DPP-4 inhibitors prevent also the degradation of insulin secretagogues, such as glucagon-like peptide-1 (GLP-1), thereby ameliorating hyperglycaemia without causing hypoglycaemia. Due to this effect DPP-4 inhibitors are effective for the treatment of T2DM. Other interventions which increase GLP-1 receptor activation, such as roux-en-Y gastric bypass surgery and GLP-1 analogue therapy, can improve also psoriasis severity.