Wednesday, February 25, 2009

DIABETES AND THE HEART

Almost 15-20% of our population, including those in the rural areas of Malaysia, suffer from diabetes mellitus. And approximately 30-40% of our heart patients have diabetes as well.

"Once you are afflicted with diabetes, your risk for every medical illness becomes worse"


Diabetics do worse in all measures of heart disease outcomes, be it angioplasty outcomes, bypass surgery outcomes, heart attacks outcomes and even plain angina attack outcomes. That is why cardiologists spend a lot of their time understanding diabetes. We will try and understand how diabetes is the bad-tempered close relative of CAD.
Diabetes mellitus
Diabetes is "kencing manis", or sweet urine, giving us our first impression that diabetes is a condition of too much sugar in the urine. There is too much sugar in the blood, causing the excess sugar to overflow into the urine.
Well this impression is largely correct. But the reverse must also quickly be mentioned, so as to correct a very large and present misconception, and that is, if there is no sugar in the urine, I do not have diabetes. Well this is not true. Back in the 60s and early 70s, we used to use urine sugar as a way of testing for diabetes. You remember the Benedict's solution as a way of testing for sugar in the urine? This has been found to be unreliable and largely abandoned, although being a cheap test, some clinics continue to use it as a rough guide to diabetes follow-up.
Sugar is a simple molecule, circulating freely in the blood circulation, reaching all organs, and helping all cells to function. It is the energy-providing, life-sustaining molecule that all cells require.
Diabetes occurs when there is too much sugar in the blood stream and yet this high blood sugar level somehow cannot get into the cells where it is required. As we often say, it is almost like the saying "water, water everywhere, but not a drop to drink".
Now to the science of diabetes through the eyes of a cardiologist - the pancreas is a leaf-shaped organ situated at the back of the abdomen, lying stretched across the spine. This organ is mainly responsible for the regulation and maintenance of blood sugar levels within a narrow range of about 4-6 mmols/litre.
Too low a level will make the cells malfunction, just as would too high a blood sugar level. Depending on which cells or organs are affected most, hypoglycaemia (low sugar level) it may present as lethargy and tiredness on the one hand, or violence and aggression on the other.
Of course, extreme hypoglycaemia can result in coma. Hypoglycaemia is a much lesser medical issue then hyperglycaemia (high blood sugar), and is usually the result of drug treatment for hyperglycaemia.
The pancreas produces insulin, a hormone that is required for the proper maintenance of blood sugar levels. It basically facilitates the movement of sugar from the blood stream into cells and tissues for their energy-requiring functions. Sugar in the cells is broken down to produce energy to drive the cell's function.
Insulin production is increased in response to high circulating blood sugar level, as will occur after meals containing carbohydrates/sugar.
The increased outpouring of insulin after a meal causes the sugar in the blood stream to move into cells and tissues (eg muscle cells, brain cells and heart muscle cells) so that these cells can use the sugar to produce energy for their important functions.
Excess sugar is stored in the liver with the help of insulin. In the event of low sugar levels in the blood, the pancreas also produces another hormone, called glucagon, which functions to facilitate the movement of sugar out of the liver cells where sugar is stored and to the blood stream to normalise the blood sugar level. So like all body systems, there is always a "yin-yang" balancing to maintain body equilibrium.






No comments:

Post a Comment