A lipid profile—also called a lipid panel—is a blood test that gives your doctor a head-up as to abnormalities in your cholesterol level. The lipid profile includes total cholesterol, LDL cholesterol, HDL cholesterol, cholesterol-HDL ratio, LDL-HDL ratio, and triglycerides.
A fairly routine test, a lipid profile is an indicator of your risk for heart disease and stroke. It’s done as a screening test every four to six years, according to the American Heart Association. Those who are battling high cholesterol or have a history of heart disease may have a diagnostic lipid profile more often. Medicare covers medically necessary diagnostic blood tests in full. Medicare also covers screening lipid profile blood tests once every five years at no cost to the participant.
WHAT IS A LIPID?
A lipid is a fatty substance that can’t dissolve in blood, as the American Heart Association puts it. Cholesterol, cholesterol compounds, and triglycerides all are lipids. They are transported in the blood as part of large molecules called lipoproteins. Abnormalities in lipids can contribute to heart disease.
Note: A diagnostic test is done on patients who already have a problem and the physician needs to see if it’s improved or worsened. A screening test is done when you have not yet been diagnosed with the problem, but the doctor wants to check your current status. This is very important to understand because of the differences in insurance coverage. Screening tests generally have frequency limitations but are often covered in full, like Medicare’s five-year limit on a screening lipid profile, while diagnostic tests rarely have limitations, as long as the medical criteria is sound, and could have a co-insurance or deductible fee.
Lipid Profile Parts
LDL cholesterol, which is low-density lipoprotein cholesterol, is the bad cholesterol—the one where you want to see a low (note the L in LDL) number on your lipid profile. LDL contributes to fatty buildup in your arteries and raises your heart-disease risk, causing things like blocked arteries.
HDL cholesterol, which is high-density lipoprotein cholesterol, is the good cholesterol—the one where you want a high number (note the H in HDL) on your lipid profile. HDL helps remove LDL from the arteries, lowering your risk of heart disease, and taking it back to the liver where it’s eliminated from the body.
The American Heart Association differentiates LDL from HDL by using this example: “Think of LDL cholesterol as being like a family member who carries stuff all through the house and drops it along the way…. HDL cholesterol is like someone who picks up the dropped stuff and puts it away. This (good!) person helps keep the house from becoming impassable.”
Triglycerides are unused calories, or stored energy. High triglycerides raise your risk of heart disease. These are the most common fats in the body. If your lipid profile shows a high triglyceride level combined with a high LDL and low HDL, it’s a recipe for potential cardiac problems. High triglycerides aren’t just associated with heart disease. They cause heart disease.
What should the numbers be in your lipid profile? Well, it’s a little controversial at the moment. The American College of Cardiology recently added a new category of “extreme risk” patients, suggesting these patients should have a target of 55 mg/dL LDL. However, official new guidelines won’t be released until 2018.
For now, according to the Centers for Disease Control and Prevention, your normal lipid profile should show:
- Total cholesterol less than 200 mg/dL
- LDL (“bad” cholesterol) less than 100 mg/dL
- HDL (“good” cholesterol) 40 mg/dL or higher
- Triglycerides less than 150 mg/dL
Ratios are important. Your doctor will analyze your lipid profile results, paying attention to the HDL-LDL and total cholesterol-HDL ratios, which can affect your physician’s medical decisions. For instance, a premenopausal woman with a higher LDL may find her LDL-HDL ratio is actually good because estrogen raises levels of HDL in the body, so she doesn’t go on cholesterol meds. When she reaches menopause, and estrogen plummets, problems could arise and may change the doctor’s recommendation.
Your lipid profile is affected by your weight, physical activity, diet, age, gender, and heredity, according to the National Institutes of Health. None of these factors require a science degree to understand. Those of us who are overweight tend to have higher blood-cholesterol levels because we eat more than we need. Aging narrows arteries and raises cholesterol. While diet can help keep levels under control, physical activity can actually lower LDL and raise HDL levels. Heredity is beyond our control, of course, but important to bear in mind.
WHAT IS CHOLESTEROL ANYWAY?
Cholesterol is a fat-like substance made in your body by your liver in amounts adequate to do its job, which is to make necessary steroid hormones, vitamin D, and cell membranes. We do not have to consume any cholesterol to meet our needs, although we all do. Cholesterol is found in saturated fats and trans fats.
According to the National Cancer Institute, these are the main sources of cholesterol in our diets: eggs and egg-mixed dishes, chicken and chicken-mixed dishes, beef and beef-mixed dishes, burgers, and regular cheese. Increasing these foods in your diet will likely raise your lipid profile.
HDL—Too Much of a Good Thing?
Researchers at the University of Copenhagen Faculty of Health and Medical Sciences found that there may be limits to how high the HDL in our lipid profile should be, with results showing those with higher-total HDLs had a higher mortality rate. For men with extremely high HDL levels, the mortality rate was 106 percent higher than for the normal group. For women with extremely high levels, the mortality rate was 68 percent higher. This news, published in The European Heart Journal, may change the way we look at that number.
“Doctors like myself have been used to congratulating patients who had a very high level of HDL in their blood. But we should no longer do so, as this study shows a dramatically higher mortality rate,” says Børge Nordestgaard, Professor at the Department of Clinical Medicine and one of the authors of the study.
The study also found excessive mortality for people with extremely low levels of HDL in the blood. The people with medium levels of HDL in the blood had the lowest mortality. For men, this level was 1.9 mmol/L. For women, it was 2.4 mmol/L. So, HDL levels are a bit like Goldilocks—we want that middle number that’s “just right.”