Endocrine Abstracts

Introduction and Objectives: The tolerability of extended-release metformin (XRM) is clearly superior to that of conventional metformin, with the potential to improve patient compliance, effectiveness and outcomes. Since 2005 the NICE guidelines for type 2 diabetes mellitus (T2DM) recommend its use in patients with metformin-caused gastrointestinal disturbances. XRM is recently available in Spain as a fixed combination with sitagliptin, but not in monotherapy. We assessed the efficacy and tolerability of XRM/sitagliptin in patients with T2DM previously labeled as metformin-intolerant and treated with a DPP4 inhibitor (DPP4i), and additionally analyzed the data for quality of life before and after the switch.

Patients and Methods: Consecutive patients with T2DM, HbA1c >7% and GFR (CKD-EPI) >45 ml/min/1.73m² labelled as metformin-intolerant due to gastrointestinal symptoms, and treated with a DPP4i were switched to the 50 mg sitagliptin plus 1000 mg XRM combination, taking 1 pill daily in the first month and afterwards 2 pills if the tolerance was good. Tolerance data were obtained by questionnaire in the follow-up visit. Quality of life was assessed by the well-validated questionnaire EuroQol-5D-3L on health-related quality of life, before the onset of treatment and again after 3-4 months on treatment. The questionnaire consists of 5 triple-answer questions (on mobility, personal care, daily activities, pain or discomfort, and anxiety or depression), and a visual analogue scale (VAS) or "thermometer" for health. All Included patients granted informed consent.

Results: 69 of a total 72 patients completed the EuroQol-5D-3L before and after the switch from DPP4i to XRM/sitagliptin. The questionnaire was never administered to the patients by their prescribing physicians. The Quality of life score increased from 0.759±0.121 to 0.866±0.130; this change was driven mainly by the pain/discomfort score. The VAS score increased from 68.3±13.8 to 82.5±15.5 (both P<0.01). The reductions in fasting plasma glucose were 36 mg/dl with 1 pill of XRM/sitagliptin (1000/50 mg), and 44 mg/dl with 2 pills, and the reductions in HbA1c were 0.6% with 1 pill and 0.9% with 2 pills (all P<0.01). 51 patients (74%) tolerated 2 pills, 8 (12%) tolerated 1 tablet and 10 (14%) did not tolerate any.

Conclusions: A large majority of the patients with T2DM labelled as metformin-intolerant and treated with an DPP4i tolerated the XRM/sitagliptn combination, and their glycemic control was significantly improved The switch from DPP4i to the XRM/sitagliptn combination was associated with increased quality of life, particularly in relationship with decreased pain and discomfort.