Smoking and Your Health: How to Quit (and Why You Should)

by Liz Highleyman

By now, it is firmly established that smoking is a major risk factor for serious chronic illnesses, including cardiovascular disease and cancer. In the early years of the epidemic, many people with HIV/AIDS assumed there was little point in worrying about chronic progressive diseases, since they probably would not live long enough for these to develop. But this changed with the advent of HAART in the mid-1990s. With life expectancy dramatically extended by combination antiretroviral therapy, HIV positive people now need to pay attention to the same health issues that affect HIV negative people as they age.

Studies suggest that HIV positive people are more likely to smoke than HIV negative individuals. Research has yielded conflicting data about the effects of smoking on HIV disease progression, but most studies have shown some harm, and certainly none has demonstrated any benefit. Further, concerns about elevated lipid levels and other complications related to antiretroviral therapy have underlined the importance of changing modifiable risk factors such as smoking, diet, and exercise.

Quitting smoking is not easy, but it can be accomplished. Strategies to assist smoking cessation have evolved over the years as the urgency of the problem has become increasingly evident. A growing body of research shows that people who receive counseling, support, nicotine replacement therapy, and antismoking medications are more likely to quit than those who rely on willpower alone.

No matter how long a person has smoked, quitting can make a big difference in terms of health benefits, some of which begin within days of stopping. According to the U.S. Surgeon General, “Smoking cessation represents the single most important step that smokers can take to enhance the length and quality of their lives”—and this holds true for HIV positive and HIV negative smokers alike.

Smoking as a Public Health Issue

The detrimental effects of smoking are well known, but worth a review. According to the U.S. Centers for Disease Control and Prevention (CDC), cigarette smoking is the nation’s leading preventable cause of death, contributing to both cardiovascular disease and cancer. Smoking causes an estimated 440,000 deaths annually, or about one out of every five; about 10% of these are due to second-hand smoke. Worldwide, the World Health Organization (WHO) estimates that five million deaths per year are attributable to smoking. On average, smokers have a lifespan about 15 years shorter than that of nonsmokers.

Although smoking is much less socially acceptable today than it was half a century ago, the CDC estimates that about 45 million people in the U.S. still smoke, or about 21% of the total population. American women smoke less than men (18% vs 24%), but the gap has narrowed dramatically since the 1960s. Worldwide, the WHO estimates that approximately 1.3 billion people smoke.

Smoking rates vary among racial/ethnic groups in the U.S., being highest among Native Americans (32%). Whites and blacks are about equally likely to smoke (22%), while rates are lower among Latinos (16%) and Asians (13%). Several studies suggest that gay/lesbian/bisexual/transgender people smoke more than the population as a whole; in one survey, the rate of current smoking among gay men was 27%.

Health Hazards of Smoking

Cigarette smoking affects every system of the body. Some harmful effects are caused by nicotine itself, while others are due to the carbon monoxide, tars, and other toxins in cigarette smoke. Many detrimental effects of smoking are related to reduced oxygen levels in body tissues. Smoking also leads to oxidative damage, elevated levels of destructive free radicals, and chronic inflammation.

The immediate effects of smoking include increased blood pressure and elevated heart rate. Over time, breathing capacity diminishes as smoking damages the alveoli (tiny air sacs) in the lungs. But the most serious outcomes of smoking develop over the long term, including cancer, chronic lung disease, and cardiovascular disease.

Lung Cancer

The disease most commonly associated with tobacco smoking is lung cancer, caused by the tars and other carcinogens in the smoke. In the U.S., lung cancer is the leading cause of cancer-related mortality, accounting for about 25% of all cancer deaths. Lung cancer kills more women each year than breast cancer. The high mortality rate is due in part to the fact that lung cancer is difficult to detect early and hard to treat. Smokers are much more likely than nonsmokers to develop lung cancer, with a 13-fold higher risk for women and a 24-fold higher risk for men.

Studies indicate that people with HIV have a higher risk of lung cancer than the general population, and the rate has risen since the advent of HAART. In a study conducted early in the HAART era, British researchers found that HIV positive people were about eight times more likely to develop lung cancer. In a more recent analysis of the large Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) study, HIV positive current smokers were three times more likely to die of cancer than nonsmokers, mostly due to lung cancer.

Researchers from Johns Hopkins University reported last year that, overall, HIV positive people (smokers and nonsmokers together) were more than twice as likely as HIV negative individuals to develop lung cancer; however, 85% of those who got lung cancer were smokers. In another recent study, Gregory Kirk and colleagues, also from Johns Hopkins, looked at lung cancer rates among participants in the AIDS Link to the Intravenous Experience (ALIVE) study, a cohort of more than 2,000 HIV positive and at-risk injection drug users in Baltimore. After adjusting for potential confounding factors, including smoking, HIV positive participants had more than three times the risk of death due to lung cancer. While being HIV positive was associated with lung cancer independent of smoking, all but one of the individuals who developed lung cancer were smokers.

Although lung cancer is not known to have an infectious cause like some AIDS-defining malignancies, a recent meta-analysis by Andrew Grulich and colleagues at the National Centre in HIV Epidemiology and Clinical Research, University of New South Wales, showed that it occurs more often in both HIV positive people and organ transplant recipients who take immunosuppressive drugs, indicating that immune dysfunction plays a role.

Cervical and Anal Cancer

Women who smoke have a significantly higher risk of cervical cancer, caused by human papillomavirus (HPV), as demonstrated by several studies in HIV negative women. One analysis of 1,812 women, for example, found that those who smoked a pack or more per day had four times the risk of precancerous cell changes (intraepithelial neoplasia) or cervical cancer; even former smokers still had a three-fold increase in risk.

Women with HIV are already at greater risk of infection with cancer causing strains of HPV, so smoking may be particularly detrimental. Among nearly 1,800 HIV positive and 500 at-risk participants in the Women’s Interagency Health Study (WIHS), women with HIV were three times more likely than HIV negative women to be infected with HPV at baseline, more likely to acquire new HPV infection during follow-up, and more likely to have high-risk HPV types 16 and 18. Among the HIV positive women, the risk was significantly higher for smokers. For this reason, HIV positive women who smoke should receive regular Pap smears and HPV tests in order to catch neoplasia at an early, more treatable stage. (See “Women and HIV: Human Papillomavirus” in the Summer 2007 issue of BETA for more