Cigarette smoking and prostatism: A biphasic association?

Objective. To evaluate the association between cigarette smoking and prostatism in a community-based setting using standardized urinary symptom scores, peak urinary flow rates, and prostatic volume as indicators of disease. Methods. A population-based cohort of 2,115 Caucasian men aged forty to seventy-nine years from Olmsted County, Minnesota, was administered a previously validated questionnaire that elicited information on frequency of urinary symptoms (approximating the American Urological Association's symptom index), and a detailed history on cigarette smoking, including both amount and pack-years of smoking. Peak urinary flow rates were measured by a standard uroflowmeter (Dantec 1000). The prostatic volume was measured for a subsample of 471 men by transrectal ultrasound. Results. Compared to never-smokers, smokers were less likely to have moderate to severe urinary symptoms (age-adjusted odds ratio 0.82; 95% confidence interval [CI] 0.61 to 1.08). This varied by smoking intensity, however; in men who smoked less than 1 pack a day the age-adjusted odds ratio was 0.53 (95% CI 0.33 to 0.83) and among men smoking 1 to 1.4 packs a day, the odds ratio was 0.87 (95% CI 0.56 to 1.36). For men who smoked 1.5 packs or more a day, the odds ratio was elevated at 1.32 (95% CI 0.84 to 2.07). Smokers were less likely to have peak flow rates less than 15 mL/sec compared with never-smokers (age- and voided volume-adjusted odds ratio 0.48; 95% CI 0.35 to 0.66), or prostatic volume greater than 40 mL (odds ratio 0.54; 95% CI 0.19 to 1.55). Conclusions. These data from a community-based sample suggest that light or moderate smokers are less likely to have moderate to severe prostatism, whereas heavy smokers are at least as likely to have moderate to severe prostatism compared with never-smokers.