Diabetes and impaired glucose tolerance. A prevalence estimate based on the Busselton 1981 survey.

We have estimated the prevalence of diabetes and impaired glucose tolerance from the Busselton 1981 Population Survey using the 1980 World Health Organization (WHO) criteria. Standardized to the Australian non-Aboriginal population aged 25 years and over, the prevalence rates in this white community were 2.5% for known diabetes; 0.9% for newly discovered diabetes; 2.9% for impaired glucose tolerance; and 6.3% for all categories of abnormal glucose tolerance. There appears to have been a real increase in the frequency of diabetes since 1966. Using fasting serum C-peptide values and clinical criteria, 14% of all diabetic subjects were insulin-dependent. The male:female ratio for all categories of abnormal glucose tolerance was 1.4:1. Data from the United States indicate spectacularly higher rates for diabetes and impaired glucose tolerance in the white population. A national study of the prevalence of diabetes and impaired glucose tolerance in Australia is recommended. For epidemiological purposes, a single blood glucose value two hours after a 75 g oral glucose tolerance test is sufficient to categorize glucose tolerance as defined by WHO.