Relationship Between Fat Mass and Obesity-Associated (FTO) Gene Polymorphisms with Obesity and Metabolic Syndrome in Ethnic Mongolians

Comparison of the risk of obesity in the FTO rs9939609 genotype in a multiethnic group in Asia systematic review and meta-analysis

Aim

This study aims to examine the comparative risk of obesity in the FTO rs9939609 genotype in multiethnic groups in Asia, considering that obesity has become a global disease.

Data synthesis

Data searches were carried out in several electronic databases: PubMed, Scopus, Google Scholar, ScienceDirect, ClinicalTrials.gov and NCBI. The search involved a combination of keywords related to genetics and obesity risk. Pooled Odds Ratio (POR) with 95% CI was calculated based on the pooled data. Review Manager (RevMan) 5.4.1 were used to analyze the data.

Results

From 18 studies, the results of the dominant genetic model AA vs. TT showed POR 95%Cl = 1.95 (1.36-2.80); p < 0.00001, in AA vs. TA genetic recessive model, POR 95%Cl =1.31 (1.07-1.60); p = 0.002, then the final model of TA vs. TT codominance genetic model obtained POR 95%Cl = 1.52 (1.04-2.23); p < 0.00001. The overall risk of bias was low.

Conclusion

From this research, it was found that there was a comparison of the genotype that had a higher risk of obesity, namely the AA genotype in multiethnic groups in Asia.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=546434.

Association of FTO variants rs9939609 and rs1421085 with elevated sugar and fat consumption in adult obesity

This cross-sectional study explores the impact of FTO gene single nucleotide polymorphisms (SNPs) rs9939609 and rs1421085 on dietary habits contributing to obesity risk in Thai adults. The study enrolled 384 participants from Bangkok, categorized as non-obese (BMI < 25 kg/m2) or obese (BMI ≥ 25 kg/m2) based on WHO Asia Pacific Guidelines. Genotyping for FTO variants was performed using DNA from blood samples. While both SNPs adhered to Hardy-Weinberg equilibrium, the association between risk alleles and anthropometric measurements was not statistically significant. However, risk allele carriers showed significantly higher intakes of sugar and saturated fat compared to homozygous dominant individuals. In the obese group, the odds ratio for high-sugar intake was 2.22 (95% CI 1.13-4.37, p = 0.021) for rs9939609 risk allele carriers. For high-saturated fat intake, the odds ratio was 1.86 (95% CI 1.02-3.40, p = 0.041). Similar associations were observed for rs1421085. Risk allele carriers also exhibited significantly higher leptin levels (p < 0.043) and a positive correlation with myeloperoxidase levels (p < 0.038). These findings highlight the complex relationship between FTO risk alleles, increased consumption of sugar and saturated fat, and obesity-related parameters. The insights emphasize the importance of considering both genetic and dietary factors in obesity prevention strategies.

The Role of FTO Risk Haplotype in Overweight/Obesity and Lipid Parameters-Results From the Central China Population Study

Background: Fat mass and obesity-associated gene (FTO) genes rs9939609 is strongly associated with obesity and rs17817449 is an important and potential gene for obesity, have been well established. We aim to evaluate the relationship between FTO gene and overweight/obesity and confirm the influence of obesity on glucose and lipid metabolism parameters. Methods: We investigated 183 normal weight subjects and 193 individuals with overweight/obesity. Firstly, the effect of overweight/obesity on glucose and lipid metabolism parameters was analyzed. Then, the FTO genes rs9939609 and rs17817449 were counted to explore whether polymorphisms were associated with overweight/obesity and metabolic parameters. Results: Significant differences existed in glucose and lipid parameters between the group with overweight/obesity and control group. The rs9939609 and rs17817449 were strongly correlated with overweight/obesity. Haplotype analysis revealed that GA and GT haplotypes had 2.99 and 1.81 fold risk of overweight/obesity. FTO polymorphism also has effects on glucose and lipid metabolism parameters. Conclusions: There is a linkage imbalance between rs9939609 and rs17817449 in a Central China general population cohort, which also reflected the influence of FTO gene on the risk of overweight/obesity and total cholesterol (TC), triglyceride (TG), and high-density lipoprotein (HDL) disorders. The new findings could provide new clues to predict obesity and metabolic diseases.

The association between FTO rs9939609 polymorphism and serum lipid profile in adult women

BACKGROUND

FTO gene is considered to play an important role in many metabolic diseases. Evidence from studies indicated the possible association between the FTO rs9939609 polymorphisms with serum lipid profile. Therefore, this study aimed to investigate the association of FTO rs9939609 polymorphism with lipid profile in Iranian women.

METHODS

This cross-sectional study was carried out on 380 adult women. Information about age, height, weight, BMI, physical activity, and dietary intake were collected. The serum levels of Low Density Lipoprotein (LDL), High Density Lipoprotein (HDL), Triglyceride (TG), and total cholesterol were measured. The FTO gene was genotyped for rs9939609 polymorphism. The participants were divided into two groups of TT and AT/AA considering dominant model of FTO rs9939609 polymorphism.

RESULTS

General characteristics of the participants with different FTO genotypes were not significantly different. The lower levels of HDL were observed in AT/AA genotypes compared to the TT wild type genotype of FTO rs9939609 polymorphism (P = 0.004). Adjustments of age, BMI, and physical activity did not change the results.

CONCLUSIONS

However, the significant association between FTO genotype and the HDL level was disappeared after further adjustments for dietary intake. Further studies are warranted to identify the underlying mechanisms of the possible association between FTO gene and serum lipid profile.

Association of FTO, ABCA1, ADRB3, and PPARG variants with obesity, type 2 diabetes, and metabolic syndrome in a Northwest Mexican adult population

AIM

To identify associations among allelic variants of the genes FTO, ABCA1, ADRB3, and PPARG with anthropometric and biochemical traits, metabolic diseases (obesity, T2D or metabolic syndrome) in an adult population from Northwest Mexico.

METHODS

Blood samples were collected from 846 subjects including 266 normal weight subjects, 285 with obesity, and 295 with T2D. Of the 846 persons in the study, 365 presented metabolic syndrome diagnostic criteria. Anthropometric and biochemical traits were recorded and 4 single nucleotide polymorphisms (SNPs): FTO rs9939609 A-allele, ABCA1 rs9282541 A-allele, ADRB3 rs4994 G-allele, and PPARG rs1801282 G-allele were genotyped by real-time PCR.

RESULTS

FTO rs9939609 A-allele was significantly associated with obesity (p: 8.3 × 10-4), and metabolic syndrome (p: 0.001), but no individual SNPs were significantly associated with T2D. Finally, the cumulative risk of the four SNPs was significantly associated with obesity (p: 1.95 × 10-4).

CONCLUSION

Associations in FTO, ABCA, ADRB3, and PPARG SNPs presented in this study with obesity and metabolic syndrome could represent a risk for developing metabolic diseases in Northwest Mexican adult subjects.

The association between sarcopenia susceptibility and polymorphisms of FTO, ACVR2B, and IRS1 in Tibetans

Background

Hypoxia within the plateau has a negative effect on skeletal muscle and may play a role in the development of sarcopenia in humans. Tibetans having lived in the Qinghai‐Tibet Plateau for thousands of years, are a high‐risk group for sarcopenia; however, they have a distinctive suite of genetic traits that enable them to tolerate environmental hypoxia and are genetically significantly different from Han Chinese and other lowland populations. Sarcopenia has been consistently found to be associated with single‐nucleotide polymorphisms, but few studies have investigated the role of single‐nucleotide polymorphisms in a range of muscle phenotypes and sarcopenia in Tibetan peoples.

Methods

Our study aimed to investigate the skeletal muscle mass and fat mass of 160 Tibetans (80 men and 80 women) from Lhasa (altitude of 3600 meters) and analyze the association between the polymorphisms of fat mass and obesity protein (FTO) rs9939609, FTO rs9936385, activin type IIB receptor (ACVR2B) rs2276541, insulin receptor substrate 1 (IRS1) 2943656 and sarcopenia.

Result

FTO rs9939609 and rs9936385 polymorphisms were associated with lower limb skeletal muscle mass and sarcopenia for Tibetan women, and TT homozygotes had a higher risk for sarcopenia. But ACVR2B rs2276541 and IRS1 2943656 polymorphisms were unassociated with sarcopenia in Tibetan.

Conclusion

In Tibetans, FTO rs9939609 and rs9936385 polymorphisms were associated with sarcopenia, and ACVR2B rs2276541 and IRS1 2943656 polymorphisms were unassociated with sarcopenia.

Association between the FTO SNP rs9939609 and Metabolic Syndrome in Chilean Children

Background: The increasing prevalence of obesity in children has raised the incidence of Metabolic Syndrome (MetS) in this age group. Given the short- and long-term health impact of MetS, it is essential to prevent its onset by detecting its main triggers. Besides, genetic factors play an essential role in influencing which individuals within a population are most likely to develop obesity in response to a particular environment. In this regard, a common variation in the FTO gene is reproducibly associated with BMI and obesity from childhood and the genetic load has been linked to several cardiovascular risk factors, highlighting the FTO single nucleotide polymorphism (SNP) rs9939609. Therefore, this study aimed to establish the relationship between the FTO SNP rs9939609 and MetS. Methods: A cross-sectional study was carried out on 220 children from the Biobío region (Chile). MetS diagnosis was established through the modified Cook criteria, using prevalence ratios, COR curves, and linear regressions to determine its association with MetS and its components. Results: The prevalence of MetS was significantly increased among carriers of the risk allele (A): TT, 20.2%; TA, 25.4%; AA, 44.7% (p = 0.006). Also, the presence of A was associated with altered MetS-related variables. Conclusions: The FTO SNP rs9939609 was associated with a raised prevalence of MetS among A allele carriers, and was higher in the homozygous genotype (AA).

Ginsenoside Rb1 Facilitates Browning by Repressing Wnt/β-Catenin Signaling in 3T3-L1 Adipocytes

BACKGROUND The discovery of browning in white adipose tissue has provided new ideas for treating obesity. Many studies have reported that ginsenoside Rb1 (G-Rb1) has activity against diabetes, inflammation, and obesity, but further investigation is needed on the effect and mechanism of G-Rb1 on browning. MATERIAL AND METHODS We treated 3T3-L1 adipocytes with 0-200 μM G-Rb1, and 0.5 μM Compound 3f and 30 μM SKL2001 were used to activate Wnt/b-catenin signaling. Adipocyte activity was evaluated by Cell Counting Kit-8. Oil Red O staining was used to detect the lipid droplets. Quantitative real-time polymerase chain reaction was used to measure the expression of Cd-137, Cited-1, Txb-1, Prdm-16, and Ucp-1 mRNA. Western blotting was used to measure the expression of Ucp-1, pGSK-3ß (Ser 9), GSK- 3ß, and ß-catenin proteins. The expression of Ucp-1 was also detected with immunofluorescence. RESULTS Adipocyte activity was not affected by 0-100 μM G-Rb1. However, G-Rb1 dose-dependently reduced the accumulation of lipid droplets; increased the expression of Cd-137, Cited-1, Txb-1, Prdm-16, and Ucp-1 mRNA; and increased the expression of Ucp-1, pGSK-3ß (Ser 9), GSK-3ß, and ß-catenin proteins. The accumulation of lipid droplets and the expression of Ucp-1 protein decreased as b-catenin increased. CONCLUSIONS G-Rb1 at various concentrations (0-100 μM) promoted the browning of adipocytes in a dose-dependent manner. Further, we confirmed that activation of Wnt/ß-catenin signaling could inhibit browning. Therefore, the browning promoted by G-Rb1 may be associated with the inhibition of Wnt/ß-catenin signaling.

Association of FTO rs9939609 polymorphism with serum leptin, insulin, adiponectin, and lipid profile in overweight adults

FTO gene polymorphisms are associated with obesity and food intake. This study aimed to investigate the association of FTO rs9939609 polymorphism genotypes with serum glucose, lipid profile and serum hormones level. This cross-sectional study was carried out on 196 randomly selected overweight adults. Anthropometric measurements including weight, height, body mass index (BMI), fat mass, and fat-free mass were assessed. Serum TGs, total cholesterol, HDL cholesterol, LDL cholesterol, glucose and insulin levels were measured. The FTO gene was Genotyped for rs9939609 polymorphism. Dietary intake was assessed by avalid 168-item semi-quantitative food frequency questionnaire (FFQ). The homozygotes for the FTO rs9939609 risk allele (A) had higher serum leptin (p = 0.005, F: 5.131) and lower HDL (p = 0.001, F: 7.687) level than TT genotype. The differences between TT and AT genotypes were not significant. The association remained significant for HDL level after adjustments for age and sex, calorie intake, physical activity, and BMI. The association between rs9939609 polymorphism genotypes and leptin was disappeared after adjustments for calorie intake and physical activity. In conclusion, rs9939609 risk allele was associated with higher serum leptin and lower HDL levels in overweight people. Further studies are warranted.

Assessment of the FTO gene polymorphisms (rs1421085, rs17817449 and rs9939609) in exercise-trained men and women: the effects of a 4-week hypocaloric diet

Background

Variations in the fat mass and obesity-associated gene (FTO) are associated with obesity; however, it is unclear if changes in energy intake affect the adaptive response to caloric restriction in those with risk variants. The three FTO single nucleotide polymorphisms (SNPs), rs1421085, rs17817449 and rs9939609, are in strong linkage disequilibrium. Thus, the purpose of this investigation was to determine the role of these FTO SNPs vis-à-vis the effects of a 4-week hypocaloric diet on body composition in exercise-trained men and women. Two salivary biomarkers that associate with energy expenditure were also assessed (cortisol and salivary alpha-amylase, sAA).

Methods

Forty-seven exercise-trained men (n = 11) and women (n = 36) (mean ± SD: age 32 ± 9 years; height 169 ± 8 cm, body mass index 24.5 ± 2.9 kg/m², hours of aerobic training per week 4.9 ± 3.8, hours of weight training per week 3.9 ± 2.4, years of training experience 13.4 ± 7.0) completed a 4-week hypocaloric diet (i.e., decrease total calories by ~ 20–25% while maintaining a protein intake of ~ 2.0 g/kg/d). Subjects were instructed to maintain the same training regimen and to decrease energy intake via carbohydrate and/or fat restriction during the treatment period. Body composition was assessed via dual-energy X-ray absorptiometry (DXA) (Model: Hologic Horizon W; Hologic Inc., Danbury CT USA). Total body water was determined via a multifrequency bioelectrical impedance (BIA) device (InBody 770). Saliva samples were collected pre and post intervention in order to genotype the participants as well as to determine the concentrations of cortisol and sAA.

Results

Of the 47 subjects, 15 were of normal risk for obesity whereas 32 were carriers of the FTO gene risk alleles. Subjects were grouped based on their genotype for the three FTO SNPs (i.e., rs1421085, rs17817449 and rs9939609) due to their strong linkage disequilibrium. We have classified those with the normal obesity risk as “non-risk allele” versus those that carry the “risk allele” (i.e., both heterozygous and homozygous). Both groups experienced a significant decrease in total energy intake (p < 0.01); non-risk allele: pre kcal 2081 ± 618, post kcal 1703 ± 495; risk allele: pre kcal 1886 ± 515, post kcal 1502 ± 366). Both groups lost a significant amount of body weight (p < 0.01); however, there was no difference between groups for the change (post minus pre) in each group (risk allele change: − 1.0 ± 1.2 kg, non-risk allele change: − 1.2 ± 1.4 kg). Additionally, both groups lost a significant amount of fat mass (p < 0.01) with no differences between groups for the change in fat mass (risk allele change for fat mass: 1.1 ± 0.7 kg, non-risk allele change − 0.9 ± 0.4 kg). There were no significant changes in either group for fat free mass or total body water. The change in salivary alpha-amylase or cortisol was not different between groups.

Conclusions

In the short-term (i.e., 4 weeks), exercise-trained men and women consuming a hypocaloric diet that is relatively high in protein experience similar changes in body composition due exclusively to a decrement in fat mass and independent of FTO allele status. Therefore, weight and fat loss on a hypocaloric diet is, at least in the short-term, unaffected by the FTO gene.