Smoking threatens health gains from hepatitis C treatment, US researchers warn

People with hepatitis C in the United States are at least three times more likely to smoke than the general population but little is being done to help them stop smoking, and US researchers say it is folly to spend huge sums on hepatitis C treatment without trying to help patients stop smoking.

The researchers’ findings are published in The American Journal of Medicine.

Smoking contributes to three of the five leading causes of death in the United States: heart disease, stroke and cancer. Hepatitis C independently increases the risk of cardiovascular disease, liver cancer and cancers of the head, neck, lung, pancreas, kidney and anorectum. “There is some evidence that these risks may be additive,” say the authors, noting that smoking increases the risk of developing liver cancer in people with hepatitis C.

They point out that between 2006 and 2010, deaths due to cardiovascular disease, respiratory disease and non-hepatic cancers – all linked to tobacco use – exceeded those from liver-related causes among people with hepatitis C in the United States.

To assess the potential burden of tobacco-related disease among people with hepatitis C, investigators from Albert Einstein College of Medicine, New York, analysed the prevalence of smoking in the National Health and Nutrition Examination Survey (NHANES) between 1999 and 2014.

The cohort consisted of 43,793 adults, of which 1.3% had hepatitis C (524). Of these, 312 were current smokers. People with hepatitis C were three times more likely to smoke (62.4% vs 22.9%, p < 0.001). Smokers with hepatitis C were significantly more likely to be black, poor, have less education and to lack medical insurance compared to smokers without hepatitis C.

Among smokers, those with hepatitis C were more likely to be daily smokers (p = 0.04) and had smoked for longer (30.4 years vs 23.9 years, p < 0.001). But, based on an assessment of smoking frequency, smokers with hepatitis C were judged to have the same degree of nicotine dependence as those without hepatitis C. Depression was more frequent among smokers with hepatitis C and among all people with hepatitis C, and both these groups also had significantly higher depression scores compared to HCV-negative people.

Smokers with hepatitis C were more likely to lack medical insurance, including Medicaid, compared to non-smokers with hepatitis C.

People with hepatitis C and current smokers each had a higher risk of hypertension and current depression.

“There is a cigarette smoking epidemic embedded within the hepatitis C epidemic in the US,” the authors write. “Public health authorities together with hepatitis C care providers will need to make a concerted effort to combat tobacco use in this group.

“The US is poised to spend $27 billion annually on DAAs [direct-acting antivirals] to improve the quality and quantity of life for hepatitis C+ individuals, yet there is no organized strategy to combat the tobacco use that is destined to offset those benefits.

“It is public health folly to spend tens of billions of dollars annually on antiviral hepatitis C medications and ignore the lethal addiction affecting more than 60% of them.”

They note that black race, lower socioeconomic status, psychiatric illness and lower educational attainment are associated with greater difficulty in quitting smoking, suggesting that smokers with hepatitis C are likely to need more intensive and prolonged interventions to help them stop smoking.