Abnormal lipids: an introduction
Having healthy, normal lipids is important for a person whether they have type 2 diabetes or not. Abnormal lipids are associated with increased risk for cardiovascular disease. So by making sure your lipids are well controlled, you are taking a powerful step to protect yourself from cardiovascular disease, including heart disease and stroke.
Lipids are a group of fatty or waxy chemical compounds in the body. The important lipids to know about are low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and triglycerides. Another important measure when it comes to abnormal lipids is total cholesterol, which is the sum of HDL and LDL cholesterol (it also includes a type of LDL cholesterol called very-low-density lipoprotein [VLDL] cholesterol).
When you have abnormal lipid levels, typically your LDL cholesterol is elevated, your HDL cholesterol is too low, and your triglycerides are elevated. When LDL cholesterol and triglyceride levels are elevated your blood, your risk for cardiovascular disease, including heart disease and stroke increases.1
LDL cholesterol LDL cholesterol is often called “bad” cholesterol (think of “L” standing for “lousy”). High levels of LDL cholesterol are associated with cardiovascular disease, including heart disease. This type of cholesterol is linked to atherosclerosis, the formation of plaques on the inner walls of your arteries resulting in hardening and narrowing of the arteries and increased risk for several cardiovascular events, including heart attack and stroke.
HDL cholesterol. HDL cholesterol is often called “good” cholesterol (think of “H” standing for “healthy”). High levels of HDL cholesterol are actually associated with decreased risk for cardiovascular disease, including heart disease. That is, the higher your HDL cholesterol, the better (within certain limits).
Triglycerides. Triglycerides are another type of lipid associated with cardiovascular disease, including heart disease.
Lipid disorders linked to greater risk in people with diabetes
High cholesterol and other lipid disorders are no more common in people with diabetes than in the general population. Results from large studies conducted in the US population, including the Framingham Heart Study and the National Health and Nutritional Examination Survey (NHANES), have demonstrated this. NHANES found that elevated LDL cholesterol greater than 100 mg/dL occurred in about 25% of people in the general population, roughly the same percentage as among people with diabetes.2
Type 2 diabetes: a cause of lipid disorders
Having type 2 diabetes increases your risk for having abnormal lipids increases your risk for cardiovascular disease. Increases in lipids (typically elevations in triglycerides and low HDL cholesterol) are associated with insulin resistance, the hallmark of type 2 diabetes. Studies have shown that as insulin resistance develops and progresses in a person with type 2 diabetes, it appears to increase the density LDL particles and overall volume of LDL cholesterol. Additionally, as insulin resistance progresses levels of HDL cholesterol (the “good” cholesterol) decrease.3
How high should my cholesterol be?
If you have type 2 diabetes, you are at increased risk for heart disease. Therefore, your LDL cholesterol level should generally be below 100 mg/dL, your triglycerides should be be below 150 mg/dL, and your HDL cholesterol should be greater than 40 mg/dL (for men) and greater than 50 mg/dL (for women). If you have heart disease and diabetes, you should aim to keep your LDL cholesterol lower—below 70 mg/dL4
However, there are some exceptions to this. For instance, in some older persons, the decision whether to treat high cholesterol will depend on whether there is an underlying illness or health condition that makes the individual a poor candidate for drug or other treatment.4
Your doctor can help you determine exactly what your lipid targets should be and how to best achieve them (with lifestyle changes and/or medication) by considering various risk factors for heart disease, including1,6:
- Your gender
- Your age
- Blood pressure
- Total cholesterol
- HDL cholesterol
- Your specific lipid profile (levels of LDL and HDL cholesterol and triglycerides)>/li>
- Whether you currently take one or more blood pressure medications
- Whether you smoke
- Whether you have diabetes
Understanding total cholesterol
Total cholesterol (the sum of LDL and HDL cholesterol) above a certain level is associated with cardiovascular disease, including heart disease. However, whether your total cholesterol is a problem, depends on how high your LDL cholesterol is in relation to your HDL. Levels of total cholesterol are considered1:
Normal: less than 200 mg/dL (5.17 mmol/L)
Borderline high: 200 to 239 mg/dL (5.17 to 6.18 mmol/L)
High: 240 mg/dL (6.21 mmol/L) or greater
What are the treatment options for abnormal lipids
People with high LDL cholesterol can benefit from healthy lifestyle changes, including losing weight and keeping it off (if overweight or obese), getting regular aerobic exercise, and eating a healthy diet, including vegetables and whole grains, low-fat dairy products, lean meats or other leaner protein sources and meat alternatives, and food higher in unsaturated fats (liquid oils such as olive oil or canola oil) in place of trans fats or saturated fats (found in butter, meat, and egg yolks).6
Lifestyle modifications for lowering LDL cholesterol
Medications for improving lipids. There are a variety of medications that are used to reduce elevated LDL cholesterol and triglycerides, and even some for increasing low HDL cholesterol. Your doctor will be able to recommend the best medications for you. Different categories of lipid-lowering drugs are designed to target specific lipids, and include statins, cholesterol absorption inhibitors, bile acid sequestrates, nicotinic acid, and fibrates.6
Statins. Statins are the key category of drugs when it comes to lowering LDL cholesterol. They are effective in lowering LDL cholesterol and protecting against heart disease, heart attack, stroke, and death from cardiovascular causes. Statins can decrease LDL cholesterol levels by 20% to 60% and can also decrease triglycerides and increase HDL cholesterol levels slightly.6
Other lipid-lowering medications. Other types of prescription lipid-lowering medications include cholesterol absorption inhibitors (ezetimibe [Zetia]), bile acid sequestrates (cholestyramine [Qestran], Colestipol [Colestid], Colesevelam [WelChol]), nicotinic acid (niacin in immediate- or extended-release formulations), fibrates (gemfibrozil [Lopid], fenofibrate [Tricor, Triglide]), and different combinations of these agents.6
The cholesterol absorption inhibitor ezetimibe (Zetia) can lower LDL cholesterol levels. However, there are no studies showing improved outcomes (lower rates of heart disease and cardiovascular events). Therefore, more study is needed to clarify the overall benefits of this drug in people with elevated LDL cholesterol.6
Bile acid sequestrants work in the intestine to reduce the amount of cholesterol that is absorbed from foods. These medications can be effective in reducing mild-to-moderately increased LDL cholesterol. However, bile acid sequestrants are associated with side effects that can be bothersome, including bloating, nausea, and cramping. In some cases bile acid sequestrants have been associated with liver injury. The medications also interact with a number of common drugs taken for heart disease, including digoxin (Lanoxin) and warfarin (Coumadin), so care must be taken when co-administering these medications.6
Nicotinic acid (the vitamin niacin) is sometimes used in people with elevated cholesterol and a type of lipid disorder called familial hyperlipidemia. Nicotinic acid is associated with side effects, including nausea, itching, numbness, flushing, and tingling. Additionally, in some cases it can cause liver injury and, therefore, requires regular liver function monitoring.6
Fibrates are used to lower triglyceride levels and increase HDL cholesterol. They may cause muscle pain or weakness.
Nutritional supplements for lowering lipids. There are several nutritional supplements that have become popular for use in treatment of high cholesterol and lipid disorders. Before you take any supplement or vitamin, you should check with your doctor first. There is a real risk that a supplement or vitamin will interact with a drug that you are taking and can result in a health problem. Nutritional supplements used for lipid disorders include fish oil, soy protein, garlic, and plant stanols and sterols (also contained in orange juice and spreads containing vegetable oils). Remember to talk to your doctor before adding any of these to your treatment plan.6