Epidemiology
The statistics on cirrhosis suffer from the uncertainty of diagnosis, which can be confirmed only on autopsy or by liver biopsy. Nevertheless, the figures generated from many sources are sufficiently consistent to establish that geography, race, age, sex, economic and social class and occupation; the amount, duration, and pattern of alcohol consumption; and prevalence of hepatitis viruses all modify the occurrence of cirrhosis.
The prevalence rate of cirrhosis in autopsies averages 3 to 4 percent for most countries in Europe, 5 to 8 percent for North and South Americas, and 1 to 2 percent for Japan. Among selected populations of patients, the prevalence rate of cirrhosis ranges from 0.7 percent in Copenhagen, to 1.3 percent in Wurzburg (Germany), 1.5 percent in Athens, and 3.8 percent in Abidjan (Ivory Coast).The older epidemiological studies, discussed by John Galambos (1979), disclosed a rising incidence of cirrhosis, especially among women. Recent investigations have confirmed this trend. In the United States, deaths from cirrhosis rose 71.7 percent from 1950 to 1974, while those due to cardiovascular disease fell 2 percent. The age-adjusted death rates from cirrhosis in the United States in the period 1960-74 by race and sex showed that the increase was marked for nonwhite males, moderate for nonwhite females, and only slight for white males and females. For blacks in the United States, mortality rates for cirrhosis were similar to or slightly lower than those of the white population before 1955. The pattern changed rapidly after that, with American blacks experiencing an epidemic of cirrhosis compared to the increase in whites. The rise in cirrhosis deaths followed a geographic pattern. Rates among the blacks quadrupled in urbanized coastal and northern regions and remained low in the southern rural areas of the United States.
Among whites the pattern was reversed, with the death rates increasing more in the southern than in the northern industrial areas. For urban America, both male and female mortality rates for cirrhosis in the nonwhite population are at least double those of the white population. The overall cirrhosis mortality in the United States dropped in the late 1970s and, with the exception of 1979, declined further in the early 1980s.Elsewhere, in Birmingham, England, the annual incidence of cirrhosis rose from 5.6 per 100,000 population in 1959 to reach a peak of 15.3 in 1974, and then fell slightly. The annual death rate for cirrhosis in Denmark climbed from 7.5 per 100,000 population in 1963 to 9.7 in 1978. When analyzed according to sex and age, the increase in mortality rate was 3-fold among young and middle-aged men, but fell by 50 percent among older women. In western Australia cirrhosis mortality for males over age 30 increased from 14.1 per 100,000 in 1971 to 21.0 in 1982. Deaths from alcoholic cirrhosis increased in Finland and Denmark 10-and 5-fold, respectively, from 1961 to 1974. During the same period, males in Sweden and Norway had, respectively, a 3-fold and 2-fold increase in mortality due to alcoholic cirrhosis.
The steady rise in cirrhosis death rates in industrialized nations is linked to the increased per capita consumption of alcohol. Mortality figures from the United States, England, and France have dropped whenever the sale of alcohol has been prohibited or restricted during the twentieth century. A doubling of alcohol intake in a country is followed by a 4-fold increase in alcohol-induced disease. The association between alcohol and cirrhosis has been further strengthened by the confirmation of a dose-response relation. The relative risk (RR) for cirrhosis among the French has been defined as follows:
The risk of cirrhosis increases with the daily intake of alcohol much faster in females than in males.
Similar trends in cirrhotic risks also occur in Canadian men and women for comparable levels of alcohol consumption. Although progression to severe liver injury is accelerated in women, the male/ female ratio remains at least 2:1 for most groups. There are some notable exceptions, such as American Indian women - who account for 50 percent of the cirrhosis deaths of this ethnic group.In the West, alcoholic cirrhosis comprises the major share of all cirrhosis. An estimated 75 percent of cirrhosis in the United States is alcoholic in origin; 15 percent is viral, and 10 percent is cryptogenic. A different distribution pertains in Great Britain, where 50 percent is alcoholic, 25 percent is cryptogenic, and 25 percent is viral. In Asia and Africa, where the prevalence Ofhepatitis B virus is high and the per capita consumption of alcohol is low, the proportion of virus-related cirrhosis to the alcoholic type is the reverse of that seen in the West. Past literature written on the disease from data gathered from east European countries suggests no association between cirrhosis and viral hepatitis. The studies were done, however, before the introduction of serologic markers for hepatitis, and thus, the type of viral heptatitis was not identified. The occurrence rate of hepatitis B virus cirrhosis is uncertain (see Table VIII.28.1). Epidemiological studies strongly support the association between chronic hepatitis B infection and the development of primary hepatocellular carcinoma. Infection at birth results in chronic hepatitis, cirrhosis, and carcinoma 2 to 3 decades later. How the virus causes the carcinoma is not understood, but the process involves cirrhosis, especially among males. Cirrhosis, like its sequela, hepatocellular carcinoma, is common in countries where hepatitis B virus is endemic.