Oral hypoglycaemic agents, mainly biguanides, thiazolidinediones and dipeptidyl peptidase-4 (DPP-4) inhibitors, are now known for their anti-inflammatory properties, whereas other oral hypoglycaemic agents, such as sulfonylureas, meglitinides, and α-glucosidase inhibitors, have not been thoroughly studied for their effects on inflammation and COPD [76]. This evidence concerns the gene DPP4 and chronic obstructive pulmonary disease.