Liver Cirrhosis Is More Common in U.S. than Previously Believed

New estimates indicate that more than 600,000 people in the U.S. have liver cirrhosis -- about 200,000 more than previously thought -- according to a study published online in the Journal of Clinical Gastroenterology. Cirrhosis was associated with hepatitis C virus (HCV) infection, heavy alcohol use, and diabetes.

Cirrhosis is an advanced stage of liver disease characterized by scarring that interferes with normal function. Over years or decades hepatitis B or C, heavy alcohol use, and other factors that injure the liver can cause cirrhosis, which in turn can progress to hepatocellular carcinoma and end-stage liver failure.

Steven Scaglione from Loyola University Medical Center and colleagues estimated the prevalence of cirrhosis in the general U.S. population using data from the National Health And Nutrition Examination Survey (NHANES) between 1999 and 2010.

Results

• Cirrhosis prevalence was approximately 0.27%, or 633,323 adults.
• 69% of people with cirrhosis were unaware they had liver disease.
• Cirrhosis prevalence was higher among blacks, Mexican-Americans, people living below the poverty level, and those with less education.
• Viral hepatitis (mostly HCV), diabetes, and heavy alcohol use accounted for more than half (53.5%) of all cases.
• Mortality was 26.4% per 2-year interval among people with cirrhosis compared with 8.4% among propensity-matched control subjects.

While this figure is substantially higher than the previous estimate of 400,000, it is still likely too low since NHANES excludes populations with high hepatitis C rates such as undocumented immigrants prisoners, and homeless people.

"Public health efforts are needed to reduce this disease burden, particularly among racial/ethnic minorities and individuals at lower socioeconomic status," the study authors concluded.

Below is an edited excerpt from a recent Loyola press release describing the study findings in more detail.

Liver Cirrhosis More Common than Previously Thought, Study Finds

Maywood, Il. -- Cirrhosis of the liver is more common than previously thought, affecting more than 633,000 adults yearly, according to a study published in the Journal of Clinical Gastroenterology.

And surprisingly, 69 percent of the adults identified as possibly having cirrhosis may not know they have this disease.

"Although some of these individuals may simply have forgotten or been confused about the question, this raises the possibility of a large number of undiagnosed cases of cirrhosis," first author Steven Scaglione, MD, and colleagues reported. Dr. Scaglione is an assistant professor in the departments of Medicine (Hepatology) and Public Health Sciences of Loyola University Chicago Stritch School of Medicine.

Alcohol abuse, diabetes and hepatitis C were the most significant contributing factors in more than 50 percent of the cirrhosis cases. All three of these factors are potentially preventable, Dr. Scaglione said.

Cirrhosis is end-stage scarring of the liver. Symptoms include jaundice, fatigue, bleeding or bruising easily, nausea, swelling and confusion. But many patients have no symptoms. Cirrhosis can lead to liver failure and liver cancer. In the United States, cirrhosis is the 12th leading cause of death overall and the fifth leading cause of death for patients aged 45 to 54.

Dr. Scaglione and colleagues performed the first ever study to estimate the prevalence of cirrhosis in the general population. They examined data from the National Health and Nutrition Examination Survey (NHANES), an annual survey of a representative sample of U.S. adults conducted by the Centers for Disease Control and Prevention.

The prevalence of cirrhosis was approximately 0.27 percent, which corresponds to 633,323 adults in the United States. Previous best-guess estimates pegged the number of adults with cirrhosis at about 400,000.

Among the study’s other findings:

• People with cirrhosis had a mortality rate of 26.4 percent during a two-year interval, compared with a 8.4 percent two-year mortality rate among similarly matched adults who did not have cirrhosis.
• Compared with the general population, people with cirrhosis tended to be older. Men were more at risk for cirrhosis than women. Prevalence was higher among poor people and people without a domestic partner. Prevalence declined with increasing levels of education.
• A quarter of people with cirrhosis reported they drank alcohol in excess during the prior year, and nearly half tested positive for the hepatitis C virus.

The study has limitations. The technique used to determine whether subjects in the survey had cirrhosis has not been validated in the general population. Thus it’s possible the technique may have misclassified some patients with mild liver disease as cirrhotics. The study took a snapshot of a representative population at a specific time, rather than following the population over time. And the true prevalence of cirrhosis is likely higher than the study found, because the NHANES survey did not include prisoners, immigrants and military veterans.

2/5/15

Reference

S Scaglione, S Kliethermes, G Cao, et al. The Epidemiology of Cirrhosis in the United States: A Population-based Study. Journal of Clinical Gastroenterology. October 8, 2014 (Epub ahead of print).

Other Source

Loyola Medicine. Liver Cirrhosis More Common than Previously Thought, Study Finds. Press release. January 5, 2015.