Introduction

Cigar smoking is increasing in the United States, mainly in young and middle-aged men, but also among teenagers and women. The habit is known to be a risk factor for certain cancers (mouth, pharynx, larynx, esophagus and lung) and chronic obstructive pulmonary disease (COPD). To date, there has been no firm indication that it is associated with increased risk of cardiovascular disease, but the article summarized here provides the evidence.

Methods

The population studied comprised 17,774 men between 30 and 85 years enrolled in the Kaiser Permanente Medical Care Program between 1964 and 1973. They stated they had never smoked cigarettes, and were not current pipe smokers. Information on lifestyle, serum cholesterol, diabetes, cardiovascular and COPD was obtained at the health check-up on entry.

Subsequent cardiovascular and COPD incidence was determined from hospitalization records, using International Classification of Diseases codes, and cancer incidence from the same source as well as from local tumor registries. Patients were followed from 1971 through 1995 for first hospitalization or death from cardiovascular or COPD, and from 1971 through 1996 for diagnosis of cancer.

There were 1,546 cigar smokers at entry - 8.7% of the collective - and their outcome data were compared with those of the 16,228 non-cigar smokers. Age-adjusted rates were estimated by regression analysis, and the relative risks associated with cigar smoking calculated using Cox proportional-hazard models. Multivariate analyses incorporated the following factors: the demographic information collected at enrollment, body mass-index, history of diabetes, occupational hazard exposure (solvents, pesticides, chemical gases, asbestos, silica), and alcohol consumption. For the cardiovascular outcome analyses, systolic blood pressure and cholesterol levels were added to these factors, and occupational hazards omitted.

Results

About 75% of the cigar smokers smoked fewer than 5 cigars a day. In general, cigar smokers were slightly older, had a higher body-mass index, higher blood pressure, higher cholesterol levels and were more likely to have diabetes, than non-cigar smokers; also, they consumed more alcoholic drinks per day than non-smokers.

Age-adjusted rates of occurrence for all cardiovascular outcomes and COPD were consistently higher for cigar smokers than for non-smokers. The relative risk for coronary heart disease was 1.27 (95% CI: 1.12-1.45), and for COPD was 1.45 (95% CI: 1.10-1.91). The incidences of the other conditions evaluated (ischemic stroke, hemorrhagic stroke, peripheral arterial disease) were not statistically-significantly different between cigar smokers and non-smokers.

Multivariate analyses of cancer incidences showed that cigar smokers had about twice the risk of cancer of the esophagus, upper aerodigestive tract (oropharynx plus nose, larynx and esophagus) and lung as non-smokers. Dose-response relationships were seen - the risks associated with cigar smoking were significantly greater among those who smoked 5 or more cigars daily, compared with those who smoked fewer than 5. For oropharyngeal cancer, there appeared to be synergism between cigar smoking and alcohol consumption. Incidences for cancer of the pancreas, kidney, bladder and colorectum were not different between cigar smokers and non-smokers.

Comment

These findings have been compared with those for cigarette smoking. Typical relative risks associated with current cigarette smoking by men are 1.5 to 3.0 for coronary heart disease, 9 to 25 for COPD, 8 to 24 for lung cancer and 4 to 12 for oropharyngeal cancer. However, as about half the cigar smokers in the Kaiser Permanente cohort reported having quit smoking after 8 years into the study, the effects of cigar smoking may have been underestimated. This is born out by the values for the relative risks for cancer of the oropharynx and upper aerodigestive tract, which are lower than those from other studies.

Cigar smoke contains the same toxic and carcinogenic compounds as cigarette smoke, with 4 or more cigars daily providing about the same smoke as 10 cigarettes per day. However, cigar smoke is not usually deeply inhaled, which may account for the lowered relative risks of COPD and lung cancer among cigar smokers, compared with cigarette smokers.

The resurgence of cigar smoking in the United States in recent years is a matter of concern. It may be that young or middle-aged persons think that cigar smoking is a safer alternative to cigarette smoking. This study proves them wrong. Older persons, even if non-smokers themselves can, as elders, play an effective role by offering their children and grandchildren appropriate advice on the risks of all forms of tobacco.