Objective: To assess treatment adherence to dipeptidyl peptidase-4 inhibitor vildagliptin compared with sulphonylureas (SU) in Muslim patients with type 2 diabetes mellitus who were fasting during Ramadan in the UK.
Research design and methods: This prospective, observational cohort study was conducted in four UK centres. Patients already taking vildagliptin (50 mg twice a day) or an SU as add-on therapy to metformin were followed up for ≤16 weeks. They were asked to record all missed doses of anti-diabetes medications.
Results: Of the 72 patients enrolled (vildagliptin, n = 30; SU, n = 41; not allocated to treatment, n = 1), 59 (81.9%) completed the study (vildagliptin, n = 23; SU, n = 36), including one patient in the SU arm who completed but failed to provide information on missed doses; all patients in the SU arm were taking gliclazide. In the vildagliptin arm one patient (4.3%) missed a total of four doses while in the SU arm 10 patients (27.8%) missed a total of 266 doses (mean [SD] number of doses missed per patient: 26.6 [16.5]). The mean (SD) proportions of doses missed during fasting were 0.2% (0.9) and 10.4% (21.7) in the vildagliptin and SU arms, respectively, with a significant mean between-group difference of -10.2% (95% CI: -19.3%, -1.1%; p = 0.0292). There were no patients in the vildagliptin arm who missed more than 20% of OAD doses compared with 19.4% in the SU arm (p = 0.0358). Of the patients receiving an SU, 15 (42%) collectively reported 34 hypoglycaemic events (HEs) and one grade 2 HE; of these, fewer were non-adherent (n = 6, 40%) than adherent (n = 9, 60%). No patients reported HEs in the vildagliptin arm.
Conclusion: During Ramadan fasting, treatment with vildagliptin resulted in better treatment adherence compared with SU in Muslim patients with type 2 diabetes mellitus. Study limitations are the sample size and the lack of diet and exercise data.