Reducing the Risk of Foot and Leg Amputations in Type 1 Diabetes
What is the problem and what is known about it so far?
People with diabetes are more likely to have a toe, foot, or leg amputated than other people. This is because many people with diabetes have blood vessel disease, which reduces blood flow to the feet, and nerve disease, which reduces sensation in the feet. Together, these problems make it easy to get sores and infections that may lead to amputation. Most amputations are preventable with good foot care.
Despite changes in care over the years, toe, foot, and leg amputations (called “lower-extremity amputations” or LEAs) are still common. Research has shown links between various risk factors such as high blood glucose and high blood pressure and a person’s chances of having an LEA. But more research is needed to find out which patients with diabetes are most at risk over the long term and what can be done to help them avoid the need for an LEA.
Why did the researchers do this particular study?
The researchers wanted to find out how common LEAs are in people with type 1 diabetes over a long period of time.
Who was studied?
The study included 943 patients who participated in the Wisconsin Epidemiologic Study of Diabetic Retinopathy, a long-term study of eye disease in people with type 1 diabetes.
How was the study done?
The researchers looked at information gathered in the long-term eye disease study. They included participants who did not have a toe, foot, or leg amputation at the start of the study and who participated in long-term follow-up exams for many years. They looked at how many patients got diabetes-related LEAs over the years. They also looked at other possible risk factors such as age, sex, age at diabetes diagnosis, length of time with diabetes, blood glucose and blood pressure control, weight, smoking status, and the presence of other diabetes-related complications.
What did the researchers find?
Over the course of 25 years, about 10 percent of the participants had an LEA. Those who were male, were heavy smokers, had high blood pressure, had diabetic eye disease, and had worse blood glucose control were more likely to have an LEA.
What were the limitations of the study?
Although the percentage of participants who got an LEA was high, the actual number of such patients was fairly low, which limited the researchers’ ability to find other possible other links to LEAs. Also, because people with heart disease are more likely to die early, early deaths might have caused the researchers to find a weaker link between some risk factors such as smoking and high blood pressure than really exists. Also, some possible links, such as blood vessel disease and cholesterol levels were not measured.
What are the implications of the study?
People with type 1 diabetes have a high chance of needing an LEA over the long term. Those with high blood glucose or high blood pressure and those who are heavy smokers are particularly at risk. Controlling diabetes and blood pressure and avoiding heavy smoking can reduce a person’s chances of needing a toe, foot, or leg amputation later on.