Is it safe for a person with HCV to have a few drinks? Individualised risk assessment needed

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Heavy alcohol consumption is associated with liver fibrosis in individuals infected with hepatitis C virus (HCV), according to a study published in the March edition of Hepatology.

Although the study did not find that drinking light or moderate amounts of alcohol worsened fibrosis, the investigators were unable to demonstrate that light or moderate drinking had no impact on the development of fibrosis, as they found a spectrum of fibrosis rates present in patients who drank even small amounts of alcohol. However, they concede that for some groups of patients, particularly middle-aged men, the cardiovasuclar benefits of drinking one or two units of alcohol a day could outweigh the risks of liver fibrosis.

Although it has been demonstrated that heavy alcohol consumption worsens the course of HCV liver disease, studies have produced conflicting data about the impact of light or moderate consumption. To help clarify if light or moderate alcohol consumption had an effect on the rate of liver damage in HCV-infected individuals, 800 patients undergoing a liver biopsy -- for whom detailed alcohol histories were available -- were assessed.

Glossary

fibrosis

Thickening and scarring of connective tissue. Often refers to fibrosis of the liver, which can be caused by an inflammatory reaction to long-term hepatitis infection. See also ‘cirrhosis’, which is more severe scarring.

p-value

The result of a statistical test which tells us whether the results of a study are likely to be due to chance and would not be confirmed if the study was repeated. All p-values are between 0 and 1; the most reliable studies have p-values very close to 0. A p-value of 0.001 means that there is a 1 in 1000 probability that the results are due to chance and do not reflect a real difference. A p-value of 0.05 means there is a 1 in 20 probability that the results are due to chance. When a p-value is 0.05 or below, the result is considered to be ‘statistically significant’. Confidence intervals give similar information to p-values but are easier to interpret. 

multivariate analysis

An extension of multivariable analysis that is used to model two or more outcomes at the same time.

cardiovascular

Relating to the heart and blood vessels.

equivalence trial

A clinical trial which aims to demonstrate that a new treatment is no better or worse than an existing treatment. While the two drugs may have similar results in terms of virological response, the new drug may have fewer side-effects, be cheaper or have other advantages. 

In univariate analysis, heavy drinking (five units of alcohol a day, equivalent to five glasses of wine, or two and a half pints of normal strength beer, or five pub measures of spirits) was associated with an increase in the mean risk of fibrosis (p=0.01). If an individual drank eight or more units of alcohol, the rate of liver fibrosis was even faster (p=0.006). Such an association could not be demonstrated for light or moderate alcohol consumption, but the investigators did find that liver fibrosis was present in patients with all levels of alcohol consumption (light, moderate, and heavy), meaning that they could not rule out an association between even modest alcohol consumption and fibrosis.

In multivariate analysis the association between alcohol consumption above five drinks a day and progression of liver disease ceased to be significant (p=0.06), but the investigators found that increasing age (p

The investigators ask, "is there a 'safe' level of alcohol intake in patients with chronic HCV infection? This study does not find this to be the case. We did not find a statistically significant association between alcohol intake and mean fibrosis on liver biopsy until a consumption level of 50g/day of alcohol, and this only in univariate analysis... however, both mean fibrosis and the odds ratio for fibrosis increased step-wise even among patients with less than 50g/day of alcohol consumption... a 'safe' level of alcohol intake is not demonstrated."

However, the investigators concede that light or moderate drinking might have only a minimal, or even no effect, on fibrosis. They add, "Balancing this small risk of liver disease progression against potential cardiovascular benefit may be particularly pertinent for middle-aged men, who constitute the majority of patients with HCV worldwide, and are also at greatest risk of cardiovascular disease." They recommend that "risk-benefit assessment should be individualised for each patient."

An editorial accompanying the study argues, however, that the investigators' interpretation of their data is too cautious, and that drinking small daily amounts of alcohol is "probably not detrimental to HCV-infected patients". In addition, "one drink may have more cardiac benefit than it has fibrogenic detriment... I’ll drink to that".

Further information on this website

Hepatitis C - overview

Hepatitis C - factsheet

References

Monto A et al. Risks of a range of alcohol intake on hepatitis C-related fibrosis. Hepatology 39: 826-834, 2004.

Córdoba J et al Driving under the influence of minimal hepatic encephalopathy. Hepatology 39: 599-601, 2004