Association of human fetuin-A rs4917 polymorphism with obesity in 2 cohorts

Effects of exercise training on Fetuin-a in obese, type 2 diabetes and cardiovascular disease in adults and elderly: a systematic review and Meta-analysis

Background

Elevated levels of fetuin-A are associated with increased risks of metabolic syndrome, type 2 diabetes and nonalcoholic fatty liver disease. This meta-analysis investigated whether exercise interventions can reduce fetuin-A in adults.

Methods

We searched clinical trials that objectively assessed fetuin-A and included study arms with exercise intervention. The pre-intervention and post-intervention data were used for meta-analysis. The effect sizes were calculated as standardized mean differences or changes in fetuin-A and expressed as Hedges’ g using random-effects models.

Results

The overall Hedges’ g for fetuin-A in all included interventions was − 0.640 (95%CI − 1.129 to − 0.151; n = 9), but this effect was not observed in obese (g = − 0.096; 95%CI, − 0.328 to 0.135) and type 2 diabetes/dysglycemia (g = − 0.56; 95%CI, − 1.348 to 0.236) individuals. Additionally, the random-effects meta-regression analysis showed that there was not a greater decrease in fetuin-A in individuals who achieved greater body mass index reductions (regression coefficient = 0.065; 95%CI, − 0.185 to 0.315).

Conclusion

Supervised exercise is associated with reductions in fetuin-A levels in adults and elderly. However, the results of the present meta-analysis should be interpreted with caution because of the variety of type of exercises and individual obesity related-disorders involve. Therefore, additional high-quality randomized controlled trials describing the effect of supervised exercise interventions on fetuin-A in adults are still needed. 

Electronic supplementary material

The online version of this article (10.1186/s12944-019-0962-2) contains supplementary material, which is available to authorized users.

Circulating Triglycerides and the Association of Triglycerides with Dietary Intake Are Altered by Alpha-2-Heremans-Schmid Glycoprotein Polymorphisms

BACKGROUND

Circulating fetuin-A (FetA) inhibits insulin receptor signaling and activates the toll-like receptor 4 proinflammatory cascade; thus, it may contribute to metabolic syndrome. Polymorphisms in alpha-2-Heremans-Schmid glycoprotein (AHSG), the gene which codes FetA, may influence metabolic syndrome progression in higher-risk ethnic groups. We aimed to identify whether individual variation in AHSG influences biomarkers of metabolic disease and obesity in young Mexican adults.

METHODS

The participants were Mexican college applicants (18-25 years, n = 641). Dietary intake, anthropometric data, and blood for the analysis of biomarkers and genetics were collected. Single nucleotide polymorphisms (SNPs) in AHSG (rs2518136 and rs4917) were genotyped.

RESULTS

Neither AHSG SNP was associated with body mass index (BMI) or waist circumference. rs4917 C allele carriers had lower triglycerides (TG) than T allele homozygotes (98.85 ± 2.3 vs. 112.2 ± 5.2 mg/dL, p = 0.0113). BMI was strongly associated with TG (p < 0.0001) regardless of genotype. The relationship between circulating TG and dietary intake of carbohydrates and saturated fat was significant in rs4917 CT allele heterozygotes only (p = 0.03 and p = 0.02, respectively).

CONCLUSIONS

rs4917 T allele carriers had higher TG. This relationship was exaggerated in individuals with overweight and obesity. Dietary intake was significantly associated with TG in only those with heterozygosity at rs4917, suggesting that these individuals may be more susceptible to dietary interventions.

Environmental factors, seven GWAS-identified susceptibility loci, and risk of gastric cancer and its precursors in a Chinese population

Gene–environment interactions may increase gastric cancer (GC) risk. Seven susceptibility loci identified by genome‐wide association studies (GWASs) suggest that genetic factors play a role in gastric carcinogenesis. Meanwhile, Helicobacter pylori (H. pylori) infection, smoking, and alcohol drinking are also important environmental factors for gastric cancer. However, studies to explore the role of gene–environment interactions in gastric carcinogenesis, and particularly the relationship between the seven susceptibility loci and their potential interactions with H. pylori infection, smoking, and alcohol drinking in risk of GC, and severe intestinal metaplasia (IM)/dysplasia, have been inconclusive. A total of 1273 subjects in a Chinese population were recruited, and genotyping was carried out using the competitive allele‐specific PCR (KASP) method. Unconditional logistic regression was applied to model the associations between genetic polymorphisms and the disease risk. Effect modifications by H. pylori infection, smoking and alcohol drinking were evaluated. PSCA rs2294008/rs2976392 showed a significant, multiplicative interaction with H. pylori infection in risk of GC. Meanwhile, PRKAA1 rs13361707 had an additive interaction with H. pylori infection. SLC52A3 rs13042395 showed an interaction with alcohol drinking in risk of GC. Moreover, three SNPs, MUC1 rs4072037, ZBTB20 rs9841504 and PRKAA1 rs13361707, were associated with precancerous gastric lesions (severe IM/dysplasia). Our data suggest that genetic predisposition factors identified by GWAS may interact with environmental risk factors, Particularly for H. pylori infection and alcohol consumption, to increase the risk of GC.

Human Fetuin-A Rs4918 Polymorphism and its Association with Obesity in Healthy Persons and in Patients with Myocardial Infarction in Two Hungarian Cohorts

Background

Human fetuin A (AHSG) has been associated with the development of obesity, insulin resistance, type 2 diabetes mellitus, and atherosclerosis. Observations on the role of AHSG rs4918 single-nucleotide polymorphism are contradictory. We investigated the association between variants of rs4918 and parameters of obesity, lipid status, tumor necrosis factor-α (TNFα), adipokines (adiponectin, resistin, leptin), and insulin resistance in healthy persons and in patients with previous myocardial infarction.

Material/Methods

This was a cross-sectional study comprising cohort 1 (81 healthy individuals) and cohort 2 (157 patients with previous myocardial infarction). We used the allele-specific KASP genotyping assay to detect rs4918 polymorphism.

Results

In cohort 1, G-nucleotide carriers had significantly lower serum TNFα, adiponectin, and higher leptin concentrations than in non-G carriers. These differences, however, were not observed in cohort 2. In cohort 2, G-carriers had lower BMI and waist circumferences than in non-G carriers. The G allele was more frequent among lean than obese patients (RR=1.067, 95%CI=1.053–2.651, p=0.015). An association between BMI and rs4918 polymorphism was observed among patients without diabetes (CC/CG/GG genotypes: p=0.003, G vs. non-G allele: p=0.008) but not in diabetics. In addition, a strong linearity between BMI and the CC/CG/GG genotypes (association value: 4.416, p=0.036) and the frequency of the G allele (7.420, p=0.006) could be identified. In cohort 2, non-obese, non-diabetic G-carriers still had lower BMI and waist circumferences than in non-G carriers.

Conclusions

The rs4918 minor variant is associated with lower TNFα and adiponectin, higher leptin levels in healthy persons, and more favorable anthropomorphic parameters of obesity in cohort 2.

Allelic Imbalance of mRNA Associated with α2-HS Glycoprotein (Fetuin-A) Polymorphism

Alpha 2-HS glycoprotein (AHSG), also designated as fetuin-A, exhibits polymorphism in population genetics consisting of two major alleles of AHSG^∗1 and AHSG^∗2. The serum level in the AHSG^∗1 homozygote is significantly higher than that of the AHSG^∗2 homozygote. This study examined the molecular mechanism for the cis-regulatory expression. To quantitate allele-specific mRNA in intra-assays of the heterozygote, RT-PCR method employing primers that were incorporated to the two closely located SNPs was developed. The respective magnitudes of AHSG^∗1 to AHSG^∗2 in the liver tissues and hepatic culture cells of PLC/PRF/5 were determined quantitatively as 2.5-fold and 6.2-fold. The mRNA expressional difference of two major alleles was observed, which is consistent with that in the serum level. The culture cells carried heterozygous genotypes in rs4917 and rs4918, but homozygous one in rs2248690. It was unlikely that the imbalance was derived from the SNP located in the promotor site. Furthermore, to investigate the effect of mRNA degradation, RNA synthesis in the cell culture was inhibited potently by the addition of actinomycin-D. No marked change was apparent between the two alleles. The results indicated that the cis-regulatory expressional difference is expected to occur at the level of transcription or splicing of mRNA.