Issue 159 - August/September 2006
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Why smoking is more likely to kill you than HIV, by Edwin J Bernard

Until recently, studies examining the effects of smoking tobacco on HIV-positive individuals suggested that HIV-positive smokers did not die any sooner than HIV-positive non-smokers. Most people pointed to the results of the gay men's Multicenter AIDS Cohort Study, which had found no association between smoking and the risk of developing AIDS or dying1. However, since this was conducted in 1987, prior to the availability of potent anti-HIV therapy, it is likely that the negative longer-term effects of smoking were masked by HIV's relatively short survival expectations.

In fact, even as early as 1992 evidence began to accrue that smoking increased the risk of acquiring infections that affect the lungs, such as Pneumocystis pneumonia (PCP)2. Similar conclusions regarding smoking and bacterial pneumonia3, and emphysema4, followed. And, as the effects of potent anti-HIV therapy began to have a significant impact on life expectancy, smoking began to appear as a factor that influenced the impact of other important illnesses, such as cardiovascular disease, which was first seen in the Swiss HIV Cohort in 20015 and confirmed in several major studies since.

One of the main conclusions of a 2005 review article by respected metabolic experts Steven Grinspoon and Andrew Carr, was that "cigarette smoking is the most important modifiable risk factor among HIV-infected patients," and that "cessation of smoking is more likely to reduce cardiovascular risk than either the choice of antiretroviral therapy or the use of any lipid-lowering therapy."6

More recent studies have found evidence suggesting that HIV-positive smokers are at an increased risk of smoking-related cancers, over and above the risk associated with smoking in the HIV-negative population. Earlier this year, investigators from John Hopkins Hospital in the United States found that, compared with the general population, the risk of lung cancer more than doubled in all HIV-positive individuals, but that the risk doubled again in HIV-positive smokers7. And another Swiss HIV Cohort study found that HIV infection trebled the risk of cancers of the lip, mouth, pharynx, or lung compared with HIV-negative people, and that these cancers were only seen in smokers8. HIV-positive smokers were also found have an increased risk of developing cervical cancer9 and kidney disease10.

The first data to find an association between smoking and reduced life expectancy in HIV-positive individuals were finally published last year. Here, a study of 867 HIV-positive American army veterans on potent anti-HIV therapy found that smokers were twice as likely to die during the study period compared with non-smokers11. This June, a second study, of 924 US women also on potent anti-HIV therapy, confirmed these data. It found that HIV-positive cigarette smokers had a 50% increased risk of dying during the study period compared with HIV-positive non-smokers, leading the investigators to conclude that smoking negates some of the benefits of potent anti-HIV therapy12.

The good news is that it's never too late to stop. Research in the general population, which calculated the risk of lung cancer in lifelong smokers aged 75 at 16% (if they hadn't died of other causes by then), found that this risk was reduced to 6% if smokers stopped at 50, 3% if smokers stopped at 40, and 2% if smokers stopped at 3013.

Amongst HIV-positive people, improvements in cardiovascular risk have already been seen in a French study of 233 men and women, of whom 59% were smokers. During the three years of the study, only 24 of the 137 smokers stopped smoking, but this was enough for the investigators to detect a significant difference in their risk of future cardiovascular disease. In fact, stopping smoking was the only modifiable factor that reduced the risk significantly over the three years: the use of lipid-lowering drugs and switching from a protease inhibitor to a non-nucleoside reverse transcriptase inhibitor (NNRTI) did not significantly reduce the risk14.

AIDS Treatment Update asked Dr Graeme Moyle, of London's Chelsea & Westminster Hospital, to explain the impact of smoking on people living with HIV, and how best to go about stopping.

Question 1

Why has it taken so long to see an effect of smoking on life-expectancy in HIV-positive people?

 

GM: Obviously, we've known for many decades that smoking is bad for you and affects health in many, many ways. One of the reasons we haven't seen its negative effects until recently is that we haven't looked for diseases that have a long lag time, like cancer or cardiovascular disease. Thanks to potent anti-HIV therapy, it is likely that many people living with HIV today are going to live long enough to also be prone to the chronic prevalent diseases that affect all ageing populations. Since many of these diseases are smoking-related (like cancers of the mouth and lung) or increased in their prevalence by smoking (like cardiovascular disease, chronic lung disease, anal and cervical cancer), it makes sense to stop smoking, if you want to live as long and as healthy a life as possible.

 
Question 2

More than ever before, then, it seems that lifestyle factors - like diet, exercise and smoking - are important for HIV-positive people. But although there's a global movement to stop people smoking, HIV-positive people, and gay men in particular, are much more likely to smoke than the general population15. Why do you think that's the case?

 

GM: I can only speculate, but one of the reasons I've heard is that 'I'm going to die of HIV anyway, so what does it matter if I smoke?' That's clearly something that could have been a justifiable thought process fifteen years ago, but it’s not the case today. Also, some people have said to me that smoking helps them feel less stressed. Actually there's no evidence that it reduces stress, but people do perceive that as part of their addiction process. Certainly, withdrawing from an addiction may make you feel less good, but perpetuating the addiction doesn't make you feel any more relaxed. In fact, blood pressure, and a number of other measures of stress, tend to actually increase when you're smoking cigarettes, rather than reduce. So the idea that people relax with a cigarette is actually inaccurate.

 
Question 3

What do you say to your patients if you know they're smokers?

 

GM: We discuss strategies around reducing cigarettes with the aim of stopping. For example, limiting the times and places you allow yourself to smoke, and then gradually building up control over the cigarettes. Also, using patches and gum to reduce cravings. I talk about putting the savings from not smoking aside each day with a particular objective in mind, like a nice holiday. To show one of the benefits of stopping, I calculate their cardiovascular disease risk, which is much higher if you smoke, and then show them how significantly the risk can be reduced if they stop smoking. It's all part of coming to terms with ageing with HIV: I also talk about planning their pension, in contrast from the bad old days when it was about planning a will. So we talk about planning for the future. In this context, stopping smoking gives a better chance of reaching that future in a healthy condition.

 
Question 4

Does that mean that people who are in their 20s, or early to mid-30s don't need to think about giving up smoking compared to people who are in their 40s and 50s?

 

GM: While it's very hard to measure the risk of smoking on cardiovascular disease in someone in their 20s it doesn't mean there aren't benefits to stopping sooner rather than later. However, I think the issue for younger people is that they're setting themselves up for a chronic addictive behaviour that is going to be more difficult to give up as the years go by. So it's probably better to try and deal with that addiction now rather than later, and not allow it to become a self-perpetuating beast that you never escape. Also, since smoking can cause some problems that HIV-positive people are already prone to, including mouth sores, oral thrush, and dental and gum problems, quitting at any age can help improve these quite quickly.

 
Question 5

What about simply cutting down, rather than stopping completely?

 

GM: One of the messages about smoking is that there are really only two choices: not smoking or smoking. Smoking a 'milder' tar brand or smoking ten instead of 20 a day doesn't substantially reduce the risk of smoking-related diseases in the same way that stopping smoking does. Even very small numbers of cigarettes per day have a substantial cardiovascular risk impact. Researchers from Denmark16 found that women who smoke just three cigarettes a day double their chances of having a heart attack and of dying early; men run similar risks if they smoke six cigarettes or a cigar each day.

 
Question 6

How do you help your patients to stop smoking?

 

GM: Within our hospital, and I think this is broadly true of most hospital settings, there are stopping smoking services. Additionally, there are many stopping smoking services available throughout the UK. The best way to access these services is through general practitioners. Unfortunately, many HIV-positive people don't have GPs, or are not open about their HIV status to their GPs. However, there are other ways to access these services (see 'How to stop').

 
Question 7

Do any of the drug treatments than can be used to stop smoking interact with any anti-HIV drugs?

 

GM: No, neither nicotine replacement therapy nor bupropion (Zyban; an antidepressant that can reduce cravings and anxiety) have any important interactions with HIV medications. Both of these are available on prescription through your GP, but I would say that one does not necessarily have to reveal one's HIV status to the GP in order to access them. The new diet pill, rimonabant (Accomplia), has also been reported to reduce craving for cigarettes as well as for food. However, it doesn't have an approval for this indication making it less likely that doctors will be willing to prescribe it for smoking cessation.

 
Question 8

Although not legal in the UK, marijuana is being used by some HIV-positive people to help with pain symptom management and side-effects such as nausea, lack of appetite and insomnia. Are the risks the same as with tobacco?

 

GM: Many people are generally taking it with tobacco anyway, but in reality you can't quite smoke as many joints per day as you might do cigarettes! Of course, it's important to discourage the use of illegal substances, but from a medical perspective, if a person has an occasional joint as part of symptom or side-effect management, then the contribution to cardiovascular risk from that sort of level of consumption is going to be modest and probably closer to not smoking than it would be to smoking.

 
Question 9

What would be your take-home message to HIV-positive cigarette smokers?

 

GM: You're going to live a long time with your HIV, so you've got to now think about what might kill you, seeing that it's not likely to be your HIV anymore. Smoking comes high on the list of what might kill you in the future. So, it's sensible to stop. And the sooner you stop, the better.

 

How to stop

You can find your local NHS Stop Smoking Service at www.givingupsmoking.co.uk. Information is also available by phone (0800 169 0 169 in England; 0800 848 484 in Scotland; 0800 085 2219 in Wales; and 0800 858 585 in Northern Ireland). You can also text GIVE UP with your full postcode to 88088.

You local HIV support centre may also run a workshop specifically for HIV-positive people. For example, Positive East runs stop smoking courses for HIV-positive people in East London. For more information, visit www.positiveeast.org.uk, phone 020 7791 2855, or email fresh@theglobecentre.co.uk.

In addition, GMFA runs stop smoking courses for gay men of any HIV status in central London. The next workshop begins on Thu 31st Aug from 19:00-21:00 and continues each Thursday until 12th October. Email: workshops@gmfa.org.uk or telephone 020 7738 3712 for more information or visit www.metromate.org.uk.

Smoking cessation guidelines for HIV-positive patients

The New York Department of Health have published the first ever smoking cessation guidelines aimed at HIV-positive individuals17. These were last updated in June 2005.

They include the following key points and recommendations:

  • Cigarette smoking is highly prevalent among both HIV-infected patients and substance users.
  • Clinicians should use evidence-based interventions to promote smoking cessation in HIV-infected patients.
  • Clinicians should routinely assess HIV-infected patients' smoking status and readiness to quit.
  • Clinicians should identify and discuss barriers to quitting smoking for HIV-infected smokers who are not interested in stopping in the immediate future, but may consider it at a later time.
  • Clinicians should advise all smokers to quit and should offer smoking cessation assistance including pharmacotherapy to smokers who are interested in quitting.
  • Clinicians should follow up attempts to quit with discussions of relapse prevention. Relapses should be followed up with discussions of new strategies for the next attempt to quit.

References

1. Galai N et al. Effect of smoking on the clinical progression of HIV-1 infection. J Acquir Immune Defic Syndr Hum Retrovirol 14: 451-458, 1997.

2. Buskin SE et al. Heavy smoking increases the risk of Pneumocystis carinii pneumonia (PCP). Eighth International Conference on AIDS, Amsterdam, abstract WeC1030, 1992.

3.Burns DN et al. Cigarette smoking, bacterial pneumonia, and other clinical outcomes in HIV-1 infection. J Acquir Immune Defic Syndr Hum Retrovirol 13: 374-383, 1996; Conley LJ et al. The association between cigarette smoking and selected HIV-related medical conditions. AIDS 10: 1121-1126, 1996.

4.Diaz P et al. Increased susceptibility to pulmonary emphysema among HIV-seropositive smokers. Ann Intern Med 132: 369-372, 2000.

5.Depairon M et al. Premature atherosclerosis in HIV-infected individuals - focus on protease inhibitor therapy. AIDS 15: 239-334, 2001.

6.Grinspoon S et al. Cardiovascular risk and body-fat abnormalities in HIV-infected adults. N Engl J Med. 6;352(1): 48-62, 2005.

7.Engels EA Elevated incidence of lung cancer among HIV-infected individuals. J Clin Oncol. 20;24(9):1383-1388, 2006.

8.Clifford GM et al. Cancer risk in the Swiss HIV Cohort Study: associations with immunodeficiency, smoking, and highly active antiretroviral therapy. J Natl Cancer Instl 16;97(6): 425-432, 2005.

9.Minkoff H et al. Relationship between smoking and human papillomavirus infections in HIV-infected and -uninfected women. Journal of Infectious Diseases, 189: 1821-1828, 2004.

10.Miguez-Burbano MJ et al. Renal disease in HIV infected subjects: The deleterious effect of smoking. Fifteenth International AIDS Conference, Bangkok, abstract MoPeB3274, 2004.

11. Crothers K et al. The impact of cigarette smoking on mortality, quality of life, and comorbid illness among HIV-positive veterans. Journal of General Internal Medicine 20 (12), 1142-1145, 2005.

12. Feldman JG et al. Association of cigarette smoking with HIV prognosis among women in the HAART era. Am J Public Health 96(6): 1060-1065, 2006.

13. Peto R et al. Smoking, smoking cessation, and lung cancer in the UK since 1950: combination of national statistics with two case-control studies. BMJ 321(7257): 323-329, 2000.

14.Thiebaut R et al. Change in atherosclerosis progress in HIV infected patients: ANRS Aquitaine Cohort, 1999 - 2005. AIDS: 19(7): 729 - 731, 2005.

15. Smith C et al. Cardiovascular disease risk factors and antiretroviral therapy in an HIV-positive UK population. Sixth International Congress on Drug Therapy in HIV Infection, Glasgow, abstract P162, 2002.

16. Prescott E. Importance of light smoking and inhalation habits on risk of myocardial infarction and all cause mortality. A 22 year follow up of 12 149 men and women in The Copenhagen City Heart Study. Journal of Epidemiology and Community Health 56: 702-706, 2002.

17. Available to download from: www.hivguidelines.org/public_html/sub-smoking/sub-smoking.htm