Researchers examined data on 36,375 adults with no history of heart disease or diabetes and a low 10-year risk for events like heart attacks or strokes
Healthy adults who don’t keep their LDL-C, or ‘bad cholesterol’ in check are more likely to die prematurely from cardiovascular disease than peers with lower cholesterol levels, a US study suggests.
Researchers examined data on 36,375 adults with no history of heart disease or diabetes and a low 10-year risk for events like heart attacks or strokes. Most had levels of the type of cholesterol that builds up in blood vessels and can lead to blood clots and heart attacks, known as low-density lipoprotein cholesterol (LDL-C), below the threshold that usually leads doctors to prescribe cholesterol-lowering drugs. During the study follow-up period of about 27 years, 1,086 people died of cardiovascular disease and 598 died from coronary heart disease.
Compared to people with very low LDL-C levels under 100 milligrams per deciliter (mg/dL) of blood, individuals with LDL-C levels ranging from 100 to 159 mg/dL had a 30 to 40 per cent higher risk of dying of cardiovascular disease. With LDL-C levels of 160 mg/dL to 189 mg/DL, people had a 90 per cent higher risk of death from cardiovascular causes. LDL-C levels of at least 190 mg/DL, which is where guidelines suggest statin use even for otherwise healthy people, carried 70 per cent greater risk. Compared to people with LDL-C levels below 100 mg/dL, people with LDL-C of 100 to 129 mg/DL died of cardiovascular disease about 1.8 years sooner and people with LDL-C of 160 mg/dL or higher died around four years sooner, the researchers calculated.
“The biggest take-home message from this study is that it demonstrates that having a low 10-year estimate cardiovascular risk does not eliminate the risk posed by elevated LDL cholesterol or (other forms of bad cholesterol) over a course of a lifetime,” said lead study author Dr Shuaib Abdullah from University of Texas Southwestern Medical Center in Dallas and VA North Texas Health Care System.
“Life-style interventions, such as avoiding diets high in saturated and trans-fatty acids, increasing fibre intake, maintaining ideal weight, and engaging in regular aerobic activity may lower LDL cholesterol and have been associated with improved cardiovascular outcomes,” Abdullah said by email.
“In those individuals in whom LDL cholesterol or (other forms of bad cholesterol) remain elevated despite these interventions, statins may be considered after discussion with the health care provider about their risks and benefits,” Abdullah advised.
Prescribing statins, or cholesterol-lowering drugs, to healthy people at low risk for death from heart attacks or strokes has been controversial partly because these drugs were tested primarily in intermediate and high-risk groups, the study authors note in circulation. Research to date hasn’t offered a clear picture of whether statins can help younger, healthier people live longer.
The American Heart Association and the American College of Cardiology advise against statins for low-risk individuals unless LDL-C levels are at least 190 mg/dL. These recommendations also urge doctors to discuss the pros and cons of statins with low-risk individuals who have LDL-C levels of at least 160 mg/dL.
Based on the study results, these discussions should lead more low-risk patients to consider statins, the authors conclude.
The study wasn’t designed to prove whether or how slightly elevated, but not dangerously high LDL-C levels might kill people, or if statins would reduce their risk of death.
Still, the results suggest that more people may want to consider treatments to lower LDL-C when it reaches 160 mg/dL instead of waiting for it to hit 190 mg/dL, said Dr Christie Ballantyne, coauthor of an accompanying editorial and chief of cardiology at Baylor College of Medicine in Houston.
“Lipoproteins play a fundamental role in the disease process of (hardening of the arteries),” Ballantyne said by email. “The bad lipoprotein particles carry LDL and (other bad cholesterol) which gets into the artery wall and sets off an inflammatory process which not only leads to plaques and blockages but also causes the plaques to be unstable and rupture with blood clots than cause the artery to be blocked off leading to heart attacks and strokes.”