Many patients with dangerously high cholesterol or a genetic predisposition to it don't take statin drugs that can lower cholesterol, a US study suggests.
Statins were being taken by just 52 per cent of adults with what's known as familial hypercholesterolemia, a genetic disorder that causes extremely high cholesterol and an increased risk of early cardiovascular disease.
And only 38 per cent of adults with non-genetic severe dyslipidemia took statins.
"All of these adults should be on a statin," lead study author Dr. Emily Bucholz of Boston Children's Hospital said by email.
Heart specialists recommend that people take statins when they have levels of low-density lipoprotein (LDL) - the bad kind of cholesterol that builds up in blood vessels and can lead to blood clots and heart attacks - of at least 190 milligrams per deciliter of blood.
Commonly prescribed statins include atorvastatin (Lipitor), lovastatin (Mevacor), simvastatin (Zocor) and rosuvastatin (Crestor).
For the study, researchers examined survey data collected from 1999 to 2014 from US adults age 20 and over.
Overall, less than 1 per cent of adults had a family history of severely elevated cholesterol, and about 6.6 per cent had the condition themselves, researchers report in Circulation.
Older adults, people with insurance, and patients diagnosed with high blood pressure or diabetes were more likely to take statins for dangerously elevated cholesterol or a family genetic risk for the condition, the study found.
Young people, and patients without insurance or a regular source of care, were less likely to take statins.
Statin use did increase among high-risk patients during the study period.
The proportion of people with severely elevated cholesterol taking statins increased from 29 per cent to 48 per cent during the study, mirroring an overall trend for statin use in the general population.
Only about 30 per cent of patients took high-intensity statins - higher doses recommended for people at the greatest risk for health problems associated with dangerously high cholesterol levels.
One limitation of the study is that researchers lacked data to see whether patients failed to take statins that were prescribed or if doctors didn't give prescriptions, the authors note. Some patients might have tried statins and stopped using the drugs because of side effects like muscle aches.
"This study highlights a need for further study of the reasons for the mismatch between dyslipidemia screening and treatment," said Dr. Ian Kronish, of the Center for Behavioral Cardiovascular Health at Columbia University Medical Center in New York City.
"We need a better understanding as to whether the low rates of treatment are being driven by clinical inertia - that is, providers are not recommending statins in eligible patients, or whether low treatment is due to patient disagreement or non-adherence to treatment recommendations," Kronish, who wasn't involved in the study, said by email.
If physicians don't recommend statins to patients with high cholesterol, they should get a second opinion from another doctor, advised Dr. Robert Eckel, of the University of Colorado Denver Anschutz Medical Campus.
While statins are a good first choice, if these drugs don't work or have intolerable side effects, patients can also try alternative drugs like ezetimibe (Zetia), colesevelam (Welchol) or newer, more expensive drugs in a family of medicines known as PCSK9 inhibitors.
"Once treated, this should be lifelong," Eckel, a past president of the American Heart Association who wasn't involved in the study, said by email.