Laparoscopic Sleeve Gastrectomy Effects on Overactive Bladder Symptoms
Morbidly obese patients may experience lower urinary tract symptoms. However, most studies focus only on urinary incontinence, with little regard to other symptoms as those suggestive for overactive bladder syndrome. Laparoscopic sleeve gastrectomy (LSG) is commonly used to treat obesity; this procedure is effective, safe, and capable of reducing the impact of comorbidities associated with severe increase in body weight. Therefore, we investigated if LSG improves overactive bladder symptoms in morbidly obese patients.
Materials and Methods
We prospectively recruited 120 morbidly obese patients (60 men, 60 women), evaluated by history taking, comorbidity assessment, physical examination, urinalysis and urine culture, renal and pelvic ultrasound, a 3-day voiding diary, and the overactive bladder questionnaire short form. Outcomes of these investigations were assessed 7 days before and 180 days after LSG was performed. Controls were obese individuals (60 men and 60 women) from a LSG waiting list. Preliminary statistical data were used to compare sex, age, and weight distributions in the two study populations; then, the following parameters were compared before and after surgery: number of micturitions per day, urgency episodes per day, number of urgency incontinence (UUI) episodes per day, mean voided volume for micturition, liquid intake count per day, and OAB-q SF score.
Symptoms of overactive bladder were common in the morbidly obese cohort, affecting more women than men. Compared with untreated patients, patients treated with LSG had significantly reduced body mass index 180 days postoperatively; this outcome was associated with improvement in overactive bladder symptoms, whereas no change occurred in untreated controls. Regarding lower urinary tract symptoms, in treated patients the OAB-q SF score significantly improved (showing a significant reduction in total score), and a statistically significant improvement in voiding diary parameters was observed.
All of the patients in our cohort who had obesity and OAB also had diabetes; therefore, the correlation between OAB-q SF scores and HbA1c value was investigated. However, Pearson’s analysis showed no correlation between the OAB-q SF scores and HbA1c measurements at baseline in morbidly obese individuals .
Central obesity, as measured by waist circumference, may predict LUTS severity, and severe obesity is associated with increased risk of urinary disorders. Therefore, reducing obesity might be an important target for the prevention of and intervention for LUTS. Despite the evidence that bladder irritation is common in morbidly obese patients, no studies have explored OAB syndrome or evaluated if it improves after bariatric surgery. Therefore, we decided to investigate this topic in our study. We found that OAB syndrome is common in obese individuals. The exclusion criteria were selected to minimize the influence of potential urologic, neurologic, and iatrogenic causes of OAB. OAB-q SF scores were consistent with data obtained by the three-day voiding diary and support the reliability of the results at baseline and follow-up, proving the correlation between obesity and OAB. The specific mechanism underlying the effect of obesity on OAB pathogenesis has not been yet described. Previous studies indicate that poor lifestyle factors are causally linked to diabetes and obesity, and may contribute to the onset of OAB. In particular, low physical activity appears to be an important modifiable causal factor for OAB, operating directly as well as indirectly via pathways involving obesity or diabetes.This result has been strongly supported by the evidence of a direct association between diabetes and OAB, which has been reported in a recent investigation using the OAB-q SF and voiding diary in type II diabetic individuals. Other investigations showed that obesity and concurrent type 2 diabetes mellitus lower urinary tract fibrosis and are inextricably and biologically linked to urinary voiding dysfunction. However, the effect of irritation on obesity can be postulated based on the assumption that fat in the pelvis reduces bladder expansion and thus increases urinary frequency and determines low mean urinary volumes for micturition, as showed by voiding diaries in our study. Therefore, if all these observations support the hypothesis of both indirect and direct correlation between obesity and OAB, a significant improvement in OAB symptoms should be expected after BMI reduction provided by bariatric surgery, as observed in our investigation.
In morbidly obese patients, the onset of OAB symptoms may have a complicated pathophysiology involving endocrine, dysmetabolic, respiratory, and cardiovascular factors of variable distribution, but very often expressed contemporarily in these patients. Therefore, as already shown for other comorbidities associated with obesity, the best method to overcome OAB symptoms in morbidly obese individuals is to restore normal BMI, thus reducing all contributing factors leading to OAB onset. In our pilot investigation, in fact, OAB symptoms resulted well represented in morbidly obese patients, with a moderate prevalence in women and the significant decrease in BMI at the 6- month follow-up after LSG results in amelioration of OAB symptoms.
1. Pinto AM, Subak LL, Nakagawa S, Vittinghoff E, Wing RR, Kusek JW, Herman WH, West DS, Kuppermann M. The effect of weight loss on changes in health-related quality of life among overweight and obese women with urinary incontinence. Qual Life Res. 2012;21(10):1685-94.
2. Ranasinghe WK, Wright T, Attia J, McElduff P, Doyle T, Bartholomew M, Hurley K, Persad RA. Effects of bariatric surgery on urinary and sexual function. BJU Int 2011;107(1):88-94.