Trial design
We conducted an investigator-initiated, multi-centre, open-label, two-treatment (pioglitazone 30mg once daily [P], vildagliptin 50mg once daily [V]), two-period (16-weeks each), randomised, crossover trial. There was no washout period between medications because medication withdrawal could have caused detrimental rebound hyperglycaemia and this was deemed unnecessary due to neither of the two medications having a continuing glucose lowering effect beyond 4 weeks. The primary outcome of HbA1c measurement, which reflects glycaemia over the preceding 8-12 weeks, would therefore reflect results only from the last medication during the 16-week treatment period, without any carry over effect from the first medication. The strength of the PV/VP crossover design is that both interventions were evaluated for each participant, which allows comparison at the individual rather than group level alone (