The Study of Sulphonylurea Synergy with Incretins (LOGIC) is a Proof-of-Concept Physiological
study in the form of two matched isoglycaemic clamps. A matched clamp consists of an of oral
glucose tolerance test followed by an isoglycaemic intravenous glucose infusion (IGII). The
study will investigate whether there is synergy between a physiological sulphonylurea (SU)
stimulus and the incretin effect, causing augmentation of insulin secretion in patients with
type 2 diabetes mellitus (T2DM). The study will take place at The Clinical Research Centre at
Ninewells Hospital in Dundee over five visits. It will evaluate 20 patients with T2DM on no
diabetes therapy, or metformin monotherapy.
All participants will undergo two matched clamps. The first matched clamp will be with no
intervention. The second intervention matched clamp, low-dose liquid gliclazide will be
administered 1-hour prior to each test. The sulphonylurea, Gliclazide, in this this instance
will be used as a physiological stimulus and will only be given on two occasions as part of
the second matched clamp. The first eight participants will participate in the dose-ranging
phase. They will receive either 10mg or 20mg gliclazide as a stimulus to augment the incretin
effect. A further twelve participants will then be recruited to complete the study utilising
the dose which caused the greatest increment in insulin secretion. LOGIC will also evaluate
the cohort for effect of KCNJ11 genotype on physiological response.