BackgroundObesity is a well-recognized risk factor for insulin resistance and type 2 diabetes (T2D), although the precise mechanisms underlying the relationship remain unknown. In this study we identified alterations of DNA methylation influencing T2D pathogenesis, in subcutaneous and visceral adipose tissues, liver, and blood from individuals with obesity.MethodsThe study included individuals with obesity, with and without T2D. From these patients, we obtained samples of liver tissue (n = 16), visceral and subcutaneous adipose tissues (n = 30), and peripheral blood (n = 38). We analyzed DNA methylation using Illumina Infinium Human Methylation arrays, and gene expression profiles using HumanHT-12 Expression BeadChip Arrays.ResultsAnalysis of DNA methylation profiles revealed several loci with differential methylation between individuals with and without T2D, in all tissues. Aberrant DNA methylation was mainly found in the liver and visceral adipose tissue. Gene ontology analysis of genes with altered DNA methylation revealed enriched terms related to glucose metabolism, lipid metabolism, cell cycle regulation, and response to wounding. An inverse correlation between altered methylation and gene expression in the four tissues was found in a subset of genes, which were related to insulin resistance, adipogenesis, fat storage, and inflammation.ConclusionsOur present findings provide additional evidence that aberrant DNA methylation may be a relevant mechanism involved in T2D pathogenesis among individuals with obesity.Electronic supplementary materialThe online version of this article (10.1186/s12881-018-0542-8) contains supplementary material, which is available to authorized users.

The majority of patients presented taste and olfactory changes soon after surgery independently of type of procedure. Patients submitted to LGBP referred more often a different smell in food. Higher %EWL was observed in patients presenting any food aversion, especially in the LGBP group.

Just like in morbid obesity, LGBP and LSG are effective and safe procedures in super obese patients. LGBP had better weight loss at 1 year.

Conservative management of asymptomatic gallbladder disease in candidates to bariatric surgery is safe and can be offered in every case, based on the low percentage of patients requiring further cholecystectomy after 12 months. Also, a conservative management can be offered to patients developing de novo sludge/cholelithiasis without related symptoms.

In our series, LGP presented a high failure rate and an increased number of symptomatic patients. Revisional surgery proved to be safe and effective. Revision to LSG was faster and had less hospital stay. Revision to LGBP showed better %EWL at 18 months.