Effect of oral antidiabetic drug withdrawal in type 2 diabetes

Oral hypoglycaemic agents were withdrawn in 22 Type 2 diabetic patients to establish whether long-term use of these products is really necessary. Discontinuation of the drugs resulted in significant increases of HbA1 (8.1 +/- 1.1 to 11.3 +/- 2.4%) and fasting (9.1 +/- 2.1 to 13.6 +/- 4.0 mmol l-1) and postprandial (12.3 +/- 3.0 to 18.7 +/- 5.7 mmol l-1) plasma glucose levels after 12 weeks (all p less than 0.01). This was associated with a reduction of fasting (12.4 +/- 6.2 to 8.0 +/- 3.4 mU l-1) and postprandial (35.7 +/- 13.2 to 19.3 +/- 13.4 mU l-1) serum insulin concentrations, and fasting (0.8 +/- 0.4 to 0.5 +/- 0.2 nmol l-1) and postprandial (1.8 +/- 0.6 to 1.0 +/- 0.5 nmol l-1) serum C-peptide concentrations (all p less than 0.01). Only one patient did not show metabolic deterioration after drug withdrawal. In multivariate analysis no significant correlations could be found between measures of baseline diabetic control and the deterioration after drug withdrawal.