Tuesday, June 19, 2012


Here's an interesting statement, in which correlation and causality are confounded:
A condition like high blood pressure is sneaky. You don’t feel it, and it generally doesn’t cause any outward signs or symptoms. Yet it silently damages blood vessels, the heart, kidneys, and other organs.
So let's think for a moment about causality - if folks with hypertension also are more likely to have blood vessel damage, does that mean it is caused by the high blood pressure?  Obviously, not.  There could be a third factor that's causing both.

So the authors move on:
High blood pressure — also known as hypertension — isn’t a disease. It is a sign that something is wrong in the body. In some people with hypertension, the culprit is a narrowing of the arteries supplying the kidneys (renal artery stenosis), or an overactive thyroid gland (hyperthyroidism) or adrenal glands (aldosteronism). When these are treated, blood pressure drops back to normal. More often, though, doctors find no underlying cause for high blood pressure. This condition is called essential hypertension.
So, in this analysis from the smart folks writing this magazine for Harvard, the fact that 80% of those with hypertension can reduce their BP back to normal by restricting carbs isn't even worth mentioning.  That is inexcusable.  It is not a secret, it's a treatment that requires no medication, and has as side effects the following:  proven superior results (by interventions studies up to one year) for weight loss, lipid profile improvement, reduction of gout, and reduction of NAFLD.  In short, there's absolutely no drawback to this treatment.   

Back to the causality v. correlation issue:
High blood pressure contributes to the development of stroke, heart attack, heart failure, and kidney disease. In the United States, it directly accounts for about 60,000 deaths a year and contributes to another 300,000.
This is statistical gymnastics - neat tricks but only as accurate as the assumptions of those doing the calculations.  The fundamental question - is high blood pressure a cause of or a correlate with the other diseases of civilization? - has not been answered to my knowledge aside from the fact that it seems to be a correlate.  The evidence of that is that the best intervention for controlling HBP is also the best intervention for treating the other correlates of HBP, which are also correlates of metabolic syndrome, all of which get worse when folks are sick enough to be diagnosed as "diabetic."  IOW - did those folks suffer from the HBP or did they suffer from the underlying problem - lack of glycemic control - for which HBP is only one of several correlates?

Interesting study, but hopefully, upon review, you will see the baked in correlation v. causality issue here:
These researchers looked at the 1,007 men and women admitted to the hospital over a 10-month period for any potentially heart-related problem. These ranged from chest pain and fainting to heart attack, heart failure, atrial fibrillation, and pericarditis. In this group, 69% had been diagnosed with high blood pressure before being admitted to the hospital. Each person was followed for one year. At the end of that time, 17% of those with high blood pressure had died, compared with 9% of those with normal blood pressure. Rehospitalization for a cardiac problem followed the same pattern: 31% of those with high blood pressure, and 18% of those without (American Journal of Cardiology, published online, Aug. 24, 2011).
But, the smart folks writing this magazine want you to know there's hope:
But there is actually good news about high blood pressure: there is a lot a person can to do help keep it in check, and even prevent it from occurring in the first place.
How? The National Heart, Lung, and Blood Institute; the Centers for Disease Control and Prevention; and the American Heart Association offer these recommendations:
  • Achieve and maintain a healthy weight for your height.
  • Exercise regularly.
  • Eat a diet that is rich in fruits, vegetables, and whole grains.
  • Limit sodium intake to under 2,300 milligrams a day (one teaspoon of salt), and get plenty of potassium (at least 4,700 mg per day) from fruits and vegetables.
  • Drink alcohol in moderation, if at all.
  • Reduce stress.
  • Monitor your blood pressure regularly, and work with your doctor to keep it in a healthy range.
(sarcasm alert!)...and when all that doesn't work, keep on popping those pills.  It frankly wouldn't take all those big dollar, big brain, high credentialed organizations to give you this kind of nearly pointless, assinine advice.  I could have done that for a lot less than they have been paid over the years. (This ends the sarcasm alert)

In a follow up post, I'll throw out a bit of speculation about the "lies, damned lies, and statistics" aspect of the high blood pressure concern. 

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