|Year : 2017 | Volume
| Issue : 4 | Page : 454-458
Correlation between international prostate symptom score and uroflowmetry in patients with benign prostatic hyperplasia
CK Oranusi, AE Nwofor, O Mbonu
Department of Surgery, Nnamdi Azikiwe University/Nnamdi Azikiwe University Teaching Hospital, Nnewi, Anambra State, Nigeria
|Date of Acceptance||23-Jul-2016|
|Date of Web Publication||13-Apr-2017|
Dr. C K Oranusi
Urology division, Department of Surgery, Nnamdi Azikiwe University/Nnamdi Azikiwe University Teaching Hospital, P.M.B Nnewi, Anambra State
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Objective: To determine the correlation between severity of symptoms using the International Prostate Symptom Score (IPSS) and uroflowmetry in patients with lower urinary tract symptoms-benign prostatic hyperplasia (LUTS-BPH). Patients and Methods: We prospectively collected data from 51 consecutive men, who presented with LUTS-BPH at the Nnamdi Azikiwe University Teaching Hospital, Nnewi, Nigeria, from January 2012 through December, 2014. Symptom severity was assessed using the self-administered IPSS questionnaire. We also performed uroflowmetry using the Urodyn 1000 (Dantec, serial no. 5534). Results: The mean age of the patients was 67.2 ± 9.7 years (range 40-89 years). The most common presenting IPSS-LUTS was nocturia (100%) followed by urinary frequency (98%), straining (92.0%), weak stream (84.3%), urgency (41.2%), incomplete voiding (39.2%), and intermittency (35.3%) Most of the patients had moderate symptoms (58.8%) on IPSS with a mean value of 13.5 ± 3.0. The mean Qmax was 15.6 ± 18.7 mL/s and the mean voided volume was 193.0 ± 79.2 mL. About one-third of the patients (39.2%) had an unobstructed flow pattern based on Qmax. Correlation analysis showed a weak correlation between IPSS and voiding time (r = 0.220, P > 0.05), flow time (r = 0.128, P > 0.05), and time to maximum flow (r = 0.246, P > 0.05). These correlations were not significant (P > 0.05). IPSS showed a negative correlation with maximum flow rate (r = 0.368; P < 0.0075), average flow rate (-0.203, P > 0.05), and voided volume (r = -0.164, P > 0.05). This negative correlation was significant for maximum flow rate. Conclusion: Correlation between IPSS and Qmax was negative but statistically significant. This implies that an inverse relationship exists between IPSS and Qmax, and remains the only important parameter in uroflowmetry. There was no statistically significant correlation between IPSS and the other variables of uroflowmetry.
Keywords: Benign prostatic hyperplasia, lower urinary tract symptoms, uroflowmetry, symptom severity
|How to cite this article:|
Oranusi C K, Nwofor A E, Mbonu O. Correlation between international prostate symptom score and uroflowmetry in patients with benign prostatic hyperplasia. Niger J Clin Pract 2017;20:454-8
|How to cite this URL:|
Oranusi C K, Nwofor A E, Mbonu O. Correlation between international prostate symptom score and uroflowmetry in patients with benign prostatic hyperplasia. Niger J Clin Pract [serial online] 2017 [cited 2021 Jan 20];20:454-8. Available from: https://www.njcponline.com/text.asp?2017/20/4/454/196120
| Introduction|| |
Benign prostatic hyperplasia (BPH) is a common cause of bladder outlet obstruction (BOO) in the male geriatric population. Lower urinary tract symptoms (LUTS) suggestive of BPH are common complex clinical problems, especially in men above the age of 50 years. The prevalence of BPH increases with age and results in LUTS in about 10% of elderly men. BPH causes morbidity through the urinary symptoms with which it is associated. These symptoms can be very bothersome and impact substantially on the patient's quality-of-life (QoL). Symptom severity strongly correlates with the overall health status of the patient and thus underscores the importance of symptom assessment in men with the disease. The degree of bothersomeness may be dramatically different for different patients with the same degree of symptom severity. Majority of men with BPH undergo surgery to relieve bothersome urinary symptoms and improve QoL.
Several symptom scoring systems have been developed to assess the degree of symptom severity. These symptom scoring systems are not diagnostic of BPH, but are valid tools for objectively assessing patients' symptoms, deciding choice of treatment for patients with LUTS-BPH and monitoring effects of any intervention procedure. The most widely used scoring system is the International Prostate Symptom Score (IPSS), developed by the American Urological Association (AUA) and adopted by the World health Organization (WHO).
Uroflowmetry has been added to the assessment tools for patients with BPH. Like the IPSS, it is not diagnostic of BPH, but also gives an insight into the degree of obstruction caused by the benign prostatic enlargement (BPE). When combined with IPSS, it could offer improved sensitivity in the diagnosis of BOO due to prostatic enlargement.
This study was aimed at determining the correlation of IPSS results and uroflowmetry in patients with LUTS-BPH.
| Patients and Methods|| |
After obtaining approval from our institutional ethics committee and adequately informed patient consent, we prospectively collected data from 51 consecutive men, who presented with LUTS-BPH at the Nnamdi Azikiwe University Teaching Hospital, Nnewi, Nigeria, from January 2012 through December, 2014.
Target group were men above 40 years presenting with LUTS-BPH. Diagnosis of BPH was by a complete medical history, physical examination including Digital rectal examination, urinalysis and culture, prostate scan, and serum prostate-specific antigen to exclude the presence of prostate cancer.
Symptom severity was reviewed using the self-administered IPSS questionnaire. Relevant biodata and duration of symptoms were obtained from patients. Uroflowmetry was also performed using the Urodyn 1000 (Dantec, serial no. 5534). Patients were instructed to void only when they have a strong urge to void. To ensure consistency, three flow rate recordings were obtained from each patient at intervals of 1 week and the average recorded for each patient. Voided urine volumes greater than or equal to 150 mL was used for the study. The machine works on the principle of rotational velocity which is kept constant by a tachometer and feedback circuit. As urine hits the rotating disk, more electrical energy is required to maintain the constant angular velocity and measurement of the extra current can be plotted graphically.
Values were expressed as means with standard deviation for quantitative variables. The Z-test was used for comparison between groups based on their means. The Pearson correlation coefficient was used to assess correlation. P-values <0.05 were regarded as statistically significant. All statistical analysis was carried out using SPSS statistical package, 20.0 for Windows (SPSS Inc, Chicago, IL).
| Results|| |
A total of 51 patients were recruited for the study. [Table 1] lists the patient clinical characteristics. The mean age of the patients was 67.2 ± 9.7 years (range 40-89 years). Fifty-five percent of the patients had PSA values within the normal range (0-4 ng/mL). The most common presenting IPSS-LUTS was nocturia (100%) followed by urinary frequency (98%), straining (92.0%), weak stream (84.3%), urgency (41.2%), incomplete voiding (39.2%), and intermittency (35.3%). Most of the patients had moderate symptoms (58.8%) on IPSS with a mean value of 13.5 ± 3.0. The mean QoL index was 4.3 ± 1.13. Uroflowmetry studies showed the mean Qmax to be 15.6 ± 18.7 mL/s and the mean voided volume was 193.0 ± 79.2 mL. About one-third of the patients (39.2%) had an unobstructed flow pattern based on Qmax [Table 2].
[Table 3] shows the correlation analysis between IPSS and the various components of uroflowmetry. Correlation analysis showed a weak correlation between IPSS and voiding time (r = 0.220, P > 0.05), flow time (r = 0.128,P > 0.05), and time to maximum flow (r = 0.246, P > 0.05). These correlations were not significant (P > 0.05). IPSS showed a negative correlation with maximum flow rate (r = -0.368; P < 0.0075), average flow rate (-0.203,P > 0.05),and voided volume (r = -0.164, P > 0.05). This negative correlation was significant for maximum flow rate.
| Discussion|| |
LUTS can be due to mechanical obstruction to urine flow or due to bladder hypo-contractility. These pathophysiologic elements are all common in the elderly and may be present alone or in combination. LUTS-BPH consists of BPE, BOO, and LUTS. However, patients with LUTS-BPH do not always share these components, and as such they do not show similar degree of symptoms. Factors such as dynamic urethral resistance, prostate capsule, and anatomic pleomorphism rather than actual prostate size can influence severity of symptoms. Many patients with LUTS-BPH will benefit from invasive procedures to remove the enlarged gland, some may not benefit from such treatments due to persistence of bothersome LUTS after surgery. It is therefore imperative that patients with LUTS be properly investigated and categorized based on the cause of LUTS. Objective symptom assessment using various symptom scoring systems, such as IPSS, uroflowmetry, and urodynamics, have proved very useful tools in the assessment of patients with LUTS-BPH before definitive treatment.
This study showed that most of our patients (58.8%) presented with moderate IPSS scores. Often patients attribute these urinary symptoms to changes in age and so fail to present until these symptoms become bothersome. Bothersome LUTS is significantly a leading indication for surgery in patients with LUTS-BPH. The mean QoL score for our patients was 4.13 ± 1.13, implying that most patients in this study were mostly unsatisfied with their symptoms at the time of presentation. Moderate to severe LUTS related to BPH have a 40% incidence among men in their 50s and are considered among the urologic conditions with the highest medical and social impact., The most common symptom of LUTS from this study was nocturia (100%) followed by urinary frequency (98%) and straining to pass urine (92%). A survey of LUTS symptoms among Europeans showed that the most common symptom was nocturia (71%) similar to our finding, followed by incomplete emptying (59.9%) and urgency (58%), weak urinary stream (57%), and frequency (49.3%). The European study also found that the most prevalent combination of symptoms was the triad of nocturia, frequency, and a feeling of incomplete voiding. A major difference between the countries surveyed was recorded in the frequency rate: frequency was the most common symptom in France. The researchers explained the differences in the prevalence of LUTS in Europe, by the larger proportion of patients with a recent diagnosis in the UK (fewer symptoms at the beginning of the disorder) compared with patients from France who had more patients diagnosed late. This difference in LUTS pattern seen in this study and the European study may be difficult to explain clinically. Late presentation, presence of co-morbidities, and attributing symptoms to aging rather than a disease process either alone or in combination may explain the differences.
Uroflowmetry electronically measures urine flow rate throughout the course of micturition. Like IPSS, the results of uroflowmetry are largely nonspecific for symptoms. However, the gold standard for the diagnosis of BOO is with urodynamics studies. Uroflowmetry is a simple, accurate, and noninvasive method of assessing the dynamics of micturition. For this reasons, it can be incorporated easily into the routine preoperative assessment of patients with LUTS. The most important parameter in uroflow study is the Qmax, Shoukry et al., in their study, concluded that Qmax correlated well with the degree of prostatic obstruction. The average flow rate is less reliable and the other values are immaterial. The range of normal Qmax among Nigerian men has been previously determined from previous study by the same author. This ranges from >25 mL/s in men <40 years, >23 mL/s in those between 40 and 60 years, and >17 mL/s in men aged above 60 years. In this study, the mean Qmax for patients with LUTS-BPH was 15.6 ± 18.7 mL. Traditionally, Qmax less than 10 mL/s indicate an obstruction and a Qmax greater than 15 mL/s indicates no obstruction. A Qmax between 10 and 14 mL/s is described as equivocal. Significantly, most of our patients (39.2%) had unobstructed flow pattern, implying that some other factors other than mechanical obstruction maybe involved in their LUTS. There was a negative correlation between the IPSS scores and Qmax, Qave, and voided volume. However, the analysis was statistically more significant with Qmax (r = -0.368, P < 0.05). This implies that an inverse relationship exists between IPSS and Qmax. Several studies in the literature have compared symptom severity with obstructive indices due to BPH. Barry et al. reported no correlation between severity of symptoms in men with prostatism due to BPH and prostate size, degree of bladder trabeculation, uroflowmetry, or postvoid residual urine. El Din et al. evaluated the correlation between uroflowmetry, prostate volume, postvoid residue, and LUTS as measured by IPSS, and also concluded that the correlation between objective noninvasive parameters of lower urinary tract dysfunction and LUTS was weak. It may therefore be justified to say that uroflowmetry cannot be used to confirm the diagnosis of BPH in a patient with LUTS among Nigerian men and Qmax remains the only important parameter in uroflowmetry studies especially when compared to symptom severity.
Some limitations were observed during this study. First, patients were required to have three flow rate recordings and the average Qmax taken for each patient. Most patients did not return after one or two flow readings. This significantly affected the sample size for the study. Second, as the reliability of the urine flow test depended to some extent on the volume of urine passed, patients had to either stay in hospital for long durations to be able to void significant volumes of urine or the test postponed to another day to have a more accurate recording. Finally, there was also difficulty in patients' understanding and interpretation of the QoL variables on IPSS. Words like “pleased,” “delighted,” and “happy” could not be clearly delineated even in the local languages. This again may affect the result ratings. Nonetheless, this study offers useful information to expand current knowledge in the symptomatology and dynamics of micturition in patients with LUTS-BPH.
| Conclusion|| |
Patients with LUTS-BPH should be properly investigated and managed to improve their symptoms. There was a negative correlation between severity of symptoms on IPSS and Qmax, Qave, and voided volume. The correlation between IPSS and Qmax was statistically significant. This implies an inverse relationship between IPSS and Qmax. There was no statistically significant correlation between IPSS and the other variables of uroflowmetry. Clinically, Qmax remains the only important parameter in uroflowmetry.
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Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3]