The association between the rs11196218A/G polymorphism of the TCF7L2 gene and type 2 diabetes in the Chinese Han population: a meta-analysis

Associations of TCF7L2 rs11196218 (A/G) and GLP-1R rs761386 (C/T) Gene Polymorphisms with Obesity in Chinese Population

INTRODUCTION

This study aimed to investigate the genetic polymorphism associations with obesity of the transcription factor 7-like 2 (TCF7L2) gene rs11196218 (A/G) and glucagon-like peptide 1 receptor (GLP1-R) gene rs761386 (C/T) in the Chinese population.

PATIENTS AND METHODS

This was a case-control pilot study involving 60 patients with obesity and 69 non-obesity Chinese adults, and the two groups were sex and age matched. Anthropometric indices of obesity, fasting blood glucose, blood pressure, and blood lipids were assessed. Both polymorphisms were genotyped using matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF).

RESULTS

There were significant differences in the allelic frequencies of the TCF7L2 rs11196218 and GLP1-R rs761386 between obesity and non-obesity groups (P = 0.003, OR = 2.32, 95% CI [1.31~4.09]; P = 0.034, OR = 1.94, 95% CI [1.05~3.60], respectively). In allele model, the genotypic frequencies of TCF7L2 rs11196218 and GLP1-R rs761386 also differed between obesity and non-obesity groups (P = 0.014 and 0.033, respectively). In dominant model, the TCF7L2 rs11196218 A-carrier (AA/AG) had a higher risk of obesity than GG genotype (P = 0.014, OR = 2.54, 95% CI [1.21~5.35]). Comparison of clinical and biochemical parameters between genotypes showed no significant difference.

CONCLUSION

These findings suggest that the rs11196218 (A/G) polymorphism of the TCF7L2 gene and the rs761386 (C/T) polymorphism of the GLP1-R gene were associated with obesity in the Chinese population.

Smoking increases the risk of diabetic foot amputation: A meta-analysis

Accumulating evidence suggests that smoking is associated with diabetic foot amputation. However, the currently available results are inconsistent and controversial. Therefore, the present study performed a meta-analysis to systematically review the association between smoking and diabetic foot amputation and to investigate the risk factors of diabetic foot amputation. Public databases, including PubMed and Embase, were searched prior to 29th February 2016. The heterogeneity was assessed using the Cochran's Q statistic and the I² statistic, and odds ratio (OR) and 95% confidence interval (CI) were calculated and pooled appropriately. Sensitivity analysis was performed to evaluate the stability of the results. In addition, Egger's test was applied to assess any potential publication bias. Based on the research, a total of eight studies, including five cohort studies and three case control studies were included. The data indicated that smoking significantly increased the risk of diabetic foot amputation (OR=1.65; 95% CI, 1.09-2.50; P<0.0001) compared with non-smoking. Sensitivity analysis demonstrated that the pooled analysis did not vary substantially following the exclusion of any one study. Additionally, there was no evidence of publication bias (Egger's test, t=0.1378; P=0.8958). Furthermore, no significant difference was observed between the minor and major amputation groups in patients who smoked (OR=0.79; 95% CI, 0.24-2.58). The results of the present meta-analysis suggested that smoking is a notable risk factor for diabetic foot amputation. Smoking cessation appears to reduce the risk of diabetic foot amputation.

Impaired glucose tolerance in first-episode drug-naïve patients with schizophrenia: relationships with clinical phenotypes and cognitive deficits

BACKGROUND

Schizophrenia patients have a higher prevalence of type 2 diabetes mellitus with impaired glucose tolerance (IGT) than normals. We examined the relationship between IGT and clinical phenotypes or cognitive deficits in first-episode, drug-naïve (FEDN) Han Chinese patients with schizophrenia.

METHOD

A total of 175 in-patients were compared with 31 healthy controls on anthropometric measures and fasting plasma levels of glucose, insulin and lipids. They were also compared using a 75 g oral glucose tolerance test and the homeostasis model assessment of insulin resistance (HOMA-IR). Neurocognitive functioning was assessed using the MATRICS Consensus Cognitive Battery (MCCB). Patient psychopathology was assessed using the Positive and Negative Syndrome Scale (PANSS).

RESULTS

Of the patients, 24.5% had IGT compared with none of the controls, and they also had significantly higher levels of fasting blood glucose and 2-h glucose after an oral glucose load, and were more insulin resistant. Compared with those patients with normal glucose tolerance, the IGT patients were older, had a later age of onset, higher waist or hip circumference and body mass index, higher levels of low-density lipoprotein and triglycerides and higher insulin resistance. Furthermore, IGT patients had higher PANSS total and negative symptom subscale scores, but no greater cognitive impairment except on the emotional intelligence index of the MCCB.

CONCLUSIONS

IGT occurs with greater frequency in FEDN schizophrenia, and shows association with demographic and anthropometric parameters, as well as with clinical symptoms but minimally with cognitive impairment during the early course of the disorder.

Association of the Transcription Factor 7 Like 2 (TCF7L2) Polymorphism With Diabetic Nephropathy Risk: A Meta-Analysis

It is assumed that genetic factors may participate in the development of diabetic nephropathy (DN). The association between TCF7L2 gene polymorphism and DN risk is still unclear. To evaluate the relationship, we performed this meta-analysis. Eligible relevant studies were searched and selected from PubMed, Embase, and ISI Web of Science. Summary effect estimates were derived using a random effects model, with attention to study quality and publication bias. Ethnical approval was not necessary, because this meta-analysis was based on published articles, and did not involve patient consent. A total of 7 studies were identified. Analysis of all studies indicated significant association between TCF7L2 gene polymorphism and DN risk (odds ratio [OR] = 1.31, 95% confidence interval (CI) = 1.10-1.56, Pheterogeneity < 0.00001, P = 0.002). Subgroup analysis showed similar results in Asian (OR = 1.33, 95% CI = 1.10-1.62, Pheterogeneity = 0.03, P = 0.004), in Caucasian (OR = 2.27, 95% CI = 1.78-2.90, Pheterogeneity = 0.17, P < 0.00001), in rs7903146 mutation (OR = 1.61, 95% CI = 1.25-2.07, Pheterogeneity < 0.00001, P = 0.0002), However, no association was observed in Negroid (OR = 1.10, 95% CI = 0.90-1.35, Pheterogeneity < 00001, P = 0.36). Our results suggest that TCF7L2 gene polymorphism may contribute to the risk of DN. However, more studies should be launched in the future.