Background: The thiazolidinediones are a class of antidiabetes medication that enhance the actions of insulin in muscle, liver, and adipose tissue. Data have been lacking on their use in combination with both sulfonylurea and metformin among patients of type 2 diabetes who are on insulin therapy secondary to failure of routine oral hypoglycemic drugs in controlling their diabetes.
Objective: To determine the effects of pioglitazone in combination with sulphonylurea and metformin on diabetes control in patients being treated with insulin due to secondary failure of oral hypoglycemic agents.
Patients: One hundred and twenty-four consecutive type 2 diabetes patients (mean age, 57.13 years) attending four centres in Mumbai, who were being treated with insulin were selected. They were switched on to triple drug combination of glibenclamide 5 mg, metformin 500 mg and pioglitazone 15 mg along with insulin. Study participants were required to have type 2 diabetes mellitus for atleast 5 years. Patients were excluded if they had any of the following: serum creatinine concentration greater than 1.5 mg/dl, alanine aminotransferase (ALT) level more than two times the upper limit of normal, symptomatic angina, cardiac insufficiency or history of myocardial infarction.
Results: Pioglitazone 15 mg with glibenclamide 5 mg and metformin 500 mg, significantly decreased hemoglobin HbA1c level from 11.5% to 7.32% (P < 0.001), average fasting blood glucose from 194.8 mg/ dl to 124.06 mg/dl (p < 0.01), average post-prandial blood glucose from 256.24 to 162.32 mg/dl (p < 0.01). At 6 months, 43.35% of patients did not need to be continued on insulin. The total insulin requirement in 124 patients reduced by 71.81%. There were no significant side effects, liver enzymes were within acceptable levels, average weight gain was 2.23 kg, significant hypoglycemia was observed in 28 patients with two requiring hospitalisation, these patients were those who did not stick to follow-up schedules.
Conclusions: With proper patient selection, pioglitazone with glibenclamide and metformin can be safely used in patients receiving insulin with good results.