Melanocortin-4 receptor (MC4R) rs17782313 polymorphism interacts with Dietary Approach to Stop Hypertension (DASH) and Mediterranean Dietary Score (MDS) to affect hypothalamic hormones and cardio-metabolic risk factors among obese individuals

Single nucleotide polymorphism-based biomarker in primary hypertension

Primary hypertension is a multiplex and multifactorial disease influenced by various strong components including genetics. Extensive research such as Genome-wide association studies and candidate gene studies have revealed various single nucleotide polymorphisms (SNPs) related to hypertension, providing insights into the genetic basis of the condition. This review summarizes the current status of SNP research in primary hypertension, including examples of hypertension-related SNPs, their location, function, and frequency in different populations. The potential clinical implications of SNP research for primary hypertension management are also discussed, including disease risk prediction, personalized medicine, mechanistic understanding, and lifestyle modifications. Furthermore, this review highlights emerging technologies and methodologies that have the potential to revolutionize the vast understanding of the basis of genetics in primary hypertension. Gene editing holds the potential to target and correct any kind of genetic mutations that contribute to the development of hypertension or modify genes involved in blood pressure regulation to prevent or treat the condition. Advances in computational biology and machine learning enable researchers to analyze large datasets and identify complex genetic interactions contributing to hypertension risk. In conclusion, SNP research in primary hypertension is rapidly evolving with emerging technologies and methodologies that have the potential to transform the knowledge about genetic basis related to the condition. These advances hold promise for personalized prevention and treatment strategies tailored to an individual's genetic profile ultimately improving patient outcomes and reducing healthcare costs.

Are there any interactions between modified Nordic-style diet score and MC4R polymorphism on cardiovascular risk factors among overweight and obese women? A cross-sectional study

BACKGROUND

Cardiovascular disease (CVD) is the leading cause of death in women globally. Recent studies have reported that the minor allele (C allele) for melanocortin 4 receptor (MC4R) rs17782313 may be related to the incidence of obesity and the risk of CVD. Therefore, the present study aimed to investigate the interactions between the modified Nordic-style diet score (MND) and MC4R gene variant on markers of CVD.

METHODS

The current cross-sectional study was conducted on 282 Iranian women, aged 18-48 years, with a body mass index (BMI) ≥ 25. MND score was assessed using a 147 items food frequency questionnaire (FFQ). Genotyping of the MC4R (rs17782313) was conducted by the PCR method. The anthropometric measurements and serum profiles were assessed by standard protocols.

RESULTS

The means and standard deviation (SD) of age, weight, and BMI of individuals were 36.67 ± 9.10 years, 81.29 ± 12.43 kg, and 31.26 ± 4.29 kg/m², respectively. The overall prevalence of rs17782313 genotypes was 30.1%, 24.8%, and 45.1% for TT, TC, and CC, respectively. Our results showed significant negative interactions between high MND score and rs17782313 SNP in terms of visceral fat level (VFL) (β: -10.84, 95% CI: -20.64 to -1.04, P = 0.03) and total cholesterol (β: -24.24, 95% CI: -49.87 to 1.38, P = 0.06) in the crude model. After adjusting confounders, the interaction between high MND scores and VFL remained significant.

CONCLUSION

In conclusion, the results of the present study suggest that diet, gene variants, and their interaction should be considered in metabolic disease risk assessment. Further studies are needed to confirm these data and better elucidate the interaction.

The effect of TCF7L2 polymorphisms on inflammatory markers after 16 weeks of legume-based dietary approach to stop hypertension (DASH) diet versus a standard DASH diet: a randomised controlled trial

Backgrounds

This randomized controlled trial aimed to investigate the effects of replacing red meat with legumes in the dietary approach to stop hypertension (DASH) diet on inflammatory markers over 16 weeks in overweight and obese individuals with type 2 diabetes. Also, the modulatory effects of TCF7L2 rs7903146 variant on this effect were assessed.

Methods

In this trial, 300 participants with type 2 diabetes, aged 30–65 years with an identified TCF7L2 rs7903146 genotype, were studied. The participants were randomly assigned to the DASH diet or the legume-based DASH diet over 16 weeks. In the DASH diet group, the participants were instructed to follow the standard DASH diet. The legume-based DASH diet was similar to the standard DASH diet, with the exception that one serving of red meat was replaced with one serving of legumes at least five days a week. At the beginning of the study and 16-week follow-up, venous blood samples were collected from all participants who fasted for 12–14 h overnight. The serum concentration of High-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) was measured using an enzyme-linked immunosorbent assay (ELISA) kit. Also, the serum malondialdehyde (MDA) concentration was assessed based on a colorimetric method using a commercial kit. The primary outcome was the difference in hs-CRP changes between the diets. A secondary outcomes was the difference in IL-6, TNF-α, and MDA between the groups among total population and based on TCF7L2 rs7903146 risk allele (CT + TT) and non-risk allele (CC) separately.

Results

The hs-CRP level reduced in the legume-based DASH diet group as compared to the DASH diet group in the 16-week follow-up group. The levels of TNF-α, IL-6, and MDA reduced after the legume-based DASH diet relative to the DASH diet. Reduction of inflammatory markers was observed in both carriers of rs7903146 risk allele and non-risk allele.

Conclusions

Substituting one serving of red meat with one serving of legumes in DASH diet, at least five days a week, could improve the hs-CRP, TNF-α, IL-6, and MDA in participants with type 2 diabetes regardless of having rs7903146 risk or non-risk allele.

Trial registration IRCT, IRCT20090203001640N17.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12986-022-00671-7.

Diverse effect of MC4R risk alleles on obesity-related traits over a lifetime: Evidence from a well-designed cohort study

This population-based longitudinal study is the first investigation that assesses the association of common MC4R SNPs with the obesity-related parameters over time and determines the effect of risk alleles during the three adulthood life periods (early, middle, and late) in a large Iranian cohort, a population with a unique genetic make-up that has been understudied and relatively unexplored. We obtained the genotype of 5370 unrelated adults who participated in the ongoing Tehran Cardiometabolic Genetic Study (TCGS) cohort project for the common MC4R SNPs. Linear regression and linear mixed model analyses were performed to examine the effect of MC4R polymorphisms on maximum BMI and other obesity-related factors over time. We recognized that several SNPs associated with the maximum BMI and the increased BMI, waist circumference, and waist-hip ratio across Iranian adults over a lifetime. Interestingly, we found that rs9954571-A has a yet unreported protective role against obesity-related factors, including BMI, waist circumference, waist-hip ratio, and triglyceride level. Additionally, a survey of the impact of the MC4R risk score throughout the adulthood life periods indicated that the MC4R risk score is influenced both the elevated BMI and waist circumference only during the early adulthood period. Our findings can expand our knowledge about the MC4R genetic variant's contributions to adulthood obesity and highlight the importance of evaluating the genetic components affecting obesity over a lifetime, which could be considered for obesity clinical screening and treatment.

The interaction between dietary approaches to stop hypertension and MC4R gene variant in predicting cardiovascular risk factors

Objective: The genetic variants near the melanocortin-4 receptor gene (MC4R), a key protein regulating energy balance and adiposity, have been related to obesity and cardiovascular risk factors. However, qualitative and quantitative aspects of diet may modulate the association of this polymorphism with obesity and cardiovascular diseases (CVDs). The aim of this study was to evaluate interactions among MC4R rs17782313, the Dietary Approaches to Stop Hypertension (DASH) diet and risk factors for CVDs. Method: This cross-sectional study was conducted on 266 Iranian women categorized by body mass index (BMI) range of 25-40 kg/m² as overweight or obese. CVD risk factors included waist circumference (WC), lipid profile, blood pressure, insulin circulation and fasting blood sugar (FBS). Insulin and FBS were used to calculate homeostatic model assessment insulin resistance (HOMA-IR) Body composition was assessed by a multi-frequency bioelectrical impedance analyzer, InBody 770 scanner. Results: The findings of this study show that high adherence to the DASH diet in the CC groups were associated with decreased SBP and DBP compared to the TT group. In addition, a significant difference between women with high adherence to the DASH diet compared to low adherence was observed for body weight (p < 0.001), fat free mass (FFM) (p = 0.01) and BMI (p = 0.02). Women with the CC genotype had higher insulin (mg/dl) (mean and SD, for TT: 14.6 ± 4.6, TC: 17.3 ± 9.2, CC: 15.3 ± 4.8, p = 0.04) and HOMA-IR (mean for and SD, TT: 3.1 ± 1.07, TC: 3.9 ± 2.4, CC: 3.2 ± 1.1, p = 0.01) than TT group. Inclusion of potential confounding variables (age, physical activity, BMI and daily caloric intake) did not attenuate the difference. Conclusion: Among overweight/obese Iranian women with the CC genotype, incorporating the DASH diet may serve as a dietary prescription to decrease CVD risk. A dietary intervention trial is warranted.

Chronological Age Interacts with the Circadian Melatonin Receptor 1B Gene Variation, Determining Fasting Glucose Concentrations in Mediterranean Populations. Additional Analyses on Type-2 Diabetes Risk

Gene-age interactions have not been systematically investigated on metabolic phenotypes and this modulation will be key for a better understanding of the temporal regulation in nutrigenomics. Taking into account that aging is typically associated with both impairment of the circadian system and a decrease in melatonin secretion, we focused on the melatonin receptor 1B (MTNR1B)-rs10830963 C>G variant that has been associated with fasting glucose concentrations, gestational diabetes, and type-2 diabetes. Therefore, our main aim was to investigate whether the association between the MTNR1B-rs10830963 polymorphism and fasting glucose is age dependent. Our secondary aims were to analyze the polymorphism association with type-2 diabetes and explore the gene-pregnancies interactions on the later type-2 diabetes risk. Three Mediterranean cohorts (n = 2823) were analyzed. First, a cross-sectional study in the discovery cohort consisting of 1378 participants (aged 18 to 80 years; mean age 41 years) from the general population was carried out. To validate and extend the results, two replication cohorts consisting of elderly individuals were studied. In the discovery cohort, we observed a strong gene-age interaction (p = 0.001), determining fasting glucose in such a way that the increasing effect of the risk G-allele was much greater in young (p = 5.9 × 10^-10) than in elderly participants (p = 0.805). Consistently, the association of the MTNR1B-rs10830963 polymorphism with fasting glucose concentrations in the two replication cohorts (mean age over 65 years) did not reach statistical significance (p > 0.05 for both). However, in the elderly cohorts, significant associations between the polymorphism and type-2 diabetes at baseline were found. Moreover, in one of the cohorts, we obtained a statistically significant interaction between the MTNR1B polymorphism and the number of pregnancies, retrospectively assessed, on the type-2 diabetes risk. In conclusion, the association of the MTNR1B-rs10830963 polymorphism with fasting glucose is age-dependent, having a greater effect in younger people. However, in elderly subjects, associations of the polymorphism with type-2 diabetes were observed and our exploratory analysis suggested a modulatory effect of the number of past pregnancies on the future type-2 diabetes genetic risk.