Association between polymorphisms of fat mass and obesity-associated gene and metabolic syndrome in Kazakh adults of Xinjiang, China

Genetic factors associated with obesity risks in a Kazakhstani population

Objectives

There is limited published literature on the genetic risks of chronic inflammatory related disease (eg, obesity and cardiovascular disease) among the Central Asia population. The aim is to determine potential genetic loci as risk factors for obesity for the Kazakhstani population.

Setting

Kazakhstan.

Participants

One hundred and sixty-three Kazakhstani nationals (ethnic groups: both Russians and Kazakhs) were recruited for the cross-sectional study. Linear regression models, adjusted for confounding factors, were used to examine the genetic associations of single nucleotide polymorphisms (SNPs) in 19 genetic loci with obesity (73 obese/overweight individuals and 90 controls).

Results

Overall, logistic regression analyses revealed genotypes C/T in CRP (rs1205), A/C in AGTR1 (rs5186), A/G in CBS (rs234706), G/G in FUT2 (rs602662), A/G in PAI-1 (rs1799889), G/T (rs1801131) and A/G (rs1801133) in MTHFR genes significantly decrease risk of overweight/obesity. After stratification for ethnicity, rs234706 was significantly associated with overweight/obesity in both Russians and Kazakhs, while rs1800871 was significant in Kazakhs only.

Conclusions

This study revealed that variations in SNPs known to be associated with cardiovascular health can also contribute to the risks of developing obesity in the population of Kazakhstan.

Rs9939609 polymorphism of the fat mass and obesity-associated (FTO) gene and metabolic syndrome susceptibility in the Chinese population: a meta-analysis

PURPOSE

The relationship between the rs9939609 allele of fat mass and obesity-associated (FTO) gene and metabolic syndrome (MS) susceptibility has been evaluated by many studies, however, the results still remained controversial in the Chinese population. In order to provide more accurate results, we performed this meta-analysis.

METHODS

We searched PubMed, and Wanfang Med Online in both English and Chinese, and eight eligible studies comprising of 5345 cases and 9523 controls were eventually selected into our meta-analysis. The meta-analysis was performed using the STATA 12.0 software.

RESULTS

In pooled analysis, the FTO gene rs9939609 polymorphism significantly increased MS susceptibility under per-allele comparisons (A vs. T) (OR 1.21, 95% CI 1.10-1.35, P < 0.001) and in dominant model (OR 1.35, 95% CI 1.13-1.62, P < 0.001). Subgroup analyses under per-allele comparisons (A vs. T) indicated that the elevated risk was observed in adults (OR 1.26, 95% CI 1.08-1.47, P = 0.003) but not in children and adolescents (OR 1.14, 95% CI 0.95-1.36, P = 0.17), and that the risk for increasing MS was only identified in IDF groups (OR 1.22, 95% CI 1.03-1.43, P = 0.018) but not in NCEP ATP III groups (OR 1.14, 95% CI 0.95-1.36, P = 0.17); in both population-based (PB) and hospital-based (HB) groups, A alleles of rs9939609 appeared to be linked to increased MS susceptibilities (HB group: OR 1.51, 95% CI 1.10-2.08, P = 0.01; PB group: OR 1.19, 95% CI 1.09-1.30, P < 0.001). No significant association was established in dominant model subgroup analyses except PB group (OR 1.29, 95% CI 1.05-1.53, P < 0.001).

CONCLUSION

Our results suggested that the FTO gene rs9939609 polymorphism significantly increased MS susceptibility in Chinese. Our results should be verified by well-designed studies with larger sample size.

Common genetic variation in obesity, lipid transfer genes and risk of Metabolic Syndrome: Results from IDEFICS/I.Family study and meta-analysis

As the prevalence of metabolic syndrome (MetS) in children and young adults is increasing, a better understanding of genetics that underlie MetS will provide critical insights into the origin of the disease. We examined associations of common genetic variants and repeated MetS score from early childhood to adolescence in a pan-European, prospective IDEFICS/I.Family cohort study with baseline survey and follow-up examinations after two and six years. We tested associations in 3067 children using a linear mixed model and confirmed the results with meta-analysis of identified SNPs. With a stringent Bonferroni adjustment for multiple comparisons we obtained significant associations(p < 1.4 × 10⁻⁴) for 5 SNPs, which were in high LD (r² > 0.85) in the 16q12.2 non-coding intronic chromosomal region of FTO gene with strongest association observed for rs8050136 (effect size(β) = 0.31, p_Wald = 1.52 × 10⁻⁵). We also observed a strong association of rs708272 in CETP with increased HDL (p = 5.63 × 10⁻⁴⁰) and decreased TRG (p = 9.60 × 10⁻⁵) levels. These findings along with meta-analysis advance etiologic understanding of childhood MetS, highlighting that genetic predisposition to MetS is largely driven by genes of obesity and lipid metabolism. Inclusion of the associated genetic variants in polygenic scores for MetS may prove to be fundamental for identifying children and subsequently adults of the high-risk group to allow earlier targeted interventions.

Assessing the Causality Factors in the Association between (Abdominal) Obesity and Physical Activity among the Newfoundland Population-A Mendelian Randomization Analysis

A total of 1,263 adults from Newfoundland and Labrador were studied in the research. Body mass index (BMI) and percent trunk fat (PTF) were analyzed as biomarkers for obesity. The Mendelian randomization (MR) approach with two single-nucleotide polymorphisms in the fat-mass and obesity (FTO) gene as instruments was employed to assess the causal effect. In both genders, increasing physical activity significantly reduced BMI and PTF when adjusted for age and the FTO gene. The effect of physical activity was stronger on PTF than BMI. Direct observational analyses showed significant increase in BMI/PTF when physical activity decreased. A similar association in MR analyses was not significant. The association between physical activity and BMI/PTF could be due to reversed causality or common confounding factors. Our study provides insights into the causal contributions of obesity to physical activity in adults. Health intervention strategies to increase physical activity among adults should include some other plans such as improving diet for reducing obesity.