Differential unfolded protein response in skeletal muscle from non-diabetic glucose tolerant or intolerant patients with obesity before and after bariatric surgery

Aims Not all people with obesity become glucose intolerant, suggesting differential activation of cellular pathways. The unfolded protein response (UPR) may contribute to the development of insulin resistance in several organs, but its role in skeletal muscle remains debated. Therefore, we explored the UPR activation in muscle from non-diabetic glucose tolerant or intolerant patients with obesity and the impact of bariatric procedures. Methods Muscle biopsies from 22 normoglycemic (NG, blood glucose measured 120 min after an oral glucose tolerance test, G120