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European Urology
European Urology 42 (2002) 583±589
Urodynamic Characterisation of Women with Naive Urinary Incontinence: A Population-Based Study in Subjectively Incontinent and Healthy 53^63 Years Old Women Pia Telemanb, Marianne Gunnarssona, Jonas Lidfeldtc, Christina Nerbrandc, GoÈran Samsioeb,c, Anders Mattiassona,* a
Department of Urology, University Hospital, S-221 85 Lund, Sweden Department of Obstetrics and Gynecology, University Hospital, Lund, Sweden c The WHILA Study Group, Department of Community Medicine and Medicine, Lund University, Lund, Sweden b
Accepted 19 September 2002
Abstract Objectives: To compare the urodynamic characteristics in a group of middle-aged women with untreated urinary incontinence with the ®ndings in a control group of healthy women. Methods: Sixty women with mild-to-moderate urinary incontinence and 28 symptom-free women, 53±63 years old, were randomly chosen out of a large health questionnaire study. All were investigated with a detailed history, gynaecological examination, urinalysis, frequency±volume chart, and urodynamics including cystometry and pressure-¯ow analysis. Results: The maximum urinary ¯ow was signi®cantly higher in the incontinent group of women, 22 1 ml/s, than in the healthy controls, 16 2 ml/s (p < 0:01). The acceleration of ¯ow, with a theoretical maximum of 08, was also signi®cantly faster in the incontinent, 208, than in the healthy women, 328 (p 0:01). In the ®ve women with urge incontinence only, maximum urinary ¯ow was 26 2:4 ml/s and the ¯ow acceleration 78. In incontinent women, both a lower opening pressure and detrusor pressure at maximum ¯ow were seen compared with the healthy women, though the difference did not reach statistical signi®cance. The incontinent and the healthy women did not differ regarding bladder volumes or pressures during ®lling. Conclusion: The ®ndings of this study indicate the presence of an increased ef®ciency of the urethral opening mechanism in incontinent women compared to normal, irrespective of the type(s) of symptoms present. # 2002 Elsevier Science B.V. All rights reserved. Keywords: Female urinary incontinence; Urodynamics; Neuromuscular disorder; Urethral opening 1. Introduction Certain factors have been identi®ed to be of crucial importance for the etiology of urinary incontinence. Besides ageing, the single most important one seems to be childbirth [1±3]. Vaginal delivery causes injury to nerves and muscles. Descent and downward rotation of the bladder and urethra during stress as a consequence of an enlarged pelvic hiatus is a common ®nding in incontinent women [4±8]. Hereditary factors like a defect collagen structure are also believed to predispose *
Corresponding author. Tel. 46-46-17-19-94; Fax: 46-46-211-25-98. E-mail address:
[email protected] (A. Mattiasson).
to the development of incontinence [9±13]. The resulting decreased resistance or weakness of tissues often leads to a passive opening of the bladder neck during strain. In spite of all this, the pathophysiology of disorders that eventually might result in female urinary incontinence is still mainly unclear. Even if stress and urge incontinence have been proposed to share some common anatomical characteristics as in the proposed integral theory [14], the functional and pathophysiological mechanisms are not completely understood. Incontinence is appearing as a consequence of a process in the lower urinary tract and the involved parts of the nervous system. Clari®cation of the structural and functional components at the cell, tissue and organ
0302-2838/02/$ ± see front matter # 2002 Elsevier Science B.V. All rights reserved. PII: S 0 3 0 2 - 2 8 3 8 ( 0 2 ) 0 0 4 4 6 - 3
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P. Teleman et al. / European Urology 42 (2002) 583±589
levels in normal individuals as well as in disease should be given high priority [15]. The primary reason to do this study was to further study and characterise the pathophysiology of the neuromuscular disorder(s) of the lower urinary tract associated with female incontinence. 2. Patients and methods A total of 88 women, 53±63 years old, were investigated. One group (n 60) had a history of previously untreated, i.e. naive, mildto-moderate urinary incontinence, while the control group comprised subjectively healthy, i.e. continent, controls (n 28). Of the invited 10,766 women in the original population-based questionnaire study WHILA (Women's Health In the Lund Area) [16], 6917 (64%) responded. Of these, 32% stated that they had urinary incontinence of any degree. During the last year of the WHILA study, women claiming urinary incontinence who had not previously been treated for incontinence, conservatively or surgically, were consecutively offered participation in the present study. Women who had undergone previous vaginal surgery were excluded from participation. The number of women ful®lling the inclusion criteria during this period was 64; out of these, 60 accepted to participate. Likewise 28 symptom-free women were recruited. The characteristics of the groups are listed in Table 1. The mean duration of incontinence was 7.0 years (range 0.5±50) with a median of 3.0 years. Written consent was given by all participants and the study was approved by the local ethics committee at Lund University. 2.1. Clinical investigation At an initial visit, a full medical and urogynaecological history was taken and a gynaecological investigation was performed. Prolapse protruding to or outside of the vaginal introitus [17] occurred in one (4%) of the healthy and two (3%) of the incontinent women. An increased bladder neck mobility (de®ned as rotation
Table 1 Characteristics of the two studied groups
Age Parity Body Mass Index (kg/m2) Premenopausal (number) HRT-users Cystocele: stage II
Healthy (n 28)
Incontinent (n 60)
57 (53±63) 2.2 25 0 20 (71%) 1 (4%)
57 (53±63) 1.8 27 4 (7%) 32 (53%) 2 (3%)
HRT: hormonal replacement therapy.
>458 during strain) was observed in 37 (62%) and 4 (14%) of the incontinent and asymptomatic groups, respectively. Two groups of incontinent women were identi®ed, those with and those without a history of an urge component. The urge component group included both ``urge only'' (n 5) and ``mixed'' (n 25) incontinent women. The remaining 30 women in the symptomatic group had a history of stress incontinence. One of the initially 60 women dropped out after the ®rst visit due to minimal bother and lack of motivation. Thus, 59 incontinent and 28 healthy women underwent urodynamic investigation. 2.2. Urodynamics The urodynamic investigations were performed according to the recommendations of the International Continence Society for good urodynamic procedures [18]. The measurements of ¯ow acceleration were new and did thus not follow any recommendations or standards. The recordings were made on a Lifetech 1106 equipment. The identity and group belongings of the investigated subjects were removed from all urodynamic recordings and replaced by a serial number, thus the investigator (AM) was blinded to the whole material. Cystometry was made with sterile water at a ®lling rate of 50 ml/ min ®rst in the sitting position and then repeated in the standing position with provocation. Filling and recording of the intravesical
Fig. 1. Measuring acceleration of urinary ¯ow by calculating the angle A between the perpendicular through the point where ¯ow starts and the line between this zero point and the point representing 10 ml/s
A 90 a.
P. Teleman et al. / European Urology 42 (2002) 583±589
pressure, respectively, were performed by means of two transurethral plastic baby-feeding tubes (Ch 6). Rectal pressure was recorded by means of a water-®lled balloon and taken as an expression for the intra-abdominal pressure. Pressure-¯ow investigation was performed at the end of each cystometric investigation with the two baby-feeding tubes in the urethra and the subject in the sitting position. Acceleration of ¯ow: The urinary ¯ow curves were analysed regarding the acceleration of urinary ¯ow at the initiation of voiding. The angle A between the perpendicular through the point where the ¯ow started and the line between this zero point and the point representing 10 ml/s on the ¯ow curve recorded at a paper speed of 1 mm/s with a scale where 10 mm represented 10 ml/s, was calculated and taken as an expression for the acceleration of ¯ow (Fig. 1). The theoretical maximum acceleration could thus be expressed as 08. 2.3. Statistics Statistical analyses were made by Mann±Whitney's U-test and Wilcoxon signed rank sum test as well as ANOVA. The p-values
