Overactive Bladder (OAB): What We Thought We Knew and What We Know Today☆
Section snippets
Introduction: what is OAB?
The term overactive bladder (OAB) refers to the symptom complex of frequency, urgency and nocturia, with or without urge urinary incontinence (‘OAB wet’ or ‘OAB dry’). The precise definition has been the subject of much debate, and there is still need for consensus today. Traditionally, OAB was associated with the unstable bladder described in terms of detrusor hyperreflexia (if neurological disease was present) or detrusor instability (if the cause was unknown or non-neurogenic). But the
The epidemiology of OAB
The epidemiology of OAB is somewhat complex and confused. Although it is generally accepted to be a common condition in the general population, prevalence studies have been hampered by widely differing patient populations and variations in definitions and diagnoses. Typically, the prevalence of OAB has been underestimated, as many studies have been limited to patients with incontinence (i.e. with just one symptom of OAB). Studies have also tended to overlook men.
Two recent, large-scale studies
The pathophysiology of OAB
All patients with OAB share the symptoms of urgency, frequency, urge incontinence and nocturia, regardless of etiology, suggesting that the underlying causative mechanisms are similar. Unstable bladder tissue from animal models and patients with OAB displays increased spontaneous myogenic activity, fused tetanic contractions, altered responsiveness to stimuli, and characteristic changes in smooth muscle ultrastructure. Examination of the peripheral innervation and the micturition reflex in
Associated conditions
It is probably naı̈ve to consider OAB as just a myogenic or afferent disorder. Some individuals seem predisposed to OAB. It is more likely to occur in women, in the elderly, and in association with irritable bowel syndrome, depression, anxiety and attention deficit hyperactivity disorder (ADHD) (Table 1).
A future role for genomics
Data from a growing number of studies are suggestive of a genetic component in urinary incontinence. Studies have shown, for example, that bladder problems in childhood are predictive of incontinence later in life [39]. Similarly, a three-fold increase in prevalence of stress incontinence among first degree relatives has been demonstrated [40]. More recently, a study of night and day voiding problems in a large 4-generation family was able to show inheritance consistent with a single
Summary and conclusions
OAB is a highly prevalent disorder in women and men. Prevalence increases with age, with some evidence to suggest that the first symptoms appear in childhood. Although the etiology of OAB is poorly understood, improved knowledge around pathogenesis suggests it is due to altered responsiveness in smooth muscle, nerve and urothelium. There is also evidence for the co-existence of OAB with conditions such as depression, anxiety, and ADHD, the common link being alterations in the monoamine
References (41)
- et al.
M2 receptors in genito–urinary smooth muscle pathology
Life Sci.
(1999) - et al.
Effect of chronic bladder outlet obstruction on the blood flow of the rabbit urinary bladder
J. Urol.
(2001) A neurological basis for the overactive bladder
Urology
(1997)- et al.
Urinary incontinence and depression
J. Urol.
(1999) - et al.
Neurally mediated voiding in spontaneously hypertensive rats
Brain Res.
(1998) - et al.
The spontaneously hypertensive rat (SHR) as an animal model of childhood hyperactivity (ADHD): Changed reactivity to reinforcers and to psychomotor stimulants
Behav. Neural Biol.
(1992) - et al.
Role of ovarian hormones in the pathogenesis of impaired detrusor contractility: Evidence in ovariectomized rodents
J. Urol.
(2001) - et al.
Adult female incontinence and childhood bedwetting
J. Urol.
(1994) - et al.
Female urinary stress incontinence—does it have familial prevalence?
Am. J. Obstet. Gynecol.
(1996) - et al.
Linkage study of a large Danish 4-generation family with urge incontinence and nocturnal enuresis
J. Urol.
(2001)
The standardisation of terminology of lower urinary tract function: Report from the standardisation sub-committee of the International Continence Society
Neurourol. Urod.
The overactive bladder
Br. J. Urol. Int.
How widespread are the symptoms of an overactive bladder and how are they managed? A population-based prevalence study
Br. J. Urol. Int.
Costs and resources associated with the treatment of overactive bladder using retrospective medical care claims data
Managed Care Interface
Cost effectiveness and quality of life considerations in the treatment of patients with overactive bladder
Am. J. Manag. Care
What is the pathophysiology of detrusor hyperreflexia?
Neurourol. Urodyn.
Cited by (16)
A standardised mini pig model for in vivo investigations of anticholinergic effects on bladder function and salivation
2007, Pharmacological ResearchEditorial: Spontaneous contractile activity in rat bladder
2003, Journal of UrologyEffect of urgency symptoms on the risk of depression in community-dwelling elderly men
2013, Korean Journal of UrologyElectrical stimulation with non-implanted electrodes for urinary incontinence in men
2013, Cochrane Database of Systematic ReviewsElectrical stimulation with non-implanted electrodes for urinary incontinence in men
2013, Cochrane Database of Systematic Reviews
- ☆
Sources of funding: This paper is adapted from a presentation originally given at a symposium at the XVIIth European Association of Urology (EAU) Meeting, 23–26 February 2002, Birmingham, UK. The EAU Symposium was supported by an unrestricted grant from Pfizer Inc.