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Effect of diabetes on the heart and blood vessels


We have been looking at the ravages or complications of diabetes. We have already covered its effect on the limbs, kidneys and bladder. This week we will look at its effect on the cardiovascular system or its effect on the heart and blood vessels.{{more}}

We have already established that high sugar levels affect walls of the blood vessels, such that they become damaged and swollen. The blood flowing through these vessels is reduced and in the presence of hypertension, these vessels are more likely to rupture or burst. The vessels typically affected are the small arterioles and the microscopic capillaries. This is called diabetic blood vessel disease or diabetic microangiopathy. Because the vessel walls are inflamed, they are more “sticky”; hence they are more prone to forming clots by “sticky” blood cells called platelets; besides, if the patients has high cholesterol or smokes, the vessel walls are even more sticky, hence are more prone to clots. These scenarios explain why diabetics are more prone to heart attacks and strokes.

Heart attacks are 3-5 times more common in diabetics then the normal population. The usual cause is a reduction of blood to the heart muscle from a clot forming in a damaged blood vessel. Hypertensives, smokers and those with high cholesterol are particularly at risk. A heart attack is the most common cause of death in diabetics and these attacks may be “silent”, as the nerves that cause pain are affected by diabetes; so diabetics do not “feel” the pain of a heart attack as they should. They also mistake heart attacks as “heart burn” from stomach upset, as the attacks may be associated nausea and vomiting and diabetics tend to suffer from acid reflux. Diabetics usually know they are at risk for a heart attack by being told by their doctor that they have ischaemic heart disease or IHD. This condition is very easy to diagnose, as it involves a few questions, blood tests and a heart test. Baby aspirin and medication to treat high cholesterol help to reduce the risk of a diabetic heart attack.

Strokes are 2-3 times more common in diabetics than in the general population. The cause is related to the diabetic blood vessel disease outlined above. Uncontrolled hypertension and high cholesterol increase this risk. Like IHD is to the heart, so cerebrovascular disease is to the brain. In other word before the big “stroke”, there are usually symptoms of brain disease, like early dementia and forgetfulness, dizziness and ringing in the ears or mini-strokes called TIAs or transient ischaemic attacks. Controlling hypertension and high cholesterol can reduce the big stroke and improving the circulation to the brain is possible by the use of baby aspirin, vasodilators and medications like Plavix.

As you would expect the heart and blood vessels give life to every organ in the body, so you would expect that almost any organ may be affected by diabetes since any blood vessel may be affected. This explains the main findings of diabetic eye disease. By looking at the back of the eye, one “sees” through an eye telescope, called an ophthalmoscope, all the changes that affect the other blood vessels in the body. All the changes of the damaged small blood vessels, bleeding at the back of the eye and then trying to repair themselves and forming new blood vessels. These changes are also seen in other organs, but only after the person had died and the organs are examined under a microscope. However, the back of the eye of a living diabetic displays all these changes long before the person has died and the more severe and advanced the changes, the more advanced and poorly controlled the diabetes; hence the more complications present in other organs. In other words what you see at the back of the eye reflects what is going on in the other organs in the body.

For comments or question contact:
Dr Rohan Deshong
Tel: (784) 456-2785