Role of interaction between variants in the PPARG and interleukin-6 genes on obesity related metabolic risk factors

A Personalized Diet Approach Study: Interaction between PPAR-γ Pro12Ala and Dietary Insulin Indices on Metabolic Markers in Diabetic Patients

BACKGROUND

The objectives were to investigate the effect of the interaction between peroxisome proliferator-activated receptor gamma (PPAR-γ) Pro12Ala polymorphisms and dietary insulin load and insulin index (DIL and DII) on Cardio-metabolic Markers among diabetic patients.

METHODS

This cross-sectional study was conducted on 393 diabetic patients. Food-frequency questionnaire (FFQ) was used for DIL and DII calculation. PPAR-γ Pro12Ala was genotyped by the PCR-RFLP method. Biochemical markers including TC, LDL, HDL, TG, SOD, CRP, TAC, PTX3, PGF2α. IL18, leptin and ghrelin were measured by standard protocol.

RESULT

Risk-allele carriers (CG, GG) had higher obesity indices WC (P _interaction =0.04), BMI (P _interaction =0.006) and, WC (P _interaction =0.04) compared with individuals with the CC genotype when they consumed a diet with higher DIL and DII respectively. Besides, carriers of the G allele who were in the highest tertile of DIL, had lower HDL (P _interaction =0.04) and higher PGF2α (P _interaction =0.03) and PTX3 (P _interaction =0.03). Moreover, the highest tertile of the DII, showed an increase in IL18 (P _interaction =0.01) and lower SOD (P _interaction =0.03) for risk allele carriers compared to those with CC homozygotes.

CONCLUSION

We revealed PPAR-γ Pro12Ala polymorphism was able to intensify the effect of DIL and DII on CVD risk factors; risk-allele carriers who consumed a diet with high DIL and DII score have more likely to be obese and have higher inflammatory markers. Also, protective factor against CVD risk factors were reduced significantly in this group compared to CC homozygotes. This article is protected by copyright. All rights reserved.

G Allele of the rs1801282 Polymorphism in PPARγ Gene Confers an Increased Risk of Obesity and Hypercholesterolemia, While T Allele of the rs3856806 Polymorphism Displays a Protective Role Against Dyslipidemia: A Systematic Review and Meta-Analysis

BACKGROUND

The relationships between the rs1801282 and rs3856806 polymorphisms in nuclear receptor peroxisome proliferator-activated receptor gamma (PPARγ) gene and obesity indexes as well as serum lipid levels have been extensively investigated in various studies, but the results were inconsistent and even contradictory.

METHODS

PubMed, Google Scholar, Embase, Cochrane Library, Web of Science, Wanfang, CNKI and VIP databases were searched for eligible studies. The random-effTPDEects model was used, and standardized mean difference (SMD) with 95% confidence interval (CI) was calculated to estimate the differences in obesity indexes and serum lipid levels between the subjects with different genotypes in a dominant model. Heterogeneity among studies was assessed by Cochran's x²-based Q-statistic test. Publication bias was identified by using Begg's test.

RESULTS

One hundred and twenty studies (70,317 subjects) and 33 studies (18,353 subjects) were identified in the analyses for the rs1801282 and rs3856806 polymorphisms, respectively. The G allele carriers of the rs1801282 polymorphism had higher levels of body mass index (SMD = 0.08 kg/m², 95% CI = 0.04 to 0.12 kg/m², p < 0.001), waist circumference (SMD = 0.12 cm, 95% CI = 0.06 to 0.18 cm, p < 0.001) and total cholesterol (SMD = 0.07 mmol/L, 95% CI = 0.02 to 0.11 mmol/L, p < 0.01) than the CC homozygotes. The T allele carriers of the rs3856806 polymorphism had lower levels of low-density lipoprotein cholesterol (SMD = -0.09 mmol/L, 95% CI = -0.15 to -0.03 mmol/L, p < 0.01) and higher levels of high-density lipoprotein cholesterol (SMD = 0.06 mmol/L, 95% CI = 0.02 to 0.10 mmol/L, p < 0.01) than the CC homozygotes.

CONCLUSIONS

The meta-analysis suggests that the G allele of the rs1801282 polymorphism confers an increased risk of obesity and hypercholesterolemia, while the T allele of the rs3856806 polymorphism displays a protective role against dyslipidemia, which can partly explain the associations between these polymorphisms and cardiovascular disease.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/, identifier [CRD42022319347].

Mechanistically acting anti-obesity compositions/formulations of natural origin: a patent review (2010-2021)

Introduction: Current health trends indicate that the rate of incidence of obesity has risen considerably. According to the World Health Organization (WHO) report 2017, the issue of obesity has grown to an epidemic proportion, with over 4 million people dying every year. Orlistat, a potent pancreatic lipase (PL) inhibitor for long-term treatment of obesity has been recently reported to cause hepatic and renal toxicities. Hence, there is a need to develop newer, safer and efficacious therapeutics that targets obesity and its associated disorders.Areas covered: The present article attempts to review patents on compositions of natural origin that include either combination of two or more lead NPs/whole extract(s)/ mixture of one or more NPs/extracts from various plants and micro-organisms. Patents that were granted during the period 2010 to 2021 have been considered.Expert opinion: The article highlights the recent trends in the rise of the global obesity population. Patents are classified based on the mechanism of action of extracts/NPs. It has been observed that in the years 2013, 2017 and 2019 maximum number of patents from China, South Korea, United States and Japan have been filed for the anti-obesity compositions.

Interaction between the dietary indices and PPAR-γ Pro12Ala gene variants on cardiovascular risk factors in patients with type 2 diabetes mellitus

AIMS

We investigated the interaction between peroxisome proliferator-activated receptor gamma (PPAR-γ) Pro12Ala polymorphism and healthy eating index (HEI), Dietary Quality Index-International (DQI-I), and dietary phytochemical index (DPI) on cardiovascular disease (CVD) risk factors in patients with type 2 diabetes mellitus (T2DM).

METHODS

This cross-sectional study was conducted on 393 diabetic patients. PPAR-γ Pro12Ala was genotyped by the PCR-RFLP method. Biochemical markers including total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglyceride (TG), superoxide dismutase (SOD), C-reactive protein (CRP), total antioxidant capacity (TAC), pentraxin-3 (PTX3), isoprostaneF2α (PGF2α). Interleukin 18 (IL18), leptin, and ghrelin were measured by standard protocol. Food-frequency questionnaires (FFQ) were used for dietary indices (DQI-I, DPI, HEI) calculation.

RESULTS

Homozygous carriers of the rs1801282 C allele showed higher leptin compared G allele carriers (P = .015). The rs1801282-DQI-I interactions were significant on waist circumference (WC) (P = .019). Thus, C-allele carriers in the higher tertile of DQI-I had higher WC compared with GG homozygous. Further, an interaction was observed between PPAR rs1801282 polymorphism and DQI-I on serum IL-18 level (P = .032). Besides, a significant rs1801282-DPI interaction was shown on HDL concentration (P = .041), G allele carriers who were in the highest tertile of DPI, had lower HDL. Moreover, there were significant rs1801282-HEI interactions on serum leptin (P = .021). Individuals with (CC, CG) genotypes in the higher tertile of HEI, had lower leptin concentration.

CONCLUSION

Higher dietary indices (DQI-I, DPI, HEI) may affect the relationship between PPAR-γ Pro12Ala polymorphism and WC, ghrelin, leptin, HDL, and IL-18 concentration in patients with T2DM.

Network pharmacology-based analysis on bioactive anti-diabetic compounds in Potentilla discolor bunge

ETHNOPHARMACOLOGICAL RELEVANCE

Potentilla discolor Bunge (PDB) is a commonly used herbal for alleviating diabetes mellitus and its complications. Although accumulating evidences show the anti-diabetic efficacy of PDB, the vital anti-diabetic compounds and their functional targets remain elusive.

AIM OF THE STUDY

To investigate the anti-diabetic ingredients and their functional mechanisms in PDB, gas chromatograph-mass spectrometry analysis was performed on PDB extract and 21 were testified as anti-diabetic compounds.

MATERIALS AND METHODS

Subsequently their potential protein targets were also identified. The bioinformatics analysis was implemented by network pharmacology-based approaches. STRING analysis was performed to reveal enrichment of these target proteins, protein-protein interactions, pathways and related diseases. Cytoscape was used to determine the potential protein targets for these components in PDB, indicating that 21 anti-diabetic compounds in PDB regulate 33 diabetes-related proteins in 28 signal pathways and involve 21 kinds of diabetes-related diseases. Among the 21 potential anti-diabetic components predicted by network analysis, tricetin was firstly experimentally validated at the molecular and cellular level.

RESULTS

Results indicated that this active small-molecule compound may have beneficial effects on improving glucose uptake.

CONCLUSIONS

We envisage that network analysis will be useful in screening bioactive compounds of medicinal plants.

Peroxisome Proliferator-Activated Receptor-γ Gene Polymorphism in Psoriasis and Its Relation to Obesity, Metabolic Syndrome, and Narrowband Ultraviolet B Response: A Case-Control Study in Egyptian Patients

Background:

Psoriasis is a common dermatologic disease with multifactorial etiology in which genetic factors play a major role. Peroxisome proliferator-activated receptor (PPAR)-γ is expressed in keratinocytes and is known to affect cell maturation and differentiation in addition to its role in inflammation.

Aim:

To study the association between PPAR-γ gene polymorphism and psoriasis vulgaris in Egyptian patients to explore if this polymorphism influenced disease risk or clinical presentation.

Methods:

Forty-five patients with psoriasis vulgaris and 45 age, sex and body mass index matched healthy volunteers who have no present, past or family history of psoriasis as a control group were enrolled. Selected cases included obese and nonobese participants. Detection of PPAR-γ gene polymorphism was done with restriction fragment length polymorphism polymerase chain reaction. Narrow-band ultraviolet B (NBUVB) was given for every case three times/week for 12 weeks.

Results:

Homopolymorphism, heteropolymorphism, and Ala allele were significantly associated with cases (P = 0.01, P = 0.01, and P = 0.004, respectively) and increased risk of occurrence of psoriasis by 5.25, 3.65, and 3.37 folds, respectively. Heteropolymorphism was significantly associated with nonobese cases compared to obese ones (P = 0.01). Ala allele was significantly associated with obese cases (P = 0.001) and increased risk of occurrence of psoriasis in obese participants by 1.14 folds. Homopolymorphism, heteropolymorphism, and Ala allele were more prevalent among obese cases without metabolic syndrome (MS) than obese cases with MS but without statistical significance. Percentage of decrease of mean Psoriasis Area and Severity Index score before and after 3 months of treatment with NBUVB was higher in cases with heteropolymorphism with no significant difference between homo- and heteropolymorphism.

Conclusion:

PPAR-γ gene polymorphism is associated with and increased the risk of psoriasis and its associated obesity in Egyptian patients. It has no role in NBUVB response in those patients. Future large-scale studies on different populations are recommended.

PPARG rs3856806 C>T Polymorphism Increased the Risk of Colorectal Cancer: A Case-Control Study in Eastern Chinese Han Population

Purpose: Functional variants in the peroxisome proliferator-activated receptor gamma (PPARG) and PPARG co-activator 1 (PPARGC1) family (e.g., PPARGC1A and PPARGC1B) genes were predicted to confer susceptibility to colorectal cancer (CRC). The aim of the present study was to explore the relationship between PPARG, PPARGC1A, PPARGC1B polymorphism and the risk of CRC.

Patients and methods: We conducted a case-control study with 1,003 CRC cases and 1,303 controls. We selected the PPARG rs3856806 C>T, PPARGC1A rs2970847 C>T, rs8192678 C>T, rs3736265 G>A and PPARGC1B rs7732671 G>C and rs17572019 G>A SNPs to assess the relationship between PPARG, PPARGC1A, PPARGC1B their variants and risk of CRC.

Results: We found that the PPARG rs3856806 C>T polymorphism increased the risk of CRC (TT vs. CC: adjusted OR, 1.59, 95% CI 1.08–2.35, P = 0.020; TT/CT vs. CC: adjusted OR, 1.26; 95% CI 1.06–1.49; P = 0.009 and TT vs. CC/CT: adjusted OR, 1.54; 95% CI 1.05–2.26; P = 0.028), even after a Bonferroni correction test. The stratified analysis revealed that the PPARG rs3856806 C>T polymorphism also increased the risk of CRC, especially in male, ≥61 years old, never smoking, never drinking, BMI ≥ 24 kg/m², colon cancer and rectum cancer subgroups.

Conclusion: Our findings highlight that the PPARG rs3856806 C>T polymorphism may increase the risk of CRC. In the future larger sample size case-control studies with a detailed functional assessment are needed to further determine the relationship of the PPARG rs3856806 C>T polymorphism with CRC risk.

Role of peroxisome proliferator-activated receptor gamma Pro12Ala polymorphism in human adipose tissue: assessment of adipogenesis and adipocyte glucose and lipid turnover

The protective mechanisms of peroxisome proliferator-activated receptor gamma (PPARγ) Pro12Ala polymorphism in type 2 diabetes (T2D) are unclear. We obtained subcutaneous adipose tissue (AT) before and 3 h after oral glucose (OGTT) in carriers and non-carriers of the Ala allele (12 Pro/Pro, 15 Pro/Ala, and 13 Ala/Ala). Adipogenesis, adipocyte glucose uptake and lipolysis as well as PPARγ target gene expression were investigated and compared between the genotype groups. During fasting and post-OGTT, neither basal nor insulin-stimulated adipocyte glucose uptake differed between genotypes. Compared to fasting, a decreased hormone-sensitive lipase gene expression in Pro/Pro (p < 0.05) was accompanied with a higher antilipolytic effect of insulin post-OGTT (p < 0.01). The adipocyte size was similar across groups. Preadipocyte differentiation rates between Pro/Pro and Ala/Ala were unchanged. In conclusion, no major differences in AT differentiation, glucose uptake, lipolysis or expression of PPARγ target genes were observed between different PPARγ Pro12Ala genotypes. Albeit small, our study may suggest that other pathways in AT or effects exerted in other tissues might contribute to the Pro12Ala-mediated protection against T2D.

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.

Genotype-based recall to study metabolic effects of genetic variation: a pilot study of PPARG Pro12Ala carriers

AIM

To assess practical implications of genotype-based recall (GBR) studies, an increasingly popular approach for in-depth characterization of genotype-phenotype relationships.

METHODS

We genotyped 2500 participants from the Swedish EpiHealth cohort and considered loss-of-function and missense variants in genes with relation to cardiometabolic traits as the basis for our GBR study. Therefore, we focused on carriers and non-carriers of the PPARG Pro12Ala (rs1801282) variant, as it is a relatively common variant with a minor allele frequency (MAF) of 0.14. It has also been shown to affect ligand binding and transcription, and carriage of the minor allele (Ala12) is associated with a reduced risk of type 2 diabetes. We re-invited 39 Pro12Pro, 34 Pro12Ala, and 30 Ala12Ala carriers and performed detailed anthropometric and serological assessments.

RESULTS

The participation rates in the GBR study were 31%, 44%, and 40%, and accordingly we included 12, 15, and 13 individuals with Pro12Pro, Pro12Ala, and Ala12Ala variants, respectively. There were no differences in anthropometric or metabolic variables among the different genotype groups.

CONCLUSIONS

Our report highlights that from a practical perspective, GBR can be used to study genotype-phenotype relationships. This approach can prove to be a valuable tool for follow-up findings from large-scale genetic discovery studies by undertaking detailed phenotyping procedures that might not be feasible in large studies. However, our study also illustrates the need for a larger pool of genotyped or sequenced individuals to allow for selection of rare variants with larger effects that can be examined in a GBR study of the present size.

Clinical relevance of peroxisome proliferator-activated receptor-γ gene polymorphisms with sepsis

BACKGROUND

Peroxisome proliferator-activated receptor-γ (PPARγ) is a regulator of inflammation. This study aimed to explore associations between PPARγ gene single-nucleotide polymorphisms (SNPs) and susceptibility to and clinical outcome of sepsis in the North China Han population.

METHODS

This study included 303 patients with sepsis and 303 controls. We conducted genetic typing for 13 common PPARγ gene SNPs (improved multiplex ligation detection reaction), linkage disequilibrium mapping, and haplotype inference. Associations between SNP genotypes/haplotypes and sepsis susceptibility and outcome (septic shock, organ dysfunction, or death) were assessed using unconditional logistic regression analysis.

RESULTS

For rs2972164, patients with genotypes CT/CT+TT had higher risk of sepsis than genotype CC (odds ratio [95% CI]: 1.74 [1.05-2.86], P = .03 and 1.72 [1.06-2.80], P = .026, respectively); the T allele was associated with increased sepsis risk compared with the C allele (1.64 [1.04-2.58], P = .033). For rs1801282, genotypes CG/CG+GG had lower risk of sepsis than genotype CC (0.55 [0.33-0.92], P = .024 and 0.57 [0.35-0.95], P = .03, respectively); the G allele was associated with decreased sepsis risk compared with the C allele (0.62 [0.39-1.01], P = .055). For rs4135275, genotypes AG/AG+GG had higher risk of severe organ dysfunction (multiple organ dysfunction syndrome score >8) than genotype AA (2.66 [1.16-6.09], P = .038 and 2.21 [1.00-4.85], P = .042, respectively). Haplotype TAT (rs2972164, rs4684846, and rs17036188) was associated with increased sepsis risk (1.66 [1.03-2.67], P = .038).

CONCLUSIONS

No mutation was correlated with septic shock or death. PPARγ gene polymorphisms may play a role in the occurrence and progression of sepsis in the North China Han population.

Association between polymorphism within interleukin related genes and Graves' disease: a meta-analysis of 22 case-control studies

Graves' disease (GD) is a common autoimmune disorder with a genetic predisposition. There is strong evidence to suggest that both Th1 and Th2 circulating cytokines are involved in the development of GD. In this study, we conducted a meta-analysis to assess the impact of seven variations of five IL-related genes on the susceptibility to GD. A total of 22 case-control studies involving 5338 GD patients and 6446 healthy controls were included. The results showed that only one SNP rs1800795 in IL-6 was significantly associated with GD in homozygous model (CC vs. GG: OR = 2.714, 95% CI = 1.047-7.039, p = 0.04), heterozygous model (CG vs. GG: OR = 1.295, 95% CI = 1.013-1.655, p = 0.039), dominant model (CC+CG vs. GG: OR = 1.418, 95% CI = 1.122-1.793, p = 0.003) and additive model (C vs. G: OR = 1.432, 95% CI = 1.087-1.886, p = 0.011).To explain the heterogeneity, we performed the subgroup analysis by ethnicity. The ethnicity stratification revealed that the association between rs1800795 and GD tended to be much stronger for Asian than European population in homozygous, dominant, recessive, and additive models. The remaining 6 SNPs in 4 genes did not show any significant association with GD in any genetic models. Together, our data support that rs1800795 within the IL-6 gene confers genetic susceptibility for GD. Future large-scale studies are required to validate the associations between IL-6 and others IL-related genes and GD.

Association of PPARG rs 1801282 C>G polymorphism with risk of colorectal cancer: from a case-control study to a meta-analysis

The functional single nucleotide polymorphisms in peroxisome proliferator-activated receptor gamma (PPARG) gene were predicted to be correlated with the susceptibility of colorectal cancer (CRC). The aim of the present study was to explore the relationship between PPARG rs1801282 C>G polymorphism and the risk of CRC. First, we conducted a case-control study with 387 CRC cases and 1,536 controls. We used the SNPscan method to determine the genotypes of PPARG rs1801282 C>G polymorphism. We found PPARG rs1801282 C>G polymorphism had a tendency of decreased risk to CRC risk (CG vs. CC: adjusted OR, 0.67, 95% CI = 0.43–1.04 for CG vs. CC, P = 0.073; GG vs. CC: adjusted OR, 0.68; 95% CI, 0.44–1.05; P = 0.078). The stratified analysis revealed PPARG rs1801282 C>G polymorphism also had a tendency of decreased risk to colon cancer (CG vs. CC: adjusted OR = 0.54, 95% CI = 0.27–1.08, P = 0.083). The results of subsequent meta-analysis suggested that PPARG rs1801282 C>G polymorphism might be a protective factor for CRC, especially in Asians, colon cancer and rectum cancer subgroups. In conclusion, our study indicates that PPARG rs1801282 C>G polymorphism might decrease the risk of overall CRC. Larger sample size and well-designed case-control studies are needed to confirm the potential association.

Obesity and Pro12Ala Polymorphism of Peroxisome Proliferator-Activated Receptor-Gamma Gene in Healthy Adults: A Systematic Review and Meta-Analysis

BACKGROUND

The aim of this systematic review was to evaluate the relationship between obesity and peroxisome proliferator-activated receptor-gamma (PPARx03B3;) Pro12Ala polymorphism in healthy adults.

SUMMARY

Weighted mean differences (WMDs) of body mass index (BMI) were calculated for different inheritance models and subgroups. Fifty-six studies were eligible for inclusion in the meta-analysis. The result shows that the Ala allele of this polymorphism was associated with increased WMD in mean BMI (WMD = 0.29, 95% CI 0.10-0.48, p = 0.003). The Ala carriers were associated with increased WMD in mean BMI values in both genders and in the Caucasian subgroup. The associations were seen among people with higher levels of BMI (BMI ≥35).

MESSAGE

The Ala allele of the PPARx03B3; Pro12Ala polymorphism in healthy adults was associated with increased BMI under a dominant model of inheritance.

C677T gene polymorphism of MTHFR and metabolic syndrome: response to dietary intervention

BACKGROUND

Methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms were found associated with body mass index (BMI)-defined obesity and lean mass. The aim of our study was to examine the role of the C677T MTHFR gene polymorphism in the response to diet in the management of metabolic syndrome. We investigated the body composition and metabolic factor changes after an hysocaloric balanced diet (HBD), in Italian obese women affected by metabolic syndrome (MS).

METHODS

Forty four obese women affected by MS were eligible for the study. A HBD for 12 weeks was assigned. Study participation included a complete screening for dietary habits, anthropometry, body composition, blood biochemical markers and C677T MTHFR polymorphism genotyping. The study has been registrated by ClinicalTrials.gov Id: NCT01890070.

RESULTS

The highest number of responders to HBD nutritional intervention were T(-) carriers (p ≤ 0.05). In the 81% of the total population a loss of Total Body Lean was observed. A significative loss (p ≤ 0.05) of Total Body Lean was observed in the 47% of T(-) carriers and in the 53% of T(+) carriers. Diastolic and systolic blood pressure, and waist circumference were reduced (p ≤ 0.05). The prevalence of MS parameters decreased by 84% for systolic and diastolic blood pressure; 79,5% for HDL cholesterol, 82% for fasting glucose and 77% for triglycerides.

CONCLUSIONS

MTHFR genetic variations analysis would be an innovative tool for the nutritional assessment. Our data provide the basis for personalized dietary recommendations based on the individual's genetic makeup and nutritional status.

TRIAL REGISTRATION

The study has been registrated by ClinicalTrials.gov Id: NCT01890070.

Association of the variants in the PPARG gene and serum lipid levels: a meta-analysis of 74 studies

Considerable studies have been carried out to investigate the relationship between the polymorphisms of PPARG (Pro12Ala, C161T and C1431T) and serum lipid levels, but the results were inconclusive. Hence, we conducted a meta-analysis to clarify the association. MEDLINE, EMBASE and the Cochrane Library databases were searched systematically. The subgroup analysis was performed based on ethnicity. Seventy-four studies with 54,953 subjects were included in this meta-analysis. In Pro12Ala, the group with the ‘PP’ (C/C genotype) genotype group had lower levels of total cholesterol (TC) (mean difference, MD: −0.02, P < 0.00001; I² = 28%), low-density lipoprotein cholesterol (LDL-C) (MD: −0.02, P < 0.00001; I² = 30%) and higher levels of triglyceride (TG) (MD: 0.06, P < 0.00001; I² = 30%) than the combined ‘PA+AA’ (PA = C/G genotype, AA = G/G genotype) genotype group in Asian population, and the group with the ‘PP’ genotype had higher levels of TG (MD: 0.07, P < 0.02; I² = 67%) than the combined ‘PA+AA’ genotype group in non-Asian population. No statistically significant differences in the levels of TC, TG, high-density lipoprotein cholesterol, LDL-C were detected between different genotypes in C161T(Asian or non-Asian) and C1431T(Asian) polymorphisms. This meta-analysis was a renewed and confirmed study to assess the association between PPARG polymorphisms and serum lipid levels in Asian and non-Asian populations. There is a prominent association between Pro12Ala polymorphism and the levels of TC, LDL-C and TG in Asian population. No statistically significant differences in serum lipid levels were detected between different genotypes in C161T and C1431T polymorphisms.

Peroxisome proliferator‑activated receptor γ polymorphisms as risk factors for dyslipidemia

Peroxisome proliferator‑activated receptor γ (PPARγ) may play an important role in lipid metabolism directly or by inducing the transcription of target genes. The aim of the present study was to investigate the association between common variants at the PPARγ locus (C1431T and Pro12Ala polymorphisms) and lipid serum levels. The studied population consisted of 820 subjects randomly selected from the Prevention of Multiple Metabolic Disorders and Metabolic Syndrome in Jiangsu Province cohort population. All subjects were interviewed and blood samples were obtained for laboratory analysis and DNA extraction. The TaqMan single nucleotide polymorphism genotyping assay was used for polymorphism genotyping. Individual polymorphisms and haplotype data were available for analysis. The 12Ala allele was found to be associated with significantly increased levels of triglyceride (TG) (P<0.01), whilst the 1431T allele was found to be associated with significantly increased levels of TG, total cholesterol (TC) and non‑high‑density lipoprotein (non‑HDL) (P<0.01). When P‑C, the most common haplotype, was used as the reference group, the P‑T, A‑C and A‑T haplotypes were found to be associated with significantly increased levels of TG (P<0.01). In addition, the A‑T haplotype was shown to be associated with significantly increased levels of TC and non‑HDL (P<0.01). In conclusion these results suggest that PPARγ gene variability may increase the risk of dyslipidemia.

Polymorphisms in the TNFA and IL6 genes represent risk factors for autoimmune thyroid disease

BACKGROUND

Autoimmune thyroid disease (AITD) comprises diseases including Hashimoto's thyroiditis and Graves' disease, both characterized by reactivity to autoantigens causing, respectively, inflammatory destruction and autoimmune stimulation of the thyroid-stimulating hormone receptor. AITD is the most common thyroid disease and the leading form of autoimmune disease in women. Cytokines are key regulators of the immune and inflammatory responses; therefore, genetic variants at cytokine-encoding genes are potential risk factors for AITD.

METHODS

Polymorphisms in the IL6-174 G/C (rs1800795), TNFA-308 G/A (rs1800629), IL1B-511 C/T (rs16944), and IFNGR1-56 T/C (rs2234711) genes were assessed in a case-control study comprising 420 Hashimoto's thyroiditis patients, 111 Graves' disease patients and 735 unrelated controls from Portugal. Genetic variants were discriminated by real-time PCR using TaqMan SNP genotyping assays.

RESULTS

A significant association was found between the allele A in TNFA-308 G/A and Hashimoto's thyroiditis, both in the dominant (OR = 1.82, CI = 1.37-2.43, p-value = 4.4×10(-5)) and log-additive (OR = 1.64, CI = 1.28-2.10, p-value = 8.2×10(-5)) models. The allele C in IL6-174 G/C is also associated with Hashimoto's thyroiditis, however, only retained significance after multiple testing correction in the log-additive model (OR = 1.28, CI = 1.06-1.54, p-value = 8.9×10(-3)). The group with Graves' disease also registered a higher frequency of the allele A in TNFA-308 G/A compared with controls both in the dominant (OR = 1.85, CI = 1.19-2.87, p-value = 7.0×10(-3)) and log-additive (OR = 1.69, CI = 1.17-2.44, p-value = 6.6×10(-3)) models. The risk for Hashimoto's thyroiditis and Graves' disease increases with the number of risk alleles (OR for two risk alleles is, respectively, 2.27 and 2.59).

CONCLUSIONS

This study reports significant associations of genetic variants in TNFA and IL6 with the risk for AITD, highlighting the relevance of polymorphisms in inflammation-related genes in the etiopathogenesis of AITD.

Does Pro(12)Ala Polymorphism Enhance the Physiological Role of PPARγ2?

Obesity and type 2 diabetes mellitus (T2D) are two major public health problems that have motivated the scientific community to investigate the high contribution of genetic factors to these disorders. The peroxisome proliferator activated by gamma 2 (PPARγ2) plays an important role in the lipid metabolism. Since PPARγ2 is expressed mainly in adipose tissue, a moderate reduction of its activity influences the sensitivity to insulin, diabetes, and other metabolic parameters. The present study aims to contribute to the elucidation of the impact of the Pro(12)Ala polymorphism associated with T2D and obesity through a meta-analysis study of the literature that included approximately 11500 individuals, from which 3870 were obese and 7625 were diabetic. Statistical evidence supports protective effect in T2D of polymorphism Pro(12)Ala of PPARγ2 (OR = 0.702 with 95% CI: 0.622; 0.791, P < 0.01). Conversely the same polymorphism Pro(12)Ala of PPARγ2 seems to favor obesity since 1.196 more chance than nonobese was found (OR = 1.196 with 95% CI: 1.009; 1.417, P < 0.004). Our results suggest that Pro(12)Ala polymorphism enhances both adipogenic and antidiabetogenic physiological role of PPARγ. Does Pro(12)Ala polymorphism represent an evolutionary step towards the stabilization of the molecular function of PPARγ transcription factor signaling pathway?

An age-dependent diet-modified effect of the PPARγ Pro12Ala polymorphism in children

Variation in the peroxisome proliferator-activated receptor γ gene alters the risk for adiposity in adults, with evidence of interaction with diet. We investigated the age-related association between the Pro12Ala variant (rs1801282) and diet in obesity-related traits in children. The Pro12Ala variant was assayed in 2102 young children aged 1 to 6 years and in 794 periadolescent children aged 10 to 12 years of Greek origin. In both cohorts, no differences were found in obesity traits between the Ala allele carriers and Pro/Pro homozygotes. Sex-stratified analysis showed that, in periadolescent boys, Ala carriers exhibited lower measures of skinfolds (triceps: 16.9 ± 6.9 vs 19.4 ± 7.9 mm, P = .01; subscapular: 9.6 ± 4.5 vs 11.2 ± 5.4 mm, P = .02). On the other hand, young girls who were Ala carriers presented higher measures of triceps skinfold thickness (10.5 ± 3.0 vs 9.9 ± 2.8 mm, P = .04). Nominal gene-diet interactions were revealed in periadolescents for saturated fatty acid (SFA) intake and skinfolds (P for interaction = .05). In Pro/Pro homozygous young girls, SFA and total fat (TF) intake was positively associated with higher body mass index (BMI) (P = .01), waist circumference (P = .02), and skinfold thickness (triceps-SFA: P = 10⁻⁵, triceps-TF: P = 10⁻⁹, subscapular-SFA: P = 10⁻⁶, subscapular-TF: P = 10⁻⁴). For Pro/Pro homozygotes, unsaturated fat intake was inversely associated with BMI (P = .04) in young girls, and with BMI (P = .03), waist circumference (P = .03), and triceps (P = .02) in periadolescent boys. Our results suggest that adiposity in children is influenced by the Pro12Ala polymorphism in a sex-specific and age-dependent manner. We also demonstrate evidence of an age-dependent gene-diet (SFA, TF) interaction, suggesting that the type of fat intake modifies the effect of the Pro12 allele on obesity-related measures.

Variants of ESR1, APOE, LPL and IL-6 loci in young healthy subjects: association with lipid status and obesity

FINDINGS

BMI was increased (>25) in 22% of young healthy subjects. Increased cholesterol values (>5.0 mmol/L) were found in 23% of subjects, LDL-C (>3.0 mmol/L) in 23%, triglycerides (>1.7 mmol/L) in 11% of subjects. We found statistically significant differences in subjects' weight (p = 0.015), BMI (p = 0.023), and waist-hip ratio (WHR) (p = 0.015) in regard to their diet type; subjects with Mediterranean diet had the lowest values compared to those on continental and mixed diet. Significant associations were found for: LPL genetic polymorphic variant and abdominal obesity (p = 0.013), APO epsilon4 allele and hypercholesterolemia (p = 0.003), and ESR1-TA long allele and hypercholesterolemia (p = 0.011).

BACKGROUND

Human obesity is a multifactorial syndrome influenced also by genetic factors. Among gene variants found to be involved in body weight regulation and development of obesity, particular attention has been paid to polymorphisms in genes associated with obesity-related metabolic disorders. We explored the association of genetic polymorphisms of: estrogen receptor alpha (ESR1-TA repeats); interleukin-6 (IL-6 G-174C); apolipoprotein E (APO epsilon2, epsilon3, epsilon4); lipoprotein lipase Pvu II (LPL P+/-), with clinical variables: gender, age, body mass index (BMI), diet type and biological variables: triglycerides, cholesterol, HDL-C, LDL-C, CRP, homocysteine, urate, and glucose in 105 healthy young subjects (20-35 yrs) of Croatian origin.

METHODS

Genotyping of IL-6, LPL was performed by PCR-RFLP, of APOE by real-time PCR, and of ESR1 by PCR and capillary electrophoresis. Association analyses were performed of alleles and genotypes with biological variables.

CONCLUSION

ESR-1, LPL, and APO E genetic polymorphic variants could represent predictive genetic risk markers for obesity-related metabolic disorders in young healthy subjects. Mediterranean type of diet is also an important protective factor against abdominal obesity.

PPARγ2 polymorphism and human health

The nuclear hormone receptor peroxisome proliferator activated receptor gamma (PPARγ) is an important transcription factor regulating adipocyte differentiation, lipid and glucose homeostasis, and insulin sensitivity. Numerous genetic mutations of PPARγ have been identified and these mutations positively or negatively regulate insulin sensitivity. Among these, a relatively common polymorphism of PPARγ, Pro12Ala of PPARγ2, the isoform expressed only in adipose tissue has been shown to be associated with lower body mass index, enhanced insulin sensitivity, and resistance to the risk of type 2 diabetes in human subjects carrying this mutation. Subsequent studies in different ethnic populations, however, have revealed conflicting results, suggesting a complex interaction between the PPARγ2 Pro12Ala polymorphism and environmental factors such as the ratio of dietary unsaturated fatty acids to saturated fatty acids and/or between the PPARγ2 Pro12Ala polymorphism and genetic factors such as polymorphic mutations in other genes. In addition, this polymorphic mutation in PPARγ2 is associated with other aspects of human diseases, including cancers, polycystic ovary syndrome, Alzheimer disease and aging. This review will highlight findings from recent studies.

Joint analysis of individual participants' data from 17 studies on the association of the IL6 variant -174G>C with circulating glucose levels, interleukin-6 levels, and body mass index

BACKGROUND

Several studies have investigated associations between the -174G>C single nucleotide polymorphism (rs1800795) of the IL6 gene and phenotypes related to type 2 diabetes mellitus (T2DM) but presented inconsistent results.

AIMS

This joint analysis aimed to clarify whether IL6 -174G>C was associated with glucose and circulating interleukin-6 concentrations as well as body mass index (BMI).

METHODS

Individual-level data from all studies of the IL6-T2DM consortium on Caucasian subjects with available BMI were collected. As study-specific estimates did not show heterogeneity (P>0.1), they were combined by using the inverse-variance fixed-effect model.

RESULTS

The main analysis included 9440, 7398, 24,117, or 5659 non-diabetic and manifest T2DM subjects for fasting glucose, 2-hour glucose, BMI, or circulating interleukin-6 levels, respectively. IL6 -174 C-allele carriers had significantly lower fasting glucose (-0.091 mmol/L, P=0.014). There was no evidence for association between IL6 -174G>C and BMI or interleukin-6 levels, except in some subgroups.

CONCLUSIONS

Our data suggest that C-allele carriers of the IL6 -174G>C polymorphism have lower fasting glucose levels on average, which substantiates previous findings of decreased T2DM risk of these subjects.

Genome-wide association with select biomarker traits in the Framingham Heart Study

BACKGROUND

Systemic biomarkers provide insights into disease pathogenesis, diagnosis, and risk stratification. Many systemic biomarker concentrations are heritable phenotypes. Genome-wide association studies (GWAS) provide mechanisms to investigate the genetic contributions to biomarker variability unconstrained by current knowledge of physiological relations.

METHODS

We examined the association of Affymetrix 100K GeneChip single nucleotide polymorphisms (SNPs) to 22 systemic biomarker concentrations in 4 biological domains: inflammation/oxidative stress; natriuretic peptides; liver function; and vitamins. Related members of the Framingham Offspring cohort (n = 1012; mean age 59 +/- 10 years, 51% women) had both phenotype and genotype data (minimum-maximum per phenotype n = 507-1008). We used Generalized Estimating Equations (GEE), Family Based Association Tests (FBAT) and variance components linkage to relate SNPs to multivariable-adjusted biomarker residuals. Autosomal SNPs (n = 70,987) meeting the following criteria were studied: minor allele frequency > or = 10%, call rate > or = 80% and Hardy-Weinberg equilibrium p > or = 0.001.

RESULTS

With GEE, 58 SNPs had p < 10(-6): the top SNPs were rs2494250 (p = 1.00*10(-14)) and rs4128725 (p = 3.68*10(-12)) for monocyte chemoattractant protein-1 (MCP1), and rs2794520 (p = 2.83*10(-8)) and rs2808629 (p = 3.19*10(-8)) for C-reactive protein (CRP) averaged from 3 examinations (over about 20 years). With FBAT, 11 SNPs had p < 10(-6): the top SNPs were the same for MCP1 (rs4128725, p = 3.28*10(-8), and rs2494250, p = 3.55*10(-8)), and also included B-type natriuretic peptide (rs437021, p = 1.01*10(-6)) and Vitamin K percent undercarboxylated osteocalcin (rs2052028, p = 1.07*10(-6)). The peak LOD (logarithm of the odds) scores were for MCP1 (4.38, chromosome 1) and CRP (3.28, chromosome 1; previously described) concentrations; of note the 1.5 support interval included the MCP1 and CRP SNPs reported above (GEE model). Previous candidate SNP associations with circulating CRP concentrations were replicated at p < 0.05; the SNPs rs2794520 and rs2808629 are in linkage disequilibrium with previously reported SNPs. GEE, FBAT and linkage results are posted at http://www.ncbi.nlm.nih.gov/projects/gap/cgi-bin/study.cgi?id=phs000007 webcite.

CONCLUSION

The Framingham GWAS represents a resource to describe potentially novel genetic influences on systemic biomarker variability. The newly described associations will need to be replicated in other studies.

Interleukin-6 genetic variability and adiposity: associations in two prospective cohorts and systematic review in 26,944 individuals

CONTEXT

IL-6 (IL6) is an immune-modulating cytokine associated with obesity in humans.

OBJECTIVE

Our objective was to assess the associations between the genetic variability of IL6 gene and adiposity and long-term changes.

DESIGN AND SUBJECTS

We determined the linkage disequilibrium-tagging single-nucleotide polymorphisms of IL6 gene in 2255 healthy women and 980 healthy men from two prospective cohorts. We also conducted a metaanalysis on the associations between polymorphism -174G>C (rs1800795) and adiposity.

RESULTS

IL6 haplotype 222211 (possessing rs2069827, rs1800797, rs1800795, rs1554606, rs2069861, and rs1818879; 1 codes the common and 2 codes the minor alleles) was consistently and significantly associated with greater waist circumference (P = 0.009 in men; P = 0.0003 in women) and baseline body mass index (BMI) (P = 0.01 in men; P = 0.046 in women) compared with the most common haplotype 111112. Haplotype 222211 was also associated with significantly higher early-adulthood BMI in women (P = 0.007). The haplotype-associated difference in BMI persisted significantly during the follow-up. A 5' promoter polymorphism, rs2069827, was consistently associated with significantly higher early-adulthood BMI, baseline BMI, and waist circumference in men (carriers vs. noncarriers, P = 0.01, 0.007, and 0.008) and women (P = 0.01, 0.10, and 0.0016). The data from this study and a metaanalysis of 26,944 individuals did not support substantial relations between the best-studied polymorphism, -174G>C, and adiposity.

CONCLUSIONS

Our data from two independent cohorts indicate that the variability of the IL6 gene is significantly associated with adiposity. Such associations are less likely to be caused by polymorphism -174G>C.

Weight regain after slimming induced by an energy-restricted diet depends on interleukin-6 and peroxisome-proliferator-activated-receptor-γ2 gene polymorphisms

Weight-loss maintenance after following an energy-restricted diet is a major problem that a number of studies are trying to characterise. The aim of the present study was to investigate the role of IL-6 -174G > C and PPAR-γ2 Pro12Ala variants on weight regulation in obese subjects receiving a low-energy diet and at 1 year after the acute slimming period. Sixty-seven volunteers (age 34·7 (sd 7·0) years; BMI 35·8 (sd 4·8) kg/m2) were enrolled in a 10-week dietary intervention and were contacted again 1 year after the end of this period. Body composition was measured at three times during the study. Also, PPAR-γ2 Pro12Ala and IL-6 -174G > C polymorphisms were analysed in the participants. No statistical differences were observed depending on the genetic variants at baseline for anthropometric variables, or after the intervention. However, the C allele of the -174G > C IL-6 gene polymorphism was more frequently observed (P=0·032) in subjects with successful weight maintenance (<10 % weight regain). In fact, the C allele partially protected against weight regain (odds ratio 0·24;P=0·049), while the conjoint presence of both gene variants (C+ and Ala+) further improved the ability for weight maintenance (odds ratio 0·19;P=0·043). The present study demonstrates that the C allele of the -174G > C polymorphism gives protection against regain of weight lost. Moreover, the presence of the Ala allele of the PPARγ-2 together with the C allele strengthens this protection. These findings support a role for these polymorphisms on weight regulation and suggest a synergetic effect of both variants on weight maintenance after following a diet to lose weight.

Genes, ageing and longevity in humans: problems, advantages and perspectives

Many epidemiological data indicate the presence of a strong familial component of longevity that is largely determined by genetics, and a number of possible associations between longevity and allelic variants of genes have been described. A breakthrough strategy to get insight into the genetics of longevity is the study of centenarians, the best example of successful ageing. We review the main results regarding nuclear genes as well as the mitochondrial genome, focusing on the investigations performed on Italian centenarians, compared to those from other countries. These studies produced interesting results on many putative "longevity genes". Nevertheless, many discrepancies are reported, likely due to the population-specific interactions between gene pools and environment. New approaches, including large-scale studies using high-throughput techniques, are urgently needed to overcome the limits of traditional association studies performed on a limited number of polymorphisms in order to make substantial progress to disentangle the genetics of a trait as complex as human longevity.

Genetics of obesity and the prediction of risk for health

Obesity has always existed in human populations, but until very recently was comparatively rare. The availability of abundant, energy-rich processed foods in the last few decades has, however, resulted in a sharp rise in the prevalence of obesity in westernized countries. Although it is the obesogenic environment that has resulted in this major healthcare problem, it is acting by revealing a sub-population with a pre-existing genetic predisposition to excess adiposity. There is substantial evidence for the heritability of obesity, and research in both rare and common forms of obesity has identified genes with significant roles in its aetiology. Application of this understanding to patient care has been slower. Until very recently, the health risks of obesity were thought to be well understood, with a straightforward correlation between increasing obesity and increasing risk of health problems such as type 2 diabetes, coronary heart disease, hypertension, arthritis and cancer. It is becoming clear, however, that the location of fat deposition, variation in the secretion of adipokines and other factors govern whether a particular obese person develops such complications. Prediction of the health risks of obesity for individual patients is not straightforward, but continuing advances in understanding of genetic factors influencing obesity risk and improved diagnostic technologies mean that the future for such prediction is looking increasingly bright.

Inflammaging and anti-inflammaging: a systemic perspective on aging and longevity emerged from studies in humans

A large part of the aging phenotype, including immunosenescence, is explained by an imbalance between inflammatory and anti-inflammatory networks, which results in the low grade chronic pro-inflammatory status we proposed to call inflammaging. Within this perspective, healthy aging and longevity are likely the result not only of a lower propensity to mount inflammatory responses but also of efficient anti-inflammatory networks, which in normal aging fail to fully neutralize the inflammatory processes consequent to the lifelong antigenic burden and exposure to damaging agents. Such a global imbalance can be a major driving force for frailty and common age-related pathologies, and should be addressed and studied within an evolutionary-based systems biology perspective. Evidence in favor of this conceptualization largely derives from studies in humans. We thus propose that inflammaging can be flanked by anti-inflammaging as major determinants not only of immunosenescence but eventually of global aging and longevity.

Interleukin-6 gene polymorphism -174G/C influences plasma lipid levels in women

Elevated levels of the pro-inflammatory cytokine interleukin-6 (IL-6) have been associated with cardiovascular risk factors. The objective of this study was to investigate potential associations between the promoter polymorphism IL-6 -174G/C and the following indices of metabolism: BMI, waist-to-hip ratio, and plasma levels of IL-6, cholesterol, low-density lipoprotein, triglycerides, high-density lipoprotein, leptin, and C-reactive protein in 252 42-year-old women and 245 51-year-old men. Subgroups were also studied 5 years later. The CC genotype of the IL-6 polymorphism was associated with lower levels of cholesterol and low-density lipoprotein (p < 0.001) in women. This finding was replicated in the follow-up, when a significant association between the CC genotype and low triglycerides was also observed. The association between the C allele and lipid pattern found in women was not found in men, where on the contrary, C carriers tended to display elevated triglycerides. IL-6 genotype was not associated with IL-6 plasma levels in either sample. The results suggest different effects of the IL-6 polymorphism on metabolic indices in women and men. None of the associations between IL-6 genotype and lipid pattern seemed to result from an effect of the polymorphism on IL-6 plasma levels.

IL-6 promoter polymorphisms and quantitative traits related to the metabolic syndrome in KORA S4

Interleukin-6 (IL-6) is a pleiotropic cytokine which has been proposed as "cytokine for gerontologists" and linked to age-related metabolic disturbances such as the metabolic syndrome or type 2 diabetes. Polymorphisms located in the promoter region of IL-6 have been reported to be involved in the regulation of IL-6 transcription. This study investigates whether IL-6 promoter variants -174 G/C and -573 G/C are associated with quantitative traits related to the metabolic syndrome (International Diabetes Federation criteria) in a population of normoglycemic subjects (n=878) from the latest KORA survey (KORA S4). Genotyping was performed using MALDI-TOF MS. Besides lower height (p=0.01) the -174 CC genotype was independently associated with lower waist (p=0.002) and hip (p=0.01) circumferences in men. Furthermore, the -174 CC genotype was associated with BMI (p=0.004) when adjusted for waist and hip circumference. The present study does not suggest associations with further components of the metabolic syndrome. The association with height seems to be the central factor indicating an influence of IL-6 on growth through impaired bone metabolism. However, the complex relationships need further investigation.

The Genetics of Human Longevity

Aging is due to a complex interaction of genetic, epigenetic, and environmental factors, but a strong genetic component appears to have an impact on survival to extreme ages. In order to identify "longevity genes" in humans, different strategies are now available. In our laboratory, we performed association studies on a variety of "candidate" polymorphisms in Italian centenarians. Many genes/polymorphisms gave negative results, while others showed a positive association with human longevity and a sometimes-positive association with unsuccessful aging (myocardial infarction, Alzheimer's disease, and type 2 diabetes). Results regarding genes involved in inflammation (IL-1 cluster, IL-6, IL-10, TNF-alpha, TGF-beta, TLR-4, PPARgamma), insulin/IGF-1 signaling pathway and lipid metabolism (apolipoproteins, CETP, PON1), and oxidative stress (p53, p66(shc)) will be described. In addition, a strong role of the interaction between nuclear and mitochondrial genomes (mtDNA haplogroups and the C150T mutation) emerged from our findings. Thus, the genetics of human longevity appears to be quite peculiar in a context where antagonistic pleiotropy can play a major role and genes can have a different biological role at different ages.