The rate of increase is closely tied to the number of obese and morbidly obese people in the US. There are 66 million obese people in the US (obesity is defined as a BMI of over 30%). Nearly a fifth of these people have diabetes today. Left untreated, we can forecast that many with long-term obesity problems will eventually contract Type-II diabetes as a response to long-term problems of insulin resistance.



It's no coincidence, therefore, that rates of heart disease and other circulatory problems is increasing. What is surprising is, until recently, the rate of heart disease had been declining since the 1950's. The reason for the fall was primarily due to a reduction in cigarette smoking, from over 60% of the population, to under 25% today.

In addition, we've seen an increase in certain populations which are more susceptible to circulatory disease: these maladies are much more common amongst people of Latin American and African-American subgroups. There is a certain correlation between diabetes and circulatory disease. Both African-Americans and Latinos have much higher rates of obesity and heart disease. As those subgroups have grown, so has the overall incidence of diabetes and circulatory disease.

Finally, people are living longer. As we age, we grow more susceptible to circulatory diseases. It is estimated that the number of people in the US over 75 will double between 2005 and 2030.

What is the connection between diabetes and circulatory disease? Cause and effect works in two directions: as we exercise less, we gain weight. With less exercise, we also tend to have higher levels of circulating insulin. These higher levels contribute to an overall increase in insulin resistance from the cells of the body. As insulin resistance increases, the pancreas increases insulin output in order to counteract the problem. A long period of insulin resistance is typically followed by the onset of insulin-resistant Type-II diabetes.

What effect does diabetes have on the circulatory system? Blood vessels thicken throughout the body in response two three factors related to obesity and diabetes:

High blood pressure causes a thickening of the arteries

High circulating LDL and lower HDL ratios contribute to the formation of plaque in blood vessels, which leads to a further narrowing of those vessels

Inflammation, which can result from circulating substances such as homocysteine in obese and diabetic patients, leads to higher levels of heart and circulatory disease.

The smaller the blood vessels, the greater the damage caused by this thickening and narrowing of the blood vessels. The greatest problem in both diabetics and obese people is with their circulation in the capillaries and their extremities. That's why we see blindness (as a result of constriction in the capillaries of the eye), neuropathy in the feet and hands, and a reduction in circulation in the brain and heart, all are due to a less-effective circulation and narrowing of the arteries.

Heart disease and circulatory disease are interrelated. It is estimated that 60% of those patients who undergo angioplasty will also need vascular intervention, particularly in the kidneys, iliac, SFA (superficial femoral artery) and femoral-popliteal arteries of the leg. Left untreated, patients are at a much higher risk of heart attacks, strokes, and diabetic foot ulcers.

Diabetes is closely linked to heart and other circulatory diseases. The correlation between the two means that both must be treated in order to improve a person's morbidity and mortality.