and genetic factors when studying the metabolic syndrome (MetS), a complex disorder that can lead to higher risk of type 2 diabetes and cardiovascular disease. Interest lies in clustering the LIPGENE-SU.VI.MAX participants into homogeneous groups or sub-phenotypes, by jointly considering their phenotypic and genotypic data, and in determining which variables are discriminatory. A novel latent variable model that elegantly accommodates high dimensional, mixed data is developed to cluster LIPGENE-SU.VI.MAX participants using a Bayesian finite mixture model. A computationally efficient variable selection algorithm is incorporated, estimation is via a Gibbs sampling algorithm and an approximate BIC-MCMC criterion is developed to select the optimal model. Two clusters or sub-phenotypes ('healthy' and 'at risk') are uncovered. A small subset of variables is deemed discriminatory, which notably includes phenotypic and genotypic variables, highlighting the need to jointly consider both factors. Further, 7 years after the LIPGENE-SU.VI.MAX data were collected, participants underwent further analysis to diagnose presence or absence of the MetS. The two uncovered sub-phenotypes strongly correspond to the 7-year follow-up disease classification, highlighting the role of phenotypic and genotypic factors in the MetS and emphasising the potential utility of the clustering approach in early screening. Additionally, the ability of the proposed approach to define the uncertainty in sub-phenotype membership at the participant level is synonymous with the concepts of precision medicine and nutrition. Copyright © 2017 John Wiley & Sons, Ltd.

Metabolically healthy obesity across the life course: epidemiology, determinants, and implications

In recent years, different subphenotypes of obesity have been described, including metabolically healthy obesity (MHO), in which a proportion of obese individuals, despite excess body fat, remain free of metabolic abnormalities and increased cardiometabolic risk. In the absence of a universally accepted set of criteria to classify MHO, the reported prevalence estimates vary widely. Our understanding of the determinants and stability of MHO over time and the associated cardiometabolic and mortality risks is improving, but many questions remain. For example, whether MHO is truly benign is debatable, and whether risk stratification of obese individuals on the basis of their metabolic health status may offer new opportunities for more personalized approaches in diagnosis, intervention, and treatment of diabetes remains speculative. Furthermore, as most of the research to date has focused on MHO in adults, little is known about childhood MHO. In this review, we focus on the epidemiology, determinants, stability, and health implications of MHO across the life course.

Revisiting the membrane-centric view of diabetes

Fundamental questions remain unresolved in diabetes: What is the actual mechanism of glucose toxicity? Why is there insulin resistance in type 2 diabetes? Why do diets rich in sugars or saturated fatty acids increase the risk of developing diabetes? Studying the C. elegans homologs of the anti-diabetic adiponectin receptors (AdipoR1 and AdipoR2) has led us to exciting new discoveries and to revisit what may be termed “The Membrane Theory of Diabetes”. We hypothesize that excess saturated fatty acids (obtained through a diet rich in saturated fats or through conversion of sugars into saturated fats via lipogenesis) leads to rigid cellular membranes that in turn impair insulin signalling, glucose uptake and blood circulation, thus creating a vicious cycle that contributes to the development of overt type 2 diabetes. This hypothesis is supported by our own studies in C. elegans and by a wealth of literature concerning membrane composition in diabetics. The purpose of this review is to survey this literature in the light of the new results, and to provide an admittedly membrane-centric view of diabetes.

A Variant in ADIPOR2 Is Associated with Increased Free Fatty Acid Levels in Chinese Population

BACKGROUND

Elevated free fatty acids (FFAs) are thought to play an important role in the development of insulin resistance. Adiponectin is an adipose tissue-secreted protein known for its effects on the stimulation of fatty acid oxidation. The aim of this study was to investigate the association of adiponectin receptor 2 gene variations with FFAs levels in subjects with normal fasting glucose levels in Chinese Han population.

METHODS

Four common single nucleotide polymorphisms of ADIPOR2 were genotyped using the TaqMan method to perform association studies with metabolic parameters in 1819 subjects among Chinese Han population. All the subjects were divided into two groups: normal FFAs group (FFAs ≤0.88 mmol/L) and high FFAs group (FFAs >0.88 mmol/L).

RESULTS

There was a significant association of rs2370055 with higher FFA levels in major T-allele carriers (P = 0.000). There was a significant difference in the distribution of genotypes of polymorphism rs2370055 between normal and high FFA groups. The frequencies of TT and CT genotypes are significantly higher in subjects with high FFA level than those in the normal FFAs group (P = 0.013 and P = 0.004, respectively). After adjustment for age, sex, body mass index, triglyceride, total cholesterol, high-density lipoprotein cholesterol, and low-density lipoproteincholesterol, the TT and CT genotypes are both independent risk factors for high FFAs level.

CONCLUSIONS

Our findings suggest that variants of ADIPOR2 could be a determinant for higher FFA levels, and among Chinese Han population, carriers of the CT and TT genotypes for rs2370055 even with normal glucose levels may have significantly higher insulin resistance susceptibility.

Complementary Effects of Genetic Variations in LEPR on Body Composition and Soluble Leptin Receptor Concentration after 3-Month Lifestyle Intervention in Prepubertal Obese Children

In obese individuals, weight loss might be affected by variants of the adipokine-encoding genes. We verified whether selected functional single nucleotide polymorphisms in LEP, LEPR and ADIPOQ are associated with changes in serum levels of the respective adipokines and weight loss in 100 prepubertal obese (SDS-BMI > 2) Caucasian children undergoing lifestyle intervention. Frequencies of the -2548G > A LEP, Q223R LEPR, K656N LEPR, -11377C > G and -11426A > G ADIPOQ polymorphisms were analyzed by restriction fragment length polymorphism. Serum adipokine and soluble leptin receptor (sOB-R) concentrations were measured using the ELISA method. Among the analyzed polymorphisms, only LEPR polymorphisms were associated with changes of SDS-BMI or sOB-R concentrations in children after therapy. Carriers of the wild-type K665N and at least one minor Q223R allele had the greatest likelihood of losing weight (OR = 5.09, p = 0.006), an increase in sOB-R (ptrend = 0.022) and decrease in SDS-BMI correlated with the decrease of fat mass (p < 0.001). In contrast, carrying of the wild-type Q223R and at least one minor K665N allele were associated with a decrease in sOB-R concentrations and a decrease in SDS-BMI correlated with a decrease in fat-free mass (p = 0.002). We suggest that the combination of different LEPR variants, not a single variant, might determine predisposition to weight loss in the prepubertal period.

Low-grade inflammation, diet composition and health: current research evidence and its translation

The importance of chronic low-grade inflammation in the pathology of numerous age-related chronic conditions is now clear. An unresolved inflammatory response is likely to be involved from the early stages of disease development. The present position paper is the most recent in a series produced by the International Life Sciences Institute's European Branch (ILSI Europe). It is co-authored by the speakers from a 2013 workshop led by the Obesity and Diabetes Task Force entitled ‘Low-grade inflammation, a high-grade challenge: biomarkers and modulation by dietary strategies’. The latest research in the areas of acute and chronic inflammation and cardiometabolic, gut and cognitive health is presented along with the cellular and molecular mechanisms underlying inflammation–health/disease associations. The evidence relating diet composition and early-life nutrition to inflammatory status is reviewed. Human epidemiological and intervention data are thus far heavily reliant on the measurement of inflammatory markers in the circulation, and in particular cytokines in the fasting state, which are recognised as an insensitive and highly variable index of tissue inflammation. Potential novel kinetic and integrated approaches to capture inflammatory status in humans are discussed. Such approaches are likely to provide a more discriminating means of quantifying inflammation–health/disease associations, and the ability of diet to positively modulate inflammation and provide the much needed evidence to develop research portfolios that will inform new product development and associated health claims.

Gene-gene, gene-environment, gene-nutrient interactions and single nucleotide polymorphisms of inflammatory cytokines

Inflammation plays a significant role in the etiology of type 2 diabetes mellitus (T2DM). The rise in the pro-inflammatory cytokines is the essential step in glucotoxicity and lipotoxicity induced mitochondrial injury, oxidative stress and beta cell apoptosis in T2DM. Among the recognized markers are interleukin (IL)-6, IL-1, IL-10, IL-18, tissue necrosis factor-alpha (TNF-α), C-reactive protein, resistin, adiponectin, tissue plasminogen activator, fibrinogen and heptoglobins. Diabetes mellitus has firm genetic and very strong environmental influence; exhibiting a polygenic mode of inheritance. Many single nucleotide polymorphisms (SNPs) in various genes including those of pro and anti-inflammatory cytokines have been reported as a risk for T2DM. Not all the SNPs have been confirmed by unifying results in different studies and wide variations have been reported in various ethnic groups. The inter-ethnic variations can be explained by the fact that gene expression may be regulated by gene-gene, gene-environment and gene-nutrient interactions. This review highlights the impact of these interactions on determining the role of single nucleotide polymorphism of IL-6, TNF-α, resistin and adiponectin in pathogenesis of T2DM.

Gene-gene and gene-environment interactions detected by transcriptome sequence analysis in twins

Understanding the genetic architecture of gene expression is an intermediate step in understanding the genetic architecture of complex diseases. RNA sequencing technologies have improved the quantification of gene expression and allow measurement of allele-specific expression (ASE). ASE is hypothesized to result from the direct effect of cis regulatory variants, but a proper estimation of the causes of ASE has not been performed thus far. In this study, we take advantage of a sample of twins to measure the relative contributions of genetic and environmental effects to ASE, and we find substantial effects from gene × gene (G×G) and gene × environment (G×E) interactions. We propose a model where ASE requires genetic variability in cis, a difference in the sequence of both alleles, but where the magnitude of the ASE effect depends on trans genetic and environmental factors that interact with the cis genetic variants.

Interactions between differential fatty acids and inflammatory stressors-impact on metabolic health

Current interest in obesity has established a clear link between diets high in fat and metabolic complications such as Type 2 Diabetes. Dietary fats and their metabolites act as stressors to induce a pro-inflammatory immune response which dysregulates many essential metabolic functions. Recent research suggests that different dietary fats may have varying inflammatory potentials. However the molecular mechanisms involved in the cross talk between dietary fat composition and the 'immuno-metabolism' remain enigmatic. It is probable that lipids, and their derivatives, differentially regulate IL-1β activation and inflammatory signaling via the NLRP3 inflammasome complex. Also from the translational perspective, certain nutrient sensitive genotypes and potential gene nutrient interactions offer the possibility to reduce inflammation through personalized nutrition approaches.

Interactions between ADIPOQ gene variants and dietary monounsaturated: saturated fatty acid ratio on serum lipid levels in Korean children

BACKGROUND AND AIMS

Adiponectin plays important roles in the regulation of insulin action and metabolism of glucose and lipids. We investigated whether ADIPOQ genetic variants are associated with serum lipid levels in Korean children and whether those influences might be modulated by dietary factors such as dietary monounsaturated fatty acid to saturated fatty acid ratio (MUFA:SFA).

METHOD AND RESULTS

The study included a population-based sample of 687 children aged 7-11 years in Gwacheon city, Kyunggi Province, Korea. Anthropometric and biochemical measurements and ADIPOQ genotype (-11377 C/G, +45 T/G, and +276 G/T) were determined. Dietary intake was estimated with a self reported 3-day food diary. The -11377 G allele carriers had significantly higher serum total cholesterol and LDL cholesterol compared to non-carriers. When dietary MUFA:SFA ratio was dichotomized (MUFA:SFA ≥ 1 or <1), the aggravating effects of the minor allele on serum total and LDL cholesterol were only present when the MUFA:SFA ratio was <1. Additionally, we observed that the ADIPOQ haplotype influenced serum total and LDL cholesterol levels. G-T-G haplotype carriers had higher total and LDL cholesterol levels than non-G-T-G carriers. The deleterious effect of ADIPOQ G-T-G haplotype to increase serum total and LDL cholesterol could be seen only when the MUFA:SFA ratio was <1.

CONCLUSION

In this present study, we found interaction effects between ADIPOQ genetic variants and dietary MUFA:SFA ratio on serum lipid levels in Korean children. These results suggest that individual genetic information and dietary fatty acid intake information should be assessed together to achieve an effective outcome for reducing the atherogenic lipid profile.

Regulation of glucose and lipid homeostasis by adiponectin: effects on hepatocytes, pancreatic β cells and adipocytes

Adiponectin has received considerable attention for its potential anti-diabetic actions. The adipokine exerts control of glucose and lipid homeostasis via critical effects within the liver, adipose, and pancreas. By stimulating adipogenesis, opposing inflammation, and influencing rates of lipid oxidation and lipolysis, adiponectin critically governs lipid spillover into non-adipose tissues. Ceramide, a cytotoxic and insulin desensitizing lipid metabolite formed when peripheral tissues are exposed to excessive lipid deposition, is potently opposed by adiponectin. Via adiponectin receptors, AdipoR1 and AdipoR2, adiponectin stimulates the deacylation of ceramide- yielding sphingosine for conversion to sphingosine 1-phosphate (S1P) by sphingosine kinase. The resulting conversion from ceramide to S1P promotes survival of functional beta cell mass, allowing for insulin production to meet insulin demands. Alleviation of ceramide burden on the liver allows for improvements in hepatic insulin action. Here, we summarize how adiponectin-induced changes in these tissues lead to improvements in glucose metabolism, highlighting the sphingolipid signaling mechanisms linking adiponectin to each action. ONE SENTENCE SUMMARY: We review the anti-diabetic actions of adiponectin.

Causal relationship between adiponectin and metabolic traits: a Mendelian randomization study in a multiethnic population

Background

Adiponectin, a secretagogue exclusively produced by adipocytes, has been associated with metabolic features, but its role in the development of the metabolic syndrome remains unclear.

Objectives

We investigated the association between serum adiponectin level and metabolic traits, using both observational and genetic epidemiologic approaches in a multiethnic population assembled in Canada.

Methods

Clinical data and serum adiponectin level were collected in 1,157 participants of the SHARE/SHARE-AP studies. Participants were genotyped for the functional rs266729 and rs1260326 SNPs in ADIPOQ and GCKR genes.

Results

Adiponectin level was positively associated with HDL cholesterol and negatively associated with body mass index, waist-to-hip ratio, triglycerides, fasting glucose, fasting insulin, systolic and diastolic pressure (all P<0.002). The rs266729 minor G allele was associated with lower adiponectin and higher HOMA-IR (P = 0.004 and 0.003, respectively). The association between rs266729 SNP and HOMA-IR was no longer significant after adjustment for adiponectin concentration (P = 0.10). The rs266729 SNP was associated with HOMA-IR to an extent that exceeded its effect on adiponectin level (0.15 SD 95% C.I. [0.06, 0.24], P<0.001). There was no significant interaction between rs266729 SNP and ethnicity on adiponectin or HOMA-IR. In contrast, the SNP rs1260326 in GCKR was associated with HOMA-IR (P<0.001), but not with adiponectin level (P = 0.67).

Conclusion

The association of the functional promoter polymorphism rs266729 with lower serum adiponectin and increased insulin resistance in diverse ethnic groups may suggest a causal relationship between adiponectin level and insulin resistance.

Mechanisms of obesity-induced inflammation and insulin resistance: insights into the emerging role of nutritional strategies

Obesity and associated chronic inflammation initiate a state of insulin resistance (IR). The secretion of chemoattractants such as MCP-1 and MIF and of cytokines IL-6, TNF-α, and IL-1β, draw immune cells including dendritic cells, T cells, and macrophages into adipose tissue (AT). Dysfunctional AT lipid metabolism leads to increased circulating free fatty acids, initiating inflammatory signaling cascades in the population of infiltrating cells. A feedback loop of pro-inflammatory cytokines exacerbates this pathological state, driving further immune cell infiltration and cytokine secretion and disrupts the insulin signaling cascade. Disruption of normal AT function is causative of defects in hepatic and skeletal muscle glucose homeostasis, resulting in systemic IR and ultimately the development of type 2 diabetes. Pharmaceutical strategies that target the inflammatory milieu may have some potential; however there are a number of safety concerns surrounding such pharmaceutical approaches. Nutritional anti-inflammatory interventions could offer a more suitable long-term alternative; whilst they may be less potent than some pharmaceutical anti-inflammatory agents, this may be advantageous for long-term therapy. This review will investigate obese AT biology, initiation of the inflammatory, and insulin resistant environment; and the mechanisms through which dietary anti-inflammatory components/functional nutrients may be beneficial.

A gene variation (rs12691) in the CCAT/enhancer binding protein α modulates glucose metabolism in metabolic syndrome

BACKGROUND AND AIMS

CCAAT/enhancer-binding protein alpha (CEBPA) is a transcription factor involved in adipogenesis and energy homeostasis. Caloric restriction reduces CEBPA protein expression in patients with metabolic syndrome (MetS). A previous report linked rs12691 SNP in CEBPA to altered concentration of fasting triglycerides. Our objective was to assess the effects of rs12691 in glucose metabolism in Metabolic Syndrome (MetS) patients.

METHODS AND RESULTS

Glucose metabolism was assessed by static (glucose, insulin, adiponectin, leptin and resistin plasma concentrations) and dynamic (disposition index, insulin sensitivity index, HOMA-IR and acute insulin response to glucose) indices, performed at baseline and after 12 weeks of 4 dietary interventions (high saturated fatty acid (SFA), high monounsaturated fatty acid (MUFA), low-fat and low-fat-high-n3 polyunsaturated fatty acid (PUFA)) in 486 subjects with MetS. Carriers of the minor A allele of rs12691 had altered disposition index (p = 0.0003), lower acute insulin response (p = 0.005) and a lower insulin sensitivity index (p = 0.025) indicating a lower insulin sensitivity and a lower insulin secretion, at baseline and at the end of the diets. Furthermore, A allele carriers displayed lower HDL concentration.

CONCLUSION

The presence of the A allele of rs12691 influences glucose metabolism of MetS patients.

Diverse physiological effects of long-chain saturated fatty acids: implications for cardiovascular disease

PURPOSE OF REVIEW

The purpose of this review is to discuss the metabolism of long-chain saturated fatty acids and the ensuing effects on an array of metabolic events.

RECENT FINDINGS

Individual long-chain saturated fatty acids exhibit unique biological properties. Dietary saturated fat absorption varies depending on chain-length and the associated food matrix. The in-vivo metabolism of saturated fatty acids varies depending on the individual fatty acid and the nutritional state of the individual. A variety of fatty acid metabolites are formed, each with their own unique structure and properties that warrant further research. Replacing saturated fatty acids with unsaturated fatty acids improves the blood lipid profile and reduces cardiovascular disease risk, although the benefits depend on the specific saturated fatty acid(s) being replaced.

SUMMARY

Acknowledging the complexity of saturated fatty acid metabolism and associated metabolic events is important when assessing their effects on cardiovascular disease risk. Investigating the biological effects of saturated fatty acids will advance our understanding of how they affect cardiovascular disease risk.

Nutrigenetics and metabolic disease: current status and implications for personalised nutrition

Obesity, particularly central adiposity, is the primary causal factor in the development of insulin resistance, the hallmark of the metabolic syndrome (MetS), a common condition characterized by dyslipidaemia and hypertension, which is associated with increased risk of cardiovascular disease (CVD) and type 2 diabetes (T2DM). Interactions between genetic and environmental factors such as diet and lifestyle, particularly over-nutrition and sedentary behavior, promote the progression and pathogenesis of these polygenic diet-related diseases. Their current prevalence is increasing dramatically to epidemic proportions. Nutrition is probably the most important environmental factor that modulates expression of genes involved in metabolic pathways and the variety of phenotypes associated with obesity, the MetS and T2DM. Furthermore, the health effects of nutrients may be modulated by genetic variants. Nutrigenomics and nutrigenetics require an understanding of nutrition, genetics, biochemistry and a range of “omic” technologies to investigate the complex interaction between genetic and environmental factors relevant to metabolic health and disease. These rapidly developing fields of nutritional science hold much promise in improving nutrition for optimal personal and public health. This review presents the current state of the art in nutrigenetic research illustrating the significance of gene-nutrient interactions in the context of metabolic disease.

Personalised nutrition: ready for practice?

The efficacy by which dietary interventions influence risk markers of multi-factorial diseases is mainly determined by taking population-based approaches. However, there exists considerable inter-individual variation in response to dietary interventions, and some interventions may benefit certain individuals or population subgroups more than others. This review evaluates the application of nutrigenomic technologies to further the concept of personalised nutrition, as well as the process to take personalised nutrition to the marketplace. The modulation of an individual's response is influenced by both genetic and environmental factors. Many nutrigenetics studies have attempted to explain variability in responses based on a single or a few genotypes so that a genotype may be used to define personalised dietary advice. It has, however, proven very challenging to define an individual's responsiveness to complex diets based on common genetic variations. In addition, there is a limited understanding of what constitutes an optimal response because we lack key health biomarkers and signatures. In conclusion, advances in nutrigenomics will undoubtedly further the understanding of the complex interplay between genotype, phenotype and environment, which are required to enhance the development of personalised nutrition in the future. At the same time, however, issues relating to consumer acceptance, privacy protection as well as marketing and distribution of personalised products need to be addressed before personalised nutrition can become commercially viable.

A Period 2 genetic variant interacts with plasma SFA to modify plasma lipid concentrations in adults with metabolic syndrome

Genetic variants of Period 2 (PER2), a circadian clock gene, have been linked to metabolic syndrome (MetS). However, it is still unknown whether these genetic variants interact with the various types of plasma fatty acids. This study investigated whether common single nucleotide polymorphisms (SNPs) in the PER2 locus (rs934945 and rs2304672) interact with various classes of plasma fatty acids to modulate plasma lipid metabolism in 381 participants with MetS in the European LIPGENE study. Interestingly, the rs2304672 SNP interacted with plasma total SFA concentrations to affect fasting plasma TG, TG-rich lipoprotein (TRL-TG), total cholesterol, apoC-II, apoB, and apoB-48 concentrations (P-interaction < 0.001-0.046). Carriers of the minor allele (GC+GG) with the highest SFA concentration (>median) had a higher plasma TG concentration (P = 0.001) and higher TRL-TG (P < 0.001) than the CC genotype. In addition, participants carrying the minor G allele for rs2304672 SNP and with a higher SFA concentration (>median) had higher plasma concentrations of apo C-II (P < 0.001), apo C-III (P = 0.009), and apoB-48 (P = 0.028) compared with the homozygotes for the major allele (CC). In summary, the rs2304672 polymorphism in the PER2 gene locus may influence lipid metabolism by interacting with the plasma total SFA concentration in participants with MetS. The understanding of these gene-nutrient interactions could help to provide a better knowledge of the pathogenesis in MetS.

Genetic variants in the ADIPOQ gene and the risk of metabolic syndrome: a case-control study of a Chinese Han population

Our aim was to investigate whether the ADIPOQ gene polymorphisms are associated with the metabolic syndrome (MetS). Genotypes of MetS patients (n=1049) and normal controls (n= 1092) were analysed by TaqMan® assay, and serum adiponectin concentration was measured by ELISA. The variant genotypes rs266729CG; rs1063539GC, GC/CC; rs16861205AA and rs7649121AT, AT/TT (Adjusted P=0.037, 0.044, 0.025, 0.011, 0.019, 0.020, respectively) of the ADIPOQ gene were associated with MetS. Patients with rs266729CG, CG/GG genotypes (P=0.034, 0.035) and rs7649121AT, AT/TT genotypes (P=0.013, 0.022) had higher levels of serum adiponectin than those with the CC and AA genotypes respectively. Furthermore, the prevalence of haplotypes GGAAAATC and GGGTAACC was lower in cases (10.7% and 4.5%) than in controls (12.1% and 5.9%) [Adjusted ORs (95% CIs)=0.70 (0.54–0.91), 0.65 (0.46–0.92)]. The ADIPOQ gene variants associated with the risk of MetS in this study must be validated by further functional studies to reveal any potential effects on metabolism.

Non-alcoholic fatty liver disease and metabolic syndrome in adolescents: pathogenetic role of genetic background and intrauterine environment

In the last three decades the incidence of metabolic syndrome (MetS) has been growing worldwide along with an increase of obesity, type 2 diabetes mellitus, and non-alcoholic fatty liver disease (NAFLD). In children and adolescents such epidemics are particularly worrisome, since the metabolic consequences in adulthood will significantly burden the health care system. Although the definition of MetS in childhood is still controversial, there is agreement with respect to NAFLD being the hepatic manifestation of MetS. However, the molecular pathogenesis of MetS and its contribution to NAFLD is complex and closely related to the pre- and postnatal environment as well as to genetic predisposing factors. The analysis of the possible relationships between NAFLD and MetS is particularly interesting, not only from an epidemiological point of view, but also to better understand the genetic and environmental factors contributing to the development of both diseases. We here summarize the most recent epidemiological data on the incidence of both diseases in adolescents, and several aspects linking MetS with NAFLD, discussing the possible role played by genetics and intrauterine environment.

Variants of endothelial nitric oxide synthase gene are associated with components of metabolic syndrome in an Arab population

Genetics plays a crucial role in the development of metabolic syndrome (MetS). Here we examined the association between endothelial nitric oxide synthase (eNOS) gene polymorphisms and MetS in a Saudi Arabian cohort to extend the understanding of the genetic basis of MetS in diverse ethnic populations. Anthropometric, clinical and biochemical parameters as well as genotyping for 894G>T, -786T>C variants of eNOS gene by PCR-RFLP and 4a/b by direct PCR were performed in 886 Saudi Arabians (477 MetS and 409 Non-MetS). The genotype distribution (TT, p=0.001; TC, p=0.001; TC+CC, p=0.001) and allele (T, p=0.007; C, p=0.007) frequency of the -786T>C SNP were significantly different between Non-MetS and MetS subjects which remained significant after Bonferroni correction. Moreover: 1) the GT and GT+TT genotypes of the 894G>T SNP were associated with elevated blood pressure (p=0.017, and p=0.022, respectively); 2) the ab variant of 4a/b polymorphism was associated with decreased HDL levels (p= 0.044); and 3) the TC+CC genotype and C allele of the -786T>C SNP were associated with increased fasting glucose levels (p=0.039, and p=0.028, respectively). Also, G-a-C was identified as the risk haplotype for MetS susceptibility (p=0.034). The results suggest a significant association of 894G>T, 4a/b and -786T>C polymorphisms with MetS and its components is present in an Arab population. A genetic predisposition to develop abnormal metabolic phenotypes, consistent with an increased prevalence of metabolic phenotypes can be detected in this ethnic group.

Interactions of single nucleotide polymorphisms with dietary calcium intake on the risk of metabolic syndrome

BACKGROUND

Gene-nutrient interactions may be important in modulating susceptibility to metabolic disorders.

OBJECTIVES

The objectives of this study were to assess the association of dietary calcium intake with the risk of metabolic syndrome and to investigate the interaction effects between dietary calcium intake and candidate gene polymorphisms.

DESIGN

Subjects were participants in the Korea Association Resource project, which was initiated in 2007 as a large-scale, genomewide association analysis. A total of 8031 subjects were included in the study. Associations were assessed by using multivariable-adjusted logistic regression analyses.

RESULTS

High calcium intake appeared to be associated with a low risk of metabolic syndrome after covariates in both men (P-trend = 0.03) and women (P-trend = 0.0002) were controlled for. Among 27 single nucleotide polymorphisms (SNPs) selected as possible candidate gene polymorphisms affecting the risk of metabolic syndrome, 3 SNPs [rs6445834 in Rho guanine nucleotide exchange factor 3 (ARHGEF3), rs10850335 in T-box 5 (TBX5), rs180349 in BUD13 homolog (Saccaromyces cerevisiae) (BUD13)] showed significant interaction effects with calcium intake tertiles or sufficiency in both men and women. Subjects with major allele homozygotes of these gene polymorphisms and high calcium intakes generally had a lower risk of metabolic syndrome than did those with minor allele homozygotes and low calcium intakes.

CONCLUSION

Dietary calcium intake appears to be inversely associated with the risk of metabolic syndrome and may modulate susceptibility to the syndrome in subjects who are minor allele carriers of rs6445834 in ARHGEF3, rs10850335 in TBX5, or rs180349 in BUD13.

Insulin receptor substrate-2 gene variants in subjects with metabolic syndrome: association with plasma monounsaturated and n-3 polyunsaturated fatty acid levels and insulin resistance

SCOPE

Several insulin receptor substrate-2 (IRS-2) polymorphisms have been studied in relation to insulin resistance and type 2 diabetes. To examine whether the genetic variability at the IRS-2 gene locus was associated with the degree of insulin resistance and plasma fatty acid levels in metabolic syndrome (MetS) subjects.

METHODS AND RESULTS

Insulin sensitivity, insulin secretion, glucose effectiveness, plasma fatty acid composition and three IRS-2 tag-single nucleotide polymorphisms (SNPs) were determined in 452 MetS subjects. Among subjects with the lowest level of monounsaturated (MUFA) (below the median), the rs2289046 A/A genotype was associated with lower glucose effectiveness (p<0.038), higher fasting insulin concentrations (p<0.028) and higher HOMA IR (p<0.038) as compared to subjects carrying the minor G-allele (A/G and G/G). In contrast, among subjects with the highest level of MUFA (above the median), the A/A genotype was associated with lower fasting insulin concentrations and HOMA-IR, whereas individuals carrying the G allele and with the highest level of ω-3 polyunsaturated fatty acids (above the median) showed lower fasting insulin (p<0.01) and HOMA-IR (p<0.02) as compared with A/A subjects.

CONCLUSION

The rs2289046 polymorphism at the IRS2 gene locus may influence insulin sensitivity by interacting with certain plasma fatty acids in MetS subjects.