Effect ofFTOrs9930506 on obesity and interaction of the gene variants with dietary protein and vitamin E on C-reactive protein levels in multi-ethnic Malaysian adults

Initial Weight Loss, Anthropometric Parameters, and Proinflammatory Transcript Levels in Patients with Class I Obesity

Research into early predictors of effective weight loss could help determine more effective therapeutic interventions. In this study, 106 subjects with class I obesity, genotyped with the fat mass and obesity-associated (FTO) rs9930506 gene variant, were enrolled into a 12-week weight loss program (WLP). Anthropometric and body composition measurements were controlled with bioelectrical impedance analysis (BIA) at baseline and after 4 and 12 weeks. Biopsies of abdominal subcutaneous adipose tissue (AT) and venous blood samples were collected to monitor changes in interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-α), and nuclear factor kappa B (NF-κB) mRNA levels in white blood cells (WBCs) and to assess if changes in WBC gene expression reflected changes in adipose tissue. The FTO rs9930506 variant had no effect on weight loss and no reduction in proinflammatory transcripts in WBCs or AT. Changes in anthropometric parameters were associated with changes in carbohydrate metabolism. A linear regression model showed that initial weight loss (after 4 weeks of the WLP) was the most predictive factor of weight loss success after 12 weeks of the WLP. Changes in plasma lipids or proinflammatory transcript levels in WBCs or AT were not associated with weight loss effectiveness. However, the gene expression in WBCs did reflect changes occurring in subcutaneous AT.

Dietary protein interacts with polygenic risk scores and modulates serum concentrations of C-reactive protein in overweight and obese Malaysian adults

Dietary intake may interact with gene variants and modulate inflammatory status. This study aimed to investigate the combined effect of fat mass and obesity-associated rs9930501, rs9930506, and rs9932754 and beta-2 adrenergic receptor rs1042713 on C-reactive protein (CRP) concentrations using polygenic risk scores (PRS), and modulatory effect of dietary nutrients on these associations. We hypothesized that higher protein intake is associated with lower inflammatory status in individuals genetically predisposed to obesity. PRS was computed as the weighted sum of the risk alleles possessed and stratified into first (0-0.64), second (0.65-3.59), and third (3.60-8.18) tertiles. A total of 128 overweight and obese Malaysian adults were dichotomized into groups of low and elevated inflammatory status (CRP concentrations ≤3 and >3 mg/L, respectively). One-half of the study participants (51%) were found to have elevated inflammatory status. Second- and third-tertile PRS were significantly associated with increased odds of elevated inflammatory status, 7.56 (95% confidence interval [CI], 1.98-28.80; adjusted P = .003) and 3.87 (95% CI, 1.10-13.60; adjusted P = .035), respectively. Individuals in the third-tertile PRS had significantly lower CRP concentrations (4.61 ± 1.3 mg/L vs 9.60 ± 2.6 mg/L, P = .019) when consuming ≥14% energy from protein (with an average of 18.0% ± 2.4%, 43.0% ± 7.7%, and 39.0% ± 8.0% energy from protein, carbohydrate, and fat per day). In conclusion, third-tertile PRS was significantly associated with increased odds of elevated CRP; higher protein intake may alleviate inflammatory status and reduce CRP concentrations systemically in those individuals.

Coffee Types and Type 2 Diabetes Mellitus: Large-Scale Cross-Phenotype Association Study and Mendelian Randomization Analysis

PURPOSE

To explore whether coffee intake is associated with the risk of type 2 diabetes mellitus (T2DM) from a genetic perspective, and whether this association remains the same among different types of coffee consumers.

METHODS

We utilized the summary-level results of 12 genome-wide association studies. First, we used linkage disequilibrium score regression and cross-phenotype association analysis to estimate the genetic correlation and identify shared genes between coffee intake and T2DM in addition to some other T2DM-related phenotypes. Second, we used Mendelian randomization (MR) analysis to test whether there is a significant genetically predicted causal association between coffee intake and the risk of T2DM or other T2DM-related phenotypes. For all the analyses above, we also conducted a separate analysis for different types of coffee consumers, in addition to total coffee intake.

RESULTS

Genetically, choice for ground coffee was significantly negatively associated with the risk of T2DM and some other related risks. While coffee intake and choice for decaffeinated/instant coffee had significant positive correlation with these risks. Between these genetically related phenotypes, there were 1571 genomic shared regions, of which 134 loci were novel. Enrichment analysis showed that these shared genes were significantly enriched in antigen processing related biological processes. MR analysis indicated that higher genetically proxied choice for ground coffee can reduce the risk of T2DM (T2DM: b: -0.2, p-value: 4.70×10^-10; T2DM adjusted for body mass index (BMI): b: -0.11, p-value: 4.60×10^-5), and BMI (b: -0.08, p-value: 6.50×10^-5).

CONCLUSIONS

Compared with other types of coffee, ground coffee has a significant negative genetic and genetically predicated causal relationship with the risk of T2DM. And this association is likely to be mediated by immunity. The effect of different coffee types on T2DM is not equal, researchers on coffee should pay more attention to distinguishing between coffee types.

The effect of rs9930506 FTO gene polymorphism on obesity risk: a meta-analysis

Obesity is associated with polymorphisms of the fat mass and obesity associated gene (FTO). This meta-analysis aimed to investigate the association of the rs9930506 FTO gene polymorphism and obesity. To the best of our knowledge, this study is the first meta-analysis to evaluate the relation between FTO rs9930506 polymorphism and obesity. We searched PubMed, Web of Science, and Embase to identify studies investigating the relations between the rs9930506 FTO gene polymorphism and obesity risk. We pooled adjusted odds ratios (OR) as overall and in continent subgroups. A Fixed-effects model was used to analyze the results of these studies in dominant and recessive models. By examining 3337 obesity cases and 3159 healthy controls, we identified 8 eligible case-control studies. Considering the dominant model of inheritance, there was a relationship between the rs9939506 polymorphism and obesity (OR=1.34 [1.03- 1.74]). The association remained significant in the European subgroup (OR=1.68 [1.2-2.36]), but not in the Asian subgroup. Using the recessive model, we also found a significant relationship when the overall association was investigated (OR=2.47; 95% CI 1.56-3.91). In conclusion, this study identified that the carriers of the risk allele of FTO rs9930506 polymorphism are at higher risk for obesity.

The Combined Effect of Polygenic Risk from FTO and ADRB2 Gene Variants, Odds of Obesity, and Post-Hipcref Diet Differences

BACKGROUND

Computing polygenic risk scores (PRS) to predict the degree of risk for obesity may contribute to weight management programs strategically.

OBJECTIVES

To investigate the combined effect of FTO rs9930501, rs9930506, and rs9932754 and ADRB2 rs1042713 and rs1042714 using PRS on (1) the odds of obesity and (2) post-intervention differences in dietary, anthropometric, and cardiometabolic parameters in response to high-protein calorie-restricted, high-vitamin E, high-fiber (Hipcref) diet intervention in Malaysian adults.

METHODS

Both a cross-sectional study (n = 178) and a randomized controlled trial (RCT) (n = 128) were conducted to test the aforementioned objectives. PRS was computed as the weighted sum of the risk alleles possessed by each individual participant. Participants were stratified into first (PRS 0-0.64), second (PRS 0.65-3.59), and third (PRS 3.60-8.18) tertiles.

RESULTS

The third tertile of PRS was associated with significantly higher odds of obesity: 2.29 (95% CI = 1.11-4.72, adjusted p = 0.025) compared to the first tertile. Indians (3.9 ± 0.3) had significantly higher PRS compared to Chinese (2.1 ± 0.4) (p = 0.010). In the RCT, a greater reduction in high-sensitivity C-reactive protein (hsCRP) levels was found in second and third tertiles after Hipcref diet intervention compared to the control diet (p interaction = 0.048).

CONCLUSION

Higher PRS was significantly associated with increased odds of obesity. Individuals with higher PRS had a significantly greater reduction in hsCRP levels after Hipcref diet compared to the control diet.

Association of ADRB2 rs1042713 with Obesity and Obesity-Related Phenotypes and Its Interaction with Dietary Fat in Modulating Glycaemic Indices in Malaysian Adults

Gene-diet interaction studies have reported that individual variations in phenotypic traits may be due to variations in individual diet. Our study aimed to evaluate (i) the association of ADRB2 rs1042713 with obesity and obesity-related metabolic parameters and (ii) the effect of dietary nutrients on these associations in Malaysian adults. ADRB2 genotyping, dietary, physical activity, anthropometric, and biochemical data were collected from 79 obese and 99 nonobese individuals. Logistic regression revealed no association between ADRB2 rs1042713 and obesity (p=0.725). However, the carriers of G allele (AG + GG genotypes) of rs1042713 were associated with increased odds of insulin resistance, 2.83 (CI = 1.04–7.70, adjusted p=0.042), in the dominant model, even after adjusting for potential confounders. Obese individuals carrying the G allele were associated with higher total cholesterol (p=0.011), LDL cholesterol levels (p=0.008), and total cholesterol/HDL cholesterol ratio (p=0.048), compared to the noncarriers (AA), even after adjusting for potential confounders. Irrespective of obesity, the carriers of GG genotype had significantly lower fasting glucose levels with low saturated fatty acid intake (<7.3% of TE/day) (4.92 ± 0.1 mmol/L vs 5.80 ± 0.3 mmol/L, p=0.011) and high intake of polyunsaturated fatty acid:saturated fatty acid ratio (≥0.8/day) (4.83 ± 0.1 mmol/L vs 5.93 ± 0.4 mmol/L, p=0.006). Moreover, the carriers of GG genotype with high polyunsaturated fatty acid intake (≥6% of TE/day) had significantly lower HOMA-IR (1.5 ± 0.3 vs 3.0 ± 0.7, p=0.026) and fasting insulin levels (6.8 ± 1.6 µU/mL vs 11.4 ± 2.1 µU/mL, p=0.036). These effects were not found in the noncarriers (AA). In conclusion, G allele carriers of ADRB2 rs1042713 were associated with increased odds of insulin resistance. Obese individuals carrying G allele were compromised with higher blood lipid levels. Although it is premature to report gene-diet interaction on the regulation of glucose and insulin levels in Malaysians, we suggest that higher quantity of PUFA-rich food sources in regular diet may benefit overweight and obese Malaysian adults metabolically. Large-scale studies are required to replicate and confirm the current findings in the Malaysian population.

Effect of an individualised high-protein, energy-restricted diet on anthropometric and cardio-metabolic parameters in overweight and obese Malaysian adults: a 6-month randomised controlled study

The aim of this study was to investigate the effectiveness of the Hipcref (high-protein, energy-restricted, high-vitamin E and high-fibre) diet in Malaysian adults on body composition and metabolic parameters after an intervention period of 6 months. Overweight/obese Malaysian adults (n 128; BMI≥23 kg/m2) were randomised to the Hipcref (n 65) or control diet (n 63). The intervention group received Hipcref diet charts based on their personal preferences. The control group followed a generalised dietary advice based on Malaysian Dietary Guidelines, 2010. All participants were responsible for preparing their own meals. There was a significant treatment group×time effect on anthropometric parameters (P&lt;0·05) on an intention-to-treat basis. Pairwise comparisons revealed that Hipcref diet participants had significant reduction in weight, BMI, waist circumference, fat mass and percentage body fat at months 3 and 6 compared with baseline (P&lt;0·001). The control group had significant increase in weight and BMI at months 3 and 6 compared with baseline (P&lt;0·05). The Hipcref diet group had higher reduction in fasting insulin, insulin resistance and C-reactive protein levels compared with the control group at month 6 (P&lt;0·05). Post-intervention, compared with the control group, the Hipcref diet group was found to consume significantly higher percentage energy from protein, and PUFA, higher energy-adjusted vitamin E (mg) and fibre (g), and lower total energy, lower percentage energy from fat and carbohydrate (P&lt;0·05). The success of the Hipcref diet on overweight/obese Malaysian adults may be due to the combined effect of the nutrient composition of the Hipcref diet.