Association of the TNF-alpha -308 G/A promoter polymorphism with insulin resistance in obesity

Investigations of associations between TNF-α promoter polymorphisms and genetic susceptibility to type 2 diabetes mellitus: A cross-sectional study in Chinese Han population

Type 2 diabetes (T2DM) is characterised by insulin resistance and a relative shortage of insulin secretion. Tumour necrosis factor-α (TNF-α) plays an important role in insulin resistance by impairing insulin signal transduction. The variants of the TNF-α promoter region are considered to influence its transcription and are associated with the TNF-α level. Therefore, it is worth detecting the association of the variants in the TNF-α gene with the development of T2DM. The aim of this study was to investigate the association of five variants (rs1799964, rs1800630, rs1799724, rs1800629 and rs361525) in the TNF-α gene promoter region with T2DM in a Chinese Han population. A total of 713 subjects with T2DM and 751 nondiabetic subjects were genotyped using the TaqMan method. The associations of the five variants with the development of T2DM were evaluated. The associations of the five variant genotypes with metabolic traits in nondiabetic subjects were analysed. Our data showed that the A allele of rs1800629 could increase the risk of developing T2DM (p = .002, OR = 1.563; 95% CI: 1.18-2.08). According to inheritance mode analysis, compared with the G/G genotype, the G/A+2A/A genotype of rs1800629 showed a risk effect on T2DM in the log-additive mode (p = .002, OR = 1.56; 95% CI: 1.17-2.07). The haplotypes analysis identified that the rs1799724-rs1800629CA was associated with high risk of the development of T2DM (p = .002, OR = 1.559, 95% CI: 1.173-2.072). Conversely, the rs1799724-rs1800629CG was a protective haplotype of T2DM (p = .001, OR = 0.732, 95% CI: 0.607-0.884). Moreover, compared with the rs1799964 (T/T+C/T) genotype, the rs1799964 C/C genotype was associated with higher glycosylated haemoglobin (HbA1c) levels in nondiabetic subjects (p = .017). Our results revealed that the rs1800629 in the TNF-α gene promoter region was associated with T2DM in a Chinese Han population.

Food Polyphenols and Type II Diabetes Mellitus: Pharmacology and Mechanisms

Type II diabetes mellitus and its related complications are growing public health problems. Many natural products present in our diet, including polyphenols, can be used in treating and managing type II diabetes mellitus and different diseases, owing to their numerous biological properties. Anthocyanins, flavonols, stilbenes, curcuminoids, hesperidin, hesperetin, naringenin, and phenolic acids are common polyphenols found in blueberries, chokeberries, sea-buckthorn, mulberries, turmeric, citrus fruits, and cereals. These compounds exhibit antidiabetic effects through different pathways. Accordingly, this review presents an overview of the most recent developments in using food polyphenols for managing and treating type II diabetes mellitus, along with various mechanisms. In addition, the present work summarizes the literature about the anti-diabetic effect of food polyphenols and evaluates their potential as complementary or alternative medicines to treat type II diabetes mellitus. Results obtained from this survey show that anthocyanins, flavonols, stilbenes, curcuminoids, and phenolic acids can manage diabetes mellitus by protecting pancreatic β-cells against glucose toxicity, promoting β-cell proliferation, reducing β-cell apoptosis, and inhibiting α-glucosidases or α-amylase. In addition, these phenolic compounds exhibit antioxidant anti-inflammatory activities, modulate carbohydrate and lipid metabolism, optimize oxidative stress, reduce insulin resistance, and stimulate the pancreas to secrete insulin. They also activate insulin signaling and inhibit digestive enzymes, regulate intestinal microbiota, improve adipose tissue metabolism, inhibit glucose absorption, and inhibit the formation of advanced glycation end products. However, insufficient data are available on the effective mechanisms necessary to manage diabetes.

Pathophysiology of type 2 diabetes and the impact of altered metabolic interorgan crosstalk

Diabetes is a complex and multifactorial disease that affects millions of people worldwide, reducing the quality of life significantly, and results in grave consequences for our health care system. In type 2 diabetes (T2D), the lack of β-cell compensatory mechanisms overcoming peripherally developed insulin resistance is a paramount factor leading to disturbed blood glucose levels and lipid metabolism. Impaired β-cell functions and insulin resistance have been studied extensively resulting in a good understanding of these pathways but much less is known about interorgan crosstalk, which we define as signaling between tissues by secreted factors. Besides hormones and organokines, dysregulated blood glucose and long-lasting hyperglycemia in T2D is associated with changes in metabolism with metabolites from different tissues contributing to the development of this disease. Recent data suggest that metabolites, such as lipids including free fatty acids and amino acids, play important roles in the interorgan crosstalk during the development of T2D. In general, metabolic remodeling affects physiological homeostasis and impacts the development of T2D. Hence, we highlight the importance of metabolic interorgan crosstalk in this review to gain enhanced knowledge of the pathophysiology of T2D, which may lead to new therapeutic approaches to treat this disease.

Tumour necrosis factor-α −308G/A polymorphism is associated with insulin secretory defects in Bangladeshi prediabetic/diabetic subjects

Objectives

Tumour necrosis factor (TNF)-α, an adipocytokine, is closely linked to impaired glucose tolerance (IGT) and insulin resistance (IR) in type 2 diabetes (T2D) subjects. The relationship between the polymorphisms in the TNF-α gene and IR in Bangladeshi prediabetes and T2D subjects has not yet been fully identified. This study aims to reveal the association between TNF-α gene polymorphism and IR in hyperglycaemic patients of Bangladeshi origin.

Methods

In our study, 106 IGT, 100 T2D, and 109 healthy subjects of Bangladeshi origin were recruited to identify the impact of TNF-α gene polymorphism at position −308 with a G>A transition using PCR and subsequent restriction fragment length polymorphism (RFLP).

Results

The −308G>A TNF-α genotype frequency distribution within the control, IGT, and T2D groups showed a significant association (χ² = 21.077; P = 0.001), although allele frequency distribution within the groups showed a statistically non-significant difference (χ² = 1.696; P = 0.091). β-cell functional deficiency (HOMA-B%) was observed to be significantly (P = 0.034) lower in subjects with a variant genotype. In addition, our results indicate that the study subjects’ body mass index (BMI) and residence status were positively correlated (P ≤ 0.05) with −308G>A TNF-α gene polymorphism.

Conclusions

Therefore, it can be concluded that −308G>A TNF-α gene polymorphism may have a causative relationship with lower insulin secretory capacity and higher BMI in Bangladeshi IGT and T2D populations, while the urban population's lifestyle might be associated with this polymorphism.

Association between TNF-α polymorphisms and gestational diabetes mellitus: a meta-analysis and trial sequential analysis

AIM

Previous studies have yielded controversial results about the link between tumor necrosis factor-α (TNF-α) gene polymorphisms (rs1800629, rs361525, and rs1799724) and risk of gestational diabetes mellitus (GDM). Thus, a meta-analysis was performed to obtain a more conclusive result.

MATERIALS AND METHODS

Eligible studies were retrieved in PubMed, Embase, China National Knowledge Infrastructure, and Wanfang databases on February 18 2020. Odds ratios (ORs) with 95% confidence intervals (CIs) were utilized to evaluate the relationship between TNF-α polymorphisms and GDM susceptibility in five genetic models. The subgroup stratified analysis and trial sequential analysis (TSA) were both performed.

RESULTS

In total, 15 studies on TNF-α polymorphism including 1289 GDM patients and 1445 healthy women were identified. For rs1800629, significant associations were found in Asian subgroup in five genetic models (for example: allele model, p = .001, OR = 2.20, 95% CI = 1.38-3.52). The existing samples were adequate revealed by TSA, which reached a shred of solid evidence. No association was observed between TNF-α rs361525 and rs1799724 polymorphisms with the GDM risk within all genetic models (p > .05).

CONCLUSIONS

For Asian populations, TNF-α rs1800629 is a risk factor for GDM. There was no association between two TNF-α polymorphisms (rs361525 and rs1799724) and GDM under all genetic models. More multi-ethnic and larger sample size studies are needed to confirm these null associations.

Polymorphisms in proinflammatory cytokines genes and susceptibility to Multiple Sclerosis

BACKGROUND

Multiple sclerosis (MS) is a chronic inflammatory and neurodegenerative disorder of the central nervous system (CNS). It is immunologically induced in genetically susceptible individuals. Proinflammatory cytokines play an important role as genetic polymorphisms in their genes might be involved in the susceptibility and pathogenesis of MS.

OBJECTIVE

In this study, our goal was to analyze the association between the gene polymorphisms in interleukin-16 (IL-16) (rs4072111 C/T), tumor necrosis factor-α (TNF-α) -308 G/A (rs1800629 G/A) and IL-18 -607 C/A (rs1946518 C/A) and the susceptibility and clinical features of MS in an Egyptian cohort.

METHODS

We genotyped these genetic polymorphisms in 150 subjects including 93 patients with MS and 57 unrelated healthy subjects. We employed polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP) method for determining the IL-16 (rs4072111 C/T) and TNF-α -308 G/A (rs1800629 G/A) polymorphisms, and the allele- specific polymerase chain reaction (AS-PCR) method for IL-18-607 C/A (rs1946518 C/A) polymorphism.

RESULTS

The IL-16 (rs4072111 C/T) polymorphism was not polymorphic in both MS patients and the healthy volunteers. For the TNF-α-308 G/A (rs1800629 G/A) polymorphism, the mutant AA genotype and A allele are not associated with the susceptibility of MS, however, associated with the severity and disability progression of the disease. We observed a statistically significant increase in the mean values of Expanded Disability Status Scale (EDSS) and Multiple Sclerosis Severity Score (MSSS) in patients with AA genotype and A allele compared with those of genotypes GG and GA, and the G allele, and regression analysis confirmed that this polymorphism is a predictor of disease disability using EDSS. For the IL-18 -607 C/A (rs1946518 C/A) polymorphism, the frequency of mutant AA genotype and A allele showed significant differences between the MS patients and healthy controls.

CONCLUSION

The TNF-α-308 AA genotype and A allele could be related to disability progression and severity of MS and the IL-18-607 AA genotype A allele could be related to susceptibility of the disease in the Egyptian cohort.

Association between polymorphic markers human leucocyte antigen-G and tumour necrosis factor alpha and susceptibility to recurrent miscarriages among Bulgarian women

OBJECTIVE

To analyze the role of 14 base pair (bp) insertion (ins)/deletion (del) and tumour necrosis factor alpha (TNF-α) G/A polymorphisms as risk factors for spontaneous miscarriage in patients with two or more unsuccessful pregnancies and a group of control women with at least two normal live births.

MATERIALS AND METHODS

To investigate the role of these mutations, 50 patients with two or more idiopathic recurrent miscarriages and 50 normal fertile women were tested for the presence of human leucocyte antigen-G (HLA-G) 14 bp ins/del and TNF-α -308 G/A variants. The frequencies of the studied polymorphisms were compared between the two groups.

RESULTS

Individuals with a history of miscarriages had a significantly higher prevalence of 14 bp insertion alleles compared with control patients (p=0.04). There was also a two times higher relative risk for miscarriage among carriers of this variant. No statistical difference in allele frequencies of the TNF-α -308 G/A polymorphism was established between controls and study patients (p=0.78).

CONCLUSION

The 14 bp ins HLA-G variant could be associated with a higher risk for unsuccessful pregnancy according to the results from the study. There is no association between the studied TNF-α -308 GA polymorphism and rate of spontaneous abortions.

Association of the TNF-α -308G/A polymorphism with lipid profile changes in response to aerobic training program

Promoter polymorphism of the tumor necrosis factor-α (TNF-α) gene is associated with obesity-related traits, although the role of its potential modifying effect on changes in obesity-related parameters achieved through a training program is still unknown. The aim of the present study was to examine whether the TNF-α-308G/A polymorphism (rs1800629) influences the effects of a training program. Accordingly, we studied the alleles and genotypes distribution in a group of 168 Polish Caucasian women measured for selected body mass and composition, as well as biochemical parameters before and after the realization of a 12-week aerobic training program. Our results showed that TNF-α genotypes can modulate training-induced biochemical parameter changes such as lipid profile. We demonstrated that carriers of the GG genotype are associated with decreases in post-training high-density lipoprotein cholesterol (HDL-C) levels (p<0.001). Additionally, we revealed that participants with the GG genotype had a higher low-density lipoprotein cholesterol (LDL-C) level (p=0.046) during the entire study period. It could be concluded that harboring the GG genotype of rs1800629 may be considered to be a disadvantageous factor in the context of training-induced effects on lipid profile changes in young female participants.

Role of Personalized Nutrition in Chronic-Degenerative Diseases

Human nutrition is a branch of medicine based on foods biochemical interactions with the human body. The phenotypic transition from health to disease status can be attributed to changes in genes and/or protein expression. For this reason, a new discipline has been developed called “-omic science”. In this review, we analyzed the role of “-omics sciences” (nutrigenetics, nutrigenomics, proteomics and metabolomics) in the health status and as possible therapeutic tool in chronic degenerative diseases. In particular, we focused on the role of nutrigenetics and the relationship between eating habits, changes in the DNA sequence and the onset of nutrition-related diseases. Moreover, we examined nutrigenomics and the effect of nutrients on gene expression. We perused the role of proteomics and metabolomics in personalized nutrition. In this scenario, we analyzed also how dysbiosis of gut microbiota can influence the onset and progression of chronic degenerative diseases. Moreover, nutrients influencing and regulating gene activity, both directly and indirectly, paves the way for personalized nutrition that plays a key role in the prevention and treatment of chronic degenerative diseases.

Nutrigenomics: Opportunities & challenges for public health nutrition

The hierarchical information flow through DNA-RNA-protein-metabolite collectively referred to as ‘molecular fingerprint’ defines both health and disease. Environment and food (quality and quantity) are the key factors known to affect the health of an individual. The fundamental concepts are that the transition from a healthy condition to a disease phenotype must occur by concurrent alterations in the genome expression or by differences in protein synthesis, function and metabolites. In other words, the dietary components directly or indirectly modulate the molecular fingerprint and understanding of which is dealt with nutrigenomics. Although the fundamental principles of nutrigenomics remain similar to that of traditional research, a collection of comprehensive targeted/untargeted data sets in the context of nutrition offers the unique advantage of understanding complex metabolic networks to provide a mechanistic understanding of data from epidemiological and intervention studies. In this review the challenges and opportunities of nutrigenomic tools in addressing the nutritional problems of public health importance are discussed. The application of nutrigenomic tools provided numerous leads on biomarkers of nutrient intake, undernutrition, metabolic syndrome and its complications. Importantly, nutrigenomic studies also led to the discovery of the association of multiple genetic polymorphisms in relation to the variability of micronutrient absorption and metabolism, providing a potential opportunity for further research toward setting personalized dietary recommendations for individuals and population subgroups.

The impact of TNF-α 308G>A gene polymorphism on children's overweight risk and an assessment of biochemical variables: A cross-sectional single-center experience

INTRODUCTION

The aim of this study was to assess the role of TNF-α 308 G>A gene polymorphism in children's overweight risk so as to correlate this polymorphism with anthropometric and biochemical variables.

MATERIALS AND METHOD

A cross-sectional study was carried out on 188 Romanian children ages 5-18 years, who were classified into controls (Group 1; n = 109) and overweight children (Group 2; n = 79).

RESULTS

Higher values of MUAC and TST (p < 0.001) were obtained in the overweight group. A significant association was found between TNF-α 308 G>A polymorphism and weight status in the studied population (p = 0.009). There was also a positive association between the variant genotypes (GA or AA) of TNF-α 308G>A gene polymorphism and weight status, which was more frequently found among normal weight than overweight children (74.5% versus 25.5%, respectively). The final logistic multivariable included five independent variables (TNF-α genotype, gender, cholesterol, ASAT, and ALAT), which were statistically significant predictors with negative/positive effects on children's overweight risk; this model explained 30% of the variance in the outcome variable.

CONCLUSION

The variant genotype of TNF-α 308G>A gene polymorphism was more frequent among normal weight children. In the presence of other covariates, such as age, gender, cholesterol, LDL cholesterol, ALAT, and glycemia, the TNF-α 308 G>A gene polymorphism remained an independent protective factor for children's overweight status.

TNF-α (-308) Gene Polymorphism and Type 2 Diabetes Mellitus in Ethiopian Diabetes Patients

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a metabolic disorder resulting from insulin insufficiency or function. Predisposing factors for T2DM are mainly genetic and environmental. Genetic polymorphism of cytokines like tumor necrosis factor-alpha (TNF-α) is suggestive of interference with insulin-sensitive glucose uptake and induces insulin resistance that ultimately could lead to T2DM. In this study, we assessed the effect of TNF-α (-308) G/A gene polymorphism and its association with the development of T2DM in an Ethiopian population.

METHODS

An institutional-based cross-sectional study was conducted on study subjects with T2DM and non-diabetic healthy controls. DNA was extracted and genotyping was carried out by using amplification refractory mutation system polymerase chain reaction. A genetic-polymorphism on TNF-α (-308) G/A with T2DM was evaluated by logistic regression and Student's t-test. A P-value <0.05 was considered as statistically significant.

RESULTS

In the present study, we observed a significant association between T2DM and TNF-α (-308) gene polymorphism's GG genotype [χ2 test P = 0.005, OR (95% CI) =2.667 (1.309-5.45d8)]. In contrast, no statistically significant differences were observed in the frequencies of genotypes AA and AG (χ2 test P=0.132 and 0.067, respectively). Moreover, T2DM individuals had higher concentrations of lipid profiles for those carrying the TNF-α (-308) GG genotype as compared to the control group.

CONCLUSION

TNF-α (-308) genetic polymorphism may be implicated in the genetic susceptibility for, as well as the development of T2DM and lipid metabolism in the Ethiopian population. Therefore, a large-scale study and early screening of TNF-α (-308) genetic polymorphism may help in early management and control of diabetes and related outcomes.

Metabolic syndrome: an update on diagnostic criteria, pathogenesis, and genetic links

Metabolic syndrome (MetS), today a major global public health problem, is a cluster of clinical, metabolic, and biochemical abnormalities, such as central adiposity, hypertension, insulin resistance, and dyslipidemias. These MetS-related traits significantly increase the risk of type 2 diabetes mellitus, adverse cardiac events, stroke, and hepatic steatosis. The pathogenesis of MetS is multifactorial, with the interplay of environmental, nutritional, and genetic factors. Chronic low-grade inflammation together with visceral adipose tissue, adipocyte dysfunction, and insulin resistance plays a major role in the progression of the syndrome by impairing lipid and glucose homeostasis in insulin-sensitive tissues, such as the liver, muscle, and adipocytes. Adipose-derived inflammatory cytokines and non-esterified fatty acids establish the link between central obesity IR, inflammation, and atherogenesis. Various studies have reported an association between MetS and related traits with single-nucleotide polymorphisms of different susceptibility genes. Modulation of cytokine levels, pro-oxidants, and disturbed energy homeostasis, in relation to the genetic variations, is described in this review of the recent literature, which also provides updated data regarding the epidemiology, diagnostic criteria, and pathogenesis of MetS.

TNF-α -308G/A gene polymorphism in bullous pemphigoid and alopecia areata

BACKGROUND

TNF-α -308G/A polymorphism has been investigated in few studies for an association with susceptibility to bullous pemphigoid (BP) and alopecia areata (AA). Yet, these findings had so far not been independently replicated, and no data on a possible association of TNFα -308G/A polymorphism with these diseases in Iranian population were available.

OBJECTIVES

In the present study, a possible effect of TNF-α -308G/A variation on susceptibility to BP or AA disease was evaluated.

METHODS

Genomic DNA was extracted from the blood of the patients with BP and AA as well as control subjects which genotyped for the TNF-α -308 G/A polymorphism. TNF-α gene expression levels were analyzed by real-time RT-PCR.

RESULTS

No association was observed between the TNF-α -308 G/A variation and susceptibility to BP or AA diseases in our Iranian cohort. In contrast to AA patients, expression of TNF-α gene was significantly higher in BP patients compared to control group. TNF-α gene was found to be similarly expressed in mutant and wild-type genotypes.

CONCLUSIONS

TNF-α -308G/A polymorphism is not associated with the risk to develop of BP and AA in our Iranian cohort. Furthermore, this polymorphism is contributed to altering the levels of gene expression in BP disease.

Tumor necrosis factor-α -308 A/G gene polymorphism in children with juvenile idiopathic arthritis: relation to disease activity, damage, and functional status

The study aims to evaluate the clinical significance of serum levels of tumor necrosis factor alpha (TNF-α) and -308 A/G promoter polymorphism in juvenile idiopathic arthritis (JIA) patients and find any association to the subsets, clinical and laboratory features, disease activity, and damage as well as functional disability. Forty-eight JIA children and 30 controls were included in the present study. Juvenile arthritis disease activity score in 27 joints (JADAS-27) was calculated, juvenile arthritis damage index (JADI) was assessed, and Childhood Health Assessment Questionnaire (CHAQ) measured the functional status. Serum TNF-α was assayed by ELISA and gene (-308) promoter polymorphism was determined by polymerase chain reaction. The 48 JIA children (mean age 11.5 ± 2.8 years) were 13 systemic, 17 oligoarticular, and 18 polyarticular onset. The serum TNF-α was significantly higher in patients (90.4 ± 6.3 ng/ml) compared to control (3.5 ± 2.6 ng/ml) (p < 0.0001) with a tendency to be higher in the polyarticular subtype. All controls had TNF-α -308 GG alleles. The frequency of GG genotype tended to be higher in systemic onset compared to oligoarticular and polyarticular subtypes. The serum TNF-α significantly correlated with JADAS-27 (r = 0.32, p = 0.03) and CHAQ (r = 0.37, p = 0.01) and negatively with the presence of GG alleles (r = -0.48, p = 0.001). The GG alleles were significantly negatively associated with C-reactive protein (r = -0.32, p = 0.03) with a tendency to negatively correlate with JADAS-27, CHAQ, and JADI-extrarticular (r = -0.28, p = 0.06; r = -0.25, p = 0.09 and r = -0.25, p = 0.09, respectively). There is evidence of a possible influence of the -308 SNP promoter position on the production of TNF-α, the severity of JIA which may consequently influence the response to anti-TNF-α treatment.

Adipokine Gene Single-Nucleotide Polymorphisms in Portuguese Obese Adolescents: Associations with Plasma Concentrations of Adiponectin, Resistin, IL-6, IL-1β, and TNF-α

BACKGROUND

The genetic contribution to obesity and to circulating adipokine levels has not been completely clarified. We aimed to evaluate adipokine genes' single-nucleotide polymorphism (SNP) prevalence and its association with circulating adipokine levels and risk factors for cardiovascular disease in an obese Portuguese pediatric population.

METHODS

Two hundred forty-eight obese adolescents (mean age 13.4 years old; 47.2% females) participated in a cohort study. We screened 12 SNPs by direct sequencing in five adipokine genes: adiponectin (ADIPOQ: rs16861194, rs17300539, rs266729, rs2241766, rs1501299), interleukin-1β (IL-1β; rs1143627), IL-6 (IL-6; rs1800795), tumor necrosis factor-α (TNF-α; rs1800629), and resistin (RETN; rs1862513, rs3219177, rs3745367, rs3745368). Biochemical analysis included determination of circulating adipokines, C-reactive protein (CRP) levels, lipid profile, and markers of insulin resistance.

RESULTS

Compared to males, females presented higher circulating levels of insulin, adiponectin, IL-6, resistin, and leptin concentrations, but lower TNF-α levels. No statistically significant differences were found for genotype or allelic distributions between genders. In the whole sample population, adiponectin levels were influenced by ADIPOQ rs17300539 (c.-1138G>A; lower in subjects with GG genotype). When only males were considered, IL-1β, IL-6, and TNF-α levels were associated with ADIPOQ rs1501299 (c.214 + 62G>T; higher in GG subjects). TNF-α concentrations were modulated by TNF-α rs1800629 (c.-488G>A; lower in GG males), RETN rs1862513 (c.-216C>G; higher in CC subjects), and RETN rs3219177 (c.118 + 39C>T; higher in CC subjects). Leptin levels were influenced by IL-1β rs1143627 (c.-118C>T) presenting TT individuals' lower levels.

CONCLUSIONS

Our data demonstrate that in pediatric obese patients, some adipokine gene SNPs have an association with circulating adipokine levels and lipid profile.

The role of TGF-β1 869 T > C and PPAR γ2 34 C > G polymorphisms, fat mass, and anthropometric characteristics in predicting childhood obesity at birth: A cross-sectional study according the parental characteristics and newborn's risk for child obesity (the newborns obesity's risk) NOR study

This study proposed to establish a correlation between the risk score for child obesity and anthropometric, genetic, and bioimpedance characteristics in mothers and newborns, and to assess the discriminant ability for anthropometric parameters to classify over-fatness (defined by bioimpedance body fatness %) in pregnant women.We performed a cross-sectional study on 388 couples (mother and father) and their newborns admitted in a Tertiary Hospital from Romania. The measured parameters for mothers and their newborns were risk percentage for child obesity, anthropometric characteristics (mid-upper arm circumference [MUAC], tricipital skinfold thickness [TST] of mother and newborn), genetic polymorphisms (human peroxisome proliferator-activated receptor γ [PPARγ2] 34 C > G and transforming growth factor-beta 1 [TGF-β1] 869 T > C gene polymorphisms in both mothers and newborns), and mother's bioimpedance characteristics (fat mass [FM] %).The obesity risk score according to standard predictable Northern Finland Birth Cohort equation was in our study 4.07%. We found a monotone positive significant correlation between the newborn's risk of childhood obesity and the mother's TST (P = 0.01), as well as a tendency toward statistical significance concerning correlation with mother's MUAC (P = 0.053), without any correlations with the mothers' bioimpedance parameters and also a positive correlation between the newborn's risk of childhood obesity and the newborn's anthropometrical characteristics like body mass index (BMI), MUAC, and TST (P < 0.001). We observed that the calculated newborn's risk percentage for child obesity was greater for the variant allele of the TGF-β1 869 T > C polymorphism and also for the wild-type C allele of the PPARγ2 34 C > G gene polymorphism. Our study indicated that the best predictors for over-fatness are BMI and MUAC (P = 0.01 < 0.02 and P = 0.019 < 0.02, respectively).

Acute coronary syndrome and depression: A review of shared pathophysiological pathways

OBJECTIVE

To examine the evidence for shared pathophysiological pathways in acute coronary syndrome and major depression and to conceptualise the dynamic interplay of biological systems and signalling pathways that link acute coronary syndrome and depression within a framework of neuro-visceral integration.

METHODS

Relevant articles were sourced via a search of published literature from MEDLINE, EMBASE and PubMed using a variety of search terms relating to biological connections between acute coronary syndrome and depression. Additional articles from bibliographies of retrieved papers were assessed and included where relevant.

RESULTS

Despite considerable research efforts, a clear understanding of the biological processes connecting acute coronary syndrome and depression has not been achieved. Shared abnormalities are evident across the immune, platelet/endothelial and autonomic/stress-response systems. From the available evidence, it seems unlikely that a single explanatory model could account for the complex interactions of biological pathways driving the pathophysiology of these disorders and their comorbidity.

CONCLUSION

A broader conceptual framework of mind-body or neuro-visceral integration that can incorporate the existence of several causative scenarios may be more useful in directing future research and treatment approaches for acute coronary syndrome-associated depression.

Assessment of biochemical parameters and characterization of TNFα -308G/A and PTPN22 +1858C/T gene polymorphisms in the risk of obesity in adolescents

Obesity is currently considered an inflammatory condition associated with autoimmune diseases, suggesting a common origin. Among other factors, candidate genes may explain the development of this disease. Polymorphisms in the tumor necrosis factor α (TNFα) and lymphoid protein tyrosine phosphatase (PTPN22) genes lead to an increased risk to development of immune and inflammatory diseases. The aim of the present study was to analyze the biochemical parameters and the effect of the TNFα -308G/A and PTPN22 +1858C/T polymorphisms in the susceptibility of adolescents to obesity. A group of 253 adolescent subjects were recruited and classified as obese, overweight or normal weight according to their nutritional status. Anthropometric measurements, clinical and biochemical data were analyzed. DNA was extracted from peripheral blood samples by the phenol-chloroform method, and TNFα -308G/A and PTPN22 1858C/T polymorphisms were determined by polymerase chain reaction-restriction fragment length polymorphism assays. Clinical, genetic and biochemical parameters were analyzed to determine the existence of a possible association with the development of obesity. Statistically significant differences in body mass index, insulin, triglyceride levels and homeostatic model assessment for insulin resistance (HOMA-IR) index were observed among the three groups analyzed (P≤0.05). The studied polymorphisms did not confer a risk for developing obesity in the analyzed population (P>0.05); however, significantly low levels of insulin and decreased rates of HOMA-IR were observed in the 1858 CT genotype carriers of the PTPN22 gene. In conclusion, no association between the TNFα -308G/A and PTPN22 +1858C/T polymorphisms and the risk to development of obesity in the adolescent population analyzed was observed. However, the 1858 CT genotype of the PTPN22 gene was associated with variations of certain biochemical parameters analyzed.

[Plasma IL-18 levels are related to insulin and are modulated by IL-18 gene polymorphisms]

INTRODUCTION

Atherosclerosis is an inflammatory chronic disease influenced by multiple factors. Different prospective studies have shown that plasmatic levels of inflammatory markers were related to atherosclerosis and cardiovascular disease.

OBJECTIVE

To evaluate whether plasmatic levels of interleukin 18 (IL-18) are modulated by SNPs (single nucleotide polymorphisms) of the IL 18 gene and its possible association with insulin levels and other cardiovascular risk factors.

METHODS

746 individuals were studied for a period of two years by opportunistic selection in the metropolitan area of Valencia. Parameters of lipid and glucose metabolism were analyzed by standard methodology. IL-18 was measured by ELISA.

RESULTS

Individuals with insulin resistance showed significant higher levels of IL-18. IL 18 was significantly correlated with insulin levels and other cardiovascular risk factors. The CC genotype of the rs1834481 SNP was significantly associated with lower levels of IL-18. However, the GG genotype of the rs7559479 was associated with significant higher levels of IL-18.

CONCLUSION

IL-18 is associated with insulin resistance and other cardiovascular risk factors, being those levels genetically regulated.

Association of TNF-α 308 G/A Polymorphism With Type 2 Diabetes: A Case-Control Study in the Iranian Kurdish Ethnic Group

Objectives

Tumor necrosis factor-α (TNF-α) plays roles in the development of obesity, insulin resistance, and possibility of Type 2 diabetes mellitus (T2DM). The objective of the current study was to evaluate the association of TNF-α promoter−308 G/A polymorphism with T2DM.

Methods

In all, 1038 patients with T2DM and 1023 normoglycemic controls were included in this study. All participants were genotyped using the polymerase chain reaction-restriction fragment length polymorphism method. Genotypic and allelic frequencies were then analyzed in each group. Serum lipids, fasting glucose, fasting serum insulin, homeostatic model assessment of insulin resistance, and hemoglogin A1c levels were determined by conventional methods.

Results

The allelic frequency of the A allele was significantly different between case and control participants (p = 0.006). Genotypes GA and AA were found to be significantly associated with 2.24- and 3.18-fold increased risk for T2DM, respectively. Similarly, the dominant model of -308 G/A polymorphism was found to have a higher risk for T2DM (odds ratio = 2.34, p = 0.001). Individuals with T2DM carrying the GA + AA genotypes of -308 G/A variation had significantly lower fasting plasma insulin than those carrying GG genotype.

Conclusion

Our findings revealed that there is an association between the TNF-α promoter -308 G/A polymorphism and T2DM in this population.

Association of leptin/receptor and TNF-α gene variants with adolescent obesity in Malaysia

BACKGROUND

Leptin (LEP) G-2548A (rs7799039), leptin receptor (LEPR) Q223R (rs1137101) and tumor necrosis factor (TNF)-α G-308A (rs1800629) gene variants have been reported to be associated with obesity, although results for subjects from different countries have been controversial. The aim of this study was to determine the prevalence of overweight and obesity in Malaysian adolescents and the association of these polymorphisms with overweight and obese or over-fat adolescents.

METHODS

A total of 613 adolescents (241 Malay, 219 Chinese, 153 Indian) were enrolled. Anthropometric measurements of body mass index (BMI) and body fat percentage were used to classify subjects as controls (non-overweight/obese or normal fat) or as cases (overweight/obese or over-fat). Genomic DNA was extracted from oral buccal mucosa cells for genotyping using polymerase chain reaction-restriction fragment length polymorphism and data obtained were statistically analyzed.

RESULTS

A total of 23.3% of subjects were overweight/obese whereas 11.4% were over-fat; there were significantly more overweight/obese and over-fat Indian and Malay adolescents compared to Chinese (P < 0.001). A allele was the minor one for LEPR Q223R and TNF-α G-308A in all ethnic groups, whereas G allele was minor for LEP G-2548A in Chinese and Malay adolescents, except for Indian adolescents. Indian male adolescents with AA genotype for LEP G-2548A were associated with overweight/obesity (P = 0.025; odds ratio, 3.64; 95% confidence interval: 1.15-11.54). Despite the lack of association observed for LEPR Q223R and TNF-α G-308A, Indian and Chinese subjects with AA risk genotype for LEPR Q223R/LEP G-2548A and TNF-α G-308A/LEP G-2548A, respectively, had increased mean BMI (P = 0.049, P = 0.016).

CONCLUSIONS

Genotype distribution and association of these polymorphisms with overweight/obesity vary between ethnic groups and genders. Nevertheless, the LEP G-2548A risk allele may be associated with overweight/obese Indian male adolescents in Malaysia.

Association of polymorphisms in stress-related TNFα and NPY genes with the metabolic syndrome in Han and Hui ethnic groups

BACKGROUND

Metabolic syndrome (MS) is a cluster of complicated disorders caused by the interactive influencing factors of heredity and environment, which predisposes to many cnacers. RESULTS from epidemic research indicate that stress is tightly related to the pathogenesis of MS and neoplasia. This paper aims to investigate the association between psychological stress and MS with respect to the tumor necrosis factor alpha (TNFα) and neuropeptide Y (NPY) genes in the Han and Hui ethnic groups.

METHODS

All subjects for this case-control study matched strict enrollment criteria (nationality, gender and age) and lived in the city of Wu Zhong of Ningxia Province in China. The enrolled group contained 102 matched pairs of Hui ethnic individuals and 98 matched pairs of Han ethnic individuals. Enrolled subjects completed the general Symptom Checklist-90 (SCL-90). The TNFα-308G/A variant and NPYrs16147 polymorphism were detected in case (81 males, 119 females) and control (81 males, 119 females) groups by polymerase chain reaction (PCR) amplification.

RESULTS

Nine factors of the SCL-90 were found to be statistically different (p<0.05) between case and control groups. The homozygous mutant genotype (AA) and the mutant allele (A) of the TNFα-308G/A gene were less frequently observed in the control population compared to the case group. The odds ratio (95% confidence interval) in "Allele" for MS was 2.28 (1.47-3.53), p=0.0001, while "OR" was 1.11 (0.83-1.47), p=0.15, for the NPYrs16147 gene polymorphism.

CONCLUSIONS

Psychological stress has been positively associated with MS. A previous study from our group suggested there were differences in the level of psychological stress between Hui and Han ethnic groups. Furthermore, we found that the stress-related TNFα gene was associated with MS for both Han and Hui ethnic groups. In contrast, NPY may be a possible contributor to MS and associated cancer for the Han ethnic group.

The role of TNF-α G-308A promoter polymorphism in glycemic control in Type 2 diabetes patients

BACKGROUND

TNF-α polymorphisms were shown to be associated with insulin resistance and diabetes development and complications.

AIM

To investigate the association between glycemic control in Type 2 diabetes patients and TNF-α G-308A single nucleotide polymorphism (SNP).

METHODS

This was a cross-sectional observational study, where diabetes patients from both genders (170 male and 185 female) were enrolled in the study. Patients were divided into two groups: good glycemic control (n = 158) and poor glycemic control (n = 197). Genotyping of TNF-α G-308A SNP was carried out using restriction fragment length polymorphisms-polymerase chain reaction.

RESULTS

The results showed that TNF-α G-308A SNP is strongly associated with glycemic control in type 2 diabetes patients. Patients with the AA and AG genotypes had better glycemic control than those with GG genotype (P < 0.01). Other parameters that impacted glycemic control include duration of the disease (P < 0.01) and response to insulin therapy (P < 0.01). However, no contribution for gender or statins use to glycemic control was observed (P > 0.05).

CONCLUSION

TNF-α G-308A SNP might modulate glycemic control among type 2 diabetes patients.

Association of IL-6, TNF-α and IL-10 gene polymorphisms with type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a metabolic pro-inflammatory disorder characterized by chronic hyperglycemia and increased levels of circulating cytokines suggesting a causal role of inflammation in its etiology. Polymorphism of cytokine genes including interleukin-6 (IL-6), tumour necrosis factor-α (TNF-α) and interleukin-10 (IL-10) were studied in T2DM patients as well as in normal healthy controls. Genomic DNA was isolated from both T2DM patients and controls followed by quantification and genotyping by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) using suitable primers. The genotypic, allelic and carriage rate frequency distribution in patients and controls were analyzed by SPSS (version 15.0). Odd ratios with 95 % confidence interval was determined to describe the strength of association by logistic regression model. Double and triple combinations of genotypes were analyzed by χ(2) test. Gene-gene interaction and linkage disequilibrium tests were performed using SHEsis software. Individually, IL-6, TNF-α and IL-10 did not show any association. In double combination, IL-6 -597 GA and TNF-α -308 GG genotypes increased the risk up to 21 times and in triple combination IL-6 -597 AA, TNF-α -308 GG and IL-10 -592 CA increased the risk of T2DM up to 314 times. In gene-gene interaction allele 'A' of all studied polymorphisms increased the risk of T2DM up to 1.41 times. Our results suggest that individuals having a haplotype combination of AA, GG and CA for IL-6, TNF-α and IL-10 gene polymorphisms will have higher susceptibility and be at greater risk of developing T2DM.

The relationship between dietary fatty acids and inflammatory genes on the obese phenotype and serum lipids

Obesity, a chronic low-grade inflammatory condition is associated with the development of many comorbidities including dyslipidemia. This review examines interactions between single nucleotide polymorphisms (SNP) in the inflammatory genes tumor necrosis alpha (TNFA) and interleukin-6 (IL-6) and dietary fatty acids, and their relationship with obesity and serum lipid levels. In summary, dietary fatty acids, in particular saturated fatty acids and the omega-3 and omega-6 polyunsaturated fatty acids, impact the expression of the cytokine genes TNFA and IL-6, and alter TNFα and IL-6 production. In addition, sequence variants in these genes have also been shown to alter their gene expression and plasma levels, and are associated with obesity, measures of adiposity and serum lipid concentrations. When interactions between dietary fatty acids and TNFA and IL-6 SNPs on obesity and serum lipid were analyzed, both the quantity and quality of dietary fatty acids modulated the relationship between TNFA and IL-6 SNPs on obesity and serum lipid profiles, thereby impacting the association between phenotype and genotype. Researching these diet–gene interactions more extensively, and understanding the role of ethnicity as a confounder in these relationships, may contribute to a better understanding of the inter-individual variability in the obese phenotype.

Tumor necrosis factor alpha -238G/A (rs 361525) gene polymorphism predicts progression to type-2 diabetes in an Eastern Indian population with prediabetes

Prediabetes (IPD; n=122) and normoglycemic individuals (n=100) underwent assessment of polymorphisms of TNFα (-238, -308) and IL6 (-174). After 27.25±5.64 months, 16 IPD had reverted to normoglycemia and 18 progressed to diabetes. TNFα -238AA/GA genotypes were significantly more common in IPD, had higher TNFα, higher progression to diabetes and lower reversal.

Nutrigenetics and metabolic disease: current status and implications for personalised nutrition

Obesity, particularly central adiposity, is the primary causal factor in the development of insulin resistance, the hallmark of the metabolic syndrome (MetS), a common condition characterized by dyslipidaemia and hypertension, which is associated with increased risk of cardiovascular disease (CVD) and type 2 diabetes (T2DM). Interactions between genetic and environmental factors such as diet and lifestyle, particularly over-nutrition and sedentary behavior, promote the progression and pathogenesis of these polygenic diet-related diseases. Their current prevalence is increasing dramatically to epidemic proportions. Nutrition is probably the most important environmental factor that modulates expression of genes involved in metabolic pathways and the variety of phenotypes associated with obesity, the MetS and T2DM. Furthermore, the health effects of nutrients may be modulated by genetic variants. Nutrigenomics and nutrigenetics require an understanding of nutrition, genetics, biochemistry and a range of “omic” technologies to investigate the complex interaction between genetic and environmental factors relevant to metabolic health and disease. These rapidly developing fields of nutritional science hold much promise in improving nutrition for optimal personal and public health. This review presents the current state of the art in nutrigenetic research illustrating the significance of gene-nutrient interactions in the context of metabolic disease.

Meta-analysis on theG-308ATumor Necrosis Factor α Gene Variant and Phenotypes Associated with the Metabolic Syndrome

OBJECTIVE

The G-308A tumor necrosis factor (TNF) alpha gene variant has been associated with obesity, insulin resistance, and hypertension. We performed a systematical review of the literature by means of a meta-analysis to assess the association of the G-308A TNFalpha polymorphism with the components of the metabolic syndrome.

RESEARCH METHODS AND PROCEDURES

Studies were identified by searches of the literature for reports using the terms: diabetes, insulin resistance, hypertension, obesity or metabolic syndrome and TNF, variants or polymorphism or alleles, and Nco or -308. From 824 reports, we included 31 observational studies, case control and cohort at baseline, which analyzed the association between the TNFalpha polymorphism and one or more components of the metabolic syndrome. A fixed effect model was used to pool data from individual studies.

RESULTS

Obesity [odds ratio, 1.23; 95% confidence interval (CI), 1.045 to 1.45; p = 0.013] in a total of 3562 individuals from eight homogeneous studies, systolic arterial blood pressure (standardized difference, 0.132; 95% CI, 0.016 to 0.25; p < 0.03) in a total of 1624 individuals from four homogeneous studies and plasma insulin levels (standardized difference, 0.095; 95% CI, 0.020 to 0.17; p = 0.013) in a total of 3720 subjects from 16 homogeneous studies were positively associated with the -308A variant.

DISCUSSION

These results indicate that individuals who carried the -308A TNFalpha gene variant are at 23% risk of developing obesity compared with controls and showed significantly higher systolic arterial blood pressure and plasma insulin levels, supporting the hypothesis that the TNFalpha gene is involved in the pathogenesis of the metabolic syndrome.

Associations of vascular endothelial growth factor (VEGF) gene and cytokine (IL-1B, IL-4, IL-6, IL-10, TNFA) genes combinations with type 2 diabetes mellitus in women

Aim. To study the association between vascular endothelial growth factor (VEGF) and cytokine (IL1B, IL4, IL6, IL10 and TNFA)gene polymorphism combinations with type 2 diabetes mellitus (T2DM) in women. Materials and methods. 374 Caucasian women without carbohydrate metabolism disorders from 23 to 68 years of age and 212 womenwith T2DM from 28 to 69 years of age were included in the study. The combinations of polymorphism А-2578С, С+936Т in VEGFgene with polymorphism in IL1B С-31Т, IL4 С-590Т, IL6 G-174C, IL10 A-592C and А-1082G, TNFA А-238G, A-308G and A-863Cwere studied. Results. Analysis revealed 52 combined genetic variations with different rate of occurrence between diabetic and control groups(р

The Human Obesity Gene Map: The 2004 Update

This paper presents the eleventh update of the human obesity gene map, which incorporates published results up to the end of October 2004. Evidence from single-gene mutation obesity cases, Mendelian disorders exhibiting obesity as a clinical feature, transgenic and knockout murine models relevant to obesity, quantitative trait loci (QTLs) from animal cross-breeding experiments, association studies with candidate genes, and linkages from genome scans is reviewed. As of October 2004, 173 human obesity cases due to single-gene mutations in 10 different genes have been reported, and 49 loci related to Mendelian syndromes relevant to human obesity have been mapped to a genomic region, and causal genes or strong candidates have been identified for most of these syndromes. There are 166 genes which, when mutated or expressed as transgenes in the mouse, result in phenotypes that affect body weight and adiposity. The number of QTLs reported from animal models currently reaches 221. The number of human obesity QTLs derived from genome scans continues to grow, and we have now 204 QTLs for obesity-related phenotypes from 50 genome-wide scans. A total of 38 genomic regions harbor QTLs replicated among two to four studies. The number of studies reporting associations between DNA sequence variation in specific genes and obesity phenotypes has also increased considerably with 358 findings of positive associations with 113 candidate genes. Among them, 18 genes are supported by at least five positive studies. The obesity gene map shows putative loci on all chromosomes except Y. Overall, >600 genes, markers, and chromosomal regions have been associated or linked with human obesity phenotypes. The electronic version of the map with links to useful publications and genomic and other relevant sites can be found at http://obesitygene.pbrc.edu.

The Human Obesity Gene Map: The 2003 Update

This is the tenth update of the human obesity gene map, incorporating published results up to the end of October 2003 and continuing the previous format. Evidence from single-gene mutation obesity cases, Mendelian disorders exhibiting obesity as a clinical feature, quantitative trait loci (QTLs) from human genome-wide scans and animal crossbreeding experiments, and association and linkage studies with candidate genes and other markers is reviewed. Transgenic and knockout murine models relevant to obesity are also incorporated (N = 55). As of October 2003, 41 Mendelian syndromes relevant to human obesity have been mapped to a genomic region, and causal genes or strong candidates have been identified for most of these syndromes. QTLs reported from animal models currently number 183. There are 208 human QTLs for obesity phenotypes from genome-wide scans and candidate regions in targeted studies. A total of 35 genomic regions harbor QTLs replicated among two to five studies. Attempts to relate DNA sequence variation in specific genes to obesity phenotypes continue to grow, with 272 studies reporting positive associations with 90 candidate genes. Fifteen such candidate genes are supported by at least five positive studies. The obesity gene map shows putative loci on all chromosomes except Y. Overall, more than 430 genes, markers, and chromosomal regions have been associated or linked with human obesity phenotypes. The electronic version of the map with links to useful sites can be found at http://obesitygene.pbrc.edu.

Genetic polymorphisms in adipokine genes and the risk of obesity: a systematic review and meta-analysis

Polymorphisms in adipokine genes, such as leptin (LEP), leptin receptor (LEPR), resistin (RETN), adiponectin (ADIPOQ), interleukin-1β (IL-1β), IL-6 (IL-6), and tumor necrosis factor-α (TNF-α) may be involved in the development of obesity. We conducted a systematic review of published evidence on the association between different adipokine genes and the risk of obesity. Librarian-designed searches of PubMed and HuGeNet, review of reference lists from published reviews and content expert advice identified potentially eligible studies. The genotyping information and polymorphisms of different adipokine genes, numbers of genotyped cases and controls and frequencies of genotypes were extracted from 48 eligible studies included in this review. Twenty-one polymorphisms each associated with obesity in at least one study were identified. Polymorphisms in the adipokine genes, LEP, LEPR, and RETN were not associated with obesity susceptibility, whereas ADIPOQ G276T (T vs. G: odds ratio (OR), 1.59; 95% confidence interval (CI), 1.39-1.81), IL-1β C3953T (CC vs. CT+TT: OR, 1.61; 95% CI, 1.18-2.20), and TNF-α G308A (GG vs. GA+AA: OR, 1.19; 95% CI, 1.02-1.39) polymorphisms were associated with an increased risk of obesity. The IL-6 G174C polymorphism was also associated obesity when using allelic comparisons, the recessive genetic model and the dominant genetic model with OR (95% CI) of 1.95 (1.37-2.77), 1.44 (1.15-1.80), and 1.36 (1.16-1.59), respectively. No significant evidence of publication bias was present. However, these "null" results were underpowered due to a small pooled sample size, and analysis of additional case-control studies with larger sample sizes should provide further clarifications.

Role of -675 4G/5G in the plasminogen activator inhibitor-1 gene and -308G/A tumor necrosis factor-α gene polymorphisms in obese Argentinean patients

AIM

Plasminogen activator inhibitor-1 (PAI-1) and tumor necrosis factor-α (TNF-α) are increased in the circulation of obese persons. Because a direct link between PAI-1 and TNF-α in obesity has been observed, they are candidate genes for the development of obesity. We sought to evaluate the relation between the genotypic and allelic frequencies of the -675 4G/5G PAI-1 and -308 G/A TNF-α polymorphisms and their association with the risk for obesity in an Argentinean population.

METHODS

A group of 110 consecutive obese persons and a group of 111 lean controls were recruited. Polymerase chain reaction was used to determine the frequency of PAI-1 and TNF-α polymorphisms; serum fasting glucose, insulin, and lipid levels were measured by standard methods. Insulin sensitivity was evaluated by using homeostasis model assessment.

RESULTS

The -308 TNF-α and -675 4G/5G PAI-1 genotype distribution did not significantly differ between the groups (p=0.544 and p=0.327, respectively). Homeostasis model assessment was the only positive independent determinant of body mass index (R(2)=0.493; p<0.001).

CONCLUSION

The -675 4G/5G PAI-1 and the -308 TNF-α polymorphism variants tested in this study, individually or combined, were not associated with obesity in an Argentinean population.

Risk of obesity and type 2 diabetes with tumor necrosis factor-α 308G/A gene polymorphism in metabolic syndrome and coronary artery disease subjects

Tumor Necrosis Factor-alpha (TNF-α) has been implicated in the pathogenesis of insulin resistance and obesity. The increased expression of TNF-α in adipose tissue is known to induce insulin resistance, and a polymorphism at position -308 in the promoter region of TNF-α gene may lead to its increased transcription in adipocytes. The objective of this work was to determine the role of TNFα-308G/A gene polymorphism in metabolic syndrome (MetS) and coronary artery disease (CAD) with obesity and type 2 diabetes mellitus (T2DM). A total of 250 MetS and 224 CAD patients and 214 controls were studied. TNFα-308G/A polymorphism was detected from the whole blood genomic DNA using PCR-amplification refractory mutation system. The 2 × 2 contingency tables and multiple regression analysis were used for determining the association of genotypes with obesity and type 2 diabetes mellitus (T2DM) in MetS and CAD subjects. In CAD subjects with T2DM, the AG genotypes showed a very strong association (P < 0.0001; OR 0.194, 95%CI 0.103-0.365). In CAD subjects with obesity, the AA (P = 0.049; OR 2.449) and AG genotypes showed a strong association (P < 0.0001; OR 0.206). In both males and females, AG genotype and G allele (P < 0.0001) showed a strong association with T2DM. In MetS subjects with T2DM, there was a strong association with AG (P = 0.002; OR 4.483) as well as AA+AG genotypes (P = 0.002; OR 4.255). The AA and AG genotype (P = 0.001; OR 5.497) in males showed a strong 4.6- and 5.4-fold risks, respectively, with obesity. In females, only AG genotype showed a strong 4.5-fold risk with obesity (P = 0.001). In MetS subjects with obesity, the AA genotype (P = 0.043; OR 3.352) as well as AG showed a very strong association (P = 0.001; OR 5.011). The AG genotypes showed a high 3.5-fold risk with T2DM in females (P = 0.011). In CAD subjects, AG genotype showed a protective effect in both obese males and females (P < 0.0001). Heterozygous TNFα-308G/A gene variant may be an important risk factor for MetS with T2DM and obesity in both males and females, but may have a protective role in CAD subjects with obesity and T2DM. A allele may be an important risk factor for MetS and CAD with obesity as well as CAD subjects with T2DM.

Association of the TNF-α -308G/A polymorphism with family history of type 2 diabetes mellitus in a Mexican population

AIMS

We examined the possible association of the -308G/A polymorphism of the TNF-α promoter gene in type 2 diabetes mellitus (DM2) patients and in non-diabetic subjects with and without family history of DM2.

METHODS

We studied 87 non-diabetic subjects without DM2 family history in at least one of two generations, 48 non-diabetic subjects with DM2 family history and 95 DM2 patients. Genotyping was carried out by PCR-RFLP.

RESULTS

The frequency of TNF-α -308G/A genotype was significantly lower in non-diabetic subjects without DM2 relatives (6%) as compared to DM2 patients (24%) (odds ratio (OR)=5.24; 95% confidence interval (CI)=1.9-15.8, p<0.0005), but similar to non-diabetic subjects with DM2 relatives (29%) (OR=0.77; CI=0.3-1.7, p=0.4). Logistic regression analysis showed the association of TNF-α -308G/A polymorphism with DM2 family history (OR=5.80; CI=1.77-18.98, p<0.0003).

CONCLUSIONS

Our results suggest that TNF-α -308G/A polymorphism is associated with DM2 family history and is a risk factor for DM2.

Single-nucleotide polymorphisms in the TNF gene are associated with obesity-related phenotypes in vervet monkeys

Tumor necrosis factor (TNF) promoter single-nucleotide polymorphisms (SNPs) have been extensively characterized in humans, with numerous reports of associations with obesity-related phenotypes as well an array of infectious, immune-mediated, and inflammatory disease phenotypes. Controlling for the multitude of environmental risk factors in human studies has been a major confounder of efforts to elucidate the role and relative contribution of TNF promoter SNPs. As part of an ongoing initiative to further genetically and phenotypically characterize the St Kitts-origin vervet monkey (Chlorocebus aethiops ssp.) as an animal model of human obesity, we have conducted association analyses between TNF SNPs and previously defined obesity-related phenotypes in 265 pedigreed vervets. We report eight SNPs (-809G, -756A, -352C, -322A, +1285T, +2133T, +2362A, +2405), all contained within the same haplotype block and comprising a single haplotype, to be significantly associated with BMI, waist circumference, total plasma cholesterol (P < 0.05), and high-density lipoprotein-cholesterol (HDL-C) (P < 0.01). This study provides additional validation of the St Kitts-origin vervet model of obesity by demonstrating genetic associations analogous to that shown in humans.

Meta-analysis of TNF 308 G/A polymorphism and type 2 diabetes mellitus

Background and Objectives

Many investigations have focused the association between TNF 308 G/A polymorphism and risk for type 2 diabetes mellitus (T2DM). However, the sample sizes of most of the studies were small. The aim of this study is to evaluate the precise association between this variant and risk for T2DM in a large-scale meta-analysis.

Methods

All publications were searched on the association between TNF 308 G/A polymorphism and T2DM. The key words were as follows: diabetes, tumor necrosis factor and polymorphism/variant/genotype. This meta-analysis was assessed by Review manager 5.0.

Results

There were 18 studies identified. The odd ritos (ORs) and 95% confidence intervals (CI) for GA+AA versus GG genotype of TNF 308 G/A polymorphism were 1.03 (0.95–1.12), 1.03 (0.94–1.13) and 1.03 (0.78–1.36) in overall, Caucasian and Asian populations, respectively. The sensitivity analysis further strengthened the validity of this association. No publication bias or heterogeneity was observed in this study.

Conclusion

In summary, there was no significant association detected between the TNF 308 G/A polymorphism and risk for T2DM.

Tumornecrosis-factor-α 308 GA polymorphism in atherosclerotic patients

The development of the atherosclerosis is a multifactorial process, where the clinical pattern is determined by environmental and genetic factors. Except for the classical risk factors of atherosclerosis (hypertension, lipid-metabolic disorders, diabetes, smoking) the clinical signs can be influenced by the genetic variants (polymorphisms) of the enzymes, which are responsible for the endothelial cell function and for the thrombotic factors. In our examination our aim was to define the TNF-α 308GA polymorphisms in atherosclerotic diabetic, atherosclerotic non-diabetic and healthy patients. We found correlation of the frequency of myocardial infarction and stroke in atherosclerotic diabetic and atherosclerotic non-diabetic patients. We proved that among patients with mutant TNF-α AA genotype the occurrence of cardiovascular events is significantly higher: Mutant AA homozygous genotype: control group 1, 6%, MI group 10,7%, p < 0,005, OR: 8,17 versus Normal GG allele: control group 76,7%, MI group 61,3%. The TNF-α AA genotype can have a clinical importance as a prognostic and therapeutic marker, although further studies are needed to confirm this hypothesis.

Association between anthropometric measures of obesity, metabolic disturbances and polymorphism G-308A of the tumor necrosis factor-alpha gene in children

Introduction

TNF-α is one of the most important factors in the development and course of inflammation. It is suggested that polymorphism located in the 5'regulatory region of the TNF-α gene at position 308 (guanine [G]→ adenine[A]) may increase the expression of this cytokine in fat tissue and influence the fat mass and insulin resistance.

Objective

To investigate whether the G-308A polymorphism of the TNF-α gene may influence obesity, insulin resistance, fasting plasma lipids, serum leptin levels, and the incidence of metabolic syndrome.

Materials and methods

The obese group included 124 children with simple obesity (72 girls and 52 boys) aged 10-18 (mean age 15 years) with SDS of BMI ≥ 2.0. A control group consisted of 56 healthy non-obese children (36 girls and 20 boys) aged 11-18 (mean age 14 years) with SDS of BMI < 1.0. Polymorphism identification was performed in total genomic DNA, using PCR-RFLP method.

Results

Carriers of A (AG+AA) allele among the obese children were significantly more frequent than in the control group (OR = 2.29, 95% CI 1.2-4.4, χ²= 6.24, P < 0.05). Carriers of A alleles showed a higher concentrations of fasting glucose (81.3 ± 10.5 vs. 77.4 ± 10.3 mg/dl; P < 0.05), but lower values of fasting insulin (15.1 ± 7.3 vs. 19.0 ± 9.5 μIU/ml; P < 0.05), lower values of HOMA index (3.0 ± 1.5 vs. 3.7 ± 2.0; P < 0.05). In the group of boys, carriers of A alleles showed a tendency for lower concentrations of HDL (43.8 ± 12.6 vs. 48.3 ± 11.8 mg/dl; P < 0.05). Blood pressure and leptin level did not differ between the obese children with gene polymorphism and those of wild homozygous. The incidence of the full metabolic syndrome (MetS) in the children, according to the IDF definition, was 33%. The presence of the MetS in children with wild homozygous GG and carriers of A allele of TNF-α polymorphism gene did not show statistical differences (OR = 1.38; 95% CI 0.6-3.1, χ²= 0.58).

Conclusions

1/Polymorphism G-308A of the TNF-α gene is more common in children with obesity; and 2/Polymorphism G-308A of the TNF-α gene does not seem to be associated with the grade of obesity, insulin resistance, lipid profile, leptin levels, and the incidence of metabolic syndrome in obese children.

Is there a genetic variation association in the IL-10 and TNF alpha promoter gene with gestational diabetes mellitus?

Gestational diabetes mellitus (GDM), defined as carbohydrate intolerance diagnosed for the first time during pregnancy, affects both maternal and fetal health. Possession of a specific genetic polymorphism can be a predisposing factor for susceptibility to some diseases. The aim of this study was to investigate the association between single nucleotide polymorphisms (SNP) in the promoter gene of interleukin-10 (IL-10) as well as tumor necrosis factor-alpha (TNF alpha) with the development of GDM. Two hundred and twelve consecutive series of eligible normal pregnant women (controls) and gestational diabetes mellitus women were selected based on the study's inclusion and exclusion criteria. DNA was extracted from blood and genotyped for IL-10 at three positions and TNF alpha for gene polymorphism using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Plasma levels of IL-10 and TNF alpha at different gestational periods as well as postpartum were quantified using enzyme linked immunosorbent assay (ELISA). The results of the study showed that the difference in the frequency of SNP at position -597 in the promoter of the human IL-10 gene between the control and GDM groups was statistically significant (p < 0.05). In contrast, there was no significant difference in the frequency of SNP at the other two sites in the promoter region of the human IL-10 gene (-824 and -1082) as well as position -308 in the promoter of the human TNF-alpha (p > 0.05). In addition, there was no significant difference between the two groups in terms of plasma levels of IL-10 as well as TNF alpha in different stages of pregnancy. SNP at position -597 was significantly associated with the development of GDM and shows potential for use as a predictive marker for GDM.

Association between polymorphisms in human tumor necrosis factor-alpha (--308) and -beta (252) genes and development of gestational diabetes mellitus

OBJECTIVE

The aim of this study is to investigate if an association exists between single nucleotide polymorphism (SNP) in the tumor necrosis factor-alpha (TNF-alpha) and TNF-beta genes.

METHODS

The DNA was extracted and SNP in the human TNF-alpha and TNF-beta genes at positions -308 (G/A) and 252 (A/G), respectively, was analyzed using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Plasma levels of TNF-alpha in different stages of pregnancy were quantified using enzyme linked immunosorbent assay (ELISA).

RESULTS

There was no significant difference in genotype and allele frequency of SNP at position -308 (G/A) in the promoter region of the human TNF-alpha gene as well as the SNP at position 252 (A/G) in the human TNF-beta gene between the GDM and control subjects. Using the logistic regression model, it was found that the SNP in the TNF-alpha as well as TNF-beta were not associated with development of GDM. In addition, the TNF-alpha levels in the plasma of GDM and control mothers were not significantly different.

CONCLUSIONS

In the population studied, the SNP in position -308 (G/A) of the human TNF-alpha or in position 252 (A/G) of the human TNF-beta gene is not an independent risk factor or a predictor for GDM.

Tumor necrosis factor alpha (-308), interleukin-6 (-174) and interleukin-10 (-1082) gene polymorphisms in polycystic ovary syndrome

OBJECTIVE

The imbalance between pro- and anti-inflammatory cytokines and polymorphism of cytokine genes may play a role in the etiology of the polycystic ovary syndrome (PCOS). The aim of this study was to investigate the association of polymorphisms of TNFalpha, IL-6 and IL-10 genes with the occurrence and the clinical/laboratory characteristics of PCOS in the Turkish population.

STUDY DESIGN

Single nucleotide polymorphisms (SNPs) of TNFalpha (-308 G/A), IL-6 (-174 G/C), IL-10 (-1082 G/A) genes in DNA from peripheral blood leukocytes of 97 PCOS patients and 95 healthy control women were investigated.

RESULTS

There is a tendency toward lower frequency of the IL-6 CC genotype and C allele among PCOS women compared with healthy controls although the difference did not reach a significant level. No notable differences were observed in allele or genotype frequencies for TNFalpha and IL-10 genes between groups. The concomitant presence of wild homozygous TNFalpha genotype together with mutant IL-6 C allele has a protective effect against PCOS with an OR=0.45 (95% CI=0.23-0.86). While TNFalpha (-308) and IL-10 (-1082) genotypes did not influence clinical/laboratory parameters in PCOS, IL-6 (-174) CC or pooled CG+CC genotypes have lower glucose, insulin, HOMA, cholesterol, triglyceride, and LDL-C, and higher GIR and HDL-C values than GG genotypes.

CONCLUSIONS

We suggest that the IL-6 promoter region polymorphism may be related to occurrence and metabolic abnormalities seen in PCOS in the Turkish population. However, more studies with larger sample size are necessary to support our findings in other populations before any statement can be made about the relationship between PCOS and cytokine polymorphism.