Individuals with type 1 diabetes often have additional problems with their eyes, kidneys, heart, and other organs due to high levels of blood glucose characteristic of the condition. For those with chronic kidney disease, a high risk of heart disease usually follows, but a new study shows that a rare eye condition is also linked to a risk for heart disease independently of kidney disease.
From the Joslin Diabetes Center, researchers are studying proliferative diabetic retinopathy, a condition where small blood vessels grow on the surface of the retina and tend to bleed, causing vision loss. It seems that the risk of heart disease that accompanies proliferative diabetic retinopathy works via different mechanisms than the risk of heart disease associated with kidney disease. Heart disease is the leading cause of death for people with type 1 diabetes.
"[This] suggests that biological factors that either protect against or boost damage to blood vessels are shared between the eye and cardiovascular system, but they may be different from those affecting the kidney,” explained corresponding author George King, MD.
The issue with studying the independent link between proliferative diabetic retinopathy and heart disease is that people with type 1 diabetes who also have chronic kidney disease also usually have eye problems. But thanks to the Joslin Medalist program, study researchers were able to identify 30 people - out of hundreds who have had type 1 diabetes for more than 50 years - with chronic kidney disease but not severe eye disease.
They found that high blood glucose levels do not inflict damage to all blood vessels the same way. For example, nerve damage and eye damage in individuals with type 1 diabetes are independently linked to heart disease.
In the future, the study researchers plan to study heart scans from patients with long-term type 1 diabetes, hoping to find detailed information about the various links to heart disease and other complications associated with type 1 diabetes.
"We hope that will give us the next set of clues to understand and guard against these complications," King said.
Experts estimate that more than one million Americans have type 1 diabetes, an autoimmune disease characterized by an “accidental” immune attack on beta cells, which produce insulin. This is a hormone that controls blood glucose levels.
The present study was published in the journal Diabetes Care.