Psychiatric Aspects of Diabetes—a Physician's View

A raised blood sugar level no more defines a single entity than does a raised bilirubin or a low haemoglobin. Diabetes is a heterogenous group of disorders whose only common factor is hyperglycaemia (Tattersall et al , 1980). The classification of diabetes is being revised, although the changes are of more relevance to epidemiologists than clinicians. Previous standards of normal glucose tolerance were set too low, so that some people were labelled diabetic who had no symptoms and have proved on follow-up not to be at risk of developing complications such as retinopathy (i.e. they had a non-disease). Epidemiological evidence suggests that the cut-off point for ‘true’ diabetes (i.e. a condition which leads to complications and shortening of life span) is a blood glucose level two hours after a 50 G oral glucose load of 11.1 mMol/L (National Diabetes Data Group, 1979). This corresponds to a fasting blood glucose level of 7 mMol/L or below. Hence, a single blood glucose value, either in the fasting state or two hours after a 50 G glucose load, is enough to diagnose diabetes and glucose tolerance tests should hardly ever be necessary.