Association of Smoking Status and Pack Year History With Urinary Urgency Symptoms

Overactive bladder and its hallmark symptom, urgency, are thought to be multifactorial in pathogenesis. Smoking is a particularly important risk factor to understand because it is modifiable; studies evaluating an association between smoking and urgency have been inconclusive. We therefore sought to rigorously assess the relationship between smoking and urgency in terms of both a temporal and quantitative pack year history of smoking while controlling for other possible confounding factors.

Community-based adult women were recruited using the ResearchMatch website to participate in an online survey of bladder health which included questions to assess urgency symptoms, medical comorbidities, and detailed smoking history. Smoking history was studied as the independent variable in three different formulations: smoking status (never vs. former vs. current), continuous pack year history, and categorical pack year history. The outcomes studied included urgency (any urgency in the past 7 days), moderate urgency (urgency at least half the time), and urgency urinary incontinence (UUI). Chi-square tests were performed to detect associations between smoking and these outcomes, and multivariate regression was then performed to control for possible confounders and to help determine the comparative influence of temporality versus quantity of smoking history.

In 1720 women who completed the questionnaire, current smoking status was associated with a 23% increase in the risk of experiencing urgency (RR 1.23) and a 78% increase in the risk of experiencing moderate urgency (RR 1.78) relative to never smokers. The risk of experiencing UUI was 40% higher (RR 1.40). Lifetime pack year history was also significantly associated with urgency outcomes, although only in smokers/former smokers who had a 20+ pack year history (RR 1.15, 1.60, and 1.25 for urgency, moderate urgency, and UUI, respectively). The presence of former smoking history was not significantly associated with urgency outcomes, even when controlling for cumulative pack years.

This analysis of a large cross-sectional database of women suggests a strong, consistent link between current smoking status and urinary urgency and UUI. By contrast, no increased risk of urgency was attributed to former smoking status. Analysis of pack year history suggests a dose-response relationship wherein ≥ 20 pack years was significantly associated with a higher risk of all urgency outcomes. In models controlling for pack year history, the association of current smoking with urgency remained significant and former smoking remained nonsignificant. Taken together, this supports greater attention being given to the contribution of current smoking to urgency symptoms, and to the need for further longitudinal work to determine if smoking cessation can be a strategy to treat urgency.