Troglitazone in combination with sulphonylurea improves glycaemic control in Type 2 diabetic patients inadequately controlled by sulphonylurea therapy alone

Aim The aim of this study was to investigate the effectiveness of troglitazone (a peroxisome proliferator-activated receptor-gamma agonist developed primarily for the treatment of Type 2 diabetes mellitus (DM)), 100 or 200 mg/day, in terms of glycaemic control, lipid profile and tolerability, when given in addition to existing sulphonylurea therapy. Methods A 16-week, randomized, parallel-group placebo-controlled trial in 259 Type 2 diabetic patients already on sulphonylurea therapy. Results At week 16, adjusted geometric mean HbA1c with troglitazone 100 mg (7.7%; P = 0.023) and 200 mg (7.4%; P < 0.001) was lower with sulphonylurea alone (8.2%). At all weeks, adjusted geometric mean fasting serum glucose levels were lower in both troglitazone groups, compared with sulphonylurea alone (P = 0.007 to P < 0.001). At week 16, both troglitazone groups showed reductions in immune reactive insulin compared with sulphonylurea alone (200 mg, 13%; P = 0.032: 100 mg, 5%; NS), Troglitazone reduced serum levels of nonesterified fatty acids at week 16 (100 mg, 12%; P = 0.042) and at all weeks (200 mg, 17 - 24%; P = 0.014 to P < 0.001). The incidence of drug-related adverse events was similar in all groups (23-24% of patients). There was no apparent association between hypoglycaemia and the addition of troglitazone to sulphonylurea therapy. Conclusions Troglitazone 100 or 200 mg added to usual sulphonylurea therapy in patients with Type 2 DM is associated with a significant improvement in glycaemic control, without altering the adverse-event profile of the sulphonylurea.