Monday, January 26, 2009

Which Vitamin Should I Take?

A staff member in my office asked me which vitamin(s) I would recommend for her to take. She stated her energy was down and wanted to know the best vitamins. This is also a common question I get asked by patients. The staff member seemed a little surprised when I told her I didn't really recommend any vitamins.

There is little proof that vitamins (and other dietary supplements for that matter) can actually help you. On the contrary, if anything the evidence shows that vitamins might even harm you! I have blogged in the past about this, mentioning a review of 68 trials in over 200,000 patients published in February 2007 in JAMA showed that treatment with beta carotene, vitamin A, and vitamin E may increase your risk of death!

Benefits of vitamins like E and C were linked to their antioxidant properties, and have been suggested to prevent colds, improve memory and extend life. However, I have blogged previously about a study on Vitamin E and C that was published in the Journal of the American Geriatrics Society that studied thousands of seniors showing that this did not prevent dementia. In addition, an extensive review of the literature found that vitamin C did not prevent the common cold.

The list of studies goes on and on. There is just no convincing data that these things are helpful. Part of the reason may be that supplements work when you have a diet lacking vitamins and minerals. In the US, our diets are not healthy, but clearly we are getting some nutrition given that the majority of us are overweight or obese. There are a few exceptions where vitamins and supplements may actually help:

1. Folic acid for women of child bearing age. This prevents neural tube defects in babies .
2. Calcium. Calcium is recommend for most adult women to prevent osteoporosis. However, even here there is no data to support that calcium prevents fractures. Yet, it is an important part of bone metabolism, so it is recommended.
3. Vitamin D. We are learning more and more about Vitamin D. I have blogged before about a study published in the Annals of Internal Medicine showing that women with low vitamin D levels have a much greater risk of fracture than women with normal or high vitamin D levels, and it just today it was reported that a low level of vitamin D in older patients is associated with a higher risk of cognitive impairment.

Why Does it Matter?
So what? Even if there are no studies to prove that vitamins and supplements work, they are probably safe, and may help. This is for the most part true. In addition, one can argue that research is lacking because there is no financial incentive (unlike the drug companies) to do the research needed. However, I don't like to recommend things for patients which they will need to pay out of pocket for unless I know it will help them. Whereas some pharmacies are giving away generic antibiotics, and charging only $4 for some generic medications, some women's multivitamins sell for over $34 a bottle (and that's just at Target).

Bottom Line
It's not clear whether or not vitamins really help. If you are a women of child bearing age, you should probably take calcium and folic acid. If you are a senior, you should probably take calcium and vitamin D. If you want to take a multi-vitamin, a generic, inexpensive, once daily mutli-vitamin should be fine. I would not take extra doses of other vitamins or supplements, especially vitamins A, C, or E.

Tuesday, January 13, 2009

FDA, Thanks for the Warning!

As reported in the Associated Press, the FDA just announced that it had completed its analysis of Singulair for suicide, and found absolutely no link.

"Regulators said that only one in nearly 10,000 patients taking Singulair in clinical trials reported suicidal tendencies. No patients committed suicide."

I blogged about this when the FDA announced it was going to look into the matter back in March. I am no fan of Singulair (see here ), but was extremely skeptical of this link given the relatively clean safety profile of singulair, the lack of biologic plausibility, and the fact since millions of patients with allergies and asthma take Singulair (which is unfortunate, because it doesn't work all that well and extremely expensive), if there was a really link it would've shown up by now.

I have no problem with the FDA investigating concerns with medications. This is what they are supposed to do. The problem I have is that they report the fact that they are investigating a problem, without any data or information to be informative to doctors or patients. I raised these concerns when the FDA initially proposed this strategy. There is a reason that in the United States a person is presumed innocent until found guilty. Because of our 24/7 media cycle and their desire to publish scary stories about medicine, when the FDA announces it is looking into a medication, this automatically makes headlines. Patient and physicians, being provided limited to no data as well as no clinical context, assume the worst. Many patients will simply stop taking a medication, without even informing their doctor.
Please recall that though the Vioxx scandal was one of the first events to put the spotlight on the FDA, the Avandia scare magnified this. As I have mentioned multiple times, well done studies on Avandia (see here ) have not led to the same conclusion as Dr. Nissen's poorly done meta-analysis. The ramifications of that dreaded publication by the New England Journal of Medicine have been numerous and include decreasing the availability of newer drugs for diabetes, guidelines which push patients onto insulin sooner, and the FDA needlessly worrying the public about safe (though ineffective) medications with these early warnings of investigations.

Thursday, January 8, 2009

Vytorin: To Switch or Not to Switch? That is the Question


The FDA has just released their review of the ENHANCE trial involving Vytorin. I have blogged about Vytorin, a combination of a statin medication (simvastatin) and another cholesterol lowering medication that blocks cholesterol absorption from the gut called ezetimibe (Zetia), and the ENHANCE trial many times (here, here, here, here, here, and here)


The FDA's analysis concluded that after 2 years of treatment with either Vytorin or simvastatin alone, carotid artery thickness (a marker of risk for cardiovascular disease) increased by 0.011 mm in the Vytorin group and by 0.006 mm in the simvastatin group, which was not statistically significantly different. However, the levels of LDL (bad) cholesterol decreased by 56% in the Vytorin group and by 39% in the simvastatin group, which was statistically significantly different.


Here's what the FDA concluded:

The results from ENHANCE do not change FDA’s position that an elevated LDL cholesterol is a risk factor for cardiovascular disease and that lowering LDL cholesterol reduces the risk for cardiovascular disease. Based on current available data, patients should not stop taking Vytorin or other cholesterol lowering medications and should talk to their doctor if they have any questions about Vytorin, Zetia, or the ENHANCE trial.


First, the FDA is stating that despite the fact that LDL lowering did not correlate with improvement in atherosclerosis, LDL is still a reliable surrogate marker for cardiovascular disease and thus a good target of therapy.


As I have mentioned previously, when you take a drug to prevent a heart attack or stroke, you want to know whether that drug actually decreases heart attacks or strokes (outcomes). The problem is that doing outcomes studies requires a large number of patients to be studied over a long period of time, which is difficult and costly. Therefore, many of the studies we use to make medical decisions rely on markers or proxies for disease called "surrogates." Cholesterol (specifically the bad cholesterol or LDL) is a known surrogate marker for heart attack and stroke, as is carotid artery thickness, the endpoint in ENHANCE. Though both surrogates correlate well with the outcome of heart attacks and stroke, in the ENHANCE study lowering the LDL did not cause a decrease in carotid artery thickness. Despite this, the FDA still believes that LDL is a good surrogate.


Second, the FDA states that because LDL is still a good surrogate and because Vytorin lowered LDL, depsite that fact that it failed to do any good in the ENHANCE study, the FDA recommends that patients NOT stop Vytorin. This one is more problematic.


I agree that LDL is a good surrogate, but we have been burned by surrogates before. High levels of homocysteine are linked to heart attacks, and folic acid lowers homocysteine, but when we looked at whether folic acid reduced heart attacks (outcomes), it actually caused MORE heart attacks, and is no longer recommended.


We know the lowering the LDL with a statin reduces heart attacks, and this relationship is in fact linear (the lower the LDL with a statin the lower the risk of heart attacks-see figure from 2004 NIH guideline update). The questions is whether lowering the LDL with something other than a statin, i.e. ezetimibe (Zetia) will reduce the risk of heart attacks and strokes. It may very well, but we have no evidence to date. Though ENHANCE may not have been the perfect trial to look at this, it is the only study we have using Vytorin/Zetia looking at something other than LDL, and this study was negative. Finally, it may be more about the statin than the LDL. The JUPITER study (which I have also blogged about) showed that lowering the CRP with a statin (Crestor)decreased heart attacks. LDL's were also lowered, but where CRP was elevated at the beginning of the study, LDL was relatively normal and would not have normally required a statin.
Thus, though the FDA suggests to not to stop taking Vytorin because it does lower LDL (and also does not appear to have a major safety issue), the question is whether or not you should be on Vytorin (statin plus zetia) or just a statin? Based on the figure above, by using a combination (Vytorin) instead of a statin alone to achieve LDL lowering, are you denying yourself the maximum amount of statin that you need to acheive outcomes? We don't have the studies to answer this question, but in my opinion it would be better to lower your LDL with a stronger statin like Lipitor and Crestor, then to use a weaker statin (like simvastatin) plus Zetia, i.e. Vytorin. The highest dose of Vytorin lowers cholesterol just a little bit more than the highest dose of Lipitor and Crestor, but not by much. In addition, adding Zetia to any statin will lower your LDL an additional 25%. Thus, based on the available data, it would be better to use the dose of a statin needed to lower your LDL. If the maxium dose of a statin failed to achieve the LDL to goal, or one could not tolerate the maxium dose of a statin, the adding Zetia seems a reasonable option.
Bottom Line:
1. LDL is still a good surrogate market and target for therapy.
2. The best way to lower LDL is with a statin, and lower appears to be better.
3. If you are on Vytorin, I wouldn't stop it, but would discuss with your doctor about of switching to something like Crestor or Lipitor.
4. If you are unable to reach your LDL goal on the highest tolerable dose of Crestor or Lipitor, than adding Zetia seems reasonable.


Sunday, January 4, 2009

The Problem With Insulin

Before folks like Amy Tenderich at her excellent blog Diabetes Mine gets upset with me, insulin is a miracle of modern science. Frederick Banting and J.J.R. Macleod's Nobel Prize wining discovery of insulin has saved millions of lives and helped to prevent countless complications of diabetes such as blindness and kidney failure. While patients with Type 1 diabetes, who produce no insulin on their own, rely on insulin therapy to survive, the use of insulin in Type 2 diabetes is more complicated, since patients with early stage Type 2 diabetes initially have high levels of insulin and some type 2 diabetics with prolonged beta-cell failure eventually stop making useful insulin. Though where and exactly how to use insulin in a Type 2 diabetic is debated, newer recommendations from the American Diabetes Association (ADA) are promoting earlier use of insulin in Type 2 diabetics, which may not be entirely evidence based or in the best interest of the patient. This has caused me great concern.


The Problems With Insulin


Insulin is not just another treatment for Type 2 diabetes. The main complication of insulin use is hypoglycemia, or low blood sugar. Symptoms range to feeling nervous to complete coma. Hypoglycemia from insulin is a frequent cause of ER admissions, hospitalizations, and can even cause death. For both for sugar management and prevention of hypoglycemia, patients who use of insulin require frequent blood sugar monitoring. Though these monitors have become easier to use for patients, this is still a burden as well as an added cost. In addition, for the best blood sugar control, many endocrinologists recommend a basal/bolus approach to insulin therapy which is one injection of a 24 hour long acting insulin (like Lantus) and mealtime injections of short acting inuslins (like Humalog). Thus, the basal/bolus approach requires four injections a day and several sugar checks.


Though insulin is the most effective agent for lowering blood sugar, this may not be the best thing for all type 2 diabetic patients. Three studies presented this summer at the ADA (VADT, ACCORD and ADVANCE which I have blogged about before-here and here) not only failed to show cardiovascular benefit with aggressive diabetes control, but there was substantial hypoglycemia in the intervention arms (which used more insulin) and in ACCORD, the study was stopped early because of increased deaths.


In the January issue of Diabetes Care (the ADA's journal which each year publishes updates to their guidelines), a paper explaining how to interpret these studies come to similar conclusions of my previous posts, mainly that good diabetes control (A1c less than 7%) is still very important. They also mention " it is biologically plausible that severe hypoglycemia could increase the risk of cardiovascular death in participants with high underlying CVD risk. This might be further confounded by the development of hypoglycemia unawareness, particularly in patients with coexisting cardiovascular autonomic neuropathy (a strong risk factor for sudden death). Death from a hypoglycemic event may be mistakenly ascribed to coronary artery disease, since there may not have been a blood glucose measurement and since there are no anatomical features of hypoglycemia detected postmortem."

In other words, it may have been hypoglycemia, which is caused primarily by insulin, that killed the aggressively treated diabetics.


In fact, a recent commentary in JAMA similarly mentions that "the paradox that blood glucose levels are strongly associated with the risk of cardiovascular disease but that glycemic control does not prevent cardiovascular disease may perhaps be explained by insulin resistance or hyperinsulinemia." and "If insulin levels are toxic to the cardiovascular system, then treatments designed to reduce insulin levels rather than glucose levels might be associated with a reduced risk of cardiovascular events in patients with type 2 diabetes."

In other words, glycemic control is important, but other factors such as insulin levels and insulin resistance might be more important, so driving down the sugar with insulin in type 2 diabetics may not have been the way to go.



The Problem With the Older Diabetes Pills


The two most commonly prescribed (and guideline recommended) pills for diabetes are metformin and sufonlyureas. They are generic, inexpensive, have a long track record, and will lower blood sugars in type 2 diabetics. The problem with these medications (beside side effects, particularly hypoglycemia with sulfonylureas), is that they only work for a short period of time.

Analysis have shown that though both metformin and sufonlyurea lower blood sugar; and, compared to usual care, those whose goal A1c was less than 7% had lower microvascular (eye and kidney problems) complications; about half of all patients taking either of these medications lost diabetes control by three years, with the vast majority losing control at 9 years. Though a recent report on the UKPDS showed that just being in the intervention group reduced heart attacks and strokes 10 years after the follow up period, imagine how many heart attacks and strokes might have been prevented had patients maintained glycemic control over a much longer period of time!


It should be no surprise that patients fail on metformin and sufonlyurea because they primarily work by lowering sugar, and don't seem (especially with sufonlyurea) to address the underlying defects of type 2 diabetes which are insulin resistance, beta cell dysfunction and glucose regulation. The good news is that newer agents for diabetes do address this. Published on December 7th, 2006, in one of the largest diabetes studies ever done, the ADOPT trial showed that Avandia, a thiazolidinedione or TZD, substantially reduced loss of diabetes control compared to both metformin (Avandia 32% better) and sufonlyurea(Avandia 63% better). TZD's work by reducing insulin resistance, and also can improve beta cell dysfunction and both effects were seen in ADOPT. After 5 years of treatment, only 15% of patients failed on Avandia monotherapy. This is far better than the failures from UKPDS.


The Problem With the Diabetes "Experts"

You would think that with all the problems with insulin and the older diabetes pills that diabetes experts and researchers would welcome newer therapies for Type 2 diabetes, but the trend is just the opposite.


In the editorial to the ADOPT study, Dr. David Nathan, author of the current American Diabetes guidelines stated that "given the modest glycemic benefit of rosiglitazone and higher cost metformin remains the logical choice when initiating pharmacotherapy for type 2 diabetes." Yet, at this point in time, even he seemed convinced that Avandia was a better second choice then sulfonylurea, stating "the benefits of rosiglitazone over glyburide, which is often not recommended for older patients because of its increased risk of hypoglycemia, are more convincing. "

However, only a few months later (2/1/2007), in response to the recent approval of Januvia, Dr. Nathan published this Perspective piece in the New England Journal of medicine , in which he railed against new diabetes medicines stating that newer diabetes drugs like Avandia and Januvia , "are generally no more potent, and often less effective in lowering glycemia, than the three oldest classes (insulin, the sulfonylureas, and the biguanides), all of which are more than 50 years old. Moreover, the newer classes are uniformly more expensive and are associated with adverse effects — some that are shared by the older drugs, but others that are new." In essence, Dr. Nathan is suggesting (despite the problems with insulin and the failure of the older drugs that I mentioned above), that we just stick with the status quo, and use caution before approving newer diabetes medicine. See my Letter to the Editor in the NEJM criticising this position.


The current guidelines for the medical management of diabetes (which are taken directly from Dr. Nathan's previous consensus statement) state the patients with Type 2 diabetes should be started on metformin, and when that fails, add either sulfonlyurea, insulin or TZD. The language of that paper states that TZD's are an option, but are expensive and cause side effects. In the more recently published consensus statement (also authored by Dr. Nathan) that will likely be adopted in the 2009 guidelines, Avandia and Januvia are not recommended. The recommended choices of treatment for type 2 diabetes are metformin, sulfonylurea and insulin. Less preferred are Actos and Byetta. Thus, given that we know the older medications fail, the newer guidelines will likely push more and more type 2 patients to use insulin. I have previously commented that this trend is already happening.


I recently blogged about conflicts of interest that go beyond the drug companies, and used the example of differing prostate cancer screening guidelines. The government's guideline (which wants to save money) does not recommend this practice, where as the urologist's guidelines (who benefit from aggressive screening) do recommend prostate cancer screening. Both guidelines use the same studies, and neither guideline is right or wrong, but must be interpreted from the perspective of the authors.


So, given the problems with insulin and the older diabetes pills as elicited above, why would the "experts" of the new guidelines recommend these therapies over newer therapies with potential benefits (and leave out some newer therapies altogether)?



One answer (in my opinion) is that endocrinologists make recommendations that will lead more patients toward insulin is because they have an incentive to do so. Most patients with type 2 diabetes are cared for not by specialists but by primary care physicians. Though many primary care physicians are quite comfortable using insulin, many referrals to endocrinologist come from primary care because a patient has failed pills and now needs to be started on insulin. Insulin therapy requires substantial time, education and close patient follow up. This is time that many PCP's simply don't have, whereas most endocrinologists work with a certified diabetes educator who is specifically trained just for this purpose.



One can look at the failure of Exubera, Pfizer's inhaled insulin, as evidence of how many endocrinologists cling to injections. Pfizer did not pull Exubera because it didn't work (worked great) or that patients didn't like it (my patients and I were extremely upset when this was pulled), but because endocrinologists didn't prescribe it. Whereas endocrinologist see starting insulin therapy as common and easy, my perspective as a PCP is that patients do not want to take insulin and see it as an absolute last resort. (Based on the evidence above, I would tend to agree).



The Problem With the New ADA Guidelines

To be fair, not all endocrinologists agree with the ADA or Dr. Nathan, similar to the way not all Republicans agree with George Bush. However, guidelines, especially ones from such as prestigious group as the ADA, have a tremendous influence on the way that primary care physicians practice medicine. Thus, these guidelines will likely have a tremendous impact on the way future diabetic care is delivered.

The problem with the new guidelines is that they been extremely affected by two factors: one poorly done, controversial study on Avandia (see here ) and one (or a few) highly influential endocrinologist, like Dr. Nathan, who sees no need for new diabetes meds, and would prefer that once patients lose control on the two older medicines most commonly used (which most will based on the data), that they be started on insulin. Furthermore, these recommendations which will encourage more insulin use are coming from specialist who might have an incentive to make such recommendations. Thus, these recommendations are not entirely evidence based and seem not to be in the best interest of patients to whom insulin is a burden and potential danger.

Wednesday, December 31, 2008

Happy New Year / Anniversay and Best and Worst in Medicine 2008

I started this blog one year ago, and has been a phenomenal experience. I have enjoyed posting and reading your responses. I had no idea how much work a medical blog would be and have a great amount of respect for physicians like Kevin Pho of KevinMd and Robert Centor of DB's Medical Rants who also manage a heavy clinical load and are for more prolific then I have been. Though physician blogs range from sharing experiences to deliberating they health care system, my main purpose of this blog was to clarify medical issues that are discussed in the media. In today's New England Journal of Medicine, Susan Dentzer discusses some of the pitfalls of health care journalism. I am hopeful that this blog has helped filled some of these gaps. Here are some of the Best and Worst of 2008.

THE WORST
Vytorin is Out
The EHANCE trial which I discussed in Vytorin and Zetia: What to do now? failed to show any major benefit over generic simvastatin alone. The company tried their best (as I shared the letter the sent me in Dear Doctor: Vytorin ) the make excuses, but the reality is that they never proved the benefit of having two drugs to lower cholesterol when a higher dose of a statin could do the trick. Whether or not it is the LDL cholesterol or the drug used to lower it is still debateable, but for now, statins should be used to achieve cholesterol goals. However, if goals can not be acheived with a statin alone or statins can not be tolerated adding Zetia is not a bad option as showe in the SANDS trial (Zetia In, Vytorin Out)

Too Low Could Be Bad for Diabetics
The media got it wrong when the reported that the ACCORD study was stopped (ACCORD Study: Don't stop your diabetes medicines, Please! ) Both groups did much better than would have been expected, and some argue that the trial should not have been stopped. The message got out that lowering A1c might not be important, but it clearly is. However, their may be problems if you push the A1c too low.

Side Effects, Side Effects, Side Effects
Many of my posts (and the ones that got the most responses) regarding over-hyping side effects of drugs. The Wall Street Journal reported that Lipitor made women "stupid" (Lipitor and Memory Loss), Spiriva could cause stroke ( Spriva and Stroke: FDA warnings create buzz and confusion ), kids on Singulair might commit suicide ( Vytorin and Singulair: Problems for the Company, Confusion for the Public ) and of course concerns about the only new drug for the single leading preventable cause of death in the US in a decade ( Where's the Good News about Chantix? ) Some of this may be due to the fact that the FDA, under much public scrutiny, decided that it would report to the public drugs they were investigating, even if there was no clear evidence that these drugs were harmful ( More FDA warnings should not be cause for worry ). The bottom line is that there is no perfectly safe drug. Doctors and patients must balance the risk of medication side effects with the benefit it provides. If you are at high risk for a heart attack, it is probably worth risking a rare (though serious) side effect or Lipitor.

Cipro Causes Tendon Ruptures
That said.... there are some side effects, that even if uncommon deserve attention. In my post Tendon rupture with Cipro? FDA caves to Public Citizen, I question the FDA's decision to make a label change to Cipro, suggesting that they were merely responding to public pressure. I still contend that the announcement was not helpful to physicians because no real numbers were released, helping to determine a risk benefit ration. However, the many responses I got to this post suggest that there may be much more to this story. The difference between the Cipro example and Lipitor is that there are lots of other classes of antibiotics that can be used in most cases, whereas the best drugs to treat cholesterol are statins. In addition, the numbers for even the rare side effects of statins are well documented. Not so much for tendon ruptures with quinolones.

Prevention Magazine Creates a Scare
In probably the worst example of health care journalism, Men's Health Magazine published an article about 8 drugs doctors would never take (The truth on the 8 drugs doctors wouldn't take). I learned about this from a patient whose horrible asthma was finally well controlled on Advair, but stopped becuase her fiancee read that Advair could kill you. There were many problems with this article, but the worst was that they never actually asked physicians about the drugs they wouldn't take. I did (via Sermo) and most disagreed with the list (If you want to find out the 8 drugs doctors would never take....ask them!). PLEASE be careful of what you read, and talk to your doctor before stopping any medication.

THE BEST
Asthma Inhalers go Green
Asthma inhalers are no longer made with ozone depleting CFC's. This is good news, but some patients (and even physicians) were not aware of this and some of the implications, including direct costs to the patient. Hopefully, this post clarified some of the issues.

Salmeterol Issue Clarified
With so much negative (and often incorrect) information about asthma medications, specifically products containing long acting beta agonists (LABA's) such as Advair and Symbicort, it was great to post Good News for Asthma Patients which indicated that if LABA's were taking with an inhaled corticosteroid, they were safe. The FDA recently met on this (The Lowdown on LABA's) and seemed to agree. Now if only they will take away that boxed warning on Advair and Symbicort (Dear FDA, Remove the Boxed Warning from Advair and Symbicort )

Generics Just Fine
There is a lot of confusion about generics, but a study this year reported in JAMA showed that generics are generally just as good. With the high price of medications and our economy in the tank, most patients are switching to generics when they can. Hopefully they feel more comfortable doing this. (Generics Just As Good As Brand Name )

Students Not Going Into Primary Care
OK, this is obviously not good news, but I listed it under "best" for two reasons. First, I was one of the authors on the study showing that only 2% of US students are choosing to go into primary care internal medicine (Factors Associated with Medical Students' Career Choice Regarding Internal Medicine: Pay is Not Really One of Them!), and was proud to see the article published and discussed. More importantly, the article came at a critical time. The presidential debates had focused on covering the ininsured and decreasing the cost of health care. No one (except for thousands of bloggers) were really discussing the primary care crisis. I am hopeful that this study (and others that coincidentally came out at the same time) changed the discussion. We are now seeing the first time that the Obama administration has recognized the problems in primary care.

JUPITER: CRP Likely a Factor
OK, I am probably a little biased on this one too since we were one of the Jupiter sites ( Jupiter is Out, and the News is Good!). However, this study was important becaused it showed that there is more to the story than just LDL, since the patients in this study would not have normally qualified for statins. The anti-pharma and drug safety people will be critical of this study for a while (Remember when Sidney Wolfe wanted Crestor pulled from the market? Seems like Crestor has no more side effects then placebo, at least in this study). However, the data hear is pretty strong and I am checking CRP's on most adults.

Monday, December 22, 2008

CT Angiography, Dr. Nissen and Conflicts of Interest

For the record, I am not in favor of CT angiography, primarily due to the large doses of radiation. EBCT (Heartscans) have yet to be proven, but seem a much better technology. Last week the Wall Street Journal (via KevinMD) reported on a study in the Journal of the American College of Cardiology looking at the diagnositic accuracy of this test. Though the investigators (the lead author being a Netherland's radiologist) stated that CT angiography was " reliable for ruling out significant CAD in patients with stable and unstable anginal syndromes," what was reported in the media was Dr. Steve Nissen's comment and editorial that "in more than 50% of subjects, CT angiography ‘detected’ coronary obstructions that simply were not there.” Dr. Nissen's comments are not incorrect, and I do agree with his position on this one, but it should come as no surprise that a cardiologist (especially one's whose research primarily involves conventional angiography) comes out against CT angiography.

Conflicts of Interest
Conflicts of Interest in the medical field as reported in blogs and in the media usually concern the pharmaceutical industry. There are plenty of folks out there (Dr. Carlat and Center for Science in the Public Interest to name just a few) who bring attention to this. There is no question that a drug study sponsored by the drug's maker should be interpreted with caution. However, this doesn't mean that the data should be ignored. For example, when the Toyota car salesman tells you that the Prius is one of the most fuel efficient and reliable cars, he is certainly trying to get you to buy a Prius, but it doesn't mean his data is wrong or that you shouldn't buy the Prius. You just need to interpret his "data" with some caution. This concept does not just apply to the pharmaceutical industry, but other experts or groups of experts that make recommendations that may be biased based on other factors such as research, research interests, specialty, and even political motivation.

Conflicts in Guidelines
Guidelines are the best examples when conflicts of interest should be taken into account. The American Urologic Association currently recommends PSA testing for prostate cancer in men 50 and over. The U.S. Preventive Services Task Force not only states that "the current evidence is insufficient to assess the balance of benefits and harms of prostate cancer screening in men younger than age 75 years" but also recently recommended that prostate cancer NOT be screened for in men age 75 years or older. Both guidelines are written by medical experts, and both have looked at the same studies. The difference in interpretation has to do with potential biases. Urologists who see the horrors of prostate cancer on a regular basis, likely want to eliminate this disease, and additional have a financial incentive to detect prostate cancer (the more PSA tests, the more biopsies, the more surgeries). In contrast, the USPSTF is a government sponsored agency concerned not only with the health of Americans but also the cost. If PSA screening leads to more testing, biopsies and surgeries; then this will be more costly for the health care system (especially Medicare). Thus, neither interpretation of the same data is "right" or "wrong" but must be interpreted with attention to potential biases or motivations.

Other Conflicts
Research interests are another potential conflict. Someone who researches in a particular area is not likely to discredit what has made their career. Recently, I blogged about the JUPITER study which showed that CRP may be a very important marker for cardiovascular risk. It should be pointed out that Dr. Paul M Ridker, the lead author of the study, has made his career on CRP research and currently holds a patent on the test used in this study. Political motivation can also be a factor. In my comments on the fall out of the recent FDA panel's meeting on the safety of LABA's, I mentioned that Dr. David Graham had commented against these drugs (picked up by the NY times), but that he may have been politically motivated for making these statements since he was mostly wrong back in 2004 when warning congress of the "next Vioxx" and, as part of the safety arm of the FDA, alerting the public to safety issues might increase funding to his (agreeably) underfunded division in that agency. Which brings me back to Dr. Nissen.

Dr. Nissen's Potential Conflicts
Dr. Nissen is a cardiologist at the Cleveland Clinic, which recently announced that it would make its faculty's conflict of interest public. Interestingly,they report that Dr. Nissen has no conflicts, and though he does consult for a number of drug companies, he donated "all honoraria or consulting fees directly to non-profit organizations." First, no conflict is reported because the Cleveland Clinic does not consider research funding as a conflict of interest. In fact, Dr. Nissen, who has come out strong against Avandia, has had publications and research supported by Takeda, which makes Actos, Avandia's major competitor. In addition, the anti-pharma folks (correctly) suggest that any gift or relationship can pose a potential conflict. I do not criticize Dr. Nissen for his likely excellent consulting work, and would not do so even if he kept the money (since an expert should be paid for his time and expertise), but donating the money does not exempt him from any conflict. Finaly, and possibly most importantly, Dr. Nissen gained fame (which he deserves) for bringing attention to Vioxx, and helped get it removed from the market. Because of this attention (and the attention from Avandia) Dr. Nissen has been mentioned as one of the candidate to head up the FDA. Thus, until President Obama picks the person for the job, one should expect (as in the case of CT angiogram) that any comments from Dr. Nissen will likely reflect his desire to protect the public from unnecessary testing or the dangerous medicines from profit hungry drug companies.


My beef with Dr. Nissen is not that his research is funded by drug companies or that he feels donating honorarium exonerates him from conflicts of interest. Rather, as I have blogged many times (here, here here and here), his one poorly done study which scared the public and physicians about Avandia, has radically changed the way type 2 diabetes is being treated (and not for the good of patients in my opinion) and no one is calling him out on potential conflicts or motivations.

Saturday, December 20, 2008

Rough Times for New Diabetes Drugs: The Diabetes Conspiracy Part III

It seems as if there are some individuals or groups of folks that just don't want new diabetes medicines. If diabetes was not a major problem in our country and/or if most patients with Type 2 diabetes were well controlled, then maybe this would not be so much of a problem. However, increasing rates of diabetes in the US have reached epidemic proportions, and most patients with Type 2 diabetes are not under good control (as defined by an A1c under 7%).

In the latest blow to Type 2 diabetics, the FDA recently announced that it will have stricter criteria before approving any new diabetes medications. Specifically, they are looking at cardiovascular risks:

We need to better understand the safety of new antidiabetic drugs. Therefore, companies should conduct a more thorough examination of their drugs' cardiovascular risks during the product's development stage," said Mary Parks, M.D., director, Division of Metabolism and Endocrinology Products, Center for
Drug Evaluation and Research (CDER), FDA


Though this may sound like a good thing, it means that it will take a lot more effort (time, money, patients needing to be enrolled in trials), for new diabetes pills to be approved. As the Wall Street Journal points out, this affects pending approval applications for one new diabetes drug called saxagliptin (made by Bristol-Myers Squibb Co. and AstraZeneca ) as well as a once weekly version of Byetta (made by Eli Lilly & Co. and Amylin Pharmaceuticals )

There is no question that there ought to be a balance between safety and efficacy when it comes to new drugs. Drugs that have substantial risks should be studied more carefully, even if that means delaying needed treatment for patients. The problem here is that the delayed approval for newer diabetes medicines which are currently needed is due to one highly publicized and poorly done meta-analysis, which has not be substantiated and in fact has been pretty much been disproven based on recent studies.

In the The Diabetes Conspiracy (Part I), I mentioned how the newer diabetes pills, specifically Advanida and Januvia, were being blamed for the increased cost of diabetes care, when in fact newer insulins were not only contributing equally but also being prescribed at a much faster pace. In Avandia Vindicated (Again): The Diabetes Conspiracy Part II , as well as other posts, I go over study after study which shows that there is no real heart attack risk seen with Avandia, since we now have randomized studies where over 26,000 patients have been studied for over 3.5 years, of which more than 15,000 patients took Avandia and showed absolutely no difference in heart attacks or myocardial ischemia.

The FDA's decision to make it harder for newer diabetes drugs to be approved based on one poorly done, highly publicized and likely politically motivated study is the first action to likely have a real impact on patients. If older (and cheaper) drugs worked so well, then this wouldn't be a problem. However, the reality is that we need new drugs to get a handle on this very difficult to control disease. However, there are some that would like to turn back the clock, and only use older medications which we know aren't working. These folks are waving the banner of safety to defend their position. The next step, which will go beyond headlines and also have real patient impact will be the new diabetes guidelines, which will be published in just a few weeks. When these come out, I will comment on what I anticipate to be ridiculous and impractical recommendations in The Diabetes Conspiracy Part IV.