Fat Mass And Obesity-associated Genotype Research Articles

FRIED FOOD AND POSSIBLE HEALTH HAZARDS

FRIED FOOD AND POSSIBLE HEALTH HAZARDS

Similarities in Metabolic Flexibility and Hunger Hormone Ghrelin Exist between FTO Gene Variants in Response to an Acute Dietary Challenge

The rs9939609 polymorphism of the fat mass and obesity-associated (FTO) gene has been associated with obesity, and studies have also shown that environmental/lifestyle interaction such as dietary intake might mediate this effect. The current study investigates the postprandial hormonal regulators of hunger and indirect markers of substrate utilisation and metabolic flexibility following a dietary challenge to determine if suppression of circulating ghrelin levels and/or reduced metabolic flexibility exist between FTO genotypes. One hundred and forty seven healthy, sedentary males and females (29.0 ± 0.7 yrs; 70.2 ± 1.1 kg; 169.1 ± 0.8 cm; 24.5 ± 0.3 kg/m2) complete a single experimental session. Anthropometric measures, circulating levels of active ghrelin, insulin and glucose, and substrate oxidation via indirect calorimetry, are measured pre-prandial and/or post-prandial. The FTO rs9939609 variant is genotyped using a real-time polymerase chain reaction. Metabolic flexibility (∆RER) is similar between FTO genotypes of the rs9939609 (T > A) polymorphism (p > 0.05). No differences in pre-prandial and/or postprandial substrate oxidation, plasma glucose, serum insulin or ghrelin are observed between genotypes (p > 0.05). These observations are independent of body mass index and gender. Altered postprandial responses in hunger hormones and metabolic flexibility may not be a mechanism by which FTO is associated with higher BMI and obesity in healthy, normal-weighted individuals.

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.
 AIMS: to examine the association between the FTO polymorphism (T/A, rs9939609) and fat accumulation in adult russian males.
 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.
 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.
 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.

True Interindividual Variability Exists in Postprandial Appetite Responses in Healthy Men But Is Not Moderated by the FTO Genotype

ABSTRACTBackgroundAfter meal ingestion, a series of coordinated hormone responses occur concomitantly with changes in perceived appetite. It is not known whether interindividual variability in appetite exists in response to a meal.ObjectivesThe aim of this study was to 1) assess the reproducibility of appetite responses to a meal; 2) quantify individual differences in responses; and 3) explore any moderating influence of the fat mass and obesity associated (FTO) gene.MethodsUsing a replicated crossover design, 18 healthy men (mean ± SD age: 28.5 ± 9.8 y; BMI: 27.0 ± 5.0 kg/m2) recruited according to FTO genotype (9 AA, 9 TT) completed 2 identical control and 2 identical standardized meal conditions (5025 kJ) in randomized sequences. Perceived appetite and plasma acylated ghrelin, total peptide YY (PYY), insulin, and glucose concentrations were measured before and after interventions as primary outcomes. Interindividual differences were explored using Pearson's product-moment correlations between the first and second replicates of the control-adjusted meal response. Within-participant covariate-adjusted linear mixed models were used to quantify participant-by-condition and genotype-by-condition interactions.ResultsThe meal suppressed acylated ghrelin and appetite perceptions [standardized effect size (ES): 0.18–4.26] and elevated total PYY, insulin, and glucose (ES: 1.96–21.60). For all variables, SD of change scores was greater in the meal than in the control conditions. Moderate-to-large positive correlations were observed between the 2 replicates of control-adjusted meal responses for all variables (r = 0.44–0.86, P ≤ 0.070). Participant-by-condition interactions were present for all variables (P ≤ 0.056). FTO genotype-by-condition interactions were nonsignificant (P ≥ 0.19) and treatment effect differences between genotype groups were small (ES ≤ 0.27) for all appetite parameters.ConclusionsReproducibility of postprandial appetite responses is generally good. True interindividual variability is present beyond any random within-subject variation in healthy men but we detected no moderation by the FTO genotype. These findings highlight the importance of exploring individual differences in appetite for the prevention and treatment of obesity. This trial was registered at clinicaltrials.gov as NCT03771690.

Eating Behaviours and Food Cravings; Influence of Age, Sex, BMI and FTO Genotype.

Previous studies indicate that eating behaviours and food cravings are associated with increased BMI and obesity. However, the interaction between these behaviours and other variables such as age, sex, BMI and genetics is complex. This study aimed to investigate the relationships between eating behaviours and food cravings, and to examine the influence of age, sex, body mass index (BMI) and fat mass and obesity-associated (FTO) genotype on these relationships. A total of 475 participants (252 female, 223 male, BMI: 25.82 ± 6.14 kg/m2, age: 30.65 ± 14.20 years) completed the revised 18-question version of the Three Factor Eating Questionnaire (TFEQ-R18) to assess cognitive restraint, uncontrolled eating and emotional eating, and the Food Cravings Inventory (FCI) to assess cravings for fatty food, sweet food, carbohydrates and fast food. DNA samples were genotyped for the rs9939609 polymorphism in the obesity-linked gene FTO. Questionnaire data was analysed for associations between the TFEQ-R18 and FCI subscales for the whole study group, and the group divided by sex, genotype and age (≤25 years versus >25 years). Finally, mediation analysis was used to explore the relationships between BMI, cognitive restraint and food cravings. FTO AA + AT genotype was associated with increased BMI, but not with differences in eating behavior scores or food craving scores; age was associated with increased BMI and decreases in food craving scores in which this effect was stronger in women compared to men. Increased cognitive restraint was associated with decreased food craving scores in the ≤25 years group. Mediation analysis demonstrated that in this group the association between BMI and reduced food cravings was mediated by cognitive restraint indicating that in this age group individuals use cognitive restraint to control their food cravings. The positive correlation between age and BMI confirms previous results but the findings of this study show that age, sex, FTO genotype and BMI have an influence on the relationships between eating behaviours and food cravings and that these variables interact.

Interactions between macro-nutrients’ intake, FTO and IRX3 gene expression, and FTO genotype in obese and overweight male adolescents

ABSTRACT This study is the first to identify the effects of FTO genotype on the interactions between the level of macro-nutrients intake and the expression level of fat mass and obesity associated (FTO) and homeobox transcription factor iriquois-3 (IRX3) genes This longitudinal study was carried out on 84 overweight and obese adolescent boys in Tehran, Iran. The rs9930506 SNP in FTO was genotyped at baseline and the level of FTO and IRX3 expression in PBMCs and macro-nutrients’ intake were assessed at baseline and after 18 weeks of the intervention. The results identified that the higher carbohydrates intake significantly up-regulated the FTO gene (P = 0.001) and down-regulated the IRX3 gene (P = 0.01). Protein intake up-regulated the FTO gene (P = 0.001). In carriers of GG genotype of FTO gene, the amount of dietary carbohydrate had a positive association with FTO gene expression (p = 0.001, and p = 0.04, respectively). In AA/AG carriers, dietary protein was positively associated with FTO gene expression (p = 0.001) and dietary carbohydrate was negatively associated with IRX3 gene expression (P = 0.04). Therefore, dietary carbohydrateseems to be associated with FTO and IRX3 genes expression. These associations are influenced by FTO genotype.

Effects of fat mass and obesity-associated (FTO) gene polymorphisms on binge eating in women with binge-eating disorder: The moderating influence of attachment style.

The genetics of binge-eating disorder (BED) is an emerging topic and one candidate pathway, namely the fat mass and obesity-associated (FTO) gene, may be implicated because of its role in food reward sensitivity and self-regulation of eating. The aims of this study were to examine the independent effects of variants of FTO on binge frequency in women with and without BED and to examine the moderating role of interpersonal attachment in this association. Secondary data analysis was conducted on a cross-sectional comparison of three groups of women in a trial of group treatment for BED: BED with obesity (n = 73), BED without obesity (n = 55), and normal weight without BED (n = 50). Women were genotyped for five of the most common FTO single-nucleotide polymorphisms, rs9939609, rs8050136, rs3751812, rs1421085, and rs1121980, which have been related to body mass index and energy intake. Binge frequency (Eating Disorder Examination), body composition (bioelectric impedance), and attachment (Attachment Style Questionnaire) were assessed. There were no significant between-group differences for frequencies of FTO alleles, nor were there any significant anthropometric associations. The FTO × attachment interaction was significant whereby, relative to a low-risk FTO genotype, individuals with a high-risk genotype for the SNP rs1421085 and high-avoidant attachment had higher mean binge frequency than those with high genetic risk but low-avoidant attachment (β = -7.96; t = -2.07; P = 0.042). FTO genotypes associated with risk for obesity and loss of control of eating, specifically rs1421085, may interact with insecure attachment in a way that may exacerbate binge eating among women with BED.

Plasma stearoyl-CoA desaturase activity indices and bile acid concentrations after a low-fat meal: association with a genetic variant in the FTO gene.

PurposeDietary macronutrient composition, stearoyl-CoA desaturase (SCD) activity indices, and primary bile acid (BA) concentrations are among the factors that have been associated with lipid metabolism and contributed to obesity. We investigated the association between the polymorphic expression of the fat mass and obesity-associated (FTO) gene and its relationship with SCD activity indices and primary BA concentrations after a low-fat meal.Subjects and methodsBlood plasma samples were collected from 56 young (20–36 years) healthy subjects with different rs9939609 FTO genotypes. Fasting and post-meal (2 hours after a low-fat breakfast) blood samples were collected on the subsequent morning for the analysis of DNA methylation, SCD activity indices (product-to-precursor fatty acid ratios; 16:1n-7/16:0 and 18:1n-9/18:0), and chenodeoxycholic acid (CDCA) and cholic acid (CA) concentrations. Expression of lipogenic genes was investigated post-meal to assess the relationship between the CDCA and CA concentrations and mRNA levels of lipogenic genes.ResultsThe FTO AA (obesity risk) genotype group (n=18) had higher (P<0.05) post-meal SCD-16 activity index than the FTO TT (wild type) genotype group (n=26). In both the FTO TT (n=16) and AA (n=8) genotype groups, the post-meal concentrations of CDCA and CA were lower (P<0.05) compared with the fasted state. No difference in BA concentrations between the FTO TT and AA genotype groups in both meal states was observed. After adjusting for the body mass index, the highest 50% post-meal concentrations of CA were inversely (P=0.010) correlated with the level of mRNA SCD expression.ConclusionFTO AA carriers may be at a higher risk for obesity through higher SCD activity in a low-fat diet environment. This effect may be partly pronounced by very low CA concentrations.

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).

Physical activity modifies the FTO effect on body mass index change in Japanese adolescents.

Evidence of the effects of fat mass and obesity-associated (FTO) variation and long-term effects of physical activity (PA) on adiposity in adolescents is largely scarce. This study therefore investigated whether PA modulates the effects of the FTO on body mass index (BMI) changes in Japanese adolescents between the ages of 13 and 18years. Data on 343 subjects (156 boys; 187 girls) who were enrolled in 2006 and 2007 at schools in Shunan City, Japan, were collected. Genotyping (rs1558902) was conducted, and anthropometry and blood test results were recorded for subjects in the eighth grade. A second survey involving self-reporting of anthropometry was conducted when the subjects were in the 12th grade. PA was estimated using the International Physical Activity Questionnaire. BMI and the standard deviation score for BMI (BMI-SDS) were calculated. BMI changes and BMI-SDS changes were compared between FTO genotypes using a multivariate model. The effect of the interaction between PA and the FTO genotype on BMI changes was significant in boys but not in girls. In boys, PA had a significant negative influence on BMI-SDS changes in those with the AA genotype and a significant positive influence on BMI and BMI-SDS changes in those with the TT genotype. The influence of PA on BMI change and BMI-SDS change varies on the basis of genotype. PA modified the effect of FTO on BMI change in Japanese boys.

FTO genotype impacts food intake and corticolimbic activation

Variants in the first intron of the fat mass and obesity-associated (FTO) gene increase obesity risk. People with "high-risk" FTO genotypes exhibit preference for high-fat foods, reduced satiety responsiveness, and greater food intake consistent with impaired satiety. We sought central nervous system mechanisms that might underlie impaired satiety perception in people with a higher risk of obesity based on their FTO genotype. We performed a cross-sectional study in a sample that was enriched for obesity and included 20 higher-risk participants with the AA (risk) genotype at the rs9939609 locus of FTO and 94 lower-risk participants with either the AT or TT genotype. We compared subjective appetite, appetite-regulating hormones, caloric intake at a buffet meal, and brain response to visual food cues in an extended satiety network using functional MRI scans acquired before and after a standardized meal. Higher-risk participants reported less subjective fullness (χ2 = 7.48, P < 0.01), rated calorie-dense food as more appealing (χ2 = 3.92, P < 0.05), and consumed ∼350 more kilocalories than lower-risk participants (β = 348 kcal, P = 0.03), even after adjusting for fat or lean mass. Premeal, the higher-risk group had greater activation by "fattening" food images (compared with objects) in the medial orbital frontal cortex (β = 11.6; 95% CI: 1.5, 21.7; P < 0.05). Postmeal, the higher-risk subjects had greater activation by fattening (compared with nonfattening) food cues in the ventral tegmental area/substantia nigra (β = 12.8; 95% CI: 2.7, 23.0; P < 0.05), amygdala (β = 10.6; 95% CI: 0.7, 20.5; P < 0.05), and ventral striatum (β = 6.9; 95% CI: 0.2, 13.7; P < 0.05). Moreover, postmeal activation by fattening food cues within the preselected extended satiety network was positively associated with energy intake at the buffet meal (R2 = 0.29, P = 0.04) and this relation was particularly strong in the dorsal striatum (R2 = 0.28, P = 0.01), amygdala (R2 = 0.28, P = 0.03), and ventral tegmental area/substantia nigra (R2 = 0.27, P = 0.01). The findings are consistent with a model in which allelic variants in FTO raise obesity risk through impaired central nervous system satiety processing, thereby increasing food intake. This study is registered at clinicaltrials.gov as NCT02483663.

A fat mass and obesity-associated gene polymorphism influences fat mass in exercise-trained individuals

BackgroundA single nucleotide polymorphism (SNP) in the fat mass and obesity-associated (FTO) gene is a strong predictor of obesity in humans. The FTO SNP (rs1421085) results in a T to C nucleotide substitution that may result in an increased risk for obesity in individuals who carry at least one C allele. The purpose of this investigation was to characterize the FTO genotype in a cohort of exercise-trained men and women.MethodsWe tested 108 exercise-trained individuals that included professional mixed martial arts fighters, competitive distance runners, collegiate swimmers, stand-up paddlers as well as a cohort of recreational bodybuilders. Body composition was assessed via dual-energy x-ray absorptiometry (DXA). Saliva samples were collected in order to genotype participants and quantify cortisol levels.ResultsThe physical characteristics of the subjects were as follows (mean±SD): body weight 74.5±15.6 kg; height 171.5±9.5 cm; bone mineral content 2.8±0.7 kg; fat mass 15.7±5.5 kg; lean body mass 55.9±14.4 kg; % body fat 21.6±7.0. Independent samples t tests showed that C allele carriers (n = 54) had significantly higher fat mass t(106) = 3.13, p < 0.01 and body fat percentage t(106) = 2.68, p < 0.01, relative to the TT group (n = 54) (i.e., fat mass: C/− 17.3 ±5.6 kg, TT 14.2±4.6 kg; body fat percentage: C/− group 23.4±7.4%, TT group 19.9±6.2). No other measures of body composition were associated with the FTO genotype (i.e., body mineral density, bone mineral content, or lean body mass). Moreover, cortisol levels were significantly higher in the TT group relative to the C allele carriers t(106) = 2.37, p = 0.02 (i.e., TT 0.35 ±0.35 μg/dL, C/− 0.22±0.16 μg/dL).ConclusionsOur findings demonstrate a relationship between C allele carriers on the FTO gene and a predisposition to a higher fat mass and body fat percentage. In addition, we found no relationship between cortisol and fat mass. However, due to the cross-sectional nature of this investigation, we cannot infer causality regarding the FTO gene and body composition.

FTO genotype and weight status among preadolescents: Assessing the mediating effects of obesogenic appetitive traits

Polymorphisms in the Fat Mass and Obesity Associated (FTO) gene are robustly associated with overweight and obesity among children, although the underlying mechanisms are poorly understood. We tested if appetitive traits partially mediated the association between FTO genotype and increased BMI among a sample of US preadolescents. Data were from 178 unrelated 9–10 year olds who participated in an experimental study between 2013 and 2015. Children's DNA was isolated from buccal swabs, and the rs9939609 SNP in the FTO gene was genotyped. Children's age- and sex-adjusted BMI z-scores were computed using height and weight measured at the laboratory. Parents completed the Child Eating Behavior Questionnaire that includes three validated scales of habitual appetitive traits related to drive and regulation: satiety responsiveness, enjoyment of food and food responsiveness. Structural equation modeling was used to assess if those traits mediated the relationship between FTO and BMI z-score. The sample of children was 48.9% male and 91.0% non-Hispanic white. FTO distribution was in Hardy Weinberg equilibrium, and 16.3% of participants were homozygous for the high-risk allele. Mean BMI z-score was greatest among those with the high-risk genotype (ANOVA P < 0.01). In separate structural equation models adjusted for the child's sex and maternal education, decreased satiety responsiveness and increased food responsiveness each partially mediated the positive association between the high-risk genotype and increased BMI z-score (P-value for each indirect effect <0.05). Continued research is needed to better understand how other known genetic obesity risk factors may impact appetitive traits among children.

Rs9939609 FTO genotype associations with FTO methylation level influences body mass and telomere length in an Australian rural population.

The fat mass- and obesity-associated (FTO) gene influences energy homeostasis in humans. Although the obesity-related variant, rs9939609 has been replicated across a number of cohort studies, there remains significant variance and a low to modest association. Telomere length is another commonly reported obesity risk factor. We hypothesize understanding the associations between FTO rs9939609 with FTO methylation and telomere length will provide a more accurate assessment of obesity risk. Overall, 942 participants free of diabetes or pre-diabetes were included in the retrospective study. Leukocyte genomic DNA was analyzed for rs9939609 genotyping, FTO gene methylation and leukocyte telomere length (LTL) measurement. In general linear models, rs9939609 AA genotypes were associated with increased fat percentage (3.15%, P=0.001), fat mass (4.16 kg, P=0.001), body mass index (BMI) (1.38, P=0.006) and waist circumference (3.35 cm, P=0.006), but not with FTO methylation or LTL in this overall population. However, when participants were stratified into higher and lower FTO methylation groups, the AA genotype possesses a 2.04-fold increased obesity risk in comparison to TT genotype (95%CI, 1.07-3.89, P=0.031) in participants with a higher FTO methylation level, but this association was absent in the lower FTO methylation sub-group. Moreover, AT and AA genotype carriers were associated with shorter LTL compared to TT carriers (P=0.020 and P=0.111, respectively) in the higher FTO methylation level group. However, this association was absent in the lower methylation group. Furthermore, FTO gene methylation level was significantly associated with LTL in the 942 samples (P=0.017). FTO rs9939609 is associated with obesity risk and LTL in this study, where this association is only observed at higher, but not lower, FTO methylation levels of participants. Our data suggest association of multiple factors, including FTO methylation level, may be involved in one of several mechanisms underlying the commonly reported obesity risk of this FTO polymorphism.

FTO Genotype and Type 2 Diabetes Mellitus: Spatial Analysis and Meta-Analysis of 62 Case-Control Studies from Different Regions.

Type 2 diabetes mellitus (T2DM) is a global health problem that results from the interaction of environmental factors with genetic variants. Although a number of studies have suggested that genetic polymorphisms in the fat mass and obesity-associated (FTO) gene are associated with T2DM risk, the results have been inconsistent. To investigate whether FTO polymorphisms associate with T2DM risk and whether this association is region-related, we performed this spatial analysis and meta-analysis. More than 60,000 T2DM patients and 90,000 controls from 62 case-control studies were included in this study. Odds ratios (ORs), 95% confidence intervals (CIs) and Moran’s I statistic were used to estimate the association between FTO rs9939609, rs8050136, rs1421085, and rs17817499, and T2DM risk in different regions. rs9939609 (OR = 1.15, 95% CI 1.11–1.19) and rs8050136 (OR = 1.14, 95% CI 1.10–1.18) conferred a predisposition to T2DM. After adjustment for body mass index (BMI), the association remained statistically significant for rs9939609 (OR = 1.11, 95% CI 1.05–1.17) and rs8050136 (OR = 1.08, 95% CI 1.03–1.12). In the subgroup analysis of rs9939609 and rs8050136, similar results were observed in East Asia, while no association was found in North America. In South Asia, an association for rs9939609 was revealed but not for rs8050136. In addition, no relationship was found with rs1421085 or rs17817499 regardless of adjustment for BMI. Moran’s I statistic showed that significant positive spatial autocorrelations existed in rs9939609 and rs8050136. Studies on rs9939609 and rs8050136 focused on East Asia and South Asia, whereas studies on rs1421085 and rs17817499 were distributed in North America and North Africa. Our data suggest that the associations between FTO rs9939609, rs8050136 and T2DM are region-related, and the two single-nucleotide polymorphisms contribute to an increased risk of T2DM. Future studies should investigate this issue in more regions.

Association of fatty acid-binding protein 2 and fat mass and obesity-associated gene polymorphism with primary open-angle glaucoma

PURPOSE:The present study was carried out to investigate the association of fatty acid-binding protein 2 (FABP2) and fat mass and obesity-associated (FTO) gene polymorphism with primary open-angle glaucoma (POAG) cases and controls.MATERIALS AND METHODS:This study includes 122 POAG cases and 112 controls. FABP2 and FTO gene polymorphisms in cases and controls were evaluated by polymerase chain reaction-restriction fragment length polymorphism method.RESULTS:The mean ages were 49.88 ± 12.34 and 53.74 ± 11.87 years in POAG cases and control groups, respectively. The FABP2 gene AA, AT, TT genotype frequencies were 12.90%, 62.40%, 24.80% in POAG cases and 20.60%, 64.70%, 14.70% in healthy controls, respectively. The frequencies of A and T allele in POAG cases were 44.06% and 55.94% as compared to 52.94% and 47.06% in the controls. The FTO gene AA, AT, TT genotype frequencies were 2.00%, 79.20%, 18.80% in cases and 0%, 75.50%, 24.50% in healthy controls, respectively. The frequencies of A and T allele in POAG cases were 41.58% and 58.42% as compared to 37.75% and 62.25% in the controls. No significant difference in the frequencies of FABP2 and FTO genotype was found between POAG cases and controls.CONCLUSION:We could not identify the possible association of FABP2 and FTO gene polymorphism with POAG; however, further studies with larger sample size in different population are require to clarify the role of FABP2 and FTO genes in susceptibility to POAG.

Assessing effect of interaction between the FTO A/T polymorphism (rs9939609) and physical activity on obesity-related traits

BackgroundThe first described obesity-susceptibility gene was the fat mass and obesity-associated (FTO) gene. However, knowledge about FTO's potential modifying effect on changes in body weight achieved through a training program is still limited. We decided to study the association between the FTO A/T polymorphism (rs9939609) and obesity-related traits. Additionally, we investigated whether body mass and body composition, as well as metabolic variables observed in physically active participants, are modulated by the FTO polymorphism. MethodsA group of 201 young Polish women were recruited for the study. The genotype distribution was examined in participants measured for selected changes before and after the completion of a 12-week training program. ResultsOur results confirm the association between the common FTO A/T polymorphism and increased body mass index (BMI). Subjects with AA and AT genotypes had higher BMI during the entire study period compared with the TT genotype. Although parameters such as BMI, basal metabolism rate, tissue independence, fat mass percentage, fat mass, fat-free mass, total body water, high-density lipoprotein, and glucose changed significantly during the training program, none of the examined parameters changed significantly across the FTO genotypes (genotype × training interaction). ConclusionWe confirm an association between the FTO A/T polymorphism and increased BMI; this polymorphism is therefore a candidate for influencing obesity and other disease-related phenotypes. Although the gene × physical activity interaction was not shown, we want to point out that promoting physical activity is an important approach to controlling the increasing obesity epidemic.

Genetic susceptibility for insulin resistance among Egyptian women.

The fat mass and obesity-associated (FTO) gene is recognized as the strongest predictor of obesity related traits such as insulin sensitivity and plasma glucose. The aim of this study was to investigate the association of the FTO rs17817449 genetic variant (G > T) polymorphism with risk of insulin resistance (IR) among Egyptian women. The variants in FTO rs17817449 were genotyped in 301 Egyptian women comprising two study groups, 150 women with IR and 151 healthy controls. The polymorphism of FTO rs17817449 was tested for association with IR. The frequencies of the FTO genotypes differed significantly between IR patients and healthy controls. Results revealed a significant association of TT genotype (OR, 2.33; 95% CI, 1.38–3.92; p = .001) and T-allele (OR, 1.55; 95% CI, 1.11–1.72; p .007) with IR. BMI, waist circumference, waist to hip and, body fat % were the highest in homozygotes TT genotype and the lowest in GG homozygotes in IR women but not observed in control subjects. Moreover, other abnormal metabolic risk parameters were significantly higher in TT carriers compared to GT and GG carriers in IR group. Association between FTO SNP (rs17817449) and IR was observed under recessive model.ConclusionThe present study suggests that FTO rs17817449 may have an important role in development of IR in Egyptian women.

FTO genotype and weight loss in diet and lifestyle interventions: a systematic review and meta-analysis

Studies have suggested that the fat mass and obesity-associated (FTO) genotype is associated with individual variability in weight loss in response to diet/lifestyle interventions, but results are inconsistent. We aimed to provide a summary of the literature evaluating the relation between the FTO genotype and weight loss in response to diet/lifestyle interventions. A search of English-language articles in the PubMed and Embase databases (through 30 April 2015) was performed. Eligible studies were diet/lifestyle weight-loss intervention studies conducted in adults that reported changes in body weight or body mass index (BMI) by the FTO variant rs9939609 (or its proxy). Differences in weight loss between FTO genotypes across studies were pooled with the use of fixed-effect models. A meta-analysis of 10 studies (comprising 6951 participants) that reported the results of additive genetic models showed that individuals with the FTO TA genotype and AA genotype (those with the obesity-predisposing A allele) had 0.18-kg (95% CI: -0.09-, 0.45-kg;P= 0.19; NS) and 0.44-kg (95% CI: 0.09-, 0.79-kg;P= 0.015) greater weight loss, respectively, than those with the TT genotype. A meta-analysis of 14 studies (comprising 7700 participants) that reported the results of dominant genetic models indicated a 0.20-kg (-0.43-, 0.04-kg) greater weight loss in the TA/AA genotype than in the TT genotype (P= 0.10). In addition, differences in weight loss between the AA genotype and TT genotype were significant in studies with a diet intervention only, adjustment for baseline BMI or body weight, and several other subgroups. However, the relatively small number of studies limited these stratified analyses, and there was no statistically significant difference between subgroups. This meta-analysis suggests that individuals carrying the homozygous FTO obesity-predisposing allele may lose more weight through diet/lifestyle interventions than noncarriers. Our data provide evidence for genetic variability in response to diet/lifestyle interventions on weight loss, although clinical applications of these findings need further investigations.

Physical activity and FTO genotype by physical activity interactive influences on obesity.

BackgroundAlthough the effect of the fat mass and obesity-associated (FTO) gene on adiposity is well established, there is a lack of evidence whether physical activity (PA) modifies the effect of FTO variants on obesity in Latino populations. Therefore, the purpose of this study was to examine PA influences and interactive effects between FTO variants and PA on measures of adiposity in Latinos.ResultsAfter controlling for age and sex, participants who did not engage in regular PA exhibited higher BMI, fat mass, HC, and WC with statistical significance (P < 0.001). Although significant associations between the three FTO genotypes and adiposity measures were found, none of the FTO genotype by PA interaction assessments revealed nominally significant associations. However, several of such interactive influences exhibited considerable trend towards association.ConclusionsThese data suggest that adiposity measures are associated with PA and FTO variants in Latinos, but the impact of their interactive influences on these obesity measures appear to be minimal. Future studies with large sample sizes may help to determine whether individuals with specific FTO variants exhibit differential responses to PA interventions.Electronic supplementary materialThe online version of this article (doi:10.1186/s12863-016-0357-6) contains supplementary material, which is available to authorized users.