Relationship between anxiety and overactive bladder syndrome in older women

PURPOSE: The objective of this study was to investigate the relationship between overactive bladder syndrome and anxiety in older women. METHODS: Of the 198 older women who were invited, 29 were excluded and 166 were then divided into two groups according to the Advanced Questionnaire of Overactive Bladder (OAB-V8): one group with overactive bladder symptoms (OAB-V8≥8) and the other without the symptoms of an overactive bladder (OAB-V8<8). The purpose was to conduct a frequency analysis and to investigate the relation of the social demographic data and anxiety in the two groups. The Beck Anxiety Inventory (BAI) was used to evaluate the level of anxiety. The Kolmogorov-Smirnov test was used to determine the distribution of the data. The differences between the two groups for the continuous variables were analyzed by the Mann-Whitney U test, the differences for the categorical variables were analyzed by the Chi-Square test and the association between the continuous variables was analyzed by the Spearman Correlation test. The tests were two-tailed with a confidence level of 5%. RESULTS: Overall, the frequency of an overactive bladder was present in 117 (70.5%) of the participants. The body mass index (BMI) of the group with overactive bladder symptoms was significantly higher than the BMI of those without these symptoms (p=0.001). A higher prevalence of mild, moderate and severe anxiety was observed among older women with overactive bladder symptoms. In addition, the overactive bladder symptoms group presented a positive low correlation with anxiety symptoms (r=0.345) and with BMI (r=0.281). There was a small correlation between BMI and anxiety symptoms (r=0.164). CONCLUSIONS: Overactive bladder syndrome was prevalent among older women and the existence of these symptoms was linked to the presence of mild, moderate and/or severe anxiety symptoms.


Introduction
The overactive bladder syndrome (OAB) is a clinical syndrome characterized by the urgent voiding with or without urge incontinence.It is usually associated with pollakiuria and nocturia in the absence of infection in the urinary tract or other evident pathology 1,2 .OAB is a common incapacitating condition that greatly affects the quality of life of individuals with the syndrome and is the second largest cause of urinary incontinence (UI) in women 2 .Women are usually more affected by this syndrome than men.One in four women has some complaints of lower urinary tract symptoms throughout their life and 20 to 30% of those are over the age of 55 3 .A Brazilian population-based study, conducted on middle-aged women, observed the prevalence of 18.9% of OAB symptoms 4 .Among the elderly, the presence of UI is a very common health problem 3,5 .
OAB is an important public health concern.Its high prevalence, in addition to the physical, economic, psychic, emotional, sexual and social impact in a woman's life, reflects on the health condition and directly interferes with the quality of their lives 6,7 .Despite its high impact on the quality of life, the dysfunctions of the urinary tract are most of the time neglected and underestimated 8,9 .Psychological variables, such as anxiety and depression, have been associated with urgency and urge incontinence symptoms and with other specific incontinence symptoms.Some investigators have suggested that psychosomatic disorders, such as anxiety, may play a role in the pathogenesis of OAB 10 .Anxiety is defined as a state characterized by the perception or interpretation of an event as threatening, which can manifest itself both physically as well as psychologically, and directly affects the health, well-being and quality of life of elderly people 11,12 .Although it is inconclusive that anxiety is the cause or consequence of OAB, it is believed that there is a connection between the two.However, more studies are needed to understand this relationship 12,13 .
The prevalence and the relationship between OAB and other pathologies are unclear.Studies have investigated the symptoms using different types of instruments, forms of registering the data and different criteria to define OAB, in addition to a non-homogenous population.In this context, the objective of this study was to investigate the relationship between overactive bladder syndrome and anxiety in older women.

Methods
Subject screening was conducted in older women that lived in the community and attended the elderly health awareness program in Ceilândia, Distrito Federal -Brazil, that was established by the fire brigade between August of 2012 and November of 2013.The criteria for eligibility were: female sex, age equal to or higher than 60 years, and without lower urinary tract infection that were identified through a urine test (urine culture) associated to the evaluation of symptoms (beginning of the study).Older women with a history of treatment for OAB and/ or anxiety in the last six months, history of neurological diseases (Multiple Sclerosis, Alzheimer Disease, Stroke, Parkinson's Disease), bladder cancer (hematuria and/or account), complaints of pain in the lower part of the womb during voiding for more than six months (possible indication of interstitial cystitis), history of pelvic radiotherapy, presence of advance genital prolapse that goes beyond the vaginal introits at rest (physical exam) and incapacity to respond the questionnaire appropriately were excluded from the study.A sample size calculation was performed to analyze the correlation between the variable OAB and anxiety, using the G-Power Program -commonly used in social and behavioral research.A pilot study with 41 older women, with a 5% level of confidence and with power of 80%, suggested a sample of 153 older women.
The Advanced Questionnaire of Overactive Bladder -OAB-V8 (Overactive Bladder-Validated 8) was used to scan for OAB.This instrument was created to help individuals and health professionals identify overactive bladder symptoms and had been validated for the Brazilian population.It contained eight questions that investigated the frequency of diurnal voiding, three questions that investigated the urgency, two that investigated urge incontinence, one that investigated the nocturnal enuresis, and a final one that investigated the frequency of nocturnal voiding.The symptoms were evaluated using a Likert scale from 0 (nothing) to 5 (a lot), with a maximum score of 40 points.A total score of 8 or more was characterized as a probable dysfunction in the lower urinary tract 14 .
The Beck Anxiety Inventory (BAI) was used to evaluate the level of anxiety.It was composed of 21 items that evaluated different anxiety symptoms identified through questions on self-evaluation and perception of anxiety of the individuals during the last week.Scores from 0 to 7 were considered no anxiety, from 8 to 15 as mild level, 16 to 25 as moderate level and from 26 to 63 as severe level of anxiety 15 .
In order to collect clinical and demographic variables, a medical history was conducted with questions regarding age, weight, height, number of pregnancies, number of abortions, number of vaginal births, number of caesarian sections, medication, associated diseases, previous pelvic radiotherapy and symptoms of the lower urinary tract such as voiding pain, blood in the urine, high-pubic pain and sensation of incomplete bladder emptying.After consent form the participants, the interviews were scheduled through the Health Center of the region.
The procedures for women with absence of urinary infection, as shown by the urine culture, were conducted in the following order: first the structured questionnaire for the clinical and demographic variables were collected followed by the OAB-V8, the Beck Anxiety Inventory (BAI) and the physical exam for the evaluation of physical strength and genital prolapse.Women with infection in the lower urinary tract were referred to a doctor.After the data collection, women with OAB were referred to a specific treatment.
The present research was approved by the Ethics Committee of the College of Health Sciences of the University of Brasilia by the protocol number 410.161 on September 30 th , 2013.All patients signed a free and informed consent and the study was conducted in accordance with the Declaration of Helsinki as revised in 2008.
For the continuous variables, the information collected was expressed in average and standard deviation.As for the categorical variables, the information was expressed in percentages and frequency.The distribution of the data was performed using the Kolmogorov-Smirnov test.The sample was divided into two groups, according to the presence of lower urinary tract dysfunction (overactive bladder) by the OAB-V8.The differences between the two groups for continuous variables were analyzed using the Mann-Whitney U test.For the categorical variables, the Qui-Square test was used.To analyze the association between the continuous variables, the Spearman Correlation test was used.The tests were twotailed with a confidence level of 5%.The Statistical Package for Social Sciences Program with the 16.0 version was used.
A total of 198 patients were recruited and 7 had urinary tract infection identified on examination of the urine culture.191 older women were considered eligible for the study and after the interview, 25 were excluded because of neurological diseases (7 Stroke, 1 Alzheimer's, 2 Parkinson), history of radiotherapy (1), reports of bladder cancer (1), prolapsed bladder grade IV (2), use of anxiolytic drug (7) or did not complete the questionnaire (4).Thus, analyses were conducted with 166 older women, above the sample size previous calculated.

Results
The frequency of women with OAB (OAB-V8≥8 points) was 70.5% (117).The average score in the OAB-V8 between the older women that showed signs of dysfunction was 21.8±6.6, and between those without the signs of an overactive bladder (OAB-V8<8) was 2.3±2.2points.
The clinical and demographic data of the groups with and without overactive bladder symptoms are shown in Table 1.The groups were similar in age (p=0.282),number of pregnancies (p=0.09),number of abortions (p=0.07) and number of vaginal births (p=0.089).However, older women with overactive bladder symptoms (OAB-V8≥8) presented a BMI significantly higher than those without the symptoms (OAB-V8<8) (p=0.001).
In relation to the vaginal birth, no significant difference was found between groups (p=0.343) for prevalence of women who denied vaginal birth and of women who reported one or more vaginal births.In relation to the occurrence of levels of anxiety (no anxiety, mild, moderate and severe) between the study groups, a higher prevalence of mild, moderate and severe anxiety was observed in women with overactive bladder symptoms (Table 2).
There was a small and positive correlation between the anxiety symptoms (r=0.34) and BMI (r=0.28) with the group that had overactive bladder symptoms (Table 3).A small correlation between BMI and anxiety symptoms (r=0.16) was also observed.

Discussion
The present study applied the most current definition of OAB defined by the International Urogynecological Association and International Continence Society 2 .We found a high prevalence of overactive bladder symptoms (70.5%) in older women living in the community.Taking into account the definition from 2002 1 , the European Prospective Investigation into Cancer and Nutrition (EPIC) study observed a minor prevalence of OAB in women (12.8%) and in men (10.8%) in Europe and Canada, possibly due to the lower age group studied (age>18 years) 16 .The Brazilian Lower Urinary Tract Symptoms Epidemiology Study (BLUES), which investigated the symptoms of lower urinary tract in 3,000 individuals of both sexes with ages ≥30 y.o.using the OAB-V8 instrument after some complaint of any overactive bladder symptom, found a prevalence of OAB in 5.1% of men and 10.0% of women.In addition, the study reinforced the fact that above 60 years of age, these rates are higher for both men (78%) and women (82%) 17 , corroborating the data found in the current study.Similar studies investigated the prevalence of OAB in elderly Americans and showed rates of 40.4% in men and 46.9% in women.In addition, the study reinforced the fact that this dysfunction has a great impact on the people's quality of life 18 .
When comparing clinical and demographic characteristics between the elders with and without overactive bladder symptoms, the only variable that showed signs of difference was the BMI, demonstrating that patients with OAB had a higher BMI than those without the symptoms.Additionally, the BMI showed a positive correlation with the results of the OAB-V8 questionnaire.A Brazilian study investigated the influence of BMI in OAB using urodynamic together with the King's Health Questionnaire (KHQ), which evaluates the OAB.No association was observed between BMI and the scores of the KHQ or with the urodynamic data, even in individuals that showed non-inhibited contractions of the detrusor or absence of detrusor contractions 19 .Despite the fact that several studies in the literature point to a direct relationship between the severity of the urinary incontinence to the level of obesity 19,20 , most of the results are still conflicting.In addition, most of the studies found evaluated loss of urine based on effort and not on OAB specifically.
It is well known that pregnancy is a risk factor recognized to stress urinary incontinence (SUI).Primiparous women have three times more the risk to develop SUI compared to nulliparous women when compared by age group 21 .Recent evidence has shown that the type of birth also has a significant impact on SUI, showing that symptoms of SUI double in women who have at least one vaginal birth when compared to women who have had exclusively caesarian sections 22 .However, when the relation between birth and OAB was analyzed, it was observed that this association had not been well established in the literature, keeping in mind that the urge incontinence symptoms were reported in proportions similar to those between women who had vaginal births and nulliparous women 21 .Additionally, the risk for OAB in women, between 5-10 years after giving birth, was not significant when compared to the birthing methods (vaginal or caesarian section) 22 .It is worth mentioning that the use of forceps during vaginal births could be associated with OAB 21,22 .These findings corroborate with our study, although a negative correlation was found between the OAB-V8 and the number of vaginal births and that no difference was found between the number of vaginal births between older women with or without OAB.
In relation to anxiety, it was observed that there was a higher frequency of mild, moderate and severe anxiety in women with OAB.Moreover, the anxiety symptoms showed a positive association with overactive bladder symptoms.These results corroborate the findings of other studies 23,24 that found anxiety as a common manifestation in the elderly population (prevalence of up to 26% in people with 65 years or more), and whose prevalence increased in the presence of a chronic condition such as UI 26,27 .Several studies analyzed the association between urinary incontinence and anxiety symptoms.Lim et al. 25 investigated anxiety symptoms between women with SUI and with mixed urinary incontinence and found that women with MUI had more anxiety when compared to women with just SUI.The authors emphasized the importance of the approach used when treating anxiety symptoms in patients with MUI.Similarly, Knight et al. 26 found high levels of anxiety in women with OAB compared to women without this dysfunction.Other studies 23,27 also found associations between anxiety symptoms, evaluated with the Hospital Anxiety and Depression Scale (HADS), and OAB, evaluated by the 48-hour pad-test and through the questionnaire about urinary tract dysfunctions (OAB and frequency).The results indicated anxiety as risk factor for development of these symptoms 26 .Mehta et al. 23 also investigated the relation of OBS with anxiety symptoms using the three items of the Symptom Checklist Hopkins, and, although a cause and effect relation could not be established, the authors concluded that individuals with OAB are more prone to anxiety symptoms.
The correlation findings of the present study, between BMI and anxiety, corroborate other studies 28,29 .It is important to consider that, although differences among studies [25][26][27] on the type of instruments used to evaluate anxiety and overactive bladder symptoms exist, the similar

Table 1 .
Clinical and demographic characteristics of the study groups Mann-Whitney U Test; OAB-V8: Overactive Bladder-Validated 8 question Screener; BMI: body mass index; SD: standard deviation

Table 3 .
Correlation between the variables investigated in the study