Obesity and Cardiovascular Risk: Variations in Visfatin Gene Can Modify the Obesity Associated Cardiovascular Risk. Results from the Segovia Population Based-Study. Spain.

OBJECTIVES: Our aim was to investigate if genetic variations in the visfatin gene (SNPs rs7789066/ rs11977021/rs4730153) could modify the cardiovascular-risk (CV-risk) despite the metabolic phenotype (obesity and glucose tolerance). In addition, we investigated the relationship between insulin sensitivity and variations in visfatin gene. MATERIAL AND METHODS: A population-based study in rural and urban areas of the Province of Segovia, Spain, was carried out in the period of 2001-2003 years. A total of 587 individuals were included, 25.4% subjects were defined as obese (BMI ≥30 Kg/m2). RESULTS: Plasma visfatin levels were significantly higher in obese subjects with DM2 than in other categories of glucose tolerance. The genotype AA of the rs4730153 SNP was significantly associated with fasting glucose, fasting insulin and HOMA-IR (Homeostasis model assessment-insulin resistance) after adjustment for gender, age, BMI and waist circumference. The obese individuals carrying the CC genotype of the rs11977021 SNP showed higher circulating levels of fasting proinsulin after adjustment for the same variables. The genotype AA of the rs4730153 SNP seems to be protective from CV-risk either estimated by Framingham or SCORE charts in general population; and in obese and non-obese individuals. No associations with CV-risk were observed for other studied SNPs (rs11977021/rs7789066). CONCLUSIONS: In summary, this is the first study which concludes that the genotype AA of the rs4730153 SNP appear to protect against CV-risk in obese and non-obese individuals, estimated by Framingham and SCORE charts. Our results confirm that the different polymorphisms in the visfatin gene might be influencing the glucose homeostasis in obese individuals.

Serum circulating microRNA profiling for identification of potential type 2 diabetes and obesity biomarkers.

BACKGROUND AND AIM: MicroRNAs are small non-coding RNAs that play important regulatory roles in a variety of biological processes, including complex metabolic processes, such as energy and lipid metabolism, which have been studied in the context of diabetes and obesity. Some particular microRNAs have recently been demonstrated to abundantly and stably exist in serum and to be potentially disease-specific. The aim of this profiling study was to characterize the expression of miRNA in serum samples of obese, nonobese diabetic and obese diabetic individuals to determine whether miRNA expression was deregulated in these serum samples and to identify whether any observed deregulation was specific to either obesity or diabetes or obesity with diabetes. PATIENTS AND METHODS: Thirteen patients with type 2 diabetes, 20 obese patients, 16 obese patients with type 2 diabetes and 20 healthy controls were selected for this study. MiRNA PCR panels were employed to screen serum levels of 739 miRNAs in pooled samples from these four groups. We compared the levels of circulating miRNAs between serum pools of each group. Individual validation of the twelve microRNAs selected as promising biomarkers was carried out using RT-qPCR. RESULTS: Three serum microRNAs, miR-138, miR-15b and miR-376a, were found to have potential as predictive biomarkers in obesity. Use of miR-138 or miR-376a provides a powerful predictive tool for distinguishing obese patients from normal healthy controls, diabetic patients, and obese diabetic patients. In addition, the combination of miR-503 and miR-138 can distinguish diabetic from obese diabetic patients. CONCLUSION: This study is the first to show a panel of serum miRNAs for obesity, and compare them with miRNAs identified in serum for diabetes and obesity with diabetes. Our results support the use of some miRNAs extracted from serum samples as potential predictive tools for obesity and type 2 diabetes.

The FTO obesity gene. Genotyping and gene expression analysis in morbidly obese patients.

BACKGROUND: Obesity has emerged as one of the most serious public health concerns in the twenty-first century. the fat mass and obesity associated gene (FTO) has been found to contribute to the risk of obesity in humans. Our aims in this study were to investigate the association of rs9939609 single nucleotide polymorphism (SNP) of the FTO gene with different obesity-related parameters, to assess the FTO gene expression in subcutaneous and visceral adipose tissues from morbidly obese and its correlations with other adipocytokine gene expressions. METHODS: The association between the rs9939609 FTO gene variant and obesity related parameters in 75 obese/morbidly obese adult patients and 180 subjects with body mass index (BMI) < 30 kg/m(2) (control group) was examined. Gene expression analyses: subcutaneous adipose tissue samples were obtained from 52 morbidly obese and five subjects with BMI < 30 kg/m(2). Visceral adipose tissue was also obtained from 35 morbidly obese patients. Weight, height, BMI, SBP, DBP, fasting glucose, lipid profile, proinsulin, insulin, leptin, and adiponectin (RIA) of patients were also obtained. Insulin resistance by HOMA(IR). rs9939609 of FTO genotyping using allele discrimination in real-time PCR. Genomic study of RNA extraction of adipose tissue and real-time PCR (RT-PCR) of adipocytokines and a housekeeping gene were quantified using TaqMan probes. Relative quantification was calculated using the DeltaDelta Ct formula. RESULTS: The minor-(A) allele frequency of rs9939609 FTO gene in the whole population was 0.39. A strong association between this A allele and obesity was found, even after age-sex adjustment (p = 0.013). We found higher levels of FTO mRNA in subcutaneous adipose tissue from morbidly obese than in the control group (p = 0.021). FTO gene expression was lower in visceral than in subcutaneous adipose depot. However, this finding did not reach the level of statistical significance. A negative correlation between subcutaneous FTO gene expression and serum triglyceride levels and a positive correlation with leptin, perilipin, and visfatin gene expressions was found. In the visceral adipose tissue, these positive correlations were statistically significant only for perilipin. CONCLUSIONS: Our results show: (1) A strong association between rs9939609 SNP of the FTO gene variant and obesity in Spanish morbidly obese adult patients; (2) positive correlations between FTO mRNA and leptin, perilipin, and visfatin gene expressions in subcutaneous adipose tissue; (3) FTO and perilipin gene expressions were positively correlated in visceral fat depot. Overall these results may suggest a role of FTO in the regulation of lipolysis as well as in total body fat rather in fat distribution patterns.

Variant rs9939609 in the FTO gene is associated with obesity in an adult population from Spain.

OBJECTIVE: Recently independent studies, including genome-wide scans, have shown that variation in the fat mass and obesity associated gene (FTO) were significantly associated with obesity in populations of European origin. DESIGN AND METHODS: In this study we examined the association between rs9939609 FTO variant and obesity related parameters in a population based-study of 732 unrelated individuals (46.9% males and 53.1% females; ages 35-74 years) from the province of Segovia in Central Spain (Castille). RESULTS: The AA genotype was significantly more frequent in obese individuals (defined as body mass index >or= 30 kg/m(2), n = 207; 80 males and 127 females) than in non-obese (19.9%vs. 13.7%, P = 0.026). In addition to increased obesity, AA homozygous individuals had higher waist circumference than individuals with AT heterozygous and TT homozygous genotypes. The minor A-allele of rs9939609 was associated with an increased odds ratio (OR) for obesity [OR 1.51, 95% confidence interval (CI) 1.10-2.12] as compared to the TT genotype. This difference was also statistically significant even after the adjustment for sex and age (OR 1.46, 95% CI 1.02-2.07). CONCLUSIONS: Our results support the association of FTO gene variants with obesity, including parameters of visceral (abdominal) obesity, in an adult general population from Spain. Overall we confirm the previously reported association studies between variants in FTO gene and the risk of obesity.

Association of ENPP1 (PC-1) K121Q polymorphism with obesity-related parameters in subjects with metabolic syndrome.

BACKGROUND: The metabolic syndrome (MS), a cluster of several metabolic disorders, is increasingly being recognized as a risk factor for cardiovascular disease. Ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1), originally described as a plasma cell allo-antigen and named plasma cell membrane glycoprotein (PC-1), is an inhibitor of insulin-induced activation of the insulin receptor. The single nucleotide polymorphism (SNP) K121Q in the ENPP1 gene has been studied in relation to obesity, insulin resistance and other features of MS in several populations with conflicting results. We therefore investigate the role of the K121Q SNP in the ENPP1 gene in MS in Caucasians from the province of Segovia in Central Spain (Castille). DESIGN AND METHODS: We recruited 794 unrelated persons (46.5% males and 53.5% females), ages 35-74 years from a cross-sectional population-based epidemiological survey in the province of Segovia in Central Spain (Castille). Obesity-related anthropometric measurements included BMI, waist circumference, blood pressure and lipid profile. MS was defined by International Diabetes Federation (IDF) guidelines. K121Q PC-1 genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS: The 121Q allele was associated with an increased BMI and waist circumference among subjects fulfilling the criteria for MS. These differences remained statistically significant even after the adjustment for sex, age and degree of glucose tolerance (beta = 1.347, P = 0.017 and beta = 2.824, P = 0.046; for BMI and waist circumference, respectively). Moreover, among type 2 diabetic patients those carrying the 121Q allele had higher BMI and higher leptin levels than subjects carrying the K121K genotype. CONCLUSIONS: Our results suggest that the ENPP1121Q allele might contribute to the genetic susceptibility to abdominal obesity among subjects with MS.

Common haplotypes of the C-reactive protein gene and circulating leptin levels influence the interindividual variability in serum C-reactive protein levels. The Segovia study.

C-reactive protein (CRP) is a marker of systemic inflammation significantly associated with an increased risk of cardiovascular disease in the general population. The aim of our current work was to study those clinical and genetic variables potentially associated with interindividual variability in serum CRP levels. A random sample of 844 participants (450 women, mean age 55 years) from a study carried out on the general Spanish population (The Segovia Study) was studied. Our results showed that age, gender, waist circumference, leptin, impaired glucose tolerance and smoking were the clinical variables significantly associated with variations in serum CRP levels. Among those, leptin showed the strongest association, explaining 11% of the interindividual variability in circulating CRP levels (p<0.001). To study the effect of genetic variants on serum CRP levels, 10 SNPs within the CRP locus were genotyped in 756 participants. Four of these SNPs (rs1417938, rs1800947, rs1130864, rs1205) were significantly associated with CRP levels after adjustment for clinical variables. Among the common haplotypes inferred from eight SNPs, two (CCATGCCT, p=0.025; CTATCCTT, p=0.004) explained 2.9% of the total variation in serum CRP. The results here reported show that 2.9% of the total variation in circulating CRP levels seems to be explained by genetics variations within CRP locus. Furthermore, serum leptin levels are strongly associated with serum CRP levels in our Spanish population.

An SNP in the adiponectin gene is associated with decreased serum adiponectin levels and risk for impaired glucose tolerance.

Adiponectin is a plasma protein produced by the adipose tissue. Hypoadiponectinemia has been associated with insulin resistance and several components of the metabolic syndrome (MS): type 2 diabetes, obesity, and dyslipidemia. We investigated whether single nucleotide polymorphisms (SNPs) at positions 45 and 276 in the adiponectin gene were associated with features of the MS in 747 unrelated Spanish subjects. The G allele of SNP45 and the G/G genotype of SNP276 were associated with impaired glucose tolerance (p = 0.020 and 0.042, respectively). The G/G genotype for SNP276 was associated with lower serum adiponectin levels as compared with the G/T and T/T genotypes (G/G, 10.10 +/- 0.24 microg/mL; G/T, 10.98 +/- 0.32 microg/mL; T/T, 12.00 +/- 0.92 microg/mL; p = 0.015) even after adjustment for sex, age, BMI, waist-to-hip ratio, homeostasis model assessment index, and the degree of glucose tolerance (p = 0.040). We found a significant negative association of circulating adiponectin levels with waist-to-hip ratio (r = -0.42, p < 0.001), sagittal abdominal diameter (r = -0.24, p < 0.001), triglycerides (r = -0.32, p < 0.001), homeostasis model assessment index (r = -0.14, p = 0.001), and uric acid (r = -0.36, p < 0.001) and positive association with high-density lipoprotein-cholesterol (r = 0.41, p < 0.001). Our findings indicate that serum adiponectin levels are associated with several components of the MS. The SNP276 of the adiponectin gene may affect impaired glucose tolerance and hypoadiponectinemia.