Metformin therapy and the risk of colorectal adenoma in patients with type 2 diabetes: A meta-analysis

Abstract

BackgroundExisting data evaluating the impact of metformin on the colorectal adenoma (CRA) risk in patients suffering from type 2 diabetes (T2D) are limited and controversial. We therefore summarized the studies currently available and assessed the relationship between metformin treatment and risk of CRA in T2D patients.MethodsWe systematically searched databases for eligible studies that explored the impact of metformin treatment on the occurrence of CRA in T2D patients from inception to June 2016. The summary odds ratio (OR) estimates with their 95% confidence interval (CI) were derived using random-effect, generic inverse variance methods. Sensitivity analysis and subgroup analysis were performed.ResultsSeven studies involving 7178 participants met the inclusion criteria. The pooling showed that metformin therapy has a 27% decrease in the CRA risk (OR, 0.73; 95% CI, 0.58 - 0.90). In subgroup analysis, we detected that metformin exhibits significant chemoprevention effects in Asia region (OR, 0.68; 95% CI, 0.48 - 0.96). Similar results were identified in both studies with adjusted ORs and high-quality studies (OR, 0.66; 95% CI, 0.50 - 0.86 and OR, 0.70; 95% CI, 0.58 - 0.84, respectively). Of note, an inverse relationship was noted that metformin therapy may result in a significant decrease in the advanced adenoma risk (OR, 0.52; 95% CI, 0.38 - 0.72). Low heterogeneity was observed, however, the results remained robust in multiplesensitivity analyses.ConclusionsThis meta-analysis indicates that metformin therapy is correlated with a significant decrease in the risk of CRA and advanced adenoma in T2D patients. Further confirmatory studies are warranted.

Metformin triggers the intrinsic apoptotic response in human AGS gastric adenocarcinoma cells by activating AMPK and suppressing mTOR/AKT signaling

“…Metformin, a biguanide drug, is the first line clinical agent for type 2 diabetes mellitus (T2D) treatment ( 8 , 9 ). The pharmacological mechanism of metformin is to downregulate blood glucose levels to enhance insulin sensitivity in the liver and peripheral tissues (stimulating glucose uptake into muscles and/or increasing fatty acid oxidation in adipose tissue) by activation of adenosine monophosphate (AMP)-activated protein kinase (AMPK) signaling ( 10 , 11 ).…”

The Prevention and Control of Cancer by Metformin in Patients with Type 2 Diabetes: A Systematic Mapping Review

“…Of the 156 articles, there was a mixture of study types; 76 were retrospective cohorts 5, 18-92 , 27 were case-control studies 93-119 , 15 were meta-analyses [120][121][122][123][124][125][126][127][128][129][130][131][132][133][134] , 15 were prospective cohorts [135][136][137][138][139][140][141][142][143][144][145][146][147][148][149] , 11 were systematic reviews with a meta-analysis [150][151][152][153][154][155][156][157][158][159][160] , seven were nested case-control [161][162][163][164][165][166][167] , two were randomized control studies…”

Diabetes Mellitus and Age are Risk Factors of Interval Colon Cancer: A Case-Control Study

“…Insulin resistance is also considered to be an underlying cause for the correlation between obesity and CRC [25]. Indeed, it was demonstrated that the anti-hyperglycemic agent metformin is associated with a decreased incidence of CRC [26]. It is also possible that insufficient bowel preparation, which is potentially more common in DM due to associated autonomic neuropathy and other comorbidities, increases the risk of detection failure [27], although we excluded colonoscopies with inadequate preparation from our analysis.…”