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Background: Preeclampsia (PE) is one of the leading disorders in pregnant women with maternal and fetal complications. Obesity is considered an important risk factor for the development of PE. Genetic variations in fat mass and obesity associated (FTO) gene may play a role in the development of PE. This study aimed to investigate the possible association between FTO gene rs9939609 and PE risk in a sample of Iranian pregnant women., Material and Methods: In this case-control study, 312 pregnant women were included, including 128 with PE and 184 without PE. Demographic data and blood samples were obtained from all individuals. The genotyping of rs9939609 polymorphisms was performed by the tetra-primer amplification refractory mutation system-polymerase chain reaction (TP-ARMS-PCR) method, and the results of TP-ARMS-PCR were confirmed using DNA sequencing., Results: The genotype frequency was 50%, 47.7%, and 2.3% in pregnant patients and 37%, 47.8%, and 15.2% in healthy controls for TT, AT, and AA, respectively. The risk of PE was significantly reduced in the pregnant women having the AA genotype., Conclusion: Based on the results of the present study, rs9939609 polymorphism in the FTO gene may play a protective role against PE. However, further studies are warranted. [Figure: see text].

Background: Single Nucleotide Polymorphisms (SNPs) of the Fat mass and obesity-associated (FTO) gene may be associated with obesity by regulating appetite. The present study aimed to investigate the relationship between FTO genotype and resistance to eating in male adolescents., Methods: The present cross-sectional study included 246 adolescent boys in Tehran, Iran, who were assessed for self-efficacy related to weight control using the Weight Efficacy Lifestyle (WEL), questionnaire, food intake using the Food Frequency Questionnaire (FFQ), physical activity using the International Physical Activity Questionnaire (IPAQ), and anthropometric indices using Bio-Impedance Analyzer (BIA). Moreover, the participants underwent genotyping for the rs9930506 polymorphism of the FTO gene, and the relationship between FTO genotype and resistance to eating was investigated using different models of multiple linear regression., Results: According to our findings, there was a significant reverse relationship between the FTO rs9930506 genotype and resistance to eating (β: -0.16, P = 0.01). Moreover, the relationship was still significant after adjusting for age, nutritional knowledge, BMI, and mother's BMI, educational level, and occupational status., Conclusion: According to our results, the FTO genotype had a significant effect on resistance to eating and food desires. However, there is a need for further studies to evaluate the underlying mechanisms of the effects of the FTO gene on appetite and obesity., (© 2023. The Author(s).)

Background: Obesity and body composition may be affected by the pro-inflammatory and anti-inflammatory components of diets. The aim of this study was to investigate associations between the dietary inflammatory index (DII) and body fat percentage (BF%) in male adolescents., Methods: This cross-sectional study was carried out on 535 adolescent boys in Tehran, Iran. Bio-impedance analyzer (BIA) scale was used to measure body mass index (BMI) and body composition. A validated semi-quantitative food frequency questionnaire (FFQ) was used to measure DII., Results: Participants with higher BF% (≥ 19.2%) had higher BMI (P < 0.001), DII, and intake of saturated fatty acids (SFAs), compared with the participants with lower BF%. Participants with a lower DII had significantly higher intakes of fibers (P < 0.001) and lower intakes of fats, SFAs, monounsaturated fatty acids (MUFAs), polyunsaturated fatty acids (PUFAs), oleic acid and linoleic acid (P < 0.05) compared with the participants with higher DII (P < 0.01). High BF% was positively associated to DII (OR = 1.6, CI 95%: 1.1-2.3, P = 0.019). Adjustments for age, BMI, physical activity, mothers' marital status and educational level and the number of siblings did not change the results., Conclusions: Following a diet with a low inflammatory index score was associated to lower BF% in male adolescents. Thus, a diet rich in anti-inflammatory factors may effectively improve body composition and prevent obesity in adolescents. Further comprehensive studies are necessary to verify these findings and to identify the underlying mechanisms., (© 2022. The Author(s).)

Dietary factors may play a key role in the etiology of obesity. The Index of Nutritional Quality (INQ) provides a comprehensive overview of the nutrients content of the diet. This study aimed to investigate the association between INQ and obesity in male adolescents. We hypothesize that receiving a high-quality diet reduces the risk of overweight or obese. This study was carried out on 214 obese/overweight as the case group and 321 normal-weight male adolescents as the control group. Dietary intakes of the participants were collected using a food frequency questionnaire (FFQ). The FFQ-derived dietary data were used to calculate the INQ scores. After adjustments for age and height, an inverse association was found between obesity and INQ of iron, vitamin B6, and magnesium, and a positive association was found between obesity and INQ of zinc (all P < 0.05). After further adjustments for nutritional knowledge and calorie intake, an inverse association was observed between obesity and INQ of vitamin C, iron, vitamin B6, pantothenic acid, selenium, and magnesium (all P < 0.05). The positive association of obesity and INQ of zinc remained significant after adjustments. A higher intake of vitamin C, iron, vitamin B6, pantothenic acid, selenium, and magnesium and a lower intake of zinc may be protective against adolescent obesity. More longitudinal studies are required to investigate the relationship between these nutrients and obesity.

Introduction: There is lack of data about the combination of multiple approaches to control being overweight and obesity in adolescents. This study aimed to evaluate the effect of a combination program including smart-phone nutrition education, physical activity, and cognitive behavioral therapy (CBT) programs in the management of obesity and overweight among elementary school girls in comparison with a traditional education method., Material and Methods: The primary outcome of this study is the assessment of changes in anthropometric data after 10 weeks. The secondary outcome is investigating the effect of treatment on biochemical data. Sixty-two elementary school girls aged 9-12 years with the body mass index (BMI) for age above 85th percentile will be chosen and randomly assigned to one of the two groups of control or intervention. During the 10 weeks of the intervention, smartphone games will be given to the children with some information at the beginning about the causes and complications of obesity, food sources of fiber and vitamins, and banned foods during the intervention period. Students in the intervention group will participate in an aerobics exercise for 45 minutes three times per week under the supervision of an experienced trainer and eight CBT Sessions which were designed for children by a clinical psychologist. Anthropometric measurements, including height, weight, waist circumference (WC), hip circumference and waist to hip ratio(WHR), and biochemical and metabolic lab data, including fasting blood sugar (FBS), total cholesterol, high density lipoproteins (HDL), low density lipoproteins (LDL), leptin and will be measured at the baseline and 10 weeks later at the end of intervention period . Also, both questionnaires of metabolic equivalent test (MET) and Dutch Eating Behavior Questionnaire (DEBQ) will be completed for each student at baseline and after 10 weeks. The students in the control group will receive traditional education in the form of lectures given by a nutritionist regarding weight management., Discussion: The primary outcome of this study is the assessment of changes in anthropometric data after 10 weeks. The secondary outcome is investigating the effect of treatment on biochemical data. Sixty-two elementary school girls aged 9-12 years with the body mass index (BMI) for age above 85th percentile will be chosen and randomly assigned to one of the two groups of control or intervention. During the 10 weeks of the intervention, smartphone games will be given to the children with some information at the beginning about the causes and complications of obesity, food sources of fiber and vitamins, and banned foods during the intervention period. Students in the intervention group will participate in an aerobics exercise for 45 minutes three times per week under the supervision of an experienced trainer and eight CBT Sessions which were designed for children by a clinical psychologist. Anthropometric measurements, including height, weight, waist circumference (WC), hip circumference and waist to hip ratio(WHR), and biochemical and metabolic lab data, including fasting blood sugar (FBS), total cholesterol, high density lipoproteins (HDL), low density lipoproteins (LDL), leptin and will be measured at the baseline and 10 weeks later at the end of intervention period . Also, both questionnaires of metabolic equivalent test (MET) and Dutch Eating Behavior Questionnaire (DEBQ) will be completed for each student at baseline and after 10 weeks. The students in the control group will receive traditional education in the form of lectures given by a nutritionist regarding weight management.

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.

The various studies have examined the relationship between FTO gene expression and macronutrients levels. In order to obtain better viewpoint from this interactions, all of existing studies were reviewed systematically. All published papers have been obtained and reviewed using standard and sensitive keywords from databases such as CINAHL, Embase, PubMed, PsycInfo, and the Cochrane, from 1990 to 2016. The results indicated that all of 6 studies that met the inclusion criteria (from a total of 428 published article) found FTO gene expression changes at short-term follow-ups. Four of six studies found an increased FTO gene expression after calorie restriction, while two of them indicated decreased FTO gene expression. The effect of protein, carbohydrate and fat were separately assessed and suggested by all of six studies. In Conclusion, The level of FTO gene expression in hypothalamus is related to macronutrients levels. Future research should evaluate the long-term impact of dietary interventions., (Copyright © 2017. Published by Elsevier B.V.)

Background: The FTO gene polymorphisms may influence the effects of lifestyle interventions on obesity. The present study aimed to assess the influence of the rs9930506 FTO gene polymorphism on the success of a comprehensive weight loss intervention in male adolescents with overweight and obesity. Methods: This study was carried out on 96 adolescent boys with overweight and obesity who were randomly assigned to the intervention (n = 53) and control (n = 43) groups. The blood samples of the participants were collected, and the FTO gene was genotyped for the rs9930506 polymorphism. A comprehensive lifestyle intervention including changes in diet and physical activity was performed for 8 weeks in the intervention group. Results: Following the lifestyle intervention, BMI and fat mass decreased significantly in the intervention group compared with the control group (both p < 0.05), while no change was found in weight, height or body muscle percentage between the groups. The participants in the intervention group with the AA/AG genotype and not in carriers of the GG genotype had a significantly higher reduction in BMI (−1.21 vs. 1.87 kg/m2, F = 4.07, p < 0.05) compared with the control group. Conclusion: The intervention in individuals with the AA/AG genotype has been significantly effective in weight loss compared with the control group. The intervention had no association effect on anthropometric indices in adolescents with the GG genotype of the FTO rs9930506 polymorphism. Trial Registration: Name of the registry: National Nutrition and Food Technology Research Institute; Trial registration number: IRCT2016020925699N2; Date of registration: 24/04/2016; URL of trial registry record: https://www.irct.ir/trial/21447 [ABSTRACT FROM AUTHOR]

Background: Despite the confirmed association between higher BMI with increased risk of the acute respiratory distress syndrome (ARDS), the association between obesity with mortality in critically ill patients with coronavirus disease 2019 (COVID‐19) is not clear. The present study aimed to investigate the association between obesity with treatment duration, ICU length of stay, and the risk of death in critically ill patients with COVID‐19. Methods: This case–control study was performed on 223 patients with COVID‐19 including 148 surviving patients as the control group and 75 eventually dead patients as the case group in Rasht, Iran. Data on demographic factors, comorbidities, anthropometric measurements, the length of hospitalization and the mortality were obtained from patients' medical records. Results: The mortality rate was significantly associated with weight (OR = 1.04, 95% CI: 1.002–1.083, p =.04), but not with BMI after adjustments for age, gender, length of stay in ICU, chronic diseases and smoking. The results did not change after further adjustments for biochemical and pathological factors. Conclusions: Weight was positively associated with mortality after controlling for confounding variables. Further studies should consider the patient's body composition such as fat mass to establish the relationship between obesity and COVID‐19 outcomes. [ABSTRACT FROM AUTHOR]

Background: Colorectal cancer (CRC) is one of the most common cancers in the world. Some dietary factors such as fat intake have been identified as the risk factors for CRC. This study aimed to investigate the effect of fat mass and obesity-associated (FTO) gene rs9939609 polymorphism on the association between CRC and different types of dietary fats. Methods: This case-control study was performed on 135 CRC cases and 294 healthy controls in Tehran, Iran. Data on demographic factors, anthropometric measurements, physical activity, the intake of different types of dietary fats, and FTO gene rs9939609 polymorphism was collected from all participants. The association between cancer and dietary fat intake in individuals with different FTO genotypes was assessed using different models of logistic regression. Results: Oleic acid intake was higher in the case group compared to the control group in both people with TT (7.2±3.46 vs. 5.83±3.06 g/d, P=0.02) and AA/AT genotypes (8.7±6.23 vs. 5.57 ±3.2 g/d, P<0.001). Among carriers of AA/AT genotypes of FTO rs9939609 polymorphism, a positive association was found between CRC and higher intakes of oleic acid (OR=1.12, CI95% 1.03–1.21, P=0.01) and cholesterol (OR=1.01, CI95% 1.00–1.02; P=0.01) after adjusting for age, sex, physical activity, alcohol use, smoking, calorie intake, and body mass index. Conclusion: Higher intakes of cholesterol and oleic acid were associated with a higher risk of CRC in FTO-risk allele carriers. The association of CRC and dietary fat may be influenced by the FTO genotype. Further longitudinal studies are warranted to confirm these findings. [ABSTRACT FROM AUTHOR]

Background: Dietary antioxidants may decrease body fat through reduction of oxidative stress. This study aimed to examine the association between dietary antioxidant index (DAI) and body mass index (BMI) in adolescent boys. Methods: In this cross‐sectional study, 593 adolescent boys aged 12–16 years were randomly selected and were divided into two groups of overweight and non‐overweight individuals. Data on physical activity and anthropometric measurements were collected. Dietary intake was assessed using 168‐item semi quantitative food frequency questionnaire and the DAI score was calculated to measure the antioxidant capacity of the diet. Results: The overweight adolescents had higher intake of energy (2490.55 ± 632.49 vs. 2354.33 ± 632.64 kcal/d, p = 0.01), carbohydrate (290.21 ± 71.41 vs. 272.93 ± 79.22 g/d, p = 0.01), fat (111.51 ± 40.76 vs. 104.51 ± 35.56 g/d, p = 0.04), calcium (811.70 ± 283.70 vs. 741.06 ± 251.17 g/d, p = 0.003), and vitamin D (1.41 ± 1.17 vs. 1.18 ± 1.19 μg/d, p = 0.031) in comparison with normal weight adolescents. The DAI had an inverse association with BMI after adjustment for age and caloric intake (OR: 0.85, 95% CI: 0.76–0.96, p = 0.009). Additional adjustment for dietary intake of vitamin A, vitamin E, vitamin C, zinc, manganese, and selenium did not change the results. Conclusion: The results of the study showed that following a diet rich in antioxidants may be effective in preventing obesity in adolescent boys. Further longitudinal studies are needed to confirm these finding and to determine the underlying mechanisms. [ABSTRACT FROM AUTHOR]

Background: Obesity‐induced inflammation may independently disturb the function of critical organs such as liver. This study aimed to investigate the association of obesity with serum levels of biomarkers of liver function including alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and gamma‐glutamyl transferase (GGT) in adult women. Methods: This cross‐sectional study was carried out on 360 adult women in the summer of 2020 in Tehran, Iran. The participants were categorized into two groups based on their body mass index (BMI≤29.9 and BMI > 30). The serum levels of ALT, AST, ALP and GGT were measured. Logistic regression method was used to assess the association between BMI and liver enzymes after adjusting for the confounders. Results: The mean BMI in non‐obese and obese groups was 26.32 ± 2.61 and 33.40 ± 2.80 kg/m2, respectively (p =.01). A significant association was found between BMI with ALT (β =.16, p =.002) and GGT (β =.19, p =.01) enzymes after adjustment for age. The association between BMI and GGT remained significant after further adjustments for smoking, alcohol use, physical activity and educational status. There was no significant association between BMI and liver enzymes after adjustment for dietary intake. Conclusions: Obesity was associated with the level of serum liver enzymes. However, adjustment for dietary intake disappeared the significant results. Further studies are needed to determine the independent effects of obesity on the liver function. [ABSTRACT FROM AUTHOR]

Background: Despite the significant role of the Fat Mass and Obesity-Associated (FTO) gene in obesity, the underlying mechanisms are not fully elucidated. Besides, vitamin D deficiency and obesity are mostly seen together, and it can be hypothesized that this nutrient may have an impact in the role of FTO genotype in adiposity. Objective: Thus, this study aimed to investigate the association of FTO rs9939609 gene polymorphism with eating behaviors, eating disorders, and general mental health in overweight adults, considering their vitamin D intake as a mediate confounding factor. Methods: This cross-sectional study was carried out on 197 overweight adults in Shiraz, Iran. Genotyping was performed through amplification refractory mutation system polymerase chain reaction (ARMS PCR). Mental health, vitamin D intake, eating behaviors and disorders were assessed by the validated questionnaires. Results: The risk allele of the FTO rs9939609 polymorphism (A) was significantly associated with a higher risk of eating behavior and mental health disorders (all P < 0.05). After considering vitamin D intake, the AA genotype carriers had significantly higher risks for poorer eating behavior (P = 0.002), mental health (P = 0.007), and general mental health (P = 0.039) compared with the TT carriers if they had insufficient vitamin D intake. Conclusion: In conclusion, these results indicated that the A-allele of the FTO rs9939609 polymorphism may be associated with poorer eating behaviors, mental health, and higher risk of eating disorders. It was also identified that the effect of FTO rs9939609 A risk allele on eating behavior and mental health may be limited to people with insufficient vitamin D intake. [ABSTRACT FROM AUTHOR]

Background. The prevalence of childhood obesity is increasing worldwide and can affect their linear growth through various mechanisms. Objectives. We aimed to investigate the association between obesity-related traits and height in adolescents. Material and methods. This was a categorized cross-sectional study carried out on 186 students (93 case and 93 control) 15 to 18 years of age who were randomly selected from three schools in Shiraz, Iran. Anthropometric indices including height, weight, body mass index (BMI), body fat percentage (BF) and body muscle percentage (BM) were measured. Statistical analysis was done by SPSS software (Version 16). A significance level was considered as being less than 0.05. Results. We found an inverse association for waist circumference (WC) and fat mass with height. In addition, there was a direct relationship between fat-free mass and trunk fat with height. The mean height of participants in the obesity group was significantly lower than the control group (p = 0.04). Participants in the obesity group had significant higher FM percentage (p < 0.001) and WC (p < 0.001) than the control group. There was a significant correlation between height and WC (p = 0.003), as well as between height and fat percentage (p < 0.001). We also found a direct relationship between fast-free mass and height (p < 0.001), as well as between trunk fat percentage and height (p = 0.026). We have suggested an equation to estimate adolescents’ height based on the anthropometric indices. Conclusions. Adiposity, especially central adiposity, is adversely associated with height. However, muscle percentage might reinforce linear growth. Further studies are warranted to confirm this finding. [ABSTRACT FROM AUTHOR]

Introduction: The prevalence of both obesity and vitamin D deficiency has been dramatically increased worldwide. Aim of the study: This study aimed to investigate the association between vitamin D serum level and anthropometric indices of overweight and obese male adolescents at baseline and after 18 weeks of a weight reduction intervention. Methods: This study was carried out on 90 male students aged 12 to 16 years who were randomly selected from two schools in Tehran, Iran. The participants were assigned to two groups with high and low vitamin D level based on their serum vitamin D levels at baseline. Five ml blood samples were collected at the baseline and after the 18 weeks of a weight reduction intervention. Height, weight, body mass index (BMI), body fat percent and body muscle percent were measured using a bio impedance analysis (BIA) scale. Results: Vitamin D level in non-obese adolescents was significantly higher than the obese participants (44.01 vs 37.67 ng/dl, p < 0.04). However, there was no significant correlation between changes of vitamin D level and anthropometric measurements after 18 weeks. Adjusting the effect of age did not alter the association. Further adjustments for physical activity, dietary intake of vitamin D, and fat and muscle percentage had no effect on the results. Conclusion: The serum level of vitamin D was negatively associated with obesity, but not with short-term changes of anthropometric measurements in male adolescents. [ABSTRACT FROM AUTHOR]

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 a valid 168-item semiquantitative 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. [ABSTRACT FROM AUTHOR]

Introduction: The modifying effect of FTO gene expression level on change in body mass index and body composition has not been studied before. This study aimed to investigate the association between change in the expression level of the FTO gene and changes in anthropometric measurements in obese and overweight adolescent boys.Material and Methods: Eighty-four boys aged 12 to 16 years participated in this longitudinal study. A Bio Impedance Analyzer (BIA) was used to estimate percentage of body fat (%BF) and percentage of skeletal muscle (%SM). The FTO gene expression level in peripheral blood mononuclear cells was assessed using quantitative real-time PCR (qPCR). All measurements were performed at baseline and after 18 weeks.Results: After 18 weeks, mean weight was reduced by 2.39 kg, body mass index by 0.09 kg/m2, %BF by 0.82% and %SM increased by 0.44%. Moreover, the level of FTO gene expression increased 0.42-fold higher than baseline. The change in expression level of the FTO gene was positively associated with change in %SM (β = 0.31, p = 0.02).Conclusions: FTO gene expression change was associated with change in %SM in male adolescents. Future studies are required to assess the interactions between FTO gene expression in different tissues and body composition. [ABSTRACT FROM AUTHOR]

Background and Objectives: Although a growing interest on the role of self-efficacy in weight management is reported worldwide, less research has been carried out on this association in adolescents. The aim of the present study was to investigate association of weight linked self-efficacy with anthropometric measurements in Tehrani male adolescents. Materials and Methods: The study was carried out on 535 male students aged 12-16 years old from two secondary high schools of District 5, Tehran, Iran. Weight, body mass index (BMI), body fat percentage and body muscle percentage were measured using bio impedance analyzer (BIA) scale. A validated weight efficacy lifestyle questionnaire (WEL) was used to assess weight linked self-efficacy. Results: The higher weight linked self-efficacy was significantly associated with further body muscle percentage (P<0.05). However, no significant association was seen between the self-efficacy and weight, height, BMI and body fat percentage of the male adolescents. Conclusions: Results of the current study suggest that self-efficacy for weight management may be unlinked to specific measures of obesity, while male adolescents with a higher self-efficacy in weight management may have a higher muscle mass. Further research is necessary to verify effects of self-efficacy on anthropometric indices in male adolescents. [ABSTRACT FROM AUTHOR]

Introduction: Recent studies reported that FTO exert its effects on body weight through change the expression IRX3. The aim of this study was investigation of the possible mechanisms of the effects of IRX3 gene on obesity. Material and methods: The present review was carried out using keywords such as polymorphism and/or obesity and/or BMI and/or IRX3 gene and/or Iroquois homeobox protein 3. Databases including PubMed, Science Direct, web of sciences, Scopus, and Cochran databases were used to collect all related articles published from 2000 to 2019. Results: Based on this review, there are some evidences on the association between the IRX3 polymorphisms and the IRX3 expression level with body weight. In some studies, the up-regulation of IRX3 expression was related to increased body weight, while in some other studies down-regulation of IRX3 expression was related to obesity. Conclusions: This review investigated the probable mechanisms of the effects of the IRX3 gene on obesity. Studies in this are limited and reported contradictory results. Further studies are required to evaluate the role of IRX3 gene in the associations between genes, diet, and obesity. [ABSTRACT FROM AUTHOR]

Background: Single-nucleotide polymorphisms (SNPs), which are located in the first intron of the FTO gene, are reported to be associated with body weight and the body mass index (BMI). However, their effects on anthropometric measurements in adolescents are poorly understood. Objective: This study aimed to investigate the association of three adjacent polymorphisms (rs9930506, rs9930501, & rs9932754) in the FTO gene with anthropometric indices in Iranian adolescent males. Design: The participants comprised a total of 237 adolescent males who were recruited randomly from two high schools in Tehran, Iran. The DNA samples were genotyped for the FTO gene polymorphisms by DNA sequencing. BMI, body fat percentage (BF%), and body muscle percentage (BM%) were determined using a validated bioelectrical impedance analysis scale. The association of the FTO polymorphisms with weight, height, BMI, BF%, and BM% was investigated. Results: A haplotype of rs9930506, rs9930501, and rs9932754 (GGT) in the first intron of the FTO with complete linkage disequilibrium (LD) was found to be significantly associated with higher weight (OR = 1.32), BMI (OR = 5.36) and BF% (OR = 1.46), and lower BM% (OR = 3.59) (all P<0.001). None of the students with GGC genotypes were underweight, while all of the students with AAT genotypes had high muscle mass. Conclusions: A haplotype in the first intron of the FTO gene had a strong association with obesity indices in Iranian adolescent males. The FTO gene polymorphisms might have greater effects on anthropometric indices than what was previously imagined. Moreover, we suggested that the FTO gene exerted their effects on anthropometric measurements through haplotypes (and not single SNPs). [ABSTRACT FROM AUTHOR]

BACKGROUND: The prevalence of obesity is influenced by environmental and genetic factors. Recently, it has been reported that an interaction between genotype and environmental factors can affect each other's effects on the phenotype. The purpose of this study is to evaluate the recent studies on the fat mass and obesity-associated (FTO) gene interactions with environmental factors affecting on obesity and the impact of these interactions on the success level of the lifestyle intervention. METHODS: All articles published in English from June 1990 to June 2015 were studied. RESULTS: In most studies, the role of the FTO risk alleles for obesity is significantly intensified through reduced physical activity and high calorie diet. Furthermore, the results of studies about the effect of FTO on the success level of lifestyle interventions have been contradictory. Some studies show that FTO genotype influences on the success of lifestyle interventions, while other studies did not report it. CONCLUSION: The results of these studies generally indicate that the effect of the FTO gene on obesity may be influenced by environmental factors and lifestyle. In the other hand, the FTO genotype can affect the success of lifestyle interventions in the prevention and treatment of obesity. Future studies are crucial to elucidate relationships between FTO gene and lifestyle. [ABSTRACT FROM AUTHOR]

The role of FTO genotype in the effect of FTO gene expression level on change in body mass index and body composition has not been studied. This study aimed to investigate the role of FTO genotype in the association between change in the expression level of the FTO gene with changes in anthropometric measurements in obese and overweight adolescent boys. Eighty-four boys aged 12 to 16 years participated in this longitudinal study. A bioimpedance analyzer (BIA) was used to estimate percentage of body fat (%body fat) and percentage of skeletal muscle (%skeletal muscle). The FTO gene expression level in peripheral blood mononuclear cells (PBMCs) was assessed using quantitative Real Time PCR (qPCR). The DNA samples were genotyped for the FTO gene polymorphisms by DNA sequencing. All measurements were performed at baseline and after intervention. A significant association was observed between the level of gene expression and %skeletal muscle. The gene expression fold change was significantly associated with change in %skeletal muscle in AA or AG genotype carriers (β = 0.34, p = .02). No significant association was detected between the change in FTO gene expression with change in anthropometric indices in GG genotype carriers. In conclusion, the association between FTO gene expression and body composition can be influenced by FTO genotype. Future studies are required to assess the interactions between FTO genotype, FTO gene expression in different tissues, and body composition. [ABSTRACT FROM AUTHOR]