In order to assess the interaction between alcohol intake, tobacco smoking and
coffee consumption in determining the risk of
liver cirrhosis we carried out a hospital-based case-control study involving 115 patients at their first diagnosis of
cirrhosis and 167 control patients consecutively enrolled in the General Hospitals of the Province of L'Aquila (Central Italy). The mean life-time daily alcohol intake (as g
ethanol consumed daily) was measured by direct patient interviews, whose reproducibility was > 0.80 and similar for cases and controls, as checked by interviewing the relatives of a sample of 50 cases and 73 controls. During the same patient's interview we also measured the mean consumption of
coffee (daily number of cups of filtered
coffee) and tobacco (life-time daily number of cigarettes smoked). A dose-effect relationship on the risk of
cirrhosis was present both for alcohol intake--for which the risk was significantly increased above 100 g of daily intake--and for cigarette consumption. The latter did not however improve the goodness-of-fit of a logistic regression model including alcohol intake as covariate. By contrast,
coffee consumption had a protective effect on the risk of
cirrhosis and significantly improved the goodness-of-fit of such a model. Abstaining from
coffee consumption determined both a significantly increased risk of
cirrhosis, even for daily alcohol intake below 100 g, and a multiplicative effect with alcohol intake on this risk. In patients drinking > or = 101 g
ethanol daily the relative risk increased from 5.5 (95% confidence interval: 1.4-22.0) for
coffee consumers to 10.8 (95% confidence interval: 1.3-58.1) for
coffee abstainers.(ABSTRACT TRUNCATED AT 250 WORDS)