Associations between FTO rs9939609 polymorphism, serum vitamin D, mental health, and eating behaviors in overweight adults.

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.

The antiviral immune defense may be adversely influenced by weight loss through a calorie restriction program in obese women.

BACKGROUND: Obesity and weight loss are reported to be associated with immune function. This study aimed to investigate the changes in counts of lymphocytes involved in microbial defense during weight loss in obese women. METHODS: This clinical trial involved 29 women with a body mass index (BMI) ≥ 30 kg/m2. The intervention group was prescribed a low-calorie diet (600 kcal lower than caloric requirement per day) plus Orlistat (120 mg three times daily). The control group received ad libitum diet. Anthropometric indices, obesity-related traits, and blood pressure were assessed every three weeks. Metabolic indices and plasma count of lymphocyte subpopulations (CD3, CD4, CD8, CD19, and CD16/56, as well as the ratio of CD4:CD8) were measured at baseline and after the intervention (after 10% weight loss). RESULTS: After the weight loss, natural killer cells (CD16/56) decreased in the intervention group (P=0.014) even after adapting for all confounders. No significant changes were observed in other immune markers compared to the control group. CONCLUSIONS: Caloric restriction-induced weight loss might independently weaken the antiviral immune defense. Further clinical trials are warranted to better clarify the association between weight loss, calorie restriction, and immunity.

Does vitamin D affect the association between FTO rs9939609 polymorphism and depression?

Background & objectives: Depression is a highly prevalent and multifactorial psychological disorder. Fat Mass and Obesity-Associated (FTO) gene and the serum vitamin D level are proposed to be involved in pathophysiology of depression. This study aimed to investigate the interactions between one FTO gene single nucleotide polymorphism, depression, and serum vitamin D level in overweight adults.Methods: One hundred and ninety-seven overweight adults were recruited in this cross-sectional study. FTO genotyping was performed by amplification refractory mutation system polymerase chain reaction (ARMS-PCR). Depression severity was assessed using Beck's depression inventory (BDI-II). Serum vitamin D levels were measured using a direct competitive enzyme-linked immunosorbent assay (ELISA) method.Results: A-allele carriers had higher Beck's depression score (P = 0.03). Multivariate regression models showed a positive association between the A-allele of FTO rs9939609 polymorphism and depression. Serum vitamin D level had no effect on the association between FTO genotype and depression.Conclusion: A-allele of FTO rs9939609 polymorphism might be associated with depression independent of serum vitamin D level. Further longitudinal studies are needed to confirm these results.

High dietary inflammatory index (DII) scores increase odds of overweight in adults with rs9939609 polymorphism of FTO gene.

BACKGROUND: Obesity/overweight is a public health problem globally. Dietary induced inflammation is among the most critical risk factors modulating overweight/obesity. Some people genetically are at higher risk for obesity/overweight. The first gene contributing to conventional forms of human obesity is the FTO gene. The associations between genes like the FTO, inflammation, and obesity/overweight have been investigated in limited studies. We aimed to investigate the association between the dietary inflammatory index (DII) and odds of obesity/overweight in adults with rs9939609 polymorphism of the FTO gene. METHODS: A valid 168-item semi-quantitative food frequency questionnaire was used to assess dietary intake. To investigate the role of diet in the development of inflammation, we used the DII, which is predictive of serum inflammatory markers' levels. The Inclusion criteria were defined as body mass index (BMI) from 24.9 to 29.9 kg/m2, age from 20 to 45 years, not participating in a weight management program during two past months, and no weight loss greater than 5%. We determined the genotypes of FTO rs9939609 polymorphism via amplification refractory mutation system polymerase chain reaction (ARMS-PCR) in a retrospective chart review. RESULTS: Results obtained from modeling the DII as a continuous variable and odds of obesity/overweight showed a significant association after multivariate adjustment for sex, height, fat mass, systolic blood pressure (SBP), and total energy intake (OR = 2.83 CI = 1.16-6.91). In addition, logistic regression models with the DII as a dichotomous variable adjusting for sex, height, fat mass, SBP, and total energy intake showed subjects with the DII score<0.49 were at 2.5 times higher odds of having overweight compared to subjects with the DII ≥0.49 (ORDII<0.49/≥0.49 = 2.44 CI = 1.12-5.32). CONCLUSION: Dietary induced inflammation significantly is related to odds of overweight in adults with rs9939609 polymorphism of the FTO gene. Suggesting an anti-inflammatory diet containing vitamins and minerals such as vitamin A, thiamine, niacin, and zinc, manganese, and selenium and recommending a reduction in the most inflammatory factors of diet, including saturated and trans fatty acids, could be a new strategy in the treatment and or controlling of obesity/overweight as a public health problem.

The association between FTO genotype with macronutrients and calorie intake in overweight adults.

BACKGROUND: Dietary macronutrients may indirectly affect body weight through their interactions with the fat mass and obesity associated (FTO) gene. This study aimed to investigate the association between FTO gene rs9939609 polymorphism with macronutrients intake in overweight adults. METHODS: This study was carried out on 196 overweight adults of Shiraz, Iran. Dietary intake was assessed using a validated 168-item semi-quantitative food frequency questionnaire (FFQ). The FTO gene was genotyped for rs9939609 polymorphism. The association between dietary macronutrients and the FTO genotype were assessed using linear regression after adjustments for sex, age, physical activity, and the serum levels of triglycerides, fasting blood sugar (FBS), and low density lipoprotein (LDL). RESULTS: The higher intake of carbohydrates (P < 0.001), fat (P = 0.009), and calorie (P = 0.001) were significantly associated with rs9939609 AA genotype (P = 0.001). Carriers of the AA genotype of rs9939609 had significantly higher calorie, fat, and carbohydrate intake than the carriers of the TT genotype after adjusting for age and sex (P = 0.019, P = 0.010 and P = 0.001, respectively). Further adjustments for physical activity, TG, LDL, and FBS did not change these results. CONCLUSION: The amounts of dietary calorie, carbohydrate, and fat intake were associated with FTO genotype. Further studies are warranted to confirm these associations and to identify the underlying mechanisms.

Nutritional Quality's Key Role in the Odds of Overweight in Adults with rs9939609 Polymorphism of FTO Gene- the Role of Manganese and Vitamin D.

BACKGROUND: Obesity and overweight are the most prevailing problem in most countries. Overweight people are very susceptible to diseases such as diabetes, hypertension, cardiovascular disease, metabolic syndrome, and cancers. Adequate intake of micronutrients along with a quality diet that is varied and balanced plays an important role regarding health and the immune system. Numerous studies have investigated the relationship between the quality of diet and different diseases. Genetics is a risk factor of great importance regarding obesity and overweight. Yet, the role of nutrition in relationship with the underlying mechanisms remains unclear and no specific pathways have been identified for this relation. METHODS: A valid food frequency questionnaire was employed to assess dietary intake. We calculated the INQ (Index of Nutritional Quality) of each dietary item using the following formulae: INQ=consumed amount of a nutrient per 1,000 kcal/recommended dietary allowance or adequate intake of that nutrient per 1,000 kcal. In a retrospective chart review, we determined the genotypes of FTO rs9939609 polymorphism (TT/AT/AA) via amplification refractory mutation system-polymerase chain reaction (ARMS-PCR). RESULTS: Models obtained from the resulting INQs of manganese as a continuous variable in relationship with waist circumference represented a significant association after multivariate adjustment of age, sex, height, fat free mass, weight, body mass index, marital status, TF, fasting blood sugar, low-density lipoproteins, high-density lipoproteins, total cholesterol, insulin resistance, and total energy intake (odds ratio = 0.24, CI = 0.07-0.79). CONCLUSIONS: Intake of vitamin D from sunlight and its nutritional sources and adequate intake of Mn from a wide range of vegetables, legumes, seeds, and grains might be solutions for some overweight cases with FTO rs9939609 polymorphism.

The association between FTO rs9939609 gene polymorphism and anthropometric indices in adults.

BACKGROUND: Fat mass and obesity-associated gene (FTO) is the most studied obesity-related gene up to date. We aimed to assess anthropometric indices in carriers of FTO rs9939609 polymorphism with overweight across Iranian population (Shiraz) to find out the associations of this polymorphism with obesity indices. METHODS: This was a cross-sectional study conducted on 198 overweight healthy adults aged 20-45 years old. We assessed the body composition of the participants using bioelectrical impedance analyzer. In addition, we measured the waist circumference (WC) and hip circumference (HC). Waist to hip ratio (WHR) and waist to height ratio (WHtR) were also calculated by equations. The participants' genotype was determined by ARMS-PCR. Also, data analysis was performed using SPSS software version 20 and R software version 3.6.2. RESULTS: The mean values of body mass index (BMI) and age of the participants were 26.93 ± 1.13 kg/m2 and 33.33 ± 6.35 years old, respectively. Homozygous carriers of A-allele had significantly higher values for BMI (0.60 kg/m2, p = 0.026), WHR (0.04 unit, p = 0.003), and WHtR (0.02 unit, p = 0.030) than the homozygous carriers of T-allele. Individuals with AA genotype had greater WC (2.66 cm, p = 0.042, and 4.03 cm, p = 0.002), fat mass (2.24 kg, p = 0.004, and 3.02 kg, p = 0.001), and trunk fat (1.53 kg, p = 0.001, and 2.08 kg, p = 0.001) compared to those with AT and TT genotypes, respectively. Interestingly, after adjustment of the confounders, significant associations were observed among rs9939609 polymorphism and BMI, Wt, WC, trunk fat percentage, WHR, and WHtR. CONCLUSIONS: A-allele of the FTO rs9939609 polymorphism was indicated to be associated with greater general and central obesity in adult population of Shiraz, Iran.

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

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