New study from the LIPID trial
Which lipid should we monitor?
26 February 2014
Many of us are familiar with the regular check by the
GP of our cholesterol level - the blood sample and then the number
indicating the state of our arteries and whether we need to get it
down by diet and exercise. Cholesterol is one of the risk factors
for diseases of the arteries, such as heart disease and
Decisions about treatment should start with the absolute risk. A
person with a medium or high risk should work on ways of reducing
this risk. It can be tested out at www.cvdcheck.org.au. When the doctor has made a
decision to investigate, how should he or she best monitor what is
happening to cholesterol?
Researchers have used the data from the CTC's LIPID trial to
answer this question. LIPID had over 9000 patients at risk of
cardiovascular events who had regular blood tests for over 5 years.
Half of them were taking a statin and half a placebo. This very
large data set has been analysed to see which laboratory test would
be best at predicting risk. The research group looked at total
cholesterol, LDL and HDL cholesterols and their ratios,
triglycerides, and apolipoproteins and their ratios.
They also examined how clearly and rapidly the measures would
change in response to statin treatment.
For predicting a cardiovascular event, the LDL/HDL cholesterol
ratio was the best indicator. Overall, for monitoring risk in
people who have had a heart attack and are on a statin, the ratios
of LDL/HDL cholesterol or the ratio of total/HDL cholesterol are
both worthwhile. A cholesterol difference, the non-HDL cholesterol
level, is also a good indicator and can be easily calculated.
Total cholesterol, the familiar number, was not the the best
measure from any point of view.
The drug in this study was an older statin, pravastatin, which
is not often prescribed now. Although the relationships between
cholesterol changes and outcomes appear to be consistent across the
statins, the study needs to be confirmed with the more modern
With over 2 million Australians taking statins and many more
having their blood cholesterol checked regularly, the results of
the study have widespread relevance in this country.
Glasziou PP, Irwig L, Kirby AC, Tonkin AM, Simes RJ. Which lipid
measurement should we monitor? An analysis of the LIPID study.
BMJ Open 2014; 4(2): e003512