Moderate alcohol consumption - as little as one or two drinks per day - is associated with an increased risk of mortality for people with chronic hepatitis C virus (HCV) infection, according to research conducted in the United States and published in Alimentary Pharmacology and Therapeutics.
HCV-infected patients consuming between 1 and 19g of alcohol daily (one to two glasses of wine) doubled their mortality risk compared to HCV-uninfected controls. Moderate alcohol consumption added to the already elevated mortality risk associated with HCV infection.
Chronic HCV infection is an increasingly important cause of serious illness and death in the United States. A number of factors are associated with disease progression, including excessive alcohol consumption. The impact of moderate drinking on outcomes among patients with chronic HCV is controversial.
A team of investigators therefore designed a study based on results obtained from a national health survey conducted between 1988 and 1994. Their aims were to determine the impact of moderate, excess and heavy alcohol consumption on the risk of overall, liver-related and cardiovascular-related mortality in people with chronic HCV. Moderate consumption was considered to be between 1 and 19g of alcohol per day. Excess consumption was above 20g per day and heavy consumption was drinking over 30g of alcohol per day.
The study population comprised 8985 individuals, 218 of whom had chronic HCV.
There were significant baseline differences between the HCV-infected patients and the controls. Individuals with chronic HCV were significantly more likely to report excess alcohol consumption (28 vs 7%, p = 0.0075), and had higher rates of smoking (p = 0.0007) and a higher prevalence of insulin resistance or diabetes (36 vs 16%, p = 0.0013) than the controls.
The average duration of follow-up was between 13 and 14 years.
Overall, 1320 (11%) of participants died. A total of 415 (3%) of deaths were attributed to cardiovascular disease and 32 deaths (0.27%) were due to liver disease.
Compared to the controls, participants with chronic HCV had a significantly higher risk death due to any cause (HR = 1.91; 95% CI, 1.16-3.15; p = 0.01) and liver-related death (HR = 49.52; 95% CI, 12.37-198.26; p < 0.001), but not death due to cardiovascular disease (HR = 0.053; 95% CI, 0.17-1.67; p = 0.28).
The investigators then evaluated the combined effects of chronic HCV infection and alcohol consumption on mortality risk.
For participants without excessive alcohol consumption, chronic HCV increased the risk of all-cause mortality (HR = 2.44; 95% CI, 1.59-3.75; p < 0.01) and liver-related death (HR = 74.25; 95% CI, 19.62-280-92; p < 0.001).
Excess alcohol consumption had an even more marked impact on the risk of all-cause mortality (HR = 5.12; 95% CI, 1.97-13.28; p < 0.001) and liver-related death (HR = 183.74; 95% CI, 15.98-infinity; p < 0.01). There was also a trend for associating excess drinking with an increased risk of death due to cardiovascular disease (HR = 3.34; 95% CI, 0.55-20.50; p = 0.19).
The impact of chronic HCV on mortality outcomes was then stratified according to levels of alcohol consumption.
For individuals with a history of drinking (twelve or more drinks in a lifetime), chronic HCV doubled the overall mortality risk (p = 0.01). Moderate alcohol consumption was also associated with a two-fold increase in overall mortality risk for HCV-infected participants (HR = 2.29; 95% CI, 1.36-3.88; p =0.01). Heavy consumption increased the mortality risk by a factor of seven for those with HCV (p = 0.02). The investigators also confirmed an association between heavy drinking and an increased risk of death (p = 0.02) for individuals with HCV.
“This is the first study documenting the combined effects of alcohol consumption and chronic HCV on both overall mortality and liver related mortality,” comment the authors.
“Patients with chronic HCV are at increased risk for both liver-related mortality and overall mortality. This risk increases in chronic HCV patients who consume alcohol excessively and potentially moderately.”
The authors believe their findings have implications for patient care, and that doctors should advise people with chronic HCV infection to completely abstain from drinking alcohol.
Younossi ZM et al. Moderate, excessive or heavy alcohol consumption: each is significantly associated with increased mortality in patients with chronic hepatitis C. Aliment Pharmacol Ther, online edition. DOI: 10.1111/apt.12265, 2013.