Diabetes Mellitus – A Cardiovascular Disease

"Life is not over because you have diabetes. Dale Evans Rogers (American Singer known as the "Queen of the West"),

Glucose, a form of sugar, is the body's main source of fuel. Glucose needs insulin to enter the cells to be used as energy. Insulin is produced by a large gland located behind the stomach – the pancreas. In diabetes, either the pancreas does not produce enough insulin or the cells in the muscles, liver, and fat do not use insulin properly, or both. This allows sugar to accumulate in the blood while the cells are starved. These metabolic abnormalities lead to vascular inflammation. People with diabetes are at a much higher risk of developing cardiovascular diseases like heart attack, stroke, peripheral artery disease and heart failure.

The incidence of diabetes is reaching epidemic proportions. Worldwide, it is estimated that the prevalence of diabetes will rise from 2.8% (171 million people) in 2000 to 4.4% (366 million people) in 2030. Elevated blood glucose levels are responsible for 21% of deaths from coronary heart disease and 13 % of deaths from stroke. This translates into 3.16 million deaths a year. Diabetes is also a major problem in the United States.

Many clinical trials have established that cardiovascular diseases are the most common and most serious complications in diabetics. Almost 65% patients with diabetes die of heart attack or a stroke. Dr. Garcia and his co-researchers reported in Diabetes in 1974, using data from the Framingham Study, that patients with diabetes have a two-three-fold increased incidence of cardiovascular disease and those who present in the fourth and fifth decades of life have a two- fold increase in mortality. This cardiovascular risk develops even before diabetes becomes clinically apprehensive. Researchers from the Harvard School of Public Health in Boston found that women who historically developed type 2 diabetes had a risk of heart attack almost 4 times higher than those who never developed the disease. This data from the Nurses Health Study, was published in the July 2002 issue of Diabetes Care.

The cause of the increased risk of macro-vascular cardiac disease is multi-factorial. Eighty percent of patients with type 2 diabetes are either obese or overweight. Diabetics also carry an abnormal lipid profile. Diabetics typically have elevated plasma triglycerides, normal or mildly elevated low-density lipoprotein cholesterol (LDL-C), and reduced plasma HDL-C concentrations. This encourages atherosclerosis. The combination of high blood sugar and high insulin levels are also toxic to the cardiovascular system. Further, more than two thirds of the adults with diabetes suffer from high blood pressure, another major risk factor for cardiovascular disease.

"What was so upsetting was I did not really know anything about diabetes except that Ella Fitzgerald lost her legs and later died from it." Della Reese. Diabetics also causes many micro-vascular complications. These include diabetic retinopathy, diabetic nephropathy and diabetic neuropathy. Despite good long-term sugar and blood pressure control, diabetes remains a major cause of blindness, renal failure and amputations. Two landmark studies, the Diabetes Control and Complications Trial, published in the New England Journal of Medicine in 1993 and the United Kingdom Prospective Diabetes Study Group (UKPDS) study published in the British Medical Journal in 1998, have shown that an intense control of blood glucose levels and tight blood pressure control reduce the risk of these micro vascular complications in diabetics.

An earlier report from the UKPDS Study published in the British Medical Journal in 1996, shown that increasing age, poor sugar control, increased systolic blood pressure, raised bad LDL-cholesterol, reduced good HDL-cholesterol levels and smoking were significant risk factors for coronary heart disease in diabetics. Lifestyle interventions reduce the risk of cardiovascular diseases and include eating healthy, staying active, drinking alcohol in moderation, stopping the use of tobacco products and maintaining a healthy body weight. They have been shown to prevent the development of diabetes by almost 58%. In patients who have impaired glucose tolerance, they can delay diabetes by almost 11 years. These beneficial effects of lifestyle interventions were also demonstrated in the Diabetes Prevention Program Research Group report published in the New England Journal of Medicine in 2002.

"Diabetes is like being expected to play the piano with one hand while juggling items with another hand, all while balancing with deftness and dexterity on a tightrope" – Marlene Less, Scott's Diabetes Journal. Treating diabetes and controlling your sugar may be difficult. This is because blood sugar levels ideally should be continuously maintained within a small normal range. This may require frequent medications or injections and careful monitoring of the sugar levels. Recent data suggests that the traditionally used blood sugar lowering medications may also have a dark side. In 2002, Duke researchers presented data at the 51st Annual Scientific Sessions of the American Heart Association which showed that there was a 2.6-fold increased risk of death for patients taking injected insulin and sulfonylurea drugs, compared with insulin-sensitizing therapies, such as metformin . They also found that at 90 days into the trials, 12% of diabetic patients on insulin-providing therapy had a major adverse event, compared with 5% of diabetic patients on insulin-sensitizing therapy. Treating diabetes is therefore just not limited to reducing blood glucose levels. Several metabolic abnormalities including elevated insulin levels, inflammation and lipids have to be taken into account. Most diabetics are now also placed on a class of high blood pressure pills called ace inhibitors and angiotensin receptor blockers, cholesterol lower statins and the household aspirin. Recent trials (especially the ASCOTT-LLA study, published in Lancet in 2003) have shown that even in the absence of a history of coronary heart disease or high cholesterol, statin therapy is beneficial in diabetes. The American Diabetic Association advocates the use of aspirin in diabetics with an additional risk factor. Diabetics share a common vascular inflammation seen in patients with cardiovascular disease and aspirin appears to be beneficial in decreasing cardiovascular mortality. Ace inhibitors or angiotensin receptor blockers appear to have a better cardiovascular disease effect in diabetics that goes beyond the benefit achieved by their reduction in blood pressure. The blood pressures goals are lower in diabetics and you are better protected if the blood pressure is reduced to 120/80 mm / Hg or less.

"I lay in the bed at the hospital and said, 'let's see what I have left.' And I could see, I could speak, I could think, I could read. I simply tabulated my blessings, and that wave me a start. " Dale Evans Rogers, American Singer. Many diabetics may feel this way, but recent understanding of the disease and the cardiovascular connection has made complications easier to delay or avoid. And lifestyle changes can even prevent or delay the development of diabetes. Jill Johnson said, "" Living a healthy lifestyle will only deprive you of poor health, lethargy, and fat. "And I may add, diabetes and heart disease.