Assessment of β-cell function

Abstract

Defective β-cell function is an underlying fundamental defect of diabetes. Type 1 diabetes is characterized by profound insulin deficiency. Strategies to preserve β-cell function at diagnosis of type 1 diabetes have been tested in clinical trials. In patients with type 2 diabetes, impaired β-cell function is relative rather than absolute and is usually accompanied by insulin resistance. Drugs that directly stimulate insulin release, e.g. sulphonylureas, or that enhance glucose-stimulated insulin secretion, e.g. GLP-1 analogues, are widely used in the treatment of patients with type 2 diabetes. This chapter reviews the clinical research methods available for assessing insulin secretion and their value in the early-phase development of new drugs for diabetes treatment. These range from basal pharmacokinetic measures, e.g. measurement of fasting serum insulin concentration, to dynamic tests that measure insulin responses to glucose ± non-glucose stimuli. Assessment of the role of the incretin hormones is required for novel agents that stimulate insulin secretion via activation of the incretin axis.