Central Obesity in Cases of OAB

Overactive bladder (OAB) is defined by international continence society (ICS) as urinary urgency with or without incontinence often associated with frequency and nocturia. As a chronic, unbearable condition, OAB has a deeply negative impact on QoL, including social, physical, psychological, occupational and sexual domains. Overactive bladder (OAB) is a highly prevalent symptom complex that is estimated to affect 12.8% of women and 10.8% of men.

The underlying pathophysiological mechanism of OAB and DO is poorly understood. It is thought that not only the detrusor muscle but also urothelium, peripheral afferent terminals, and pelvic blood vessels may play a role.

More recently, overweight and central obesity was found to be an independent risk factor for overactive bladder (OAB) in women. The most likely explanation is the occurrence of chronic inflammation in the bladder indicated by increased urinary chemokines. Adipocytes surrounding the human bladder can be affected, thus leading to inflammation and triggering OAB symptoms. Other authors showed that OAB is associated with increased BMI and increase of waist circumference at the upper end of the adiposity distribution for both men and women.

Obesity is not a homogeneous condition and that the regional distribution of adipose tissue is important to understanding the relation of obesity to disturbances in glucose and lipid metabolism. Central abdominal fat is composed of abdominal subcutaneous fat and visceral fat. Regional distribution appears to be an important indicator for metabolic alterations since an inconstant correlation between body mass index (BMI) and these disturbances have been found. Visceral obesity is associated with increased adipocytokine production, proinflammatory activity, deterioration of insulin sensitivity, increased risk of developing diabetes, "high-triglyceride/low-HDL cholesterol dyslipidemia," hypertension and atherosclerosis.

Away from that anthropometric measures as BMI, waist circumference (WC), waist to hip ratio (WHR) are crude measures for adiposity. WHR has been advocated as a measure of central obesity because BMI does not describe the distribution of obesity. This measurement, however, was found to be associated with SUI but not with OAB or mixed urinary incontinence, further suggesting a non-mechanical mechanism for OAB in obese women. WC is a major clinical parameter used for the indirect evaluation of increased visceral fat, In addition, WC showed shared variance with visceral adipose fat up to 75% (42) (38). Nevertheless, WC alone does not help in distinguishing between subcutaneous and visceral fat mass.

So, it might be more precise to divide central abdominal fat into subcutaneous(S) and visceral (V) fat surface area and volume and even ratio (S/V); risk factors for cardiovascular disease, particularly those related to glucose and lipid metabolism and hypertension, being>0.4; with evaluation of visceral fat functionality by visceral adiposity index (VAI) with integration with lipid profile. Adding bladder wall thickness with perivesical fat as a factor may impair bladder function and contribute to dysregulation.

The data on the association between central adiposity with OAB symptoms and Urodynamics is not mature. So, the investigators intend to conduct this study evaluating the surface area of both subcutaneous and visceral fat and its functionality with incorporation with lipid profile and bladder wall thickness and perivesical fat.