DPP4 and diabetes mellitus: DM, diabetes mellitus; INI, integrase inhibitor; NNRTI, non-nucleoside reverse transcriptase inhibitor; PUFA, polyunsaturated fatty acids; GLP-1, glucagon-like peptide 1; DPP4, dipeptidyl peptidase 4; **p < 0.01 and *p < 0.05 versus HIV-negative patients