Smoking associated with increased incidence of OAB

Smoking was linked to a higher occurrence of urgency and urgency urinary incontinence (UUI) among Japanese women who were former or current smokers, according to a study published in the International Journal of Urology.¹

Current smokers (2.54) and ex-smokers (2.27) had significantly higher results on the Overactive Bladder Symptom Score versus nonsmokers (1.70), as well as on the International Consultation on Incontinence Questionnaire‐Short Form (2.48, 2.25, and 1.49, respectively). The P values were <.0001 for all comparisons.

“The prevalence of urgency was affected by the smoking status. Younger participants (aged 20-39 years) showed a stronger influence of their smoking habit than older participants (aged ≥40 years). Urgency urinary incontinence was also affected by the smoking status,” the authors wrote.

Overall the investigators obtained 4756 complete responses for the Overactive Bladder Symptom Score and International Consultation on Incontinence Questionnaire‐Short Form questionnaire. There were 2828 nonsmokers, 938 current smokers, and 990 ex-smokers.

Smoking status had a strong impact on lower urinary tract symptoms (LUTS). Specifically, among current and former smokers, there was a higher incidence of OAB, nocturia, UUI (OABSS definition), stress urinary incontinence (SUI), mixed urinary incontinence (MUI), and post‐micturition dribble (PMD).

The relative risk for OAB were 2.0, 1.7, and 1.0 for current smokers ex-smokers, and nonsmokers, respectively. The relative risks were 1.5, 1.4, and 1.0, respectively, for UUI (OABSS definition), and 1.1, 1.2, and 1.0, respectively, for SUI. For MUI and PMD, the relative risks were 0.9, 1.4, and 1.0, and 2.4, 2.0, and 1.0 respectively.

A smoking habit had a strong effect on OAB risk in younger individuals (aged 20-39 years) versus individuals aged 40 years and older. Setting the relative risk for OAB as 1.0 for nonsmokers, the investigators determined that the relative risks were 3.3 and 1.8, respectively, for current and former smokers aged 20 to 29 years; 2.4 and 2.0 for those aged 30 to 39 years; 2.3 and 2.1 for those aged 40 to 49 years; 1.4 and 1.2 for those aged 50 to 59 years; 1.5 and 1.7 for those aged 60 to 69 years; and 1.6 and 1.3 for those aged ≥70 years.

The researchers noted some limitations of their research. The first was that the data accrued for the analysis were obtained through an online, self-administered questionnaire. The questionnaires were completed by individuals through either a computer or an app downloaded on a smartphone or tablet. “Our study, therefore, failed to obtain the satisfactory number of participants calculated by population‐based numbers,” the authors wrote.

The second key limitation noted by the researchers was that they did not assess factors related to smoking that could have impacted the results. Such factors include hypertension, caffeine use, alcohol consumption, hypertension, or psychiatric disorders.

In their final remarks, the authors wrote, “In conclusion, the prevalence of LUTS, including OAB and UUI, increases with age. Furthermore, a smoking habit exacerbates LUTS symptoms, especially among young women.”

Reference

1. Kawahara T, Ito H, Yao M, Uemura H. Impact of smoking habit on overactive bladder symptoms and incontinence in women [published online September 1, 2020]. Int J Urol. doi: 10.1111/iju.14357