Determination of individual type 2 diabetes risk profile in the North East Indian population & its association with anthropometric parameters

FTO gene variants (rs9939609, rs8050136 and rs17817449) and type 2 diabetes mellitus risk: A Meta-Analysis

BACKGROUND AND AIMS

There is tremendous increase in type 2 diabetes mellitus (T2DM) worldwide. The impact of FTO gene polymorphisms on the risk of T2DM is not yet clear because of the controversial results of studies. This meta-analysis aimed to better clarify the association between three FTO gene polymorphisms SNPs (rs9939609, rs8050136 and rs17817449) and T2DM in a larger combined population worldwide.

MATERIAL AND METHODS

A comprehensive search on the PubMed, Science Direct, and Web of Science databases was conducted to identify investigations in relationship between different FTO gene polymorphisms (rs9939609, rs8050136 and rs17817449) and T2DM globally. Published papers from January 2007 to May 2023 were collected. Inclusion criteria are limited to human case-control studies published in English and peer-reviewed, which provided data on the genotype distributions of FTO gene polymorphisms and T2DM risk. Odds ratios (OR) and 95% confidence intervals (CI) were calculated to express the results of the meta-analysis. Potential sources of bias and heterogeneity using Egger's regression analysis were also assessed.

RESULTS

Of 234695 identified articles, forty-eight studies were selected including 36,051 patients with T2DM and 51,266 control subjects. Overall, we found a significant increased risk of T2DM susceptibility and rs9939609 FTO gene polymorphism in the Allele contrast (A vs. T: OR = 1,30, 95% CI = 1.14; 1.48, P < 0,05, I2 = 0,94), Recessive model (AA vs. AT + TT: OR = 1,54, 95% CI = 1.19; 2.00, P < 0,05, I2 = 0,94), Dominant model (AA + AT vs. TT: OR = 1,26, 95% CI = 1.10; 1.45, P < 0,05, I2 = 0,89), homozygote model (AA vs. TT: OR = 1,60, 95% CI = 1.26; 2.03, P < 0,05, I2 = 0,90), and heterozygote model (AA vs. AT: OR = 1,43, 95% CI = 1.09; 1.88, P = 0,008, I2 = 0,93). we also found a significantly increased risk of T2DM susceptibility and rs8050136 FTO gene polymorphism under all models. For rs17817449 we did not find any association between with T2DM.

CONCLUSION

The present meta-analysis confirms that rs9939609 and rs8050136 in the FTO gene are significantly associated with T2DM, while rs17817449 does not show any association.

Peroxisome Proliferator-Activated Receptor α and γ Gene Polymorphisms among South Indian Patients with Diabetic Dyslipidaemia

Background

Peroxisome proliferator-activated receptors (PPAR) α and γ genes play an important role in dyslipidaemia of T2DM.

Aims

To estimate the frequency distribution of PPAR α and γ gene polymorphisms in South Indian T2DM patients with dyslipidaemia compared to healthy controls. Normative frequencies of SNPs were established and compared with data for 1000 genome populations.

Methods

Eligible 382 cases and 336 age and sex-matched controls were enrolled. Six SNPs in PPARα [rs1800206 C>G (Leu162Val), rs4253778 G>C, rs135542 T>C] and PPARγ [rs3856806 (C>T), rs10865710 (C>G), rs1805192 C>G (Pro12Ala)] genes were selected for genotyping.

Results

The allele and gene frequencies did not significantly differ between the diabetic dyslipidaemia cases and healthy controls. However, they were significantly different from that of 1000 genome populations except for rs1800206 C>G (Leu162Val) and rs1805192 C>G (Pro12Ala).

Conclusion

The studied polymorphisms in PPARα and PPARγ genes are not associated with diabetic dyslipidaemia among South Indian patients.

Risk of type 2 diabetes and KCNJ11 gene polymorphisms: a nested case-control study and meta-analysis

Due to the central role in insulin secretion, the potassium inwardly-rectifying channel subfamily J member 11 (KCNJ11) gene is one of the essential genes for type 2 diabetes (T2D) predisposition. However, the relevance of this gene to T2D development is not consistent among diverse populations. In the current study, we aim to capture the possible association of common KCNJ11 variants across Iranian adults, followed by a meta-analysis. We found that the tested variants of KCNJ11 have not contributed to T2D incidence in Iranian adults, consistent with similar insulin secretion levels among individuals with different genotypes. The integration of our results with 72 eligible published case-control studies (41,372 cases and 47,570 controls) as a meta-analysis demonstrated rs5219 and rs5215 are significantly associated with the increased T2D susceptibility under different genetic models. Nevertheless, the stratified analysis according to ethnicity showed rs5219 is involved in the T2D risk among disparate populations, including American, East Asian, European, and Greater Middle Eastern, but not South Asian. Additionally, the meta-regression analysis demonstrated that the sample size of both case and control groups was significantly associated with the magnitude of pooled genetic effect size. The present study can expand our knowledge about the KCNJ11 common variant's contributions to T2D incidence, which is valuable for designing SNP-based panels for potential clinical applications in precision medicine. It also highlights the importance of similar sample sizes for avoiding high heterogeneity and conducting a more precise meta-analysis.