Hyperlipidemia describes a condition where the amount of lipids in the blood is too high. It can include several conditions, but usually refers to a high cholesterol and triglyceride level.
At healthy levels, lipids are involved in important bodily functions, but they can cause problems if they are present in excess. A raised blood lipid level can cause accelerated hardening of the arteries or atherosclerosis.
In healthy individuals, the insides of arteries are smooth and unobstructed, but as we age, plaque accumulates in the artery walls until they narrow and stiffen.
Plaques are composed of lipids and several other materials that circulate in the blood. Eventually, plaque can accumulate enough to reduce the flow of blood through the arteries. This can reduce the amount of oxygen-rich blood that is received by the heart, which increases the risk of vascular events such as stroke and heart attack.
It may be possible for individuals to slow the progression of atherosclerosis if they can bring their blood lipid level down. This involves making lifestyle changes such as exercising and eating healthily as the first treatment approaches, but, depending on a patient’s overall risk, medication may be prescribed in combination with these lifestyle changes.
Higher levels of high-density lipoproteins (HDL) or good cholesterol are associated with a reduced risk of heart disease and stroke because HDL “mops up” cholesterol from the arteries, slowing the build up of plaque.
Low-density lipoprotein (LDL) cholesterol, on the other hand, is considered “bad” cholesterol because it can lead to obstructed arteries. It transports cholesterol around the body and builds up in the artery walls, making the vessels hard and narrow.
Another type of lipoprotein is very-low-density lipoprotein (VLDL), which contains triglycerides, a type of fat that VLDL delivers to bodily tissues. VLDL increases the size of LDL, causing narrowing of the blood vessels.
Factors within our control, such as inactivity, poor diet, obesity and smoking can raise the level LDL cholesterol and lower the level of HDL cholesterol, therefore speeding up the progress of atherosclerosis and increasing the risk of heart disease and an adverse vascular event.
There are no symptoms of hyperlipidemia and a blood test to check a person’s lipid profile is the only way to diagnose the condition. If a patient is diagnosed with hyperlipidemia, the lifestyle changes they can make and medications they can use to improve their lipid profile are described below.
Lose weight
A body mass index (BMI) of 30 or higher increases the risk of high cholesterol and losing just 5 to 10 pounds can help to lower cholesterol. Being overweight can lower your levels of HDL (good) cholesterol and weight loss can decrease the LDL level. Extra weight around the abdominal area increases the risk of heart disease more than extra weight carried around the thighs, bottom and hips.
Healthy diet
A diet that is high in cholesterol-rich foods such as full fat dairy and red meat increases the total cholesterol level, whereas a diet that is rich in fiber and contains cholesterol-lowering foods can be as successful as a statin at bringing the cholesterol level down.
People trying to lower their cholesterol should ensure that no more than 10% of their daily calories come from saturated fat. Monounsaturated fats found in foods such as canola oils and peanuts are a healthier option.
Some types of fish such as halibut and tuna contain less saturated fat and cholesterol than red meat and poultry and herring, salmon and mackerel are rich in omega-3 fatty acids, which can lower triglycerides. Trans-fats, which are found in foods such as margarine and commercially baked cakes, cookies and crackers should be eliminated form the diet because they increase LDL and lower HDL.
Certain nutrients found in whole-grain foods such as whole-grain bread, whole-wheat pasta, flour and brown rice promote heart health and fruits and vegetables can help lower cholesterol.
Exercise
Exercise helps to boost HDL, while it lowers LDL and triglycerides. A lack of exercise can therefore increase the risk of high cholesterol. A doctor may advise walking for at least 30 minutes a day on most days of the week to help reduce cholesterol.
Quitting smoking
Cigarette smoke can damage vessel walls, making them more susceptible to the accumulation of fatty deposits, hardening and narrowing. Smoking can also lower HDL and people with hyperlipidemia should quit as soon as they are diagnosed.
Lipid-lowering medications
In cases where people with hyperlipidemia have made healthy changes to their lifestyle, but their cholesterol remains high, a doctor may prescribe medication. Some of these drugs are described below.
Statins
These are one of the most common medications prescribed for hyperlipidemia. They block a substance required by the liver to produce cholesterol, which means the liver starts removing cholesterol from the blood. These agents also aid the reabsorption of cholesterol from fatty deposits in the arteries, potentially undoing the risk of heart disease. Some examples of statins include atorvastatin, lovastatin, pravastatin, and simvastatin.
Cholesterol absorption inhibitors
Cholesterol is absorbed in the small intestine and released into the bloodstream. A drug called ezetimibe inhibits this absorption, helping to reduce the level of cholesterol in the blood. This drug may be used in conjunction with a statin.
Bile-acid-binding resins
Cholesterol is required to make bile, which is need for digestion. These resins bind to bile acids and the liver is prompted to make more bile acids by using excess cholesterol, which has the effect of lowering blood cholesterol.
Combination cholesterol absorption inhibitor and statin
A combination drug called ezetimibe-simvastatin reduces cholesterol absorption in the small intestine as well as the amount of cholesterol produced by the liver.
Injectable medications
The Food and Drug Administration recently approved the drugs alirocumab and evolocumab for people with an inherited condition that causes hyperlipidemia. These agents help the liver absorb cholesterol, thereby lowering the amount circulating in the bloodstream.
Triglyceride lowering drugs
Fibrates canlower triglycerides by reducing the amount of VLDL (made up primarily of triglycerides) produced in the liver and accelerating the removal of triglycerides in the blood. An agent called niacin limits the liver’s ability to make LDL and VLDL. Omega-3 fatty acid supplements may also be prescribed as a way of lowering triglycerides.
Prevention
Cholesterol levels can be prevented from rising in the first place by following the same healthy lifestyle as described above. In short, people should maintain a healthy weight, exercise for at least 30 minutes on most days of the week, stop smoking, and eat a low-fat diet comprising fruits, vegetables and whole grains.
Further Reading
Impact of age-related alterations in lipid metabolism on general health