THURSDAY, March 27 (HealthDay News) -- Hepatitis C-related deaths in the United States have increased 123 percent in a decade, with mortality rates showing the most significant rise among middle-aged patients, according to new findings.

The increases occur from 1995 through 2004, the most recent year for which data are available. Death rates peaked in 2002, then declined slightly overall, according to the report, published in the April issue of Hepatology.

The most dramatic age-specific increases were observed among 45- to 54-year-olds who had an increase of 376 percent, and 55- to 64-year-olds who had an increase of 188 percent. For the latter group, rates rose for the duration of the study.

"The highest mortality rates were observed among males, persons aged 45 to 54 and 55 to 64 years, Hispanics, non-Hispanic blacks and non-Hispanic Native American/Alaska Natives," the authors wrote in the report. They suggested that demographic differences are related to prevalence among the various populations.

Hepatitis C virus (HCV) is the most common blood-borne infection in the United States, affecting about 1.3 percent of the population. Up to one in five sufferers develop liver cirrhosis, and up to one in 20 develop liver cancer.

HCV is the top reason for liver transplantation, and the 16th leading cause of premature death in the country. Recent evidence has suggested that disease burden and mortality from chronic HCV infection may increase in the coming years, as the number of persons with longstanding infections continues to rise.

During the study period, HCV-related mortality rates increased from 1.09 deaths per 100,000 persons in 1995 to 2.57 per 100,000 in 2002, before declining slightly to 2.44 per 100,000 in 2004. Average annual increases were smaller from 2000 to 2004 than 1995 to 1999.

The new figures came from researchers analyzing mortality rates derived from U.S. Census and multiple-cause-of-death data from 1995 to 2004. They included 56,409 HCV related deaths.

The observed increases likely reflect both true increases in mortality and the growing use of serologic tests for HCV, the authors said.

"The relatively young age of persons dying from hepatitis C-related liver disease has made hepatitis C-related disease a leading infectious cause of years of potential life lost as well as an important cause of premature mortality overall," the authors concluded.

More information

The National Institute of Diabetes and Digestive and Kidney Diseases has more about Hepatitis C .