Interaction between Pro12Ala polymorphism of PPARγ2 and diet on adiposity phenotypes

The Influence of the Differentiation of Genes Encoding Peroxisome Proliferator-Activated Receptors and Their Coactivators on Nutrient and Energy Metabolism

Genetic components may play an important role in the regulation of nutrient and energy metabolism. In the presence of specific genetic variants, metabolic dysregulation may occur, especially in relation to the processes of digestion, assimilation, and the physiological utilization of nutrients supplied to the body, as well as the regulation of various metabolic pathways and the balance of metabolic changes, which may consequently affect the effectiveness of applied reduction diets and weight loss after training. There are many well-documented studies showing that the presence of certain polymorphic variants in some genes can be associated with specific changes in nutrient and energy metabolism, and consequently, with more or less desirable effects of applied caloric reduction and/or exercise intervention. This systematic review focused on the role of genes encoding peroxisome proliferator-activated receptors (PPARs) and their coactivators in nutrient and energy metabolism. The literature review prepared showed that there is a link between the presence of specific alleles described at different polymorphic points in PPAR genes and various human body characteristics that are crucial for the efficacy of nutritional and/or exercise interventions. Genetic analysis can be a valuable element that complements the work of a dietitian or trainer, allowing for the planning of a personalized diet or training that makes the best use of the innate metabolic characteristics of the person who is the subject of their interventions.

Metabolomic Profiling of Aqueous Humor and Plasma in Primary Open Angle Glaucoma Patients Points Towards Novel Diagnostic and Therapeutic Strategy

Glaucoma is the second leading cause of blindness globally characterized by progressive loss of retinal ganglion cells (RGCs) and irreversible visual deficiency. As the most common type of glaucoma, primary open angle glaucoma (POAG) is currently an unmet medical need with limited therapy by lowering intraocular pressure (IOP). However, some patients continue to progress even though their IOP are controlled. Although early diagnosis and prompt treatment are crucial in preventing irreversible visual impairment, there are currently no biomarkers for screening POAG. Metabolomics has the advantages of illustrating the final downstream products of the genome and establishing the closest link to the phenotype. So far, there is no study investigating the metabolomic profiles in both aqueous humor and plasma of POAG patients. Therefore, to explore diagnostic biomarkers, unveil underlying pathophysiology and potential therapeutic strategies, a widely targeted metabolomic approach was applied using ultrahigh-resolution mass spectrometry with C18 liquid chromatography to characterize the metabolomic profiles in both aqueous humor and plasma of 28 POAG patients and 25 controls in our study. Partial least squares-discriminant analysis (PLS-DA) was performed to determine differentially expressed metabolites (DEMs) between POAG and age-matched controls. The area under the receiver operating characteristic curve (AUC) was calculated to assess the prediction accuracy of the DEMs. The correlation of DEMs with the clinical parameters was determined by Pearson correlation, and the metabolic pathways were analyzed using MetaboAnalyst 4.0. PLS-DA significantly separated POAG from controls with 22 DEMs in the aqueous humor and 11 DEMs in the plasma. Additionally, univariate ROC analysis and correlation analysis with clinical parameters revealed cyclic AMP (AUC = 0.87), 2-methylbenzoic acid (AUC = 0.75), 3'-sialyllactose (AUC = 0.73) in the aqueous humor and N-lac-phe (AUC = 0.76) in the plasma as potential biomarkers for POAG. Moreover, the metabolic profiles pointed towards the alteration in the purine metabolism pathway. In conclusion, the study identified potential and novel biomarkers for POAG by crosslinking the metabolomic profiles in aqueous humor and plasma and correlating with the clinical parameters. These findings have important clinical implications given that no biomarkers are currently available for glaucoma in the clinic, and the study provided new insights in exploring diagnostic biomarkers and potential therapeutic strategies of POAG by targeting metabolic pathways.

Relationship of the Pro12Ala Polymorphism on the PPARy2 Gene With the Body Composition of Practitioners of Cyclic Exercises

This study aimed to verify the association between the genotypic of the receptor gene activated by peroxisome proliferators gamma 2 (PPARy2) and the body composition and the specific indicators of adiposity in practitioners physical exercises, considering nutritional intake, age, and training load as influencing factors. It was conducted a cross-sectional study with 335 adults (47.9 ± 12.7 years, 138 men, body mass index/BMI = 27.0 ± 4.9 kg/m²), practitioners of aerobic exercises in cyclical modalities (running, walking and/or cycling, who spent 328.3 ± 193.6 kcal/day on physical training). The genotyping of the Pro12Ala polymorphism was performed using the PCR-RFLP technique and the body composition measured by bioimpedance (InBody 720). Energy expenditure was based on the compendium of physical activities and caloric intake was measured by 24 h recall questionnaire. The higher prevalence was for the Pro/Pro genotype (76.1% vs. 23.9% of Pro/Ala). Pro/Pro genotypic group showed significant higher mean values for body mass (BM) (p < 0.03 for men and p < 0.02 for women) and BMI (p < 0.00 for men and p < 0.02 for women) and %FAT (p < 0.00), waist-hip ratio (WHR) (p < 0.04), and visceral fat (VF) (p < 0.00) only in men compared to Pro/Ala. Higher frequency of Pro/Pro was observed in the category indicating BMI (p < 0.00 for men and p < 0.03 for women), WRH (p < 0.03 for men and p < 0.00 for women), and %FAT (p < 0.03) (in the latter case, only among men. It was also observed that the frequency of distribution of Pro/Ala in the eutrophic category of the BMI remained independent of all influencers, while WHR and %FAT were independent of the training load, but influenced by nutritional intake and age. In women, the frequency of Pro/Ala distribution at the lowest BMI and WHR values remained independent of all confounding variables. It is concluded that the Pro12Ala polymorphism in the PPARy2 gene consistently influences indicators of body composition and adiposity, regardless of the practitioners of physical training, but the relationship needs to be considered according to age and nutritional intake.

PPARG Pro12Ala Ala carriers exhibit greater improvements in peripheral insulin sensitivity in response to 12 weeks of aerobic exercise training

The Ala allele of PPARG Pro12Ala ( rs1801282 ) is associated with greater improvements to the glucose metabolism in exercise studies, but whether this extends to peripheral insulin sensitivity is unknown. Our objective was to investigate the effect of PPARG Pro12Ala on exercise-induced changes in peripheral insulin sensitivity. A total of 124 (91 Pro homozygotes and 33 Ala carriers) previously physically inactive healthy young men and women with overweight or class 1 obesity who completed a 12 wk aerobic exercise intervention were included in the analysis. All participants underwent a hyperinsulinemic euglycemic clamp before and after the 12 wk intervention. The prescribed exercise frequency was 5–7 days/wk, and the exercise energy expenditure was 2,100 4,200 kcal/wk for men and 1,600 kcal/wk for women. Insulin sensitivity improved significantly in both genotype groups. However, Ala carriers had a 1.13-fold (95% confidence interval 1.01; 1.26, P = 0.032) greater improvement in insulin sensitivity from baseline compared with Pro homozygotes. Our data support that PPARG Pro12Ala modifies the effect of aerobic exercise on peripheral insulin sensitivity.

PPARγ Pro12Ala Polymorphism Influences the Relationship between Dietary Fat Intake, Adiposity and Lipid Profile in Patients with Type 2 Diabetes

Abstract. Background: Peroxisome proliferator-activated receptor γ (PPARγ) Pro12Ala polymorphism (rs1801282) has been associated with metabolic syndrome components in some studies. Moreover, the PPARγ gene may mediate the physiological response to dietary fat intake in a ligand-dependent manner. Methods: Metabolic syndrome components (body mass index, waist circumference, and lipid profile) were determined in 290 type 2 diabetes mellitus patients in a cross-sectional study. DNA genotyping for determining PPARγ Pro12Ala polymorphism was conducted using the polymerase chain reaction-restriction length polymorphism method. A semi-quantitative food frequency questionnaire was used to assess the participants’ dietary intakes in the previous year. Results: There were significant differences between the two genotype groups of PPARγ Pro12Ala polymorphism, Ala carriers (Pro/Ala + Ala/Ala) versus non-Ala carriers (Pro/Pro), in terms of mean body mass index (p = 0.04) and waist circumference (p = 0.02). Below the median percentage of energy from monounsaturated and polyunsaturated fatty acids, Ala carriers had a higher body mass index (p = 0.01) compared to non-Ala carriers. Furthermore, a significant interaction between this single-nucleotide polymorphism and polyunsaturated fatty acids intake on serum triglyceride levels (p = 0.01) was seen, and in higher polyunsaturated fatty acids intake (≥ median) Ala carriers had lower triglyceride levels than non-Ala carriers (p = 0.007). Conclusions: The findings of the current study support a significant association between PPARγ Pro12Ala polymorphism and metabolic syndrome components, and they suggest that this polymorphism can modulate the biological response of dietary fat intake on body mass index and triglyceride levels.

PPARG2 Pro12Ala polymorphism influences body composition changes in severely obese patients consuming extra virgin olive oil: a randomized clinical trial

BACKGROUND

Previous intervention studies have reported the association of the PPARG2 Pro12Ala (rs1801282) and IL6 -174G > C (rs1800795) polymorphisms with weight loss; however, their results are inconsistent. We aimed to investigate the effect of the PPARG2 Pro12Ala and IL6 -174G > C polymorphisms on body weight, body composition and metabolic parameters after a 12-week nutritional intervention with a traditional Brazilian diet and extra virgin olive oil supplementation in severely obese patients.

METHODS

A total of 149 severely obese individuals [body mass index (BMI) ≥ 35 kg/m2] were randomized into three 12-week nutritional intervention groups - the extra virgin olive oil supplementation (OO) group (n = 50), the traditional Brazilian diet (DieTBra) group (n = 49), and the DieTBra plus extra virgin olive oil supplementation (DieTBra+OO) group (n = 50). Anthropometric measurements, body composition, metabolic parameters, physical activity practise and dietary intake were assessed. The associations were tested using generalized linear models adjusted for confounders.

RESULTS

The PPARG2 Pro12Ala polymorphism influenced body composition changes. Ala carriers in the intervention groups with extra virgin olive oil supplementation had greater reductions in the percentage of body fat (%BF) (OO: p = 0.049, DietBra+OO: p = 0.004) and greater increases in both fat-free mass (FFM) (OO: p = 0.020, DieTBra: p = 0.007) and lean mass (LM) (OO: p = 0.020, DieTBra+OO: p = 0.007) than did ProPro homozygotes. No association was found for the IL6 -174G > C polymorphism.

CONCLUSIONS

Extra virgin olive oil intake may modulate favourable body composition changes, promoting a decrease in the %BF and increases in the LM and FFM of severely obese individuals, even without weight loss, in the presence of the Ala allele of the Pro12Ala polymorphism.

TRIAL REGISTRATION

Registered under ClinicalTrials.gov Identifier No. NCT02463435.

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.

The combination of UCP3-55CT and PPARγ2Pro12Ala polymorphisms affects BMI and substrate oxidation in two diabetic populations

BACKGROUND AND AIM

To evaluate the combined contribution of UCP3-55CT and PPARγ2 Pro12Ala polymorphisms as correlates of BMI, energy expenditure (REE) and substrate oxidation in people with type 2 diabetes.

METHODS AND RESULTS

Two independent population with type 2 diabetes were studied: population A, n = 272; population B, n = 269. Based on both UCP3 and PPARγ2 genotypes three groups were created. Carriers of the PPARγ2 Pro12Ala in combination with the CC genotype of UCP3 (ProAla/CC, group 1); carriers of only one of these genotypes (either CC/ProPro or CT-TT/ProAla, group 2); people with neither variants (CT-TT/ProPro, group 3). In both populations BMI (kg/m(2)) was highest in group 1, intermediate in group 2 and lowest in group 3, independent of energy intake (i.e 35.3 ± 6.7 vs 33.4 ± 5.4 vs 31.8 ± 3, p < 0.02, population A; 32.4 ± 4.2 vs 31.7 ± 3.8 vs 30.1 ± 2.7; p < 0.03, population B). People with the ProAla/CC genotype (group 1) showed similar REE, but lower lipid oxidation (10.9 vs 13.9 g/kg fat free mass/day; p = 0.04) and higher carbohydrate oxidation (23.6 vs 15.6 g/kg fat free mass/day; p = 0.02) than carriers of other genotypes.

CONCLUSIONS

The combination of UCP3-55 CC and PPARγ2 Pro12Ala genotypes is associated with significantly higher BMI than other PPARγ2-UCP3 genotype combinations, partly due to a reduced ability in lipids oxidation. The relative importance of these mechanism(s) may be different in non diabetic people.