nos-trum. pronunciation: \nos'-trum\. noun. Etymology: Latin, neuter of noster our, ours.
1. a medicine of secret composition recommended by its preparer but usually without scientific proof of its effectiveness.
2. a usually questionable remedy or scheme.
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Thursday, March 18, 2010

Sudden Cardiac Death Less Likely in the Obese?

The American College of Cardiology meeting in Atlanta this week included a presentation that makes the above claim.  The abstract is here.

Seems counter-intuitive, doesn't it?  But, if we look at the data there are some caveats.  First, they were looking at people with a history of heart failure, irrespective of whether they were obese or not.  So they were Sickies already.  But the abstract doesn't break down the obese and non-obese groups by age.  What if the low-weight people tended to be older?  Wouldn't that be a confounding factor?  We don't know...

Second, they used BMI, or Body Mass Index, as their measure of obesity.  It's a commonly used measure, but it's important to remember that it is an overall index of body fat:  it's useful, but you just use height and weight to calculate it.  The limitations are:  it may overestimate body fat in athletes and others who have a muscular build, and it may underestimate body fat in older persons and others who have lost muscle mass.

You see where I'm going here, right?  If you're Methusaleh and skinny, you may have more fat than BMI says you do.  More fat, plus heart failure, plus older = higher risk of sudden cardiac death.  Suddenly (no pun intended), the research makes sense.

In any case, there's no strong lesson from this research.  DO NOT go gain weight to lessen your chances of dropping dead.

I hope that strategy sounds stupid enough...

To round out the discussion, here's the data:  among 1231 there was a 41% risk increase per 5 unit BMI reduction (the p-value was 0.01 which is good).  Graph below.  My BMI is 29, so I'm just barely in the higher risk group (BMI<30)



Supplementary-Nugget-Of-Information-Not-Emphasized-In-The-Study:  there was a 23% risk increase per 5 unit BMI reduction (p=0.009)  for all-cause mortality.

That is, the skinnier you are the more likely you are to die from any cause.  Woof...

But don't fret, or we will be SOTD*. 

*Scaring Ourselves to Death


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