High lipids, or hyperlipidemia, refers to increased levels of fats in the blood, including cholesterol and triglycerides.

Although hyperlipidemia does not cause symptoms, it can significantly increase one’s risk of developing cardiovascular diseases, including disease of blood vessels supplying the heart (coronary artery disease), brain (cerebrovascular disease), and limbs (peripheral vascular disease).

To give an idea of the scope of the “epidemic”, here are some numbers:

• 31 million adults in the USA have high lipids

• Less than half of them are on lipid-lowering treatment

• Fewer than one in three adults with high lipids on treatment has the condition under control

• Lipid levels vary by race and sex, with Mexican-American men affected the most, as 40 per cent of them have hyperlipidemia

The good news is that between 1999 and 2010, the percentage of American adults with high lipids decreased from 18 per cent to 13 per cent, correlating with an increase in treatment from 28 per cent in 1999, to 48 per cent in 2010.

What are the different lipid types?

There are different types of lipid (or lipoproteins) that can be measured by blood tests. The standard lipid profile includes a measurement of: total cholesterol, LDL (low density lipoproteins), HDL (high density lipoproteins) and triglycerides.

Total cholesterol:

• A level of less than 200 mg/dL is normal

• A level of 200 to 240 mg/dL is borderline high

• A level greater than 240 mg/dL is high

LDL cholesterol, or “bad cholesterol”, is a more accurate predictor of cardiovascular disease than total cholesterol.

Most healthcare providers make decisions on how to treat lipids based on a goal LDL level. The latter depends on several factors, including any history of cardiovascular disease and other ongoing cardiac risk factors (mainly diabetes, hypertension and smoking.

The ten-year-risk score is based on information from the Framingham Heart Study, a large study that has followed participants, as well as their children and grandchildren, for more than 50 years. The higher the Framingham risk score, the lower target LDL should be.

HDL cholesterol or “good cholesterol”

Elevated levels of HDL cholesterol actually lower the risk of cardiovascular disease. A level greater than 60 mg/dL is excellent, while an HDL level of less than 40 mg/dL is predictor of risk.

Triglycerides

High triglycerides levels are also associated with an increased risk of cardiovascular disease, although this association becomes less important once other risk factors are taken into account. Triglyceride levels are divided as follows:

• Normal: less than 150 mg/dL

• Borderline high: 150 to 199 mg/dL

• High: 200 to 499 mg/dL

• Very high: greater than 500 mg/dL.

Aside from cardiovascular risk, a triglycerides level above 500 can also increase risk of pancreas inflammation (pancreatitis). It is worth mentioning that total cholesterol and HDL levels could be measured on a random blood test, whereas LDL and triglyceride levels require eight hours of fasting.

When should one have lipid levels tested?

The United States Preventive Services Task Force recommends lipid screening should start at age 35 in men without other risk factors for coronary disease, and at age 20 to 35 in men with risk factors. These factors include:

• Diabetes, smoking, and high blood pressure

• A family history of heart disease in a close male relative younger than age 50 or a close female relative younger than age 60 years

• A family history of high cholesterol.

• Lipid screening should start at age 45 in women without, and at age 20 in women with coronary risk factors.

• The optimal time interval between screenings is uncertain; reasonable options include every five years, with a shorter interval for those with borderline-high levels and longer intervals for low-risk individuals who have normal lipid levels.

• There is no recommendation to stop screening at a particular age, though lipid levels rarely go high after the age of 65 if they were normal before. Plus, the impact of treating hyperlipidemia for prevention, after the age of 80, has not been well established.

In next week’s column, hyperlipidemia treatment with a special emphasis on statins will be discussed.

Joe Yammine is a cardiologist at Bermuda Hospitals Board. He trained at the State University of New York, Brown University and Brigham and Women’s Hospital. He holds five American Board certifications. He was in academic practice between 2007 and 2014, when he joined BHB. During his career in the US, he was awarded multiple teaching and patients’ care recognition awards.

The information herein is not intended as medical advice nor as a substitute for professional medical opinion. Always seek the advice of your physician. You should never delay seeking medical advice, disregard medical advice or discontinue treatment because of any information in this article.