Genes, fat intake, and cardiovascular disease risk factors in the Quebec Family Study

In the context of the triple burden of malnutrition: A systematic review of gene-diet interactions and nutritional status

Genetic background interacts with dietary components to modulate nutritional health status. This study aimed to review the evidence for gene-diet interactions in all forms of malnutrition. A comprehensive systematic literature search was conducted through April 2021 to identify observational and intervention studies reporting the effects of gene-diet interactions in over-nutrition, under-nutrition and micronutrient status. Risk of publication bias was assessed using the Quality Criteria Checklist and a tool specifically designed for gene-diet interaction research. 167 studies from 27 populations were included. The majority of studies investigated single nucleotide polymorphisms (SNPs) in overnutrition (n = 158). Diets rich in whole grains, vegetables, fruits and low in total and saturated fats, such as Mediterranean and DASH diets, showed promising effects for reducing obesity risk among individuals who had higher genetic risk scores for obesity, particularly the risk alleles carriers of FTO rs9939609, rs1121980 and rs1421085. Other SNPs in MC4R, PPARG and APOA5 genes were also commonly studied for interaction with diet on overnutrition though findings were inconclusive. Only limited data were found related to undernutrition (n = 1) and micronutrient status (n = 9). The findings on gene-diet interactions in this review highlight the importance of personalized nutrition, and more research on undernutrition and micronutrient status is warranted.

Role of Leu72Met of GHRL and Gln223Arg of LEPR Variants on Food Intake, Subjective Appetite, and Hunger-Satiety Hormones

Appetite regulation has been recognized as a promising target for the prevention of obesity, which has become a worldwide health issue. Polymorphisms in the genes of hormones or receptors including Leu72Met for ghrelin and Gln223Arg for the leptin receptor could play a role in dietary intake, hunger, and satiety process. The aim of this study was to analyze subjective appetite assessments, dietary intake, and appetite hormones in relationship to these polymorphisms. Subjects (n = 132) with normal BMIs were enrolled. Dietary intake was analyzed with 3-day diet records. Subjective appetite was measured by visual analogue scales. Biochemical parameters were measured after 12 h of fasting and 120′ following ingestion of a test meal. Ghrelin and leptin levels were measured by ELISA assay (enzyme-linked immunosorbent assay) and insulin by chemiluminescence assay. The polymorphisms were determined by allelic discrimination using TaqMan^® probes. Fasting ghrelin levels differed significantly between men and women. The consumption of fruit and bread/starch with added sugar servings, as indicated by dietary records, and measured ghrelin levels were higher in carriers of Leu72Met/Met72Met compared to Leu72Leu carriers; total sugar intake was higher in Gln223Gln carriers than in Gln223Arg/Arg223Arg carriers. In conclusion, the Leu72Met and Gln223Arg polymorphism in ghrelin and LEPR may contribute to differential responses to a standardized meal as evidenced by higher postprandial levels of ghrelin and may also contribute to a higher dietary sugar intake.

Dietary quality indices modifies the effects of melanocortin-4 receptor (MC4R) rs17782313 polymorphism on cardio-metabolic risk factors and hypothalamic hormones in obese adults

BACKGROUND

Although the Melanocortin-4 Receptor (MC4R) gene rs17782313 C/T has been consistently related to obesity risk, the interaction between MC4R polymorphism and diet quality indices on cardio-metabolic risk factors has not yet investigated. Therefore we aimed to test this hypothesis.

METHODS

This cross-sectional study recruited 188 (96 males and 92 females) healthy obese adults aged 20-50 years. Diet quality indices including Healthy Eating Index-2015 (HEI-2015) and Diet Quality Index-International (DQI-I) were constructed using data from a validated food frequency questionnaire. MC4R s17782313 were genotyped by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP). The interaction between MC4R polymorphism and diet quality indices was tested by Analysis of covariance (ANCOVA) multivariate interaction model.

RESULTS

There were significant gene-diet interactions between rs17782313 and HEI-2015 (P Interaction < 0.05) in modulating low-density lipoprotein cholesterol (LDL-C) levels among female group; rare allele heterozygotes of rs17782313 had highest mean of LDL-C concentration when placed in second tertile of HEI (P < 0.05). Moreover, rs17782313 and both indices (HEI and DQI-I) had significant interaction on serum glucose concentrations, systolic and diastolic blood pressure (SBP, DBP) in males (P Interaction < 0.05); when adherence to these indices was low, the obesity risk allele was associated with serum glucose concentrations, SBP and DBP. These gene-diet interactions remained significant even after adjustment for potential confounders.

CONCLUSION

Our study showed that MC4R rs17782313 interacts with adherence to the dietary quality indices (HEI and DQI-I) to influence several cardio-metabolic risk factors in obese male and females. Further large prospective studies are warranted to confirm our findings.

The Single Nucleotide Polymorphism PPARG2 Pro12Ala Affects Body Mass Index, Fat Mass, and Blood Pressure in Severely Obese Patients

BACKGROUND

The PPARG2 Pro12Ala (rs1801282) and IL6 -174G >C (rs1800795) have important function in body weight regulation and a potential role in obesity risk. We aimed to investigate the association between PPARG2 Pro12Ala and IL6 -174G >C variants and the genotypes interaction with body composition, metabolic markers, food consumption, and physical activity in severely obese patients.

METHODS

150 severely obese patients (body mass index (BMI) ≥ 35 kg/m²) from Central Brazil were recruited. Body composition, metabolic parameters, physical activity, and dietary intake were measured. The genotype was determined by the qPCR TaqMan Assays System. Multiple linear regression and multiple logistic regression models were fitted adjusting for confounders.

RESULTS

Ala carriers of the Pro12Ala polymorphism had higher adiposity measures (BMI: p=0.031, and fat mass: p=0.049) and systolic blood pressure (p=0.026) compared to Pro homozygotes. We found no important associations between the -174G >C polymorphism and obesity phenotypes. When genotypes were combined, individuals with genotypes ProAla + AlaAla and GC + CC presented higher BMI (p=0.029) and higher polyunsaturated fatty acids (PUFAs) consumption (p=0.045) compared to the ones with genotypes ProPro and GG, and individuals carriers of the PPARG2 Ala allele only (genotype ProAla + AlaAla and GG) had higher fat mass and systolic and diastolic blood pressure compared to the ones with genotypes ProPro and GG.

CONCLUSIONS

Severely obese individuals carrying the Ala allele of the PPARG2 Pro12Ala polymorphism had higher measures of adiposity and blood pressure, while no important associations were found for the IL6 -174G >C polymorphism.

Effect of interactions of polymorphisms in the Melanocortin-4 receptor gene with dietary factors on the risk of obesity and Type 2 diabetes: a systematic review

AIM

To perform a systematic review of the effect of interaction between Melanocortin-4 receptor (MC4R) single nucleotide polymorphisms and diet on the development of obesity and Type 2 diabetes.

BACKGROUND

Environmental factors, such as nutrient intakes or feeding behaviours, can modulate the association of polymorphism in the MC4R gene with obesity and Type 2 diabetes mellitus.

METHODS

A systematic literature search was conducted in the PubMed, Scopus and Google Scholar databases, with a combination of the following keywords: Diet*, nutr*, melanocortin receptor, melanocortin 4 receptor and MC4R. To assess the quality of observational studies, we used a 12-item quality checklist, derived from the STREGA statement.

RESULTS

A total of 14 articles were selected based on the inclusion and exclusion criteria. Consumption of highly salty foods and adherence to a Mediterranean dietary pattern can modulate the association between MC4R polymorphisms and the risk of obesity or Type 2 diabetes. Despite the highly contradictory results of intervention studies, after short-term lifestyle interventions, children with variant alleles of MC4R single nucleotide polymorphisms can lose more body weight, compared with non-carriers, although they may have difficulty in maintaining this weight loss in the long-term. To interpret the results of studies on adults, we need further studies.

CONCLUSIONS

The interaction between MC4R genes with dietary factors plays a significant role in the development of obesity or Type 2 diabetes phenotypes. Early detection of MC4R risk alleles in individuals and modification of their diet based on these results could be an efficient strategy to prevent obesity or diabetes in these subgroups.

Interaction between Pro12Ala polymorphism of PPARγ2 and diet on adiposity phenotypes

The aim of this report is to perform a systematic review and qualitative synthesis of the literature to address whether, and to what extent, diet modulates the effects of the Pro12Ala polymorphism of peroxisome proliferator-activated receptor gamma 2 (PPARγ2) on body weight and other measures of adiposity. A systematic search of the literature was conducted, wherein both observational and experimental studies of adults were reviewed. Overall, the results of the observational studies show little consistency. Methodological differences in their design, conduct and analysis may largely account for the apparently discrepant findings. This notwithstanding, the main picture that emerges is that the energy content and composition of the diet may affect BMI, body composition and metabolic parameters in Ala allele carriers more than in Pro/Pro homozygotes. In most studies, carriers of the Ala allele with an obesogenic lifestyle (i.e. high-energy, high-carbohydrate and, to some extent, high-fat diets) are more obese than Pro homozygotes. Well-designed intervention studies with a sufficiently large sample size consistently show that carriers of the Ala allele are more prone to weight loss when exposed to a healthy lifestyle; however, these individuals do not seem to retain these benefits when returning to a sedentary lifestyle and inadequate dieting behaviours. Some key questions in this area of research have emerged. Carefully designed and adequately powered studies are needed, particularly involving the development and validation of standardized tools for the assessment of dietary exposure, including the use of biomarkers, to move the field forward.

Genetic variants of ghrelin in metabolic disorders

An increasing understanding of the role of genes in the development of obesity may reveal genetic variants that, in combination with conventional risk factors, may help to predict an individual's risk for developing metabolic disorders. Accumulating evidence indicates that ghrelin plays a role in regulating food intake and energy homeostasis and it is a reasonable candidate gene for obesity-related co-morbidities. In cross-sectional studies low total ghrelin concentrations and some genetic polymorphisms of ghrelin have been associated with obesity-associated diseases. The present review highlights many of the important problems in association studies of genetic variants and complex diseases. It is known that population-specific differences in reported associations exist. We therefore conclude that more studies on variants of ghrelin gene are needed to perform in different populations to get deeper understanding on the relationship of ghrelin gene and its variants to obesity.

Cardiovascular disease risk factors in homeless people

BACKGROUND

Cardiovascular diseases (CVD) are associated with significant morbidity and mortality, which is highest in Eastern Europe including Estonia. Accumulating evidence suggests that life-style is associated with the development of CVD. The aim of this study was to evaluate the informative power of common CVD-related markers under unhealthy conditions.

SUBJECTS

Subjects (n = 51; mean age 45 years; 90% men) were recruited from a shelter for homeless people in Tallinn, Estonia, and consisted of persons who constantly used alcohol or surrogates, smoked, and were in a bad physical condition (amputated toes, necrotic ulcers, etc.).

METHODS

Blood pressure, pulse rate, and waist circumference were measured, and body mass index (BMI) was calculated. The following markers were measured in blood serum: total cholesterol (TChol), high-density lipoprotein cholesterol (HDL-Chol), low-density lipoprotein cholesterol (LDL-Chol), plasma triglycerides (TG), apolipoproteins A-l (ApoA1) and B (ApoB), lipoprotein(a) (Lp(a)), glycated hemoglobin (HbA1c), glucose (Gluc), high-sensitivity C-reactive protein (hsCRP), serum carbohydrate-deficient transferrin (CDT), gamma-glutamyltransferase (GGT), alanine aminotransferase (ALT), and aspartate aminotransferase (AST). Except smoking, the anamnestic information considering eating habits, declared alcohol consumption and medication intake were not included in the analysis due to the low credibility of self-reported data.

RESULTS

More than half of the investigated patients had values of measured markers (hsCRP, TChol, LDL-Chol, TG, HbA1c, ApoA1, ApoB, Lp(a), Gluc) within normal range. Surprisingly, 100% of subjects had HDL-Chol within endemic norm.

CONCLUSION

This study demonstrates that traditional markers, commonly used for prediction and diagnosis and treatment of CVD, are not always applicable to homeless people, apparently due to their aberrant life-style.

The association of ghrelin polymorphisms with coronary artery disease and ischemic chronic heart failure in an elderly Chinese population

OBJECTIVE

To investigate the association of coronary artery disease (CAD) and ischemic heart failure (IHF) with polymorphisms of the ghrelin gene in elderly Chinese patients.

DESIGN AND METHODS

Fifty-six patients with ischemic heart failure, sixty patients with coronary artery disease without heart failure, and one hundred healthy control subjects participated in the study. The polymorphisms were evaluated by polymerase chain reaction, sequencing, and fragment length polymorphism analysis.

RESULTS

Only one single nucleotide polymorphism (SNP), Leu72Met (408C/A), was observed across all samples. Gene frequencies of CC and allele frequencies of C were significantly greater in the CAD with IHF group than those in the CAD without IHF group (p=0.025, p=0.011). There was no significant association between the Leu72Met SNP with coronary artery disease risk factors.

CONCLUSION

Our results suggest that a C allele at position 408 of the ghrelin gene is associated with genetic susceptibility to ischemic heart failure in Chinese elders.

A multifactorial analysis of obesity as CVD risk factor: use of neural network based methods in a nutrigenetics context

Background

Obesity is a multifactorial trait, which comprises an independent risk factor for cardiovascular disease (CVD). The aim of the current work is to study the complex etiology beneath obesity and identify genetic variations and/or factors related to nutrition that contribute to its variability. To this end, a set of more than 2300 white subjects who participated in a nutrigenetics study was used. For each subject a total of 63 factors describing genetic variants related to CVD (24 in total), gender, and nutrition (38 in total), e.g. average daily intake in calories and cholesterol, were measured. Each subject was categorized according to body mass index (BMI) as normal (BMI ≤ 25) or overweight (BMI > 25). Two artificial neural network (ANN) based methods were designed and used towards the analysis of the available data. These corresponded to i) a multi-layer feed-forward ANN combined with a parameter decreasing method (PDM-ANN), and ii) a multi-layer feed-forward ANN trained by a hybrid method (GA-ANN) which combines genetic algorithms and the popular back-propagation training algorithm.

Results

PDM-ANN and GA-ANN were comparatively assessed in terms of their ability to identify the most important factors among the initial 63 variables describing genetic variations, nutrition and gender, able to classify a subject into one of the BMI related classes: normal and overweight. The methods were designed and evaluated using appropriate training and testing sets provided by 3-fold Cross Validation (3-CV) resampling. Classification accuracy, sensitivity, specificity and area under receiver operating characteristics curve were utilized to evaluate the resulted predictive ANN models. The most parsimonious set of factors was obtained by the GA-ANN method and included gender, six genetic variations and 18 nutrition-related variables. The corresponding predictive model was characterized by a mean accuracy equal of 61.46% in the 3-CV testing sets.

Conclusions

The ANN based methods revealed factors that interactively contribute to obesity trait and provided predictive models with a promising generalization ability. In general, results showed that ANNs and their hybrids can provide useful tools for the study of complex traits in the context of nutrigenetics.

Visceral adipose tissue in children and adolescents: a review

Research conducted among adults has mainly shown that visceral adipose tissue (VAT) is strongly linked to insulin resistance, type 2 diabetes, hypertension and dyslipidaemia, leading to increased risk of CVD or the metabolic syndrome. However, little is known about the aetiology, determinants and consequences of VAT in children. The present article reviews the current literature relating to the factors influencing visceral fat accumulation in children and adolescents. The literature used in the present study was collected by searching a PubMed database, in which studies up to 2008 exploring the factors influencing accumulation of visceral fat among children and youth were found on the basis of appropriate keywords. Further studies concerning different factors influencing deposition of VAT among children and youth should first of all concentrate on: carrying out long-term analyses among children of different ethnical groups, which should begin in the period of prepuberty and which should cover the whole period of puberty till adulthood; drawing up norms specifying the amount of VAT among healthy children; identification of anthropometric indicators which will help to determine the VAT:subcutaneous adipose tissue ratio in the most precise way; broader studies of the influence of eating habits on developing VAT deposit among children and youth.

Influence of ghrelin gene polymorphisms on hypertension and atherosclerotic disease

Ghrelin is involved in several metabolic and cardiovascular processes. Recent evidence suggests its involvement in blood pressure regulation and hypertension. The aim of the study was to determine associations of single-nucleotide polymorphisms (SNPs) and haplotypes of the ghrelin gene (GHRL) with hypertension and atherosclerotic disease. Six GHRL SNPs (rs27647, rs26802, rs34911341, rs696217, rs4684677 and a -473G/A (with no assigned rsID)) were investigated in a sample of 1143 hypertensive subjects and 1489 controls of Caucasian origin. Both single-locus and haplotype association analyses were performed. In single-locus analyses, only the non-synonymous rs34911341 was associated with hypertension (odds ratio (OR)=1.95 (95% confidence interval (CI): 1.26-3.02), P=0.003). Six common haplotypes with frequency >1% were inferred from the studied GHRL SNPs, and their frequency distribution was significantly different between hypertensive subjects and controls (chi(2)=12.96 with 5 d.f. (degree of freedom), P=0.024). The effect of rs26802 was found to be significantly (P=0.017) modulated by other GHRL SNPs, as its C allele conferred either an increased risk (OR=1.30 (1.08-1.57), P=0.005) or a decreased risk (OR=0.50 (0.23-1.06), P=0.07) of hypertension according to the two different haplotypes on which it can be found. No association of GHRL SNPs or haplotypes with atherosclerotic disease was observed. In conclusion, we observed statistical evidence for association between GHRL SNPs and risk of hypertension.

The Mediterranean diet protects against waist circumference enlargement in 12Ala carriers for the PPARγ gene: 2 years' follow-up of 774 subjects at high cardiovascular risk

The PPARγ gene regulates insulin sensitivity and adipogenesis. The Pro12Ala polymorphism of this gene has been related to fat accumulation. Our aim was to analyse the effects of a 2-year nutritional intervention with Mediterranean-style diets on adiposity in high-cardiovascular risk patients depending on the Pro12Ala polymorphism of the PPARγ gene. The population consisted of a substudy (774 high-risk subjects aged 55–80 years) of the Prevención con Dieta Mediterránea (PREDIMED) randomised trial aimed at assessing the effect of the Mediterranean diet for CVD prevention. There were three nutritional intervention groups: two of them of a Mediterranean-style diet and the third was a control group advised to follow a conventional low-fat diet. All the participants were genotyped by PCR-restriction fragment length polymorphism (RFLP). The results showed that carriers of the 12Ala allele allocated to the control group had a statistically significant higher change in waist circumference (adjusted difference coefficient = 2·37 cm; P = 0·014) compared with wild-type subjects after 2 years of nutritional intervention. This adverse effect was not observed among 12Ala carriers allocated to both Mediterranean diet groups. In diabetic patients a statistically significant interaction between Mediterranean diet and the 12Ala allele regarding waist circumference change was observed ( − 5·85 cm; P = 0·003). In conclusion, the Mediterranean diet seems to be able to reduce waist circumference in a high-cardiovascular risk population, reversing the negative effect that the 12Ala allele carriers of the PPARγ gene appeared to have. The beneficial effect of this dietary pattern seems to be higher among type 2 diabetic subjects.