Demographic and Clinical Characteristics of Patients With Type 2 Diabetes Mellitus Initiating Dipeptidyl Peptidase 4 Inhibitors: A Retrospective Study of UK General Practice.

PURPOSE: The majority of people with type 2 diabetes mellitus (T2DM) will develop chronic kidney disease in their lifetime. Because most dipeptidyl peptidase (DPP)-4 inhibitors require dose adjustment in patients with T2DM and renal impairment, we aimed to understand how these treatments are prescribed in UK clinical practice, and to determine whether recommended dose adjustments are being made at initial prescription.

METHODS: This retrospective, descriptive cohort study analyzed data from the Clinical Practice Research Datalink (CPRD). Patients of interest were those with T2DM and renal impairment initiated on a DPP-4 inhibitor between 2014 and 2015. Patients under 40 years of age and with type 1 diabetes were excluded. Descriptive statistics were calculated for baseline demographic and clinical characteristics, and the study protocol was approved by the Independent Scientific Advisory Committee for Medicines and Healthcare products Regulatory Agency database research.

FINDINGS: A total of 3425 patients diagnosed with T2DM and renal impairment and initiated on a DPP-4 inhibitor were identified. The percentages of patients prescribed the high dose of saxagliptin, alogliptin,sitagliptin, and vildagliptin were 48%, 43%, 41%, and 27%, respectively, which is not recommended given their renal dysfunction. These are conservative estimates, as they do not include patients with severe renal impairment on sitagliptin and alogliptin, whose doses should be further reduced. No patients were prescribed an inappropriately high dose of linagliptin, as there is no requirement for dose adjustment in patients with renal impairment.

IMPLICATIONS: In this study, a considerable number of patients with T2DM and renal impairment were prescribed an inappropriately high dose of saxagliptin, alogliptin, sitagliptin, or vildagliptin for their level of renal impairment at treatment initiation. This prescribing could have been due to the complexity of different dosing requirements, or a lack of awareness of the need for dose adjustment of most DPP-4 inhibitors in patients with renal impairment. Linagliptin may be used in patients with moderate or severe renal impairment without dose adjustment.