The prevalence of diabetic complications is reported from a cross-sectional study of rural diabetic subjects in Western Australia. Logistic-regression analysis has been used to discover potential risk factors associated with each complication. A distinction has been made between time-related variables (age, age at diagnosis, duration of diabetes) and other risk variables. We have attempted to identify the major time-related risk variables for each complication and then examined the effect of other risk variables after accounting for the major time-related variables. The important time-related variables were found to be duration of diabetes for retinopathy, age for macrovascular disease, duration and age at diagnosis of diabetes for sensory neuropathy, and age for renal impairment. When matched on these important time-related variables, the overall prevalences of complications for insulin-dependent (IDDM) compared with non-insulin-dependent (NIDDM) diabetic patients were essentially the same. An exception is renal impairment, for which IDDM patients had a higher prevalence than did NIDDM patients of the same age. After allowing for time-related variables, the analysis also demonstrates positive independent associations between diabetic control (glycosylated hemoglobin) and retinopathy and between diabetic control and macrovascular disease. Plasma cholesterol (positively) and high-density lipoprotein cholesterol (negatively) were related independently to both macrovascular disease and renal impairment. Very few differences in the risk-factor profiles for complications were found for IDDM compared with NIDDM patients after allowing for time-related variables.

A cohort of 888 rural, nonaboriginal persons with non-insulin-dependent diabetes mellitus identified in Western Australia through surveys in 1978-1982 were followed for death until the end of 1986. A total of 257 deaths were observed. Excess mortality in this cohort as compared with the general Australian population was investigated by calculating standardized mortality ratios and using the Cox proportional hazards regression model with hazard rates for the general population as the baseline. The overall standardized mortality ratio was 1.83 (95% confidence interval 1.51-2.16) for women and 1.43 (95% confidence interval 1.18-1.67) for men. Cause-specific comparisons with the general population showed that the majority of excess deaths could be attributed to diseases of the circulatory system. Factors assessed at the baseline survey that were independently prognostic of shorter survival were early onset of diabetes (for females only), high plasma glucose level, retinopathy, macrovascular disease, albuminuria (for females only), and elevated plasma creatinine level. Reductions in life expectancy at 60 years of age as compared with the general population averaged about 5 years but could be as much as 16 years for female diabetics with early onset of diabetes, high plasma glucose levels, and several complications.

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One thousand, two hundred and eighteen diabetic subjects living in and around country towns of Western Australia were screened for complications of diabetes. This population included 134 subjects of Aboriginal descent, who were compared with the Caucasoids taking part. In the Aboriginal group there was a greater proportion of Type 2 (non-insulin-dependent) diabetic patients, a relative female preponderance (69% compared with 51%) and a tendency to present at an earlier age of onset than their Caucasoid counterparts. Diabetic complications were at least as common in the Aboriginal group as in the Caucasoid patients. Indeed, retinopathy within 10 years of onset of diabetes was more common in the Aborigines. Peripheral neuropathy was more prevalent in Aborigines treated by diet alone or oral hypoglycaemic agents than in Caucasoids. A much greater prevalence of proteinuria was an additional feature of the Aboriginal subgroup (29% versus 4%).