March 21, 2013

Statins and Acute Kidney Injury

Yesterday, I posted the piece (directly below) about using statins to lower cholesterol.

Today, I noticed lots of online commentary about a story published in the March 19 edition of the British Medical Journal. Based on a giant Canadian study that followed two million people aged 40 and over who used statins between 1997 and 2008, researchers discovered that those taking “high potency” dosages were 34% more likely to require hospitalization from acute kidney injury (AKI) than those taking lower doses.

Because that percentage includes only participants who were hospitalized, the study likely underestimates kidney injury from statin use, according to lead author Colin Dormuth, an epidemiologist and assistant professor at the University of British Columbia. “Our estimates are probably quite conservative,” he said.

The large study focused on statins we’re all familiar with – Crestor, Lipitor, and Zocor. Their ability to reduce cholesterol levels is well known, as are the risks. But the AKI link is apparently new; even today, the Mayo Clinic’s website listed only these four “potential serious side effects” from statin use:
  • Liver damage 
  • Muscle problems 
  • Increased blood sugar or type 2 diabetes 
  • Neurological side effects 
The Numbers
So, how did the researchers define “high-potency” dose?
  • Crestor: 10mg or more 
  • Lipitor: 20mg or more (20mg was my prescription)
  • Zocor: 40mg or more 
Just how statins trigger kidney problems is still unclear. The renal issue may be related to the statin / muscle problem we already know about. Studies have also shown links between statin use and protein in the urine, typically a sign of kidney disease.

According to Dormuth, statins block the production of CoQ10, a compound that helps process food. That particular effect might relate to kidney dysfunction, too.

What's a Patient to Do?
So, if we’re taking a statin now, what are we to make of this news?

First, we should initiate a conversation with our doctor, if she doesn’t bring it up first. Luckily, there are simple blood and urine tests to monitor kidney function.

I thought of my 2013 mantra “less is more” when I read what lead author Dormuth said: "The lowest dose of statin required to achieve therapeutic goals should be prescribed."

For now, I’m glad I decided to continue my Lipitor holiday.

Additional Resources
Here is a sampling of stories about statins and AKI that lit up the online medical network over the past day:
For information about statins generally: Mayo Clinic

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