Balanced cholesterol levels are important to maintaining good health. The liver is an underrecognized part of that effort.
The liver is the largest gland in the body, located in the upper right part of the belly. It is the body’s master detoxer of drugs and other foreign substances. It stores glycogen, which the body uses for energy. It’s also important in metabolizing fat, carbohydrates, and proteins. A healthy liver does all this unnoticed.
An important function of the liver is to produce and clear cholesterol in the body. Most of the attention focused on cholesterol describes its potential for harmful health effects. But cholesterol is necessary for the creation of hormones, vitamin D, and enzymes needed for digestion.
Bundles called lipoproteins carry cholesterol throughout the body. Two important types are high-density lipoproteins (HDL) and low-density lipoproteins (LDL). “High” and “low” refer to the relative proportion of protein to fat in the bundle. The body needs both types in regulated proportions.
Healthy cholesterol levels
It’s important to know the levels of HDL (“good” cholesterol), LDL (“bad” cholesterol), and total cholesterol in your body. A rough estimate of total cholesterol is HDL, plus LDL, plus one-fifth of a third type of fat called triglyceride.
The National Heart, Lung, and Blood Institute recommends the following levels:
HDL levels of at least 40 milligrams per deciliter (mg/dL) of blood. Anything less than that increases your risk of heart disease. A level of at least 60 mg/dL helps lower your risk for heart disease.
|LDL cholesterol levels|
|Less than 100 mg/dL||optimal|
|100-129 mg/dL||near optimal/above optimal|
|130-159 mg/dL||borderline high|
|Less than 200 mg/dL||desirable|
|200-239 mg/dL||borderline high|
|240 mg/dL and above||high|
Liver function complications can hinder the organ’s ability to produce or clear cholesterol. Both conditions can create a spike in cholesterol and affect a person’s health. The following conditions can affect the liver in a way that causes cholesterol levels to be abnormal.
Nonalcoholic fatty liver disease
The most common form of liver malfunction is nonalcoholic fatty liver disease (NAFLD). It affects approximately one-quarter of the population. It’s often seen among people who are overweight or have diabetes.
NAFLD covers a spectrum of conditions. Within NAFLD is the more serious non-alcoholic steatohepatitis (NASH). A diagnosis of NASH often leads to cirrhosis, liver failure, and hepatocellular carcinoma.
Cirrhosis can cause scarring and prevent the liver from carrying out basic metabolic functions. The condition is a reaction to long-term injury to the organ. The injury can include inflammation from a disease such a hepatitis C. After hepatitis C, long-term alcohol abuse is the most common cause of cirrhosis in the United States.
Another significant cause of liver problems is damage from drugs. The liver’s job is to metabolize chemicals in the body. That makes it susceptible to injury from prescription, over-the-counter, or recreational drugs.
Common drug-induced liver injuries and the drugs associated with these conditions include:
Mixed pattern or atypical hepatitis
After discontinuing the drug, liver damage is typically not severe and often subsides. In rare cases, the damage can be severe or permanent.
High cholesterol effects
High levels of LDL cholesterol increase the risk of fatty deposits on vessels that bring blood to the heart. Too-low levels of HDL cholesterol suggest the body may not be able to clear plaques and other fatty deposits from the body. Both conditions create a risk for heart disease and heart attack.
When to see a doctor
Liver damage can progress for months or years with no symptoms. By the time symptoms appear, liver damage often is extensive. Some symptoms warrant a visit to the doctor. These include:
- jaundice (yellow skin and eyes)
- loss of appetite
- accumulation of fluid within the abdomen
- tendency to bruise easily
A doctor may be able to diagnose liver problems by observing your symptoms and completing a medical history. You may also undergo tests of your liver function. These tests include
Liver enzyme test: Common enzymes in this panel are alanine transaminase, aspartate transaminase, alkaline phosphatase, and gamma-glutamyl transpeptidase. High levels of any of these enzymes may indicate damage.
Liver protein test: Low levels of the proteins globulin and albumin can show a loss of liver function. Prothrombin is a liver protein needed for clotting. A common test measures how long it takes for your blood to clot. Slow clotting time can mean a lack of prothrombin and liver damage.
Bilirubin test: The blood transports bilirubin to the liver and gallbladder. Then it’s excreted in the stool. Blood in the urine or excess bilirubin in the blood can show liver damage.
Single lipoprotein panel: The panel tests blood cholesterol and tryglycerides together. Blood typically is drawn after fasting.
Treatment of liver disorders often starts with addressing the underlying condition. Different liver conditions call for specific dietary changes, but the American Liver Foundation has some general tips.
Treatment of high cholesterol includes dietary guidelines like those for liver disease. Medical treatment of high cholesterol also often includes a class of drugs called statins. Researchers have looked at whether statins are safe for people with liver disease to use.
“In general, statins are safe in patients with liver disease,” says David Bernstein, MD, FACG, chief of hepatology at Northwell Health, and professor of medicine at Hofstra Northwell School of Medicine in Hempstead, NY. “Patients who have decompensated cirrhosis should be monitored very closely, but in general, they are safe.”
“Is there a risk? Yes, but it’s a very small risk and patients are monitored in the first three to six months,” says Bernstein.
Therapeutic interventions promise more effective control of cholesterol, even among people with liver disease. But lifestyle changes and dietary control remain important and effective parts of a complete approach to cholesterol control with liver involvement.
The National Heart, Lung, and Blood Institute suggests how to control high levels of blood cholesterol with diet and lifestyle changes:
Bernstein suggests these lifestyle guidelines are good advice for anyone trying to keep cholesterol in check, including those with the added challenge of underlying liver disease.