ABSTRACT

Laboratory and imaging assessments of endocrine function are widely available by direct access. Biochemical investigations of endocrine function fall into two main groups, namely the collection of a single blood test, or a dynamic function investigation when multiple blood samples are collected in order to assess the secretion of hormones when their controlling mechanisms are challenged either by stimulation or by suppression. The latter investigations often involve venous cannulation and are best undertaken as an out-patient or in a programmed investigation unit. The glucose tolerance test (GTT) is a simple dynamic function test, and as it does not involve cannulation it can be performed in primary care.