Should younger adults be screened for raised cholesterol?

Research has suggested that a single blood cholesterol measurement in early adulthood can help predict the risk of developing coronary heart disease or stroke by the age of 75. The study was published in The Lancet on 14 December 2019 on behalf of the Multinational Cardiovascular Risk Consortium.

A complex statistical analysis was carried out on robust clinical data from nearly 400,000 men and women from Europe, Australia and the US who were free of cardiovascular disease when they entered the study up to 43 years earlier. Approximately one third were below 45 years of age . Each had had blood analysed for so-called “bad” non-HDL cholesterol. The calculations made allowance for modifiable risk factors in addition to non-HDL cholesterol: high blood pressure, diabetes, obesity and smoking. The non-HDL cholesterol values of those taking statins to lower cholesterol were inflated by 30%. The study authors concluded that blood non-HDL cholesterol concentrations are strongly associated with the risk of cardiovascular disease over a longer term than has been previously recognised. They had found that:

• Of men under 45 when enrolled, those with the highest cholesterol concentrations had about a 37% risk of a heart attack or stroke by the age of 75, while those with the lowest concentrations had a risk of about 16%. The figures for women under 45 were about 19% for the highest and 9% for the lowest concentrations.
• Of men who were 60 or over when enrolled, those with the highest cholesterol concentrations had about a 26% risk of a heart attack or stroke by the age 75, while those with the lowest concentrations had a risk of about 12%. The figures for women of 60 or over were about 15% for the highest and 7% for the lowest concentrations.

It appeared that younger people had a higher risk. Professor Barbara Thorand, one of the authors, commented in a News Release on 5 December 2019 "This increased risk in younger people could be due to the longer exposure to harmful lipids (fat) 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 study authors had calculated that risk would be reduced substantially if cholesterol concentrations were reduced by 50% with drug treatment at any age. However, they noted in the news release that the effects of treatment apply over a longer period (30 years) than has been studied in clinical trials (around seven years), and note that real-world benefits of lipid-lowering therapies like statins are probably lower than the cholesterol reductions seen in trials because of sub-optimal adherence and side effects.

Should younger adults be screened for raised cholesterol? At present people in the UK aged between 40 and 74 years who are not already under NHS care are invited for a free NHS Health Check every five years. An earlier check, may detect kidney problems, high blood pressure, diabetes, obesity and raised cholesterol. The results could strongly encourage the adoption of a healthy life style: a sensible diet, regular exercise and not smoking.