TRANSCRIPT VIDEO ID 4352 I 092024: Ava Rangnekar - MAAUA - Association Between Current and Pack-Year Smoking History and Urinary Urgency
Avanti Rangnekar: Thank you so much. As Diane mentioned, my name is Avanti Rangnekar. I'm a fourth-year medical student at the University of Pennsylvania, and I'm going to be discussing our research, the association between current and pack-year smoking history and urinary urgency. At a high level, we analyzed the relationship between smoking and urgency in terms of both a temporal and quantitative pack-year history of smoking.
And so, to start with a little bit of background, overactive bladder or OAB is described by the International Continence Society as urinary urgency, usually accompanied by frequency and nocturia with or without urinary urge incontinence, and in the absence of a UTI or other obvious pathology. It affects around 22 to 35% of women overall. While factors like age and BMI are well documented as having an association with OAB, the relationship between smoking and urgency has been inconsistent, and previous studies have shown mixed results. Moreover, a temporal or quantitative relationship between smoking and urgency has yet to be established.
And so, our study really aims to better qualify this relationship by examining the relationship between smoking and urinary urgency using both smoking status and cumulative pack-year history of smoking while adjusting for other influencing factors. And so, we recruited 1,720 community-based self-selected adult women from a ResearchMatch website. The median age of this group was 42, and the median pack-years was five.
Participants were asked to complete a detailed online survey that included questions around bladder health, urinary urgency symptoms, and detailed smoking history. We categorized smoking history by smoking status divided into never, former, and current smoking status, and then by pack-years both continuously and categorically.
Our outcome of interest was urinary urgency, which we evaluated using the Lower Urinary Tract Research Network Symptom Index, or the LURN-29 Index, which we measured using any urgency, moderate urgency, or urinary urge incontinence that was experienced over the past week. Our analysis involved chi-squared tests for preliminary associations and multivariate logistic regression models to calculate risk ratios controlling for confounders such as age, BMI, and other comorbidities.
And so, we found that current smokers faced a significantly higher risk of experiencing urinary urgency compared to those who have never smoked. In contrast, former smokers showed no significant increased risk of experiencing urinary urgency compared to never smokers. And then, when we looked at pack-year history—which measures the total amount of smoking over a lifetime—we found a very clear dose-response relationship, meaning that those with a pack-year history greater than 20 were at a significantly increased risk of experiencing urinary urgency. I think this can be better visualized through some of these figures and tables here. So, figure one, you can see that current smokers, shown in red, are at a significantly increased risk for experiencing urinary urgency compared to their counterparts, former and never smokers. And then, in figure two here, I think this is a really great visual of this dose-response relationship. You can see that the longer and more intense the pack-year history, the more significant your risk of experiencing urinary urgency, especially indicated by this population with greater than 20 pack-year history of smoking in red.
And then, table two, I think, just further validates some of these findings. Current smokers are at greater than a 23% increased risk for experiencing any kind of urgency, a 78% increased risk of experiencing moderate urgency, and then a 40% increased risk of experiencing urinary urge incontinence when compared to never smokers. Former smoking again showed no significant association with experiencing urinary urgency, and that's indicated by risk ratios close to one. And then again, when we look at pack-year history, you can see that the greater, longer, and more intense the pack-year history in the individual, the increased risk of experiencing urinary urgency.
In conclusion, our study found a strong association between current smoking and increased urinary urgency symptoms, indicating that current smoking is a significant risk factor for all types of urinary urgency. Moreover, we determined that the longer and more intense the smoking history, the greater the risk of urgency symptoms as well, and that was indicated by our dose-response relationship. Risks associated with former smoking and lower pack-year histories were not significant, highlighting that current smoking is likely the primary risk factor and not smoking history.
We think that these findings overall suggest that smoking cessation may in fact alleviate overactive bladder symptoms and that current smoking is a modifiable risk factor for urinary urgency. Moreover, even just minimizing the amount of smoking in terms of smoking packs can lead to a reduction in bladder symptoms as well. These findings align well with the new 2024 OAB guidelines that include smoking cessation as a primary behavioral health intervention for managing overactive bladder. Thank you very much for your attention.
Diane Newman: Thank you very much. This is really interesting research, and I really enjoyed your presentation. If you look at the literature, and what we've all thought, is that smoking really causes stress urinary incontinence, and I know that I use the LURN questionnaire, so they do ask about what type of incontinence, but you found there was really more correlation with urinary urgency as opposed to stress incontinence. Can you elaborate on that a little bit?
Avanti Rangnekar: I think it's hard to say because the physiologic mechanisms underlying this association were well beyond the scope of our study. I think there's a lot of underlying evidence to believe that it could be stress incontinence from increased frequency of coughing and other symptoms of smoking that may lead to a weaker pelvic floor. But one interesting theory that I've also read is that patients who smoke are also at an increased risk for atherosclerotic disease, and atherosclerosis can cause ischemia of the bladder, and that might also be causing some of these overactive bladder symptoms. Just another theory to throw into the mix there while we sit and still find a definitive answer.
Diane Newman: Talk to me a little bit about ResearchMatch though. Did you use parameters whenever you put in, because I know a lot of people use that.
Avanti Rangnekar: Yes.
Diane Newman: It's an online survey portal type of thing, and really you can get lots of women to answer it, right?
Avanti Rangnekar: Right, right. ResearchMatch is a national online volunteer research registry website. It is completely voluntary, as you mentioned. For our study recruitment, we limited our volunteers to community-based adult women between the ages of 18 and 100. I think it's important to mention here that our respondent population was mostly young, white, and educated women, which is definitely a bias that we can't overlook in our results. And so, the specific breakdown of that was around 88% of women were of white race while only 6% identified as Hispanic in our population. Over half—so around 68%—had received a Bachelor's degree or a higher educational degree, and the vast majority had health insurance. I think these are all very important biases to consider in our final results that can limit some of the generalizability of our findings as well.
Diane Newman: And the other thing that we find is that when we send out a call for, hey, complete this survey, if we mention incontinence or bladder symptoms or anything, people—women or men—with those symptoms tend to be the ones that answer the surveys. How did you recruit for this then? I mean, do you know what exactly you asked women? Was it about their women who smoke or?
Avanti Rangnekar: Our online survey was looking more generally at bladder health, so it included all kinds of urinary symptoms experienced, and it also involved questions around medical history, smoking history, and things like that. So we were able to make the connection using the results from the online survey without directly posing our research question of what is the association between smoking and urgency?
Diane Newman: It's sometimes very difficult on these online surveys to get the diverse population.
Avanti Rangnekar: Yeah, it is, and I think that's a really important question. Online surveys especially sometimes face challenges in reaching more diverse populations, especially if there are systemic barriers in place. For instance, access to technology and internet connectivity can vary across different communities. And additionally, cultural factors and trust in research can also play a big role in participation rates. And so, to address this, I think it's essential to use targeted outreach strategies like partnering with community organizations or tailoring survey language to be inclusive and ensuring cultural sensitivity. I think all of these things can serve to enhance accessibility.
Diane Newman: I know you talked about that you lack diversity in your sample, but that tends to be what we do find as far as individuals who come onto these surveys and answer them. But thank you very much for sharing with us this really interesting research.
Avanti Rangnekar: Yeah, no, of course.