Diabetes News for May 19, 2002

FDA Warnings On Diabetes Drugs
Metformin Danger With Kidney/Heart Problems
Artificial Pancreas To Be Tested
Preventing Foot Ulcers
Drinking May Decrease Type 2 Risk
Look To The Eyes In Type 2 Development
Higher Risk Of Cancer In Smokers, Fatty Diets
Ethnicity And Diabetes Disparities

FDA Issues New Warning About Diabetes Drugs

Since Rezulin was taken off the market in 2000 because of links to liver failure and excess deaths, research has focused more attention on the safety and efficacy of other diabetes drugs. Now, two related diabetes drugs have been given stronger warning labels. The two drugs are Avandia and Actos which are marketed by GlaxoSmithKline PLC and Eli Lilly and Co., respectively. The US Food and Drug Administration has acted after studies showed that these drugs may lead to fluid retention and congestive heart failure.

The FDA wants to warn people to stop taking these drugs if they experience rapid weight gain, water retention, shortness of breath, or other signs of heart failure. Both drugs are in the same chemical class as Rezulin, but the manufacturers note that not all thiazolidinediones are the same, and the severe problems seen with Rezulin have not been seen with the two drugs currently on the market. Ideally, these drugs assist the body to use its own insulin, so that blood sugar levels are lowered.

The issue of placing stronger labels on these two drugs coincides with a recent study conducted by researchers from the Department of Medicine at Cambridge Hospital in Massachusetts. These researchers examined data about all drugs approved by the FDA between the years 1975 and 1999. Out of 548 new drugs, 56 were subsequently given warning labels or were withdrawn from the market. The analysis of the new drugs showed that half of the changes to labels occurred after the first seven years of being on the market. Half of the withdrawals occurred after the first two years of use.

These researchers concluded that the safety of new drugs cannot be known with certainty until after they have been in use for many years. Their study can be found in the Journal of the American Medical Association (volume 287; number 17; pages 2273-5; May 1, 2002). A major purpose of releasing the study's results is to encourage physicians to be more cautious in their prescribing.

Metformin Dangerous With Kidney Disease Or CHF

Although many drugs are marketed to treat certain diseases, the drugs' benefits may be outweighed by their risks if other medical conditions exist. Some additional caution has been raised by a recent study involving the diabetes drug metformin, which is marketed as Glucophage.

Metformin is usually prescribed to people with Type 2 diabetes in order to reduce blood sugar levels by slowing the liver's glucose production. Currently, the drug is marketed with a "black-box warning" cautioning that metformin should not be prescribed for patients with more advanced cases of kidney disease nor for people who are taking drugs for congestive heart failure. Both groups are more likely than other people with diabetes to develop lactic acidosis. This build-up of lactic acid in the blood can lead to organ damage and death, and is more likely in those with kidney disease and congestive heart failure.

In a recent study, researchers from Campbell University in North Carolina reviewed the health record of 100 people with diabetes who were taking metformin. They found that 22% of these who were prescribed metformin had some degree of kidney disease, or were taking drugs for heart failure, or had both conditions. The researchers published their findings in The Journal of the American Medical Association (volume 287; pages 2504-2505; May 15, 2002) in the hopes of creating awareness about the potentially deadly results of prescribing metformin when contraindications exist.

Artificial Pancreas Slated For Tests In Europe

The newest hope for a safe, convenient, and simple method of treating Type 1 diabetes is the artificial pancreas. Researchers in London are set to begin clinical trials of a new version of this device in June.

The artificial pancreas has been designed by the insulin-pump manufacturer Disetronic, and has been funded by the European Commission. It works by delivering insulin continuously under the skin to keep blood sugar levels constant. The device includes a sensor, which is placed on the skin to measure blood glucose levels. A small computer analyzes the data collected by the sensor, and a small pump responds by delivering appropriate amounts of insulin to the body. The researchers state that the device will be small enough to wear on a belt.

The first clinical trial of the pump will take place in June in a hospital in Austria. Twelve participants will test the device in the hospital for 24 hours on two separate occasions. The participants will first be given treatement with an insulin pump, and will then use the artificial pancreas device.

Preventing Foot Ulcers

There are many products on the market that are designed to help prevent diabetes complications. These include special shoes and inserts that are marketed to prevent diabetes foot ulcers. However, a new study indicates that adequate foot care may be more effective in preventing ulcers.

A recent issue of The Journal of the American Medical Association (volume 287; page 2552; May 15, 2002) includes a study conducted by researchers from the VA Puget Sound Health Care System and the University of Washington in Seattle. The study involved 400 people with diabetes who had been treated for a foot ulcer, but who did not have advanced foot deformities. The study lasted for two years, during which time some of the participants were randomly assigned to wear therapeutic shoes and inserts, and the others wore their usual footwear.

At the end of the study, 15% of the participants who wore therapeutic shoes and customized cork inserts developed ulcers, as did 14% of the participants who wore therapeutic shoes and prefabricated polyurethane inserts. Of those who wore their usual footwear, 17% developed ulcers. The difference between those who wore therapeutic shoes and inserts and those who did not was not statistically significant.

The researchers concluded that the most important factor in preventing diabetes foot ulcers is not special shoes but careful foot care, including appropriate shoes and regular doctor visits. However, the researchers note that they did not study people who had severe foot defects, or who had high risks of developing foot ulcers. These individuals are much more likely to benefit from therapeutic shoes and orthodics.

Drinking May Decrease Risk Of Type 2

Although many studies have focused on the dangers of drinking too much alcohol, a recent study indicates that having one or two drinks a day may actually help prevent Type 2 diabetes.

Researchers from the US Department of Agriculture in Beltsville, Maryland led this study, which included 51 women without diabetes who were postmenopausal. The women participated in three eight-week treatment periods in which they had no alcohol, one drink per day, or two drinks per day. The women also consumed a diet which enabled them to maintain their body weight. Researchers took blood samples from the women throughout the study.

Results show that the women who had two drinks per day had insulin levels that were 20% lower than when they drank no alcohol. Levels of triglycerides were also 10% lower when the women had two drinks per day. Triglycerides are fats that are associated with an increased risk of heart disease. In addtion, insulin sensitivity increased by 7% when the women had two drinks. Blood glucose remained constant. These results held true regardless of the women's body weight.

The results of this study can be found in The Journal of the American Medical Association (volume 287; page 2559; May 15, 2002). More research is needed to determine the beneficial component in alcohol.

Look To The Eyes In Type 2 Development

Although vision problems are a common complication of Type 2 diabetes, a new study indicates that narrowing of blood vessels in the eyes may actually be a cause of diabetes, rather than a result.

The study was conducted by researchers at the National University of Singapore. They photographed the retinas of almost 8,000 men and women without diabetes who were between the ages of 49 and 73. They then measured the small blood vessels that carry blood to the eye. After 3.5 years, about 4% of the participants had been diagnosed with diabetes. Researchers found that those with the most narrowing of their retinal vessels were twice as likely to develop the disease as those with the least narrowing. People with the most narrow retinal arteries were 71% more likely to develop diabetes than those with the least amount of narrowing. This was true in spite of blood sugar and insulin levels, family history of the disease, blood pressure levels, and other risk factors.

The researchers believe that narrow arteries may make it difficult for insulin to move sugar out of the blood system and into muscle, where it is used as energy. More research is needed to determine if this is the case, or if artery narrowing is just a warning sign of diabetes development. This study can be found in The Journal of the American Medical Association (volume 287; page 2528; May 15, 2002).

Higher Risk Of Cancer In Smokers With Fatty Diets

Researchers already know that diet and smoking habits come into play when the risk of developing pancreatic cancer is assessed. A recent study attempted to determine which kinds of foods are most likely to increase the risk.

The study took place at the National Cancer Institute in Bethesda, Maryland. Researchers there reviewed health information on over 27,000 men between the ages of 50 and 69 who smoked. The men had been enrolled in a study in Finland. The researchers found that the men who developed pancreatic cancer consumed more butter and saturated fat, and lower amounts of carbohydrates and total calories, than the men who did not develop pancreatic cancer. The men who consumed the most saturated fat were 60% more likely to develop pancreatic cancer, and the men who consumed the most amount of butter were 40% more likely to develop the disease during the twelve-year study. The men who had the greatest intake of daily calories and carbohydrates were the least likely to be diagnosed with pancreatic cancer.

This study has been published in the American Journal of Epidemiology (volume 155; pages 783-792; May 2002). The researchers are not sure why saturated fat may increase the risk of pancreatic cancer in people who smoke, but they note that saturated fats are more likely to be stored in the body as fat than are other nutrients, and they are also used less efficiently. In addition, fat and saturated fat may decrease insulin sensitivity, leading to Type 2 diabetes. Other studies have shown a link between diabetes and pancreatic cancer.

Ethnicity And Diabetes Disparities

Many studies have shown that there is a difference in diabetes complication rates along ethnic lines. However, a new study indicates that this is not caused by a lack of access to healthcare, as is commonly believed.

The study was conducted by the Division of Research at Kaiser Permanente in Oakland, California, and has been published in The Journal of the American Medical Association (volume 287; page 2519; May 15, 2002). The researchers examined health records of over 62,000 white, African American, Asian, and Latino people with diabetes. They found that African Americans were twice as likely and Latinos were 1.5 times as likely as whites to have kidney failure. Asians were also more likely to have kidney failure than whites.

However, the rate of heart attack among African Americans and Asians with diabetes was about one-third lower than among whites. Latinos had a rate of heart attack that was one-quarter lower than whites. This held true in spite of the participants' education, diet and smoking, drinking, and exercise habits. Also, Asians and Latinos were less likely than whites to have a stroke and congestive heart failure, and the rate of lower limb amputation was two-thirds lower in Asians as compared to whites.

The researchers conclude that there may be differences in genetic factors or unknown environmental factors that lead to differences in complications. Further research is needed.