The association of the fat mass and obesity-associated gene (FTO) rs9939609 polymorphism and the severe obesity in a Brazilian population

Background: Obesity occurs due to the interaction between the genetic background and environmental factors, including an increased food intake and a sedentary lifestyle. Nowadays, it is clear that there is a specific circuit, called leptin-melanocortin pathway, which stimulates and suppresses food intake and energy expenditure. Therefore, the aim of this study was to evaluate the influence of genetic variants related to appetite regulation and energy expenditure on severe obesity susceptibility and metabolic phenotypes in a Brazilian cohort. Material and methods: A total of 490 participants were selected (298 severely obese subjects and 192 normal-weight individuals). Genomic DNA was extracted and polymorphisms in protein related to agouti (AGRP; rs5030980), ghrelin (GHRL; rs696217), neuropeptide Y (NPY; rs535870237), melanocortin 4 receptor (MC4R; rs17782313), brain-derived neurotrophic factor (BDNF; rs4074134) and fat mass and obesity-associated (FTO; rs9939609) genes were genotyped using TaqMan® probes. Demographic, anthropometric, biochemical and blood pressure parameters were obtained from the participants. Results: Our results showed that FTO rs9939609 was associated with severe obesity susceptibility. This polymorphism was also related to body weight, body mass index (BMI), waist to weight ratio (WWR) and inverted BMI. Individuals carrying the mutant allele (A) showed higher levels of BMI as well as lower values of WWR and inverted BMI. Conclusion: This study showed that FTO rs9939609 polymorphism plays a significant role in predisposing severe obesity in a Brazilian population.

Adiponectin gene variant RS rs266729: Relation to lipid profile changes and circulating adiponectin after bariatric surgery

BACKGROUND

ADIPOQ rs266729 have been associated with body mass index and metabolic parameters.

OBJECTIVES

Our aim was to assess the contribution of this genetic variant on lipid profile and serum adiponectin levels after biliopancreatic diversion surgery in morbidly obese patients in a 3-year prospective study.

SETTING

Tertiary Hospital.

METHODS

A prospective cohort study (sample) of 149 patients with morbid obesity was evaluated. Biochemical and anthropometric parameters were studied at baseline and every year for a 3-year-follow-up period.

RESULTS

Percentage of excess weight loss (65.9% versus 66.0%:ns), body mass index, weight, waist circumference, fat mass, blood pressure, fasting glucose, low-density lipoprotein cholesterol, total cholesterol, insulin, homeostasis model assessment of insulin resistance, and triglyceride levels improved in both genotype groups. A decrease in fasting insulin levels, homeostasis model assessment of insulin resistance, total cholesterol, low-density lipoprotein cholesterol, and triglycerides was higher in non-G-allele carriers than G-allele carriers. The increase of adiponectin levels (at 1 yr) found after 1 (delta: 16.2 ± 3.1 ng/mL versus 2.1 ± 1.0 ng/mL; P = .02), 2 (delta: 24.2 ± 3.1 ng/mL versus 3.1 ± 1.1 ng/mL; P = .02), and 3 years (delta: 33.2 ± 3.9 ng/mL versus 4.7 ± 1.8 ng/mL; P = .01) was higher in non-G-allele carriers than G carriers. At all times, adiponectin levels were higher in patients with genotype CC.

CONCLUSIONS

Non-G allele of ADIPOQ gene variant (rs266729) is associated with increases in adiponectin levels and better improvement of low-density lipoprotein cholesterol, triglycerides, insulin, and homeostasis model assessment of insulin resistance after biliopancreatic diversion massive weight loss than G-allele carriers.

Cardiovascular Risk Factors and Insulin Resistance after Two Hypocaloric Diets with Different Fat Distribution in Obese Subjects: Effect of the rs10767664 Gene Variant in Brain-Derived Neurotrophic Factor

BACKGROUND

The role of brain-derived neurotrophic factor (BDNF) variants on change in body weight and cardiovascular risk factors after weight loss remains unclear in obese patients.

OBJECTIVE

Our aim was to analyze the effects of the rs10767664 BDNF gene polymorphism on body weight, cardiovascular risk factors, and serum adipokine levels after a high monounsaturated fatty acids (MUFAs) hypocaloric diet (diet M) versus a high polyunsaturated fatty acids (PUFAs) hypocaloric diet (diet P).

METHODS

A Caucasian population of 361 obese patients was enrolled. Subjects who met the inclusion criteria were randomly allocated to one of two diets for a period of 3 months.

RESULTS

Two hundred and sixteen subjects (59.8%) had the genotype AA (wild-type group), and 145 (40.2%) patients had the genotypes AT (122 patients, 33.8%) or TT (23 patients, 6.4%) (mutant-type group). After weight loss with diet P and diet M and in both genotype groups, body mass index, weight, fat mass, waist circumference, systolic blood pressure, serum leptin levels, low-density lipoprotein cholesterol, and total cholesterol decreased in a significant way. Secondary to weight loss with diet M and only in the wild-type group, insulin levels (-2.1 ± 2.0 vs. -0.7 ± 2.9 IU/L, p < 0.05) and homeostatic model assessment of insulin resistance (-0.7 ± 0.9 vs. -0.3 ± 1.0 U, p < 0.05) decreased.

CONCLUSION

Our data show that the rs10767664 variant of the BDNF gene modifies insulin resistance and insulin levels after weight loss with a hypocaloric diet enriched with MUFAs.

Bariatric Surgery and Precision Nutrition

This review provides a literature overview of new findings relating nutritional genomics and bariatric surgery. It also describes the importance of nutritional genomics concepts in personalized bariatric management. It includes a discussion of the potential role bariatric surgery plays in altering the three pillars of nutritional genomics: nutrigenetics, nutrigenomics, and epigenetics. We present studies that show the effect of each patient's genetic and epigenetic variables on the response to surgical weight loss treatment. We include investigations that demonstrate the association of single nucleotide polymorphisms with obesity phenotypes and their influence on weight loss after bariatric surgery. We also present reports on how significant weight loss induced by bariatric surgery impacts telomere length, and we discuss studies on the existence of an epigenetic signature associated with surgery outcomes and specific gene methylation profile, which may help to predict weight loss after a surgical procedure. Finally, we show articles which evidence that bariatric surgery may affect expression of numerous genes involved in different metabolic pathways and consequently induce functional and taxonomic changes in gut microbial communities. The role nutritional genomics plays in responses to weight loss after bariatric surgery is evident. Better understanding of the molecular pathways involved in this process is necessary for successful weight management and maintenance.

The future of nutrition: Nutrigenomics and nutrigenetics in obesity and cardiovascular diseases

Over time, the relationship between diet and health has aroused great interest, since nutrition can prevent and treat several diseases. It has been demonstrated that general recommendations on macronutrients and micronutrients do not affect to every individual in the same way because diet is an important environmental factor that interacts with genes. Thus, there is a growing necessity of improving a personalized nutrition to treat obesity and associated medical conditions, taking into account the interactions between diet, genes and health. Therefore, the knowledge of the interactions between the genome and nutrients at the molecular level, has led to the advent of nutritional genomics, which involves the sciences of nutrigenomics and nutrigenetics. In this review, we will comprehensively analyze the role of the most important genes associated with two interrelated chronic medical conditions, such as obesity and cardiovascular diseases.