Different effects of bariatric surgery on epigenetic plasticity in skeletal muscle of individuals with and without type 2 diabetes [methylation array]

Bariatric surgery is highly effective for the treatment of obesity in individuals without (OB ) and in those with type 2 diabetes (T2D ). However, whether bariatric surgery triggers similar or distinct molecular changes in OB and T2D remains unknown. Given that individuals with type 2 diabetes often exhibit more severe metabolic deterioration, we hypothesized that bariatric surgery induces distinct molecular adaptations in skeletal muscle, the major site of glucose uptake, of OB and T2D after surgery-induced weight loss. All participants (OB, n=13; T2D, n=13) underwent detailed anthropometry before and one year after the surgery. Skeletal muscle biopsies were isolated at both time points and subjected to transcriptome and methylome analyses using a comprehensive bioinformatic pipeline. Skeletal muscle biospsies (m. vastus lateralis) were collected from 26 individuals (13 with obesity; OB and 13 with obesity and type 2 diabetes; T2D ) in two time points. Before bariatric surgery (w0); One year or 52 weeks after bariatric surgery (w52). Next, genomic DNA was isolated from all samples followed bisulfite treatment and hybridization on EPIC v1 arrays.