Researchers have just found another good reason why those with diabetes should follow their doctor’s advice. Dr. Lawrence Blonde of New Orleans’s Alton Ochsner Medical Foundation presented important research at the March gathering of the American College of Cardiology in New Orleans.
He summarized his research by suggesting that by gaining better control of their blood sugar levels, people with type 2 diabetes can delay or even prevent the onset of heart disease. According to Dr. Blonde, better control may mean more than changing your diet; it may require using insulin or other oral (taken by mouth) drugs. And in many cases, it may involve the use of several drugs in combination.
Type 2 diabetes (formerly known as adult-onset or non-insulin-dependent diabetes) occurs when the body fails to produce enough insulin–a hormone that helps the body deliver the sugar from food into cells–and/or when the body cannot use insulin efficiently. It is the most common form of diabetes and affects an estimated 16 million Americans. In contrast, fewer than 1 million suffer from type 1 diabetes (formerly known as juvenile-onset or insulin-dependent diabetes), in which the body stops producing insulin altogether.
Type 2 diabetes has traditionally developed in people over 40, particularly in those overweight. However, in the last decade it has become increasingly more common among children and young adults, especially those who are obese. Type 2 diabetes affects people of all backgrounds, but it is more common in certain groups, including African Americans, Hispanics, and Native Americans.
If you are one of the more than 10 million Americans who have been diagnosed with type 2 diabetes, you are luckier than the nearly 6 million who have the disease but don’t know it. Many of them have not been diagnosed because they have no symptoms. But people without symptoms are still at risk of long-term complications from diabetes, especially because neither they nor their doctors are looking for the early signs of complications. The most common complications of diabetes include blindness, poor healing of infections, kidney disease, and a full range of circulatory system diseases, including heart attack and stroke.
- Dr. Blonde reported the cardiovascular risks for people with diabetes in stark terms:
- 80% of people with diabetes die from cardiovascular disease.
- 50% already have coronary artery disease at the time they are diagnosed with diabetes.
- People with diabetes are less likely to recover from coronary artery disease than nondiabetics.
Drugs and Diet
However, prospects are improving for patients who are diagnosed. Dr. Blonde cited the results, published last year, of the United Kingdom Prospective Diabetes Study, which followed more than 5,000 people newly diagnosed with type 2 diabetes for an average of 10 years. The study found that using drugs to treat diabetes was considerably more effective than using diet alone. Two of the drugs used in the study were insulin and sulfonylureas, a class of medications that increase the amount of insulin produced by the body. Using drugs not only lowered the blood sugar readings below those achieved by diet alone: They also reduced the risk of other diabetes-related complications by up to 34%.
That’s the good news. The bad news is that the study found that control of blood sugar levels worsened over time, even in people using drugs. According to the researchers, this indicates that type 2 diabetes is a progressive disease–one that tends to become worse over time.
In addition, those using medications tended to gain more weight than those only watching their diet. In a 10-year period, people in the medication group gained an average of nearly 7 pounds more than those in the diet group. What’s more, drugs did not significantly reduce the risk of heart attacks or strokes any better than diet alone did. Insulin and sulfonylureas, however, are not the only medications available for type 2 diabetes. In the British study, a subgroup of 1,700 overweight people with type 2 diabetes were tested on a wider variety of drugs. People taking metformin, a newer medication that helps the body utilize insulin better, reduced their risk of circulatory problems as much as, and sometimes more than those taking insulin and sulfonylureas did. But they did not gain as much weight. And they had 39% fewer heart attacks and 30% decreased cardiovascular disease compared to the diet group. Metformin was approved for use in the United States in 1995.
These research findings do not mean that diabetic patients should all take metformin. Dr. Blonde noted that the American Diabetes Association recommends that people newly diagnosed with type 2 diabetes work with their healthcare providers to develop a diet and exercise plan for controlling their blood sugar levels. They should turn to the various oral diabetes medications or insulin only after diet and exercise prove insufficient.
What Dr. Blonde did urge doctors to do was this: When patients with type 2 diabetes need medications, give them the medication targeted to their particular case. And if that initial drug fails to produce the desired effect, patients should be given a second drug in addition to and not in place of the original prescription. For example, he noted that many people with type 2 diabetes are highly resistant to insulin, which means that their bodies have trouble utilizing it. The solution, he said, is to use insulin along with a medication that lowers this resistance and helps the body absorb insulin. For people with very high blood sugar levels, insulin may be needed even if oral medications are taken as well.
There are currently five classes of oral medications available for those with type 2 diabetes. Since Dr. Blonde’s presentation in March, one of these classes, the thiazolidinediones, has expanded from one to three approved medications, substantially altering guidelines for this class of drug.
Each of these classes of medication, however, has its advantages and disadvantages.
- Sulfonylureas increase the amount of insulin secreted by the pancreas. Sulfonylureas are probably most effective for lean or thin patients, and are generally the least expensive, as well. Three are currently on the market in the United States: glipizide (Glucotrol), glyburide (Diabeta, Micronase), and glimepiride (Amaryl).
- Repaglinide (Prandin) would be the choice for lean patients with irregular eating patterns and kidney disease or for others who may be prone to low blood sugar (hypoglycemia).
- Metformin, the only drug of the biguanide class currently available in the United States, works best for those who are overweight and whose bodies have trouble using insulin.
- Alpha-glucosidase inhibitors limit the body’s ability to absorb carbohydrates (those starchy foods the body converts into energy). There are two on the market in the United States–acarbose (Precose) and miglitol (Glyset). These drugs are best used with patients whose blood sugars tend to soar after meals.
- Thiazolidinediones, like the biguanides (metformin), lower the body’s resistance to insulin. These are most effective for patients who have trouble using insulin efficiently or who have kidney disease. There are now three thiazolidinediones available in the US: troglitazone (Resulin), rosiglitazone (Avandia), and pioglitazone (Actos). Troglitazone, the first drug of this class to be approved in the United States, has been associated with liver toxicity. Because of this, the US Food and Drug Administration recommends that those taking troglitazone have liver function tests on a regular basis. Although liver toxicity has not been associated with use of rosiglitazone and pioglitazone, the FDA recommends that patients using these drugs have their liver function monitored as a precaution.
Controlling diabetes requires a high degree of collaboration between patient and the healthcare team. But, as Dr. Blonde pointed out, the effort is worth the reward when it means avoiding heart problems that can be caused by diabetes.
Article by: David Ghitelman, Medical Writer