Letters Section Editor: Robert M. Golub, MD, Senior Editor.
To the Editor: In their meta-analysis studying the efficacy and safety of incretin therapy in persons with type 2 diabetes, Dr Amori and colleagues1 found that patients treated with dipeptidyl peptidase 4 (DPP4) inhibitors had an increased risk of nasopharyngitis (6.4% for DPP4 inhibitors vs 6.1% for comparator; risk ratio, 1.2; 95% confidence interval, 1.0-1.4). This adverse effect is consistent with our finding that DPP4 enzymatic activity in nasal tissue biopsies taken from patients with chronic rhinosinusitis was inversely correlated with the density of inflammatory cells in the nasal mucosa, and the DPP4 activity increased when chronic sinusitis was treated.2
Grouzmann E, Monod M, Landis BN, Lacroix J. Adverse Effects of Incretin Therapy for Type 2 Diabetes. JAMA. 2007;298(15):1759-1760. doi:10.1001/jama.298.15.1759-b