Type 2 diabetes drugs: risks w/o benefit
Posted by medconsumers on December 14, 2009
Yet another study, this one conducted in the U.K, has shown that the oral drugs typically prescribed for people with type 2 diabetes are killing some of them; and many more have suffered heart attacks and congestive heart failure while on the drugs. Ironically, these are the very conditions that the drugs are intended to prevent. The British Medical Journal recently published findings from a 15-year database of more than 91,000 people with type 2 diabetes. The drugs they were taking—Avandia, Actos, Glucophage, and Amaryl—will be familiar to Americans. This is the eleventh published study to acknowledge the fact that oral hypoglycemic drugs are associated with an increased risk of serious harms. This one shows that some are riskier than others.
For those of you who are on one of these drugs, I provide access to the new study and leave it to your doctor to explain. I want to move on to the larger issue of why doctors continue to prescribe these dangerous drugs and how they got on the market in the first place. That last point is more easily addressed. Drugs most often receive FDA approval on the basis of what researchers call surrogate endpoints, for example, blood sugar levels are controlled, blood pressure or cholesterol is lowered, etc. The studies are usually too short in duration to prove what matters most to the people taking the drugs—i.e., they cut the chances of heart attack, stroke, etc.
I put the question of why doctors continue to prescribe these drugs in the face of so much proven danger to Nortin M. Hadler, MD, whom I consider the informed-skeptic-in-chief on this topic. Dr. Hadler is a professor of medicine and microbiology/immunology at the University of North Carolina, Chapel Hill. He is the author of two books, each with excellent sections devoted to type 2 diabetes (see below). Of course, the place to start questioning Dr. Hadler is the very definition of type 2 diabetes, which has been expanded over the years to include more and more people.
Dr. Hadler had a ready answer, “I don’t think America realizes how much input industry has on the medical organizations and their thought leaders who are involved in writing these definitions and treatment guidelines. Several of these entities are so heavily underwritten as to be almost wholly owned subsidiaries of the pharmaceutical industry. Professional meetings have much more the tone and the feel of the marketplace than they do of the academy. And all of this happened in the last 20 years.
“There are several pharmaceutical industry-supported medical groups that compete to establish standards of care for type 2 diabetes and related conditions. Some endocrinologists believe that type 2 diabetes, obesity, high blood pressure, and high cholesterol—all cluster together because they are parts of a single metabolic syndrome, which responds poorly to the treatment of its components. Others argue strenuously for the treatment of one or the other components [of metabolic syndrome]. Rather than choosing meaningful effectiveness as their battle cry, they are more interested in turf wars. The cardiologists are averse to this metabolic syndrome notion and want to pull out cholesterol and maybe hypertension as the most important risk factors to treat. The Endocrine Society and the American Diabetes Association finally got together and came out with their definition of type 2 diabetes and guidelines for lowering blood sugar.
“All of this is driven by the belief that if we normalize cholesterol or blood sugar we will improve longevity and decrease the incidence of blindness, kidney failure, stroke, heart attacks and leg ulcers. The thought leaders are so convinced of their belief that they focus on treating the blood sugar and to question whether they are treating the patient seems unnecessary. Their shortsighted efforts are rewarded with renown by the pharmaceutical industry. Almost all the thought leaders are heavily involved in drug trials where they are paid for studying the drugs. And almost all are vying for a place on the committees that set treatment guidelines.
“We now have three randomized controlled trials of oral hypoglycemic drugs in the treatment of type 2 diabetes and based on these three, we doctors cannot offer any meaningful assurance whatsoever that taking these drugs will decrease the likelihood of having a stroke, death before your time, amputation, renal failure, blindness. Anybody who tells you otherwise is exercising firm beliefs in the face of the evidence. They are wont to argue that oral hypoglycemics might have proven effective if we had done a bigger and/or longer trial. Such an argument is on the thinnest of ice. The available trials are impressive for their duration (measured in over a decade for two of the trials) and their size. Little of importance, if anything, has been missed.
“Maybe it’s time to address the other aspect of the metabolic syndrome that is too long and too often ignored. Most people who fall into the metabolic cluster are facing serious socioeconomic challenges in our society for which type 2 diabetes is one surrogate measure and for which pharmaceuticals are irrelevant.”
When I asked Dr. Hadler about metformin, the oldest and some doctors believe the safest diabetes 2 drug, he was unmoved by the British study that showed it to be effective at reducing the risk of heart attack, stroke, etc. “When you look carefully at that study, you will see the finding [of effectiveness] was not statistically significant [which means it could be due to chance].” As someone who has done an in-depth assessment of this landmark study, called the United Kingdom Prospective Diabetes Study, Dr. Hadler states, “…we doctors cannot offer any meaningful assurance whatsoever that taking these drugs will decrease the likelihood of having a stroke, death before your time, amputation, renal failure, blindness.”
Dr. Hadler is the author of The Last Well person. How to stay well despite the health-care system and Worried Sick. A prescription for health in an overtreated America, each has a strong section on type 2 diabetes. He appears frequently on National Public Radio.
For More Information:
Type 2 diabetes is largely due to lack of exercise and poor eating habits. See our 2008 interview with Dr. Steve Blair on the importance doing at least one-half hour of brisk walking five or more times a week. And to learn how to eat well and lower your risk of type 2 diabetes and other chronic conditions, read Michael Pollen’s new book entitled, “Food Rules.”
If you would like to know more about how the pharmaceutical industry brings the thought leaders around to its way of thinking, read Our Daily Meds by former New York Times business reporter Melody Petersen.
Maryann Napoli, Center for Medical Consumers(c)