Fat Mass And Obesity-associated Polymorphisms Research Articles

Interaction Effects of FTO and MC4R Polymorphisms on Total Body Weight Loss, Post-Surgery Weight, and Post-Body Mass Index after Bariatric Surgery.

Bariatric surgery (BS) is considered the most effective intervention for patients with severe obesity and is used to maintain long-term weight loss and glycemic control. The aim of this study was to analyze the effects of genotypes and haplotypes of the fat mass and obesity-associated (FTO) and melanocortin 4 receptor (MC4R) genes on total body weight loss (TBWL), post-surgery weight, and post-BMI after bariatric surgery. We retrospectively selected 101 patients from Bajio High Specialty Regional Hospital, León Guanajuato, México, who underwent Roux-en-Y gastric bypass (RYGB) to determine their body mass index (BMI), blood pressure, biochemical characteristics, and comorbidities. Post-surgery, patients were referred for registered anthropometry and blood pressure. Glucose, lipid and hepatic profiles, and insulin, leptin, and ghrelin levels were measured, and rs9939609, rs9930506, and rs1421085 FTO and rs17782313 MC4R polymorphisms were genotyped. Six (4-8) years after BS, post-surgery weight was greater in carriers of the rs9939609 and rs1421085 risk genotypes. TBWL was lower for the rs9930506 and rs1421085 risk genotypes. Insulin and HOMA-IR were greater in patients with the three FTO polymorphisms. There were significant interaction effects of the rs9930506 and rs1421085 FTO risk genotypes on weight and BMI in response to BS. No association was found with the MC4R polymorphism. The genotypes and haplotypes of the FTO gene influence post-surgery weight, TBWL, insulin levels, and HOMA-IR.

Assessment of health risks caused by overweight in children depending on the FTO gene rs9939609 polymorphism

In this study, we aimed to estimate the association between the rs9939609 FTO (fat mass and obesity associated) polymorphism and a risk of overweight in children living in the Baikal region. We performed a case – control study that included 113 schoolchildren living in industrial centers of the Baikal region (Irkutsk, Angarsk, and Ulan-Ude). Anthropometric parameters were measured and body mass index was calculated with its values being ranked in accordance with the WHO BMI curves depending on a sex and age. Genotyping of the rs9939609 FTO polymorphism was performed by allele-specific amplification with real-time results detection. To assess likelihood of an association between the FTO gene allele and overweight and obesity, relative risk (RR) and 95 % confidence interval (CI) were calculated. The assessment revealed the A allele of the rs9939609 FTO polymorphism to be by 1.29 times more frequent in the examined children with overweight and obesity (48.44 %) than in the children form the reference group (37.65 %). The FTO rs9939609 polymorphism was authentically associated with likelihood of elevated risks of overweight and obesity in children with the homozygous AA genotype (RR = 2.806, 95 % CI: 1.650–4.772; STD = 0.271). Our study confirms that the rs9939609 polymorphism of the FTO gene is a risk factor of overweight and obesity for children from the Baikal region who have the A allele of the homozygous AA genotype. Prevailing frequency of the TT genotype (29.2 %) as compared with the AA genotype (10.62) is likely due to influence of assimilation processes on urbanized territories in the Baikal region.

Оценка риска избыточной массы тела у детей в зависимости от полиморфизма rs9939609 генa FTO

In this study, we aimed to estimate the association between the rs9939609 FTO (fat mass and obesity associated) polymorphism and a risk of overweight in children living in the Baikal region. We performed a case – control study that included 113 schoolchildren living in industrial centers of the Baikal region (Irkutsk, Angarsk, and Ulan-Ude). Anthropometric parameters were measured and body mass index was calculated with its values being ranked in accordance with the WHO BMI curves depending on a sex and age. Genotyping of the rs9939609 FTO polymorphism was performed by allele-specific amplification with real-time results detection. To assess likelihood of an association between the FTO gene allele and overweight and obesity, relative risk (RR) and 95 % confidence interval (CI) were calculated. The assessment revealed the A allele of the rs9939609 FTO polymorphism to be by 1.29 times more frequent in the examined children with overweight and obesity (48.44 %) than in the children form the reference group (37.65 %). The FTO rs9939609 polymorphism was authentically associated with likelihood of elevated risks of overweight and obesity in children with the homozygous AA genotype (RR = 2.806, 95 % CI: 1.650–4.772; STD = 0.271). Our study confirms that the rs9939609 polymorphism of the FTO gene is a risk factor of overweight and obesity for children from the Baikal region who have the A allele of the homozygous AA genotype. Prevailing frequency of the TT genotype (29.2 %) as compared with the AA genotype (10.62) is likely due to influence of assimilation processes on urbanized territories in the Baikal region.

The Effect of Association between Fat Mass and Obesity-associated Gene Polymorphism (rs9939609) on the Body Composition of Older People: A Systematic Review.

The aging population is growing faster than any other age group worldwide. Associated with aging, the prevalence of overweight and obesity is a potential risk factor for the development and aggravation of numerous pathologies. A genetic factor often associated with obesity is the fat mass and obesity-associated (FTO) (rs9939609) gene polymorphism, which has been extensively investigated in children, young, and adults. However, few studies have been carried out on the older population. This review aimed to verify the influence of the FTO (rs9939609) gene polymorphism on the body composition of the older population. We conducted a systematic review and meta-analysis on PubMed, Scielo, and LILACS databases. Statistical analysis for meta-analysis was performed using mean values of Body Mass Index (BMI) and standard deviations. The results did not show significant differences between FTO genotypes and BMI values (-0.32, 95% CI -0.45 to -0.19, I2 = 0%, p = 0.52). However, 59% of the studies identified some influence on body composition, obesity, or comorbidities. Few publications verify FTO polymorphism effects on specific groups of the older population, suggesting a reduction in the influence of this gene on the BMI with advancing age. However, we believe that more controlled studies in older populations should be performed.

Association of fat mass and obesity-associated (FTO) gene polymorphisms with non-communicable diseases (NCDs) in the Iranian population: A systematic review of observational studies.

Single nucleotide polymorphisms have been implicated in various diseases, most notably non-communicable diseases (NCDs). The aim of this study was to review available evidence regarding associations between FTO polymorphisms and NCDs in the Iranian population. A comprehensive search was conducted through PubMed/Medline and Scopus databases up to December 2021, as well as reference lists of pertinent articles and key journals. All observational studies that examined the association between FTO gene polymorphisms and NCDs in the Iranian population were included. There was no limitation on the publication year. The Newcastle-Ottawa Scale (NOS) was used to assess the study's quality. The initial search yielded 95 studies, of which 30 studies were included in the current systematic review. The underlying disorders were obesity, type 2 diabetes, breast and colorectal cancers, depression, and metabolic syndrome. These studies found an association between FTO gene polymorphisms and obesity in the Iranian population, but the relationship with other NCDs was debatable. Even though, other diseases such as diabetes and metabolic syndrome, which are closely related to obesity, may also be associated with FTO gene polymorphisms. FTO gene polymorphism appears to play a role in the occurrence of NCDs. Some of the study results may be misleading due to ethnic differences and the effect of other genetic factors on disease onset, which needs to be investigated further. Finally, FTO gene polymorphisms can be studied as a preventive or therapeutic target. The online version contains supplementary material available at 10.1007/s40200-022-01139-4.

The effect of FTO rs9939609 polymorphism on the association between colorectal cancer and dietary fiber.

BackgroundGene polymorphisms may explain the controversy on the association between colorectal cancer (CRC) and dietary fibers. The purpose of this study was to investigate the effect of fat mass and obesity-associated (FTO) rs9939609 polymorphism on the association between colorectal cancer and dietary fiber.MethodsThis case-control study was conducted on 160 CRC cases and 320 healthy controls in Tehran, Iran. The participants' food intake was assessed using a semi-quantitative food frequency questionnaire (FFQ). The frequency of rs9939609 FTO polymorphism in the case and control groups was determined using the tetra-primer amplification refractory mutation (tetra-ARMS) method.ResultsIn the participants with the TT genotype of the FTO rs9939609, the cases had higher BMI and lower intake of dietary fiber compared to the controls (P = 0.01). Among A allele carriers of FTO rs9939609 polymorphism, the cases had higher BMI (P = 0.04) and lower intake of total fiber (P = 0.02) and soluble fiber (P = 0.02). An inverse association was found between CRC and dietary fiber intake among those with the AA/AT FTO rs9939609 genotype after adjusting for age, sex, smoking, alcohol consumption, physical activity, BMI, and calorie intake (OR = 0.9, CI 95%:0.84–0.92, P < 0.05).ConclusionThis study found a link between higher dietary fiber consumption and a lower risk of CRC in A-allele carriers of FTO rs9939609 polymorphism. Future studies are needed to identify the underlying mechanisms of the association between CRC and dietary fibers in people with different FTO genotypes.

Expression features of the ovine FTO gene and association between FTO polymorphism and tail fat deposition related-traits in Hu sheep

Fat mass and obesity associated (FTO) gene is a famous dominant predictor of obesity, and plays pivotal roles in the regulating fatty acid transport and fat metabolism. In the current study, the quantitative real-time PCR (qRT-PCR), DNA-pooled sequencing and KAspar assay were performed to detect the expression features of FTO and the polymorphisms of FTO associated with the tail fat weight related-traits of Hu sheep. The results indicated that the expression of FTO gene is widely expressed in the tissues tested, and the expression level of FTO in tail fat tissue was evidently higher compared with that in the other tissues. In addition, FTO showed the highest expression level in tail fat tissue at three months. The expression of FTO mRNA was lower in the large-tail fat group compared with that in the small-tail fat group in 6 months old. Subsequently, the polymorphism loci g. 23704451C > A detected in the FTO gene was confirmed to be significantly related to the tail length and the weight of tail fat. These results suggested that the polymorphism might be regarded as novel molecular marker for the breeding of small tail sheep.

Are the FTO Gene Polymorphisms Associated with Colorectal Cancer? A Meta-analysis.

Colorectal cancer (CRC) is reported to be associated with some gene polymorphisms. However, the effect of the fat mass and obesity associated (FTO) gene on colorectal cancer is not yet clear. This meta-analysis aimed to investigate the association of the FTO gene polymorphism and colorectal cancer. PubMed, Web of science, Scopus, and Embase were explored to identify the studies investigating the relationship between rs9939609 and rs17817449 polymorphisms of FTO gene and colorectal cancer, and the published papers from 2000 to 2019were collected. This meta-analysis was conducted by using a random-effects model for the best estimation of the desired outcomes. In this study, 1528 studies were initially included and five eligible case-control studies including 13,460 cases and 22,578 controls were eligible for further analyses. No significant association was found between risk allele of FTO rs9939609 (OR = 0.98, 0.87-1.1) and rs17817449 (OR = 0.9, 0.79-1.03) polymorphisms and colorectal cancer risk. The subgroup analyses considering the source of the control group and race found no significant association between FTO polymorphisms and the risk of colon cancer. This study indicated that rs9939609 and rs17817449 FTO gene polymorphisms are not associated with colorectal cancer risk. Individual studies involving different FTO polymorphisms are needed to further evaluation of the associations between the FTO gene and colon cancer.

Effects of FTO and PPARγ variants on intrauterine growth restriction in a Brazilian birth cohort.

Intrauterine growth restriction (IUGR) is related to a higher risk of neonatal mortality, minor cognitive deficit, metabolic syndrome, and cardiovascular disease in adulthood. In previous studies, genetic variants in the FTO (fat mass and obesity-associated) and PPARγ (peroxisome proliferator-activated receptor-gamma) genes have been associated with metabolic disease, body mass index, and obesity among other outcomes. We studied the association of selected FTO (rs1421085, rs55682395, rs17817449, rs8043757, rs9926289, and rs9939609) and PPARγ (rs10865710, rs17036263, rs35206526, rs1801282, rs28763894, rs41516544, rs62243567, rs3856806, and rs1805151) single-nucleotide polymorphisms (SNPs) with IUGR, through a case-control study in a cohort of live births that occurred from June 1978 to May 1979 in a Brazilian city. We selected 280 IUGR cases and 256 controls for analysis. Logistic regression was used to jointly analyze the SNPs as well as factors such as maternal smoking, age, and schooling. We found that the PPARγ rs41516544 increased the risk of IUGR for male offspring (OR 27.83, 95%CI 3.65-212.32) as well as for female offspring (OR=8.94, 95%CI: 1.96-40.88). The FTO rs9939609 TA genotype resulted in a reduced susceptibility to IUGR for male offspring only (OR=0.47, 95%CI: 0.26-0.86). In conclusion, we demonstrated that PPARγ SNP had a positive effect and FTO SNP had a negative effect on IUGR occurrence, and these effects were gender-specific.

Role of FTO and MC4R Polymorphisms in Escalating Obesity and Their Indirect Association With Risk of T2D in Indian Population.

IntroductionObesity plays a pivotal role in the development of metabolic syndrome—excessive body fat, spikes in blood glucose levels and hypertension—and ultimately leads to cardiovascular diseases and type 2 diabetes (T2D), if left unattended. The present study aimed to investigate the associated risk of T2D with obesity risk alleles of fat mass and obesity-associated (FTO) and melanocortin 4 receptor (MC4R) genes.MethodsThe study includes 400 subjects (300 T2D diabetic cases and 100 healthy controls). Genetic analysis was done by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods.ResultsThe findings of the study show no significant increase in odds of diabetes associated with the prevalence of FTO and MC4R minor alleles. Rare allele frequencies for “A” of FTO rs9939609 were 0.34 and 0.30 in cases and controls, respectively. Rare allele frequencies for A of MC4R rs12970134 were found to be more common in controls (0.45) than cases (0.41), but the difference was insignificant (p 0.246); however, an increase in body weight with the presence of allele “A” of the FTO gene (p value < 0.001) was found, indicating indirect involvement in the development of T2D. In addition, these were also correlated with the demographic/lifestyle and clinico-pathological parameters between T2D cases and controls. We found that T2D patients with a history of smoking and high consumption of alcohol, fast foods and sweetened beverages are at high risk of T2D compared to healthy controls (p < 0.01*).ConclusionThe present study concludes that there is no direct association of rs9939609 of the FTO gene with the occurrence of diabetes in the Indian population, but its role in T2D development cannot be overlooked altogether. Furthermore, we conclude that the rs9939609 of FTO carries a potential risk of obesity and because of this FTO rs9939609 T > A is widely considered an obesity-associated allele/single-nucleotide polymorphism (SNP).

In depth analysis of the association of FTO SNP (rs9939609) with the\xa0expression of classical phenotype of PCOS: a Sri Lankan study

BackgroundPCOS is a common disorder of women due to genetic, endocrine and environmental effects that manifests from puberty. The rs9939609 variant of fat mass and obesity associated (FTO) gene is linked to metabolic derangement in PCOS. We previously identified FTO (rs9939609) as a susceptibility locus for PCOS among Sri Lankan women and also explored the role of kisspeptin. Associated factors of the FTO candidate gene among South Asians with PCOS are unknown.MethodsThis study aimed to determine the association between FTO (rs9939609) polymorphism with clinical (BMI, acanthosis nigricans, hirsutism) and biochemical (serum kisspeptin and testosterone levels) characteristics of PCOS in a cohort of Sri Lankan women. Genetic and clinical data including serum kisspeptin and testosterone concentrations of our previously reported cases (n = 55) and controls (n = 110) were re-analyzed, specifically for an association with rs9939609 variant of FTO gene.ResultsLogistic regression analysis (AA – OR = 5.7, 95% CI = 2.41–13.63, p < 0.05) and genetic inheritance analysis (AA – OR = 5.49, 95%CI = 2.34–12.88, p < 0.05) showed that FTO (rs9939609) polymorphism is significantly associated with PCOS and its metabolic manifestations. Serum testosterone was significantly higher in affected women with mutant genotypes (AA+AT) than with the normal allele (TT) (p < 0.05). Although serum kisspeptin was higher in subjects with PCOS and mutant alleles than controls, this difference was not significant (p > 0.05).ConclusionFTO gene variant rs9939609 is associated with hyperandrogenemia and metabolic manifestations of PCOS among women of Sri Lankan descent with the well-characterized phenotype. Serum kisspeptin and the FTO genotypes lack a significant association when adjusted for confounders.

Genetic variants in the fat mass and obesity-associated (FTO) gene confer risk for extreme obesity and modulate adiposity in a Brazilian population.

Obesity is a major public health problem worldwide. It has a complex etiology, influenced by environmental and genetic factors. FTO has been recognized as an important genetic factor for obesity development. This study evaluated the contribution of FTO polymorphisms (rs9939609 and rs17817449) for extreme obesity in terms of the period of obesity onset, anthropometric, and biochemical parameters. The haplotype and the combined effects of FTO risk alleles on obesity susceptibility were evaluated. We investigated 169 normal-weight subjects (body mass index, BMI: 22.8 [21.0; 24.0] kg/m2) and 123 extremely obese individuals (BMI: 47.6 [44.1; 53.1] kg/m2). Genotyping was performed by real time PCR. Our results showed a strong association between FTO variants and extreme obesity. Carriers of the AT haplotype had an increased risk for extreme obesity. Gene scores suggested that the risk of developing extreme obesity was increased 1.37-fold per risk allele added. Both polymorphisms also influenced BMI and body weight. Additionally, rs17817449 influenced triglyceride levels. No effect of FTO variants on the period of obesity onset was found. In conclusion, the FTO polymorphisms showed a strong association with development of extreme phenotype of obesity and adiposity modulation in a Brazilian population.

T/A polymorphism of the FTO gene and lifestyle are associated with fat accumulation in different age groups of men

BACKGROUND: Adiposity development and its complications are determined by lifestyle, genetic mechanisms and their interactions. Among the obesity-related genes, polymorphisms in the fat mass and obesity associated (FTO) gene are strongly associated with body fat estimates in different populations.&#x0D; AIMS: to examine the association between the FTO polymorphism (T/A, rs9939609) and fat accumulation in adult russian males.&#x0D; MATERIALS AND METHODS: The study engaged 205 participants; the age ranged from 17 to 52 years. Samples of buccal smears were collected and genomic DNA was isolated for T/A polymorphism genotyping. Anthropometric measurements were conducted with caliperometry and body composition was estimated by bioimpedance analysis.&#x0D; RESULTS: Genotype frequencies in the whole studied sample were as follows FTO*TT 14%, FTO*AT 52,6%, FTO*AA 33,4% (2HW = 1,65 p=0,193). The minor A allele was significantly associated with increased fat accumulation and abdominal adiposity.&#x0D; CONCLUSIONS: Among different lifestyle modifications regular and consistent programmes of exercise are most efficient strategy to reduce abdominal fat deposits significantly, independent of FTO genotype.

FTO gene polymorphisms and obesity risk in Chinese population: a meta-analysis.

There is tremendous increase in obesity worldwide. Many factors including diet, life style, genetic, and epigenetic changes contribute to obesity. The fat mass and obesity-associated (FTO) gene polymorphisms are strongly associated with obesity. It has been reported that FTO single-nucleotidepolymorphisms (SNPs) are associated with obesity in European populations; however, it was controversial in Chinese population. The present meta-analysis study was designed to investigate the association between FTO polymorphisms and obesity risk in Chinese population. The investigators searched studies using the following databases: PubMed, web of science, and Cochrane Central Register of Controlled Trials. A random-effects model was used to calculate the pooled odds ratios (ORs). The heterogeneity among the studies was measured by I2 value. Subgroup analysis was used to find out the potential factors influencing the heterogeneity. A total of 18 articles including 26 studies were included in the present meta-analysis. Overall, the FTO SNPs were significantly associated with obesity in Chinese population (OR 1.30; 95% CI 1.19-1.42; P < 0.001) under per-allele comparison. The subgroup analysis also showed strong association between four FTO SNPs (rs9939609, rs6499640, rs8050136, and rs1558902) and obesity risk. Furthermore, subgroup analysis stratified by children/adolescent and adult groups showed same trend. The present meta-analysis indicated that FTO SNPs are associated with obesity risk in both children/adolescents and adults in Chinese population.

Evaluation of FTO rs9939609 and MC4R rs17782313 Polymorphisms as Prognostic Biomarkers of Obesity: A Population-based Cross-sectional Study.

ObjectivesObesity is a significant risk factor for a number of chronic diseases, including diabetes, cardiovascular diseases, and cancer. Obesity usually results from a combination of causes and contributing factors, including genetics and lifestyle choices. Many studies have shown an association of single nucleotide polymorphisms (SNPs) in the fat mass and obesity-associated (FTO) and the melanocortin-4 receptor (MC4R) genes with body mass index (BMI). Therefore, recognizing the main genes and their relevant genetic variants will aid prediction of obesity risk. The aim of our study was to investigate the frequency of rs9939609 and rs17782313 polymorphisms in FTO and MC4R genes in an Iranian population.MethodsWe enrolled 130 obese patients and 83 healthy weight controls and calculated their BMI. Genomic DNA was extracted from peripheral blood and the frequency of rs9939609 and rs17782313 polymorphisms in FTO and MC4R genes was determined using the tetra-primer amplification refractory mutation system-polymerase chain reaction (ARMS-PCR).ResultsSignificant associations were found between FTO rs9939609 and BMI. Where homozygous risk allele carriers (A-A) have significant higher odds ratio (OR) of being obese than individuals with normal BMI (OR = 6.927, p < 0.005, 95% confidence interval (CI): 3.48–13.78). No significant correlation between MC4R rs17782313 and obesity were observed when compared to healthy weight individuals. Although subjects with C-C genotype had higher odds of obesity (OR = 1.889, p = 0.077, 95%CI: 0.92–3.84).ConclusionsThis study shows a relationship between FTO polymorphism and increased BMI, therefore, SNP in the FTO gene influence changes in BMI and can be considered a prognostic marker of obesity risk.

Gene Polymorphisms of Human FTO and Obesity in Part of Iranian Population

As obesity is a multifactorial characteristic, identifying genetic risk factors can help to prevent obesity prevalence. In 2007, FTO (fat mass and obesity associated) gene was identified according to genome-wide association study. Several studies revealed that FTO polymorphisms are responsible for the risk of obesity. The primary objective of our study was assessment of FTO rs9939609 and rs9926289 polymorphisms as risk factors of obesity in part of the Iranian population. In our case–control study, 62 patients with obesity and 75 controls were selected according to their BMI (obese: BMI ≥ 30 kg/m2 and control: BMI: 18.5-24.9 kg/m2). Blood samples were collected from individuals for biochemical parameters assessment and genotyping analysis. After genotyping by high resolution melting (HRM) technique, the odds ratio was used to examine the relationship between the risk factors and the disease; 95% of confidence interval was used for these calculations. The difference in the age, FBS, triglycerides, total cholesterol, and BMI between individuals with obesity and the control group was significant. The analysis of rs9939609 FTO gene showed significant association between the AA+TA genotype and TT according to the dominant model. No association was observed for genotypes of the FTO rs9926289 polymorphism. In addition, there was no significant correlation of biochemical parameters and dominant model genotypes of rs9939609 polymorphisms. Our study suggests that FTO rs9939609 polymorphisms appear to be associated with obesity in part of the Iranian population. AA+TA genotype of rs9939609 polymorphism is a risk factor of obesity. However, further examination should be carried out on large populations.

Determination of individual type 2 diabetes risk profile in the North East Indian population & its association with anthropometric parameters.

Background & objectives:Diabetes genomics research has illuminated single nucleotide polymorphism (SNP) in several genes including, fat mass and obesity associated (FTO) (rs9939609 and rs9926289), potassium voltage-gated channel subfamily J member 11 (rs5219), SLC30A8 (rs13266634) and peroxisome proliferator-activated receptor gamma 2 (rs1805192). The present study was conducted to investigate the involvement of these polymorphisms in conferring susceptibility to type 2 diabetes (T2D) in the North East Indian population, and also to establish their association with anthropometric parameters.Methods:DNA was extracted from blood samples of 155 patients with T2D and 100 controls. Genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism and DNA sequencing. To confirm the association between the inheritance of SNP and T2D development, logistic regression analysis was performed.Results:For the rs9939609 variant (FTO), the dominant model AA/(AT+TT) revealed significant association with T2D [odds ratio (OR)=2.03, P=0.021], but was non-significant post correction for multiple testing (P=0.002). For the rs13266634 variant (SLC30A8), there was considerable but non-significant difference in the distribution pattern of genotypic polymorphisms between the patients and the controls (P=0.004). Significant association was observed in case of the recessive model (CC+CT)/TT (OR=4.56 P=0.001), after adjusting for age, gender and body mass index. In addition, a significant association (P=0.001) of low-density lipoprotein (mg/dl) could be established with the FTO (rs9926289) polymorphism assuming dominant model.Interpretation & conclusions:The current study demonstrated a modest but significant effect of SLC30A8 (rs13266634) polymorphisms on T2D predisposition. Considering the burgeoning prevalence of T2D in the Indian population, the contribution of these genetic variants studied, to the ever-increasing number of T2D cases, appears to be relatively low. This study may serve as a foundation for performing future genome-wide association studies (GWAS) involving larger populations.

A complete linkage disequilibrium in a haplotype of three SNPs in Fat Mass and Obesity associated (FTO) gene was strongly associated with anthropometric indices after controlling for calorie intake and physical activity

BackgroundThe underlying mechanism of the effect of FTO genotype on body mass index (BMI) and body composition is unknown. The objective of the study was to investigate the association of FTO gene polymorphisms with anthropometric indices in adolescent boys after adjustments for dietary intake and physical activity.MethodsIn this school-based study, we enrolled 123 male adolescents without extra weight and 110 male adolescents with body mass index (BMI) higher than + 1 Z-score. The DNA samples were genotyped for the FTO gene polymorphisms by DNA Sequencing. BMI and body composition were assessed using bioelectrical impedance analyzer scale. Association of the FTO polymorphisms with Weight, height, BMI, body fat percent and skeletal muscle percent were investigated. Data on potential confounders (calorie intake and physical activity) were collected through the use of pre-tested questionnaires.ResultsAdolescents with higher BMI and body fat percent and lower skeletal muscle percent were more likely to have a newly found haplotype of rs9930506, rs9930501 & rs9932754 (GGT) in the first intron of the FTO with complete linkage disequilibrium (LD) compared with those with the lower BMI (6.15;2.28–16.63), body fat percent (9.54;0.92–47.44) and higher skeletal muscle percent (9.26;1.85–46.38). This association was not changed after controlling for age. Additional adjustments for calorie intake and physical activity did not alter the association.ConclusionsA haplotype in the first intron of the FTO gene had a strong association with obesity indices in adolescent boys after adjustments for calorie intake and physical activity. It’s suggested that the FTO genotype exert its effects on adolescents’ anthropometric indices as haplotype and through mechanisms other than changes in calorie intake and expenditure.Trial registrationThis paper reports the first phase of a comprehensive interventional study (Interactions of Genetics, lifestyle and anthropometrics study or IGLA study) and is retrospectively registered in the Iranian Registry of Clinical Trials as IRCT2016020925699N2. Date registered: April 24, 2016. (http://www.irct.ir/searchresult.php?id=25699&number=2).

FTO variant is not associated with osteoarthritis in the Chinese Han population: replication study for a genome-wide association study identified risk loci

BackgroundOsteoarthritis is the most prevalent form of arthritis worldwide and is the major cause of pain and loss of function in elderly people. A signal of the fat mass and obesity-associated (FTO) gene had been reported in a genome-wide association study of osteoarthritis. The FTO polymorphism (rs8044769) might exert its effect on osteoarthritis through obesity, because it was reported as a body mass index-associated single-nucleotide polymorphism. And replication studies showed inconsistent results for this association. Our present study is to check the association of rs8044769 with osteoarthritis and body mass index in Chinese Han population.MethodsA case-control association study was conducted by using 890 osteoarthritis cases and 844 controls in Chinese Han population. rs8044769 was genotyped in all subjects. Allelic and genotypic frequencies were compared between osteoarthritis cases and control subjects. Associations between rs8044769 and body mass index, and body mass index and osteoarthritis were also assessed.ResultsNo significant difference was detected in genotype or allele distribution between osteoarthritis cases and controls (P > 0.05). Stratification by gender and body mass index revealed negative association between rs8044769 and osteoarthritis. We did not find any solid association between rs8044769 and higher body mass index. Meanwhile, we demonstrated that higher body mass index (body mass index ≥ 25) was associated with osteoarthritis.ConclusionOur present study suggested that rs8044769 was not associated with osteoarthritis susceptibility or higher body mass index, and higher body mass index was a risk factor for osteoarthritis in the Chinese Han population. We also proposed that stratification by clinical parameters was crucial to reduce false-positive result in OA association studies.

Analysis of the Impact of Common Polymorphisms of theFTOandMC4RGenes with the Risk of Severe Obesity in Saudi Arabian Population

Obesity has reached epidemic proportions worldwide resulting in a serious public health problem. In Saudi Arabia, 28.7% of the population is obese due largely to the adoption of western dietary patterns over the last decade. The fat-mass and obesity associated (FTO) and melanocortin-4 receptor (MC4R) genes are ubiquitously expressed in the brain and pancreatic islets, and are the main link between the central nervous system and energy homeostasis based on food intake and energy expenditure. Genetic variants in the FTO and MC4R genes have been strongly associated with an increased obesity risk. To identify novel mutations in the MC4R gene and to perform correlation analyses of the known variants rs9939609 and rs1421085 in the FTO gene and rs17782313 near the MC4R gene in an obese Saudi population. A total of 136 obese patients and 104 healthy controls from King Fahd Hospital, Al-Khobar, were genotyped for single-nucleotide polymorphisms within or near the FTO and MC4R genes using the TaqMan assay. Leptin levels were determined by enzyme-linked immunosorbent assay. Targeted sequencing of MC4R exon was done by Sanger sequencing method. The study included 58 obese males and 78 obese females with a mean age of 39.78 ± 12.77 years and a mean body mass index (BMI) of 42.65 ± 9.03 kg/m2. A significant increase in the levels of leptin and triglycerides was associated with an increase of BMI. Other factors such as lactate dehydrogenase, gamma-glutamyltransferase, and high-density lipoprotein were also significantly higher in the severely obese cohort. The FTO polymorphisms were associated with a significantly increased risk for obesity and in BMI-stratified cohort, rs9939609 (T/A: odds ratio [OR] = 1.73, p = 0.007) and rs1421085 (T/C: OR = 1.56, p = 0.03) showed even stronger association. Genotyping for the near MC4R polymorphism, rs17782313 revealed an association with moderately obese patients (T/C: OR = 1.73, p = 0.038). The studied FTO gene polymorphisms were found to be significantly associated with increased BMI and were highly significantly associated with severe obesity. These FTO gene polymorphisms combined with a high-fat diet appear to promote early-onset obesity in the Saudi population. FTO polymorphisms appear to be universally associated with the risk of obesity, and further investigation into this genetic locus may provide clues for potential therapeutic targets.