Could statins help prevent lung and infection deaths?

By Sara Finlay

BMJ Group News

What do we know already?

We already know that statins work well to prevent heart attacks and strokes in people with or at risk of heart disease. One of the original studies to show this was the Anglo-Scandinavian Cardiac Outcomes Trial, also known as ASCOT, which began in 1998. In this study, more than 10,000 people in the UK, Ireland, and Scandinavia with high blood pressure were randomly allocated either the statin atorvastatin or a placebo (a dummy treatment). The statin was shown to be so much more effective than the placebo at preventing heart attacks and strokes that the trial was stopped early, in 2003. Since then, most of the people in the study have been taking statins.

What does the new study say?

The new study was a follow-up of the 4605 people in the ASCOT trial who lived in the UK. It looked at the number and causes of deaths in this group since the study began, and compared the results of those who were originally allocated statins and those who were not.

The study found that the rate of death was 14% lower in those who were originally allocated statins. Of the 4605 people, 460 (20 in 100) of the original statin group had died, compared with 520 (23 in 100) of the placebo group.

However, this wasn’t because of fewer heart attacks and strokes in people who originally took statins. Surprisingly, it was largely due to a lower rate of death from infection or respiratory illness: 74 people in the statin group, compared with 112 people in the placebo group.

How reliable is the research?

The original ASCOT trial was a large, randomised, double-blind study, which is the most reliable kind of trial to find out whether a treatment works.

The new study is built on this good-quality trial, but is much smaller. Also, the original study was not set up to test the effects of statins on respiratory illness and infection. A study that intended to do this might have been designed quite differently, so we need to be cautious about the results.

Even the new study wasn’t designed at the outset to look at rates of death from respiratory illness and infection, but rather to monitor rates of death from heart disease. It was only when the researchers noticed a marked difference in deaths from other causes that they began subdividing the different causes. This means the results are less reliable, and the researchers warn that the difference between the two groups could have been down to chance.

It’s also worth noting that, taken alone, neither death rates from infection nor death rates from respiratory illness showed a big difference between the statin and placebo groups. It is only when the rates from these two causes are pooled together that the results become stronger than you would expect to see by chance.

The study was paid for by Pfizer, which makes atorvastatin. It’s very common for drug manufacturers to fund studies into their medicines.

What does this mean for me?

More research is needed before we can say whether statins help to prevent infection or respiratory illness. The researchers of this study don’t know what caused the effect suggested by their results, and are calling for more studies to investigate the possible link.

We do know, however, that statins are effective in preventing heart attacks and strokes. To find out more, see our information on using statins to treat high cholesterol and to prevent heart attacks and strokes, or talk to your doctor.