Do calcium supplements really cause heart attack: Controversy

Posted: Sunday, August 8, 2010 | Posted by Debajyoti Datta | Labels: 1 comments

In a recent study published in the British Medical Journal, researchers found a 30% increase in myocardial infarction (heart attack) with the intake of calcium supplements. Already several other researchers have questioned the validity of the conclusions of the study.

Let us see what the questions raised are.
Firstly, the study included 15 trials, that are 15 different studies, but the caveat is that patient level data was available for only 5 studies. What this means is that direct data was available for only 5 studies, in case of the other 10 studies no direct data was available. But the researchers have based their findings on these other 10 studies also.

The second question that has been raised and which is significant is that there is no linear correlation between the dose of calcium and the incidence of heart attack. This means that increased doses of calcium does not increase the risk of heart attack. Now if calcium really does cause heart attack, the findings should have been opposite, with increased doses of calcium there would have been increased risk of heart attack. This finding seriously contradicts the conclusion that calcium causes heart attack.

Thirdly, out of the 15 trials included cardiovascular outcomes were either incomplete or absent in 7 trials. This means that the data regarding heart attack was either incomplete or absent in 7 of the included studies. Now this is a serious methodological flaw.

Fourthly, the researchers have not mentioned whether there was adequate control for other confounders like smoking or hypertension (increased blood pressure). This is important because smoking or hypertension may them-selves cause heart attack, hence they are called confounders. To explain simply, let us suppose that a smoker is taking calcium supplements and has a heart attack. Now we cannot say that the heart attack was due to calcium supplements because smoking also causes heart attack. Thus the validity of the study can be questioned, as it did not address these issues.

The findings of the study are open to question. We should not adopt a knee-jerk reaction as calcium supplement is a cheap measure to prevent osteoporosis and most Indians are deficient in calcium. The findings need to be validated by further research. In the meanwhile, there is no cause for concern.

Links:

Problem of arthritis treatment in elderly

Posted: Friday, August 6, 2010 | Posted by Debajyoti Datta | Labels: 1 comments

My father complained of pain in his right knee about one year ago. Initially he ignored it, thinking it to be due to overexertion but gradually the pain increased in intensity. There was restriction of movement in of the right knee joint. On examination, he was provisionally diagnosed as having osteoarthritis of the knee, confirmed with X-ray. He was prescribed Diacrein tablets and Aceclofenac 100 mg for pain control along with antacids. What happened next highlights the problem of treatment of arthritis in the elderly.

His arthritis was well controlled with medications. But after about 7 months on the treatment, he started feeling shortness of breath when he used the stairs. His blood pressure also spiked. When I examined him, I thought I have heard an ejection systolic murmur. Understandably I was worried. All the bad diagnoses came to my mind. He was examined by a cardiologist, my teacher actually, but he disagreed about the murmur. To establish a diagnosis, an ECG, chest X-ray and echocardiography was performed. Nothing was found. The cardiologist asked to discontinue the Aceclofenac and arranged for follow-up. A coronary angiogram was scheduled to be performed if the shortness of persisted on follow-up. On discontinuation of aceclofenac, my father did not complain of any shortness of breath. Presently, his arthritis is well controlled with acetaminophen (paracetamol).

This small anecdote demonstrates the problem in the control of pain in elderly arthritis patients besides the gastrointestinal problems caused by NSAIDs. Treatment of pain with Non steroidal anti inflammatory drugs (NSAIDs) causes significant cardiovascular problems. Several studies have shown NSAID use in elderly is an independent risk factor for hypertension (links given below). NSAIDs block the cyclooxygenase enzyme, nonselective NSAIDs block both COX-1 and COX-2 isoforms. COX-1 synthesize prostaglandins which are responsible for vasodilation and COX-2 produce prostaglandins which maintain diuresis and natriuresis. NSAIDs, thus may hypertension either by blocking the natriuresis causing sodium and water retention and by blocking vasodilation and production of vasoconstricting endothelins. A careful history taking is therefore of paramount importance while NSAIDs are prescribed to elderly as hypertension is a major risk factor for a variety of cardiovascular problems like myocardial infarction, stroke etc.

Currently there is interest in another novel group of drugs, which are CINODs (Cyclooxygenase inhibiting nitric oxide donators), which have much favourable gastrointestinal profile, and less chance of development of hypertension. As far as I know, at present CINODs are not marketed in India, but the introduction of CINODs will open up a new option arthritis treatment.

Links:

NSAID and hypertension
1.                  http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1381681/
CINODs

Naturopathy and Blasphemy

Posted: Thursday, August 5, 2010 | Posted by Debajyoti Datta | 1 comments

The guiding principles of naturopathy left me shocked. According to the Department of Ayush that promotes naturopathy, bacteria do not cause disease. Do they really believe it? Is Tuberculosis not caused by bacteria? May be they ought to look at the millions of TB bacilli multiplying within the lungs of TB patients, then the truth will dawn on them. I wonder if these practitioners of naturopathy have ever studied biology, leave alone medicine as even a student of class eight will tell you that bacteria causes disease. All their blasphemy can viewed here http://indianmedicine.nic.in/naturopathy.asp.  All diseases are same, as is their treatment is what they claim. May be when they have diarrhoea, they can treat themselves with drugs for constipation, all the treatment are same they say. I bet the result will be spectacular.

Another claim that they make is that acute diseases are our friends. Who in their right mind will make such claim? May be they can tell their philosophy to a patient dying of rabies, tetanus, pneumonia or hundreds of other deadly acute diseases. Makes me wonder what they do when they themselves are affected by so called friendly diseases.

There is a pathetic attempt at trying to impress the visitors by referring to Gandhiji. They don’t realize they are making a logical fallacy of Appeal to Authority, not that it is unexpected of them to make such a fallacy. Gandhiji may have been a virtuoso in many things but a doctor he was not. Only people who don’t have evidence to back up their claims make such attempts.

They also do a bang up job in listing their therapies. Space therapy, mud therapy, magneto therapy? Charged water? Stuff of fairy tales. Where is the evidence? Chromo therapy takes the cake in completely useless therapies. There is not an iota of biological plausibility in their claims.

If one considers that the government always says that there are not enough funds for meeting the basic health care needs of the people, the government expenditure on these completely useless therapies is totally unethical. The government fails to provide basic medicines and equipments to the hospitals because of lack of funds but it is prompt to sponsor these useless therapies. It is high time that the government stops promoting such useless therapies.