Monday, January 19, 2009

Statins and infection control

I have any number of patients who take statin drugs(1) to lower their cholesterol levels in order to reduce their risk of unwanted cardiovascular outcomes such as stroke or heart attack. I would prefer, in an ideal world, that these patients control their risk factors with healthy habits in diet, exercise, and weight control, but, alas, this is not a perfect world but rather one in which many lack time, will-power, and resources to make these changes in a timely fashion.

In addition to their ability to reduce cholesterol production and increase LDL clearance by the liver, these drugs are known to reduce inflammation in the body. Inflammation is a good thing as a first responder to infection or injury, but inflammation gone amok is part of the pathological process that increases tissue destruction in Alzheimer's disease, athersclerosis (hardening of the arteries), cancer, arthritis, and severe infections.

Danish and American researchers theorized that the anti-inflammatory effects of statins could improve outcomes for patients admitted to the hospital for pneumonia; those persons protected from over-exuberant inflammation by statins might be more likely to walk out of the hospital rather than being rolled out through a basement door on a gurney. They examined the hospital records for nearly 30,000 patients over 7 years looking for pre-admission statin use as correlated with the risk of sepsis and death associated with serious pulmonary infections. Indeed, those patients currently on statins had a 31% better chance of being alive 90 days after their pneumonia diagnosis compared with those in a statin-less state.

Wondering why? Dr. Kasturi Haldar of the Center for Rare and Neglected Diseases (I kid you not) informs us in an editorial in the same Archives issue that it's all about G proteins. Statins block the isoprenylation (whatever that is) of small G proteins. This decreased prenylation business protects against Alzheimer's disease because the beta-amyloid guck that gums of the brainworks in the disease depends on the breakdown of amyloid precursor protein, a process which in turn counts on prenylated G proteins.

In infections, little G proteins increase the inflammatory response which can fill the patient's airway with fluids and white cells instead of the air upon which we depend. G proteins might also promote the bacteria's ability to enter cells and prosper therein. As in Alzheimer's, as statins decrease the prenyl pool upon which G protein function depends, the decreased inflammatory response may reduce the inflammatory response.

So if you are ever called upon to weigh the decision of statins or not in your future health care plan, consider this side benefit of the use of these drugs.
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(1)Lipitor, Crestor, simvastatin, lovastatin, fluvastatin
(2) Thomsen, RW, et al. Preadmission Use of Statins and Outcomes After Hospitalization With Pneumonia. Arch Int Med Vol 168 (No.19), Oct. 27, 2008.

6 comments:

Beverly said...

I find this very interesting. When I started seeing a cardiologist, he put me on Lipitor, along with the other heart meds I'm on. I trust him, so I didn't question him, even though I did not have high cholesterol prior to the prescription. From everything I had read, I read the benefits, and I thought that if it would help prevent strokes and heart attacks, I should do it. I have had no side effects from the drug, for which I'm glad.

By the way, I purchased the book, "A Sick Girl Speaks" and it really contains good advice for the patient.

kenju said...

For over a year, I was on simvastatin. My high cholesterol did not respond to it as well as my doc. wanted, so she put me on a higher dosage 3 mos. ago. From the start of the increased dosage, I have had muscle pains, weakness in my legs and trouble sleeping. I will have labs done this week, and I am anxious to see if my cholesterol has come down. If not, I will be going back to the lower dosage. The side-effects are not worth it for me.

Anonymous said...

There are studies listed at what your doctors dont tell you, that state just the opposite of all this.... that statins increase the risk of heart attack and alzheimers, so I dont know what to believe. The site is www.wddty.com supposedly with clinical trials to prove it all.....
How is a patient suppose to decide anything these days?

femail doc said...

Hi Beverly: I'm glad you're reading "Sick Girl Speaks." I think it's a remarkable book.

KJ: I hope your cholesterol comes down, but I wonder if those side effects are worth it even if you're cholesterol reaches target levels.

Anon: I feel the research literature supports a strong protective effect of statins on heart attacks. Their benefits with respect to Alzheimer's are more theoretical than actual, and I certainly wouldn't put anyone on them with the goal of preventing anything other than cardiovascular disease.

It is hard to know what to believe. I will have to look around the wddty.com site with respect to its clinical trial evidence supporting those claims. I think we doctors may reach too quickly for meds, committing youngish people with borderline cholesterol levels, in the case of statins, to years of medication without clear outcome data. I have a personal 8 point formula for medical decision making that I will post about soon that may help you with your personal healthcare decisions.

Anonymous said...

thanks a lot, really

Anonymous said...

What is your take on low-dose statins?

I take 2 1/2 mg of Crestor daily and 1000 mg of Lovaza. My TC is 190 but my LDL is a tad elevated.
My CRP is 11 so that is why I'm taking the tiny dose of Crestor. I get horrible leg cramps on normal doses so I have convinced my MD to let me try this low dose idea. For six months I've followed a low-fat sugarless hifiber diet full of legumes whole grains and veggies.
I've lost 30 lbs but haven't incorporated much exercise yet because of spinal and knee difficulties. I can't wait to see if these efforts will affect the numbers. I feel better without the sugar and bad fats.