Harlan Krumholz is a professor of medicine and cardiologist at the at Yale University School of Medicine. He recently co-authored an open letter which appeared in the journal circulation (pdf here). The letter was written to the Adult Treatment Panel – a group of ‘experts’ charged with setting cholesterol guidelines for the American public. The panel is current considering this issue and is due to report later this year.
I suspect the panel, like a multitude of panels before it, will recommend that we keep strong downward pressure on our cholesterol numbers. But not all individuals in the medical and scientific community agree with this approach. One such dissenter is Professor Krumholz.
In this video below, Professor Krumholz does a good job, I think, of highlighting some of the major issues with current cholesterol policy. I advise you to watch the video but, for good measure, here’s a short summary of the salient points Professor Krumholz makes:
1. While targets are often based on levels of LDL-cholesterol, evidence shows that this is just one potential risk factor for cardiovascular disease. Many others exist, some of which are better predictors of cardiovascular disease than LDL-cholesterol.
2. Although it’s generally accepted that improvement in cardiac risk factors is beneficial, there is plenty of evidence that does not bear this out. He cites, for example, the example of the drug torcetrapib which lowered (supposedly unhealthy) LDL-cholesterol and raised (supposedly healthy) HDL-cholesterol. Torcetrapib, however, significantly increased overall risk of death in those who took it.
Professor Krumholz in his letter cites hormone replacement therapy as another example of a drug therapy that can ‘improve’ cholesterol numbers but that actually increases risk.
Other notable failures in terms of brining broad benefits to health include the drugs ezetimibe and fibrates.
3. Professor Krumholz speculates on why cholesterol ‘improvement’ may not actually improve health. One theory is that drugs which reduce cholesterol and have benefits (such as statins) do so through one or more mechanisms that are distinct from their cholesterol-lowering effects. Another is that even if cholesterol reduction is beneficial, this may be offset by the hazardous effects of a drug.
4. Professor Krumholz goes on to make the point that while we doctors are encouraged to treat peoples’ cholesterol down to a target level, not a single study has actually tested this approach.
5. He recommends an approach not based on cholesterol levels, but risk. He quite rightly points out that those at low risk of cardiovascular disease are unlikely to benefit much, but are still at risk of suffering from side-effects from treatment. He also points out the large ‘numbers needed to treat’ for relatively healthy people. Basically, about 50-100 people would need to be treated with a statin for 5 years to prevent on heart attack. This means, by the way, that 98-99 per cent of people treated will not benefit. People at higher risk stand to benefit more. However, it’s still true that the great majority who take statins will not benefit at all.
So there you have it, a neat summing up of the flaws in the conventional thinking regarding cholesterol lowering. And from a professor of medicine and cardiologist to boot. It’s a shame that the Professor Krumholz’s objectivity and ability to break out of the cholesterol ‘group-think’ is so rare in medicine. Many, many doctors would do well to follow his example.
