Cholesterol should be measured at earlier age to combat risk, scientists say
By Nina Massey, PA Science Correspondent
Cholesterol should be measured as early as the age of 25 to enable young people to mitigate against the risk of cardiovascular events, scientists say.
Interventions could include taking statins, or adopting a healthy lifestyle.
A comprehensive analysis suggests a strong link between non-HDL cholesterol - bad cholesterol - levels and long-term risk for cardiovascular disease (CVD) in people aged under 45.
Researchers suggest halving levels of bad cholesterol could decrease cardiovascular risks four-fold.
Depending on cholesterol level and the number of cardiovascular risk factors, men and women aged under 45 have a 12-43% or 6-24% risk, respectively, of having fatal or non-fatal heart disease or stroke by the age of 75.
The observational and modelling study used data from 398,846 people.
The study published in the Lancet sets out that women with bad cholesterol levels between 3.7-4.8 mmol/litre, who were younger than 45, and had at least two additional cardiovascular risk factors, had a 16% probability of experiencing a cardiovascular disease event by the age of 75.
For women aged 60 or over with the same characteristics, the estimated risk was 12%.
The study found that for men with the same characteristics, the estimated risk for those aged under 45 was 29%, and was 21% for those aged 60 or more.
Co-author Professor Stefan Blankenberg, medical and clinical director at the University Heart and Vascular Center UKE Hamburg, said: "There's one key message - you should at least put into the guidelines that LDL and non-HDL cholesterol determination should be an obligation.
"You should determine your cholesterol at the very young age.
"You need to enable these younger individuals to do something against the risk.
"The second message is that you need to show these young people their potential risk."
He added that cholesterol could be measured at the age of 25 or 30, potentially providing an opportunity to consider taking statins.
Researchers said that even those who were young and lived a healthy lifestyle could benefit from their hypothesis if they had a genetic risk.
Scientists say increased risk in younger people could be due to the longer exposure to harmful lipids in the blood.
Professor Barbara Thorand, of the German Research Centre for Environmental Health, said: "This increased risk in younger people could be due to the longer exposure to harmful lipids in the blood.
"The risk may also appear larger compared to older ages because people aged 60 years and older in our study had not developed cardiovascular disease up to this age, so they may be healthier than others of their age who were excluded from the study because they had had cardiovascular disease."
The amount of non-HDL cholesterol and low-density lipoproteins (LDL) in the blood are accepted as causal risk factors for CVD.
In the study, the authors used data from people from 38 studies from Europe, Australia and North America who had no cardiovascular disease at the start of the study.
Researchers assessed and confirmed the long-term association between cholesterol levels and cardiovascular event risk.
They then used this data to estimate the probability of a cardiovascular event by the age of 75 years for people aged 35-70 years.
This was based on a person's gender, non-HDL cholesterol levels, age, and cardiovascular disease risk factors such as smoking status, diabetes, BMI, systolic blood pressure and anti-hypertensive medication.
The model also estimated how much risk could be reduced if non-HDL cholesterol levels were halved - the authors note that the 50% reduction was hypothetical.
During follow-up, there were 54,542 fatal or non-fatal cases of heart disease and stroke.
According to the study, the risk for a cardiovascular event decreased continuously with decreasing non-HDL levels and the risk was lowest for those with the lowest non-HDL levels - below 2.6 mmol non-HDL cholesterol per litre in the study.
In people younger than 45 with levels of 3.7-4.8 mmol/litre and with at least two risk factors, they estimated the long-term risk of cardiovascular disease could hypothetically be reduced from 16% to 4% in women, and from 29% to 6% in men.
For people with the same characteristics aged 60 years or over, risk could potentially be reduced from 12% to 6% in women and from 21% to 10% in men.
The scientists note that their modelled 50% reduction suggests that the effects of treatment apply over a longer period (30 years) than has been studied in clinical trials (around seven years).
Professor Frank Kee, of Queens University Belfast, added: "The more health literate might be able to deal with this better than people who are living in disadvantage.
"So, any strategy to reduce the risk must not widen inequalities."