The natural history of stroke in diabetic patients.

A five-year follow-up of 53 diabetic patients admitted for their first stroke in 1972--73 has been performed. They were compared with two groups of 53 non-diabetic patients each with cerebrovascular disease (CVD), one randomly selected and one matched with the diabetics for age, sex and diagnosis of CVD at discharge. All patients could be traced at follow-up. The mean age at the time of first stroke was 66.5 years in male and 73.2 years in female diabetics. Manifest diabetes was diagnosed in 19% during hospitalization for stroke; of the remainder, 74% had had diabetes since less than ten years. In 85% of the diabetics there were no signs of severe angiopathy affecting eyes, kidneys or lower extremities. The majority of diabetic as well as non-diabetic CVD patients had a history of hypertension and/or heart disease. Few were overweight. Case fatality rate was significantly higher in diabetics than in non-diabetics throughout the follow-up (p less than 0.01 for diabetics vs. matched non-diabetics, p less than 0.001 for diabetics vs. randomly selected non-diabetics). The presence of heart disorder predicted mortality in the diabetic subjects. Surprisingly, hypertension diagnosed before stroke involved a more favourable long-term prognosis in all three groups (p less than 0.05). The major causes of death in diabetic CVD patients were cardiac disorders (50%) and stroke (47%). Previous investigations have identified diabetes as a risk factor for stroke. This study shows that diabetes also adversely affects the short-term as well as the long-term outcome in stroke.