|ORIGINAL RESEARCH REPORT
|Year : 2023 | Volume
| Issue : 1 | Page : 1-7
Correlation between the International Prostate Symptom Score and sonographic parameters in patients with symptomatic benign prostate enlargement
Kehinde Omotola Apata1, Emmanuel Ajibola Jeje2, Kehinde H Tijani2, Adebisi M Ogunjimi2, Rufus Wale Ojewola2, A Adekunle Adeyomoye3
1 Department of Surgery, Lagos University Teaching Hospital, Idi-Araba, Lagos; Department of Surgery, Urology Division, Ben Carson School of Medicine, Babcock University Teaching Hospital, Ilishan Remo, Ogun State, Nigeria
2 Department of Surgery, College of Medicine, University of Lagos, Lagos University Teaching Hospital, Idi-Araba, Lagos, Nigeria
3 Department of Radiodiagnosis, College of Medicine, University of Lagos, Lagos University Teaching Hospital, Idi-Araba, Lagos, Nigeria
|Date of Submission||28-Feb-2022|
|Date of Acceptance||02-Feb-2023|
|Date of Web Publication||29-Mar-2023|
Dr. Kehinde Omotola Apata
Department of Surgery, Urology Division, Ben Carson School of Medicine, Babcock University Teaching Hospital, PMB 4003, Ilishan Remo, Ogun State
Source of Support: None, Conflict of Interest: None
Background: Benign prostate enlargement is a common urological condition in the aging male that causes lower urinary tract symptoms (LUTS). The study was aimed at determining the correlation between International Prostate Symptom Score (IPSS) and sonographic parameters in a cohort of men attending the outpatient urology clinic of our teaching hospital. Methods: One hundred and fifty consecutive patients who met the inclusion criteria were enrolled into the study. The severity of LUTS was assessed using the IPSS questionnaire. Prostate volume (PV), bladder wall thickness (BWT), and postvoid residual (PVR) were determined via transabdominal ultrasound using Toshiba Nemino XG (Osaka Japan) with probe frequency 3.5MHz. The data were collected into a pro forma and analyzed using SPSS version 22 (IBM SPSS, Chicago, IL, USA). The data were subjected to Pearson's correlation and P < 0.05 was considered statistically significant. Results: The 150 patients who were enrolled had an age range of 46–85 years, while the mean age was 63.37 ± 9.45 years. The mean total IPSS was 17.58 ± 7.69. The PV, BWT, and PVR had a mean of 71.96 ± 48.75 ml, 4.63 ± 1.99 mm, and 48.01 ± 59.17, respectively. There was a weak correlation between the total IPSS and PV (r = 0.118; P = 0.149), BWT (r = 0.174; P = 0.03), and PVR (r = 0.118; P = 0.151). Correlating voiding and storage symptoms with PV showed a poor correlation. There was a statistically significant correlation between voiding symptoms and BWT (r = 0.255; P = 0.002). Conclusion: There was no correlation between total IPSS and PV with PVR. Total IPSS and voiding symptom scores had a statistically significant positive correlation with BWT.
Keywords: Benign prostate enlargement, bladder wall thickness and postvoid residual volume, International Prostate Symptom Score, prostate volume
|How to cite this article:|
Apata KO, Jeje EA, Tijani KH, Ogunjimi AM, Ojewola RW, Adeyomoye A A. Correlation between the International Prostate Symptom Score and sonographic parameters in patients with symptomatic benign prostate enlargement. J Clin Sci 2023;20:1-7
|How to cite this URL:|
Apata KO, Jeje EA, Tijani KH, Ogunjimi AM, Ojewola RW, Adeyomoye A A. Correlation between the International Prostate Symptom Score and sonographic parameters in patients with symptomatic benign prostate enlargement. J Clin Sci [serial online] 2023 [cited 2023 Jun 9];20:1-7. Available from: https://www.jcsjournal.org/text.asp?2023/20/1/1/372686
| Introduction|| |
Benign prostate enlargement (BPE) is a common disease of the aging male. It is a progressive condition that is characterized by lower urinary tract symptoms (LUTS). These symptoms may affect the quality of life (QoL) by interfering with normal daily activities and sleep patterns. This condition is one of the most common reasons for presentation in older patients with LUTS at our urological service. The relationship between symptom severity and ultrasound parameters has remained a subject of debate.
The severity of LUTS can be assessed using various validated questionnaires such as the International Prostate Symptom Score (IPSS), Boyarsky Score, Madsen–Iversen Score, and Danish Prostatic Symptom Score. IPSS is still the most widely used of all these. It is a seven-point questionnaire with a maximum score of 35. It is also a beneficial tool in the follow-up monitoring of BPE patients. The symptom severity is categorized into mild, moderate, and severe. This is considered in the selection of treatment modalities in symptomatic BPE.
The sonographic parameters estimated as part of the evaluation of patients with symptomatic BPE include prostate volume (PV), bladder wall thickness (BWT), and postvoid residual (PVR) volume. PV is an indispensable tool in the investigation of patients with benign prostate enlargement (BPE). It may be used to select patients for surgical interventional modalities such as transurethral resection of the prostate and open prostatectomies. PV and PVR urine have also been implicated in episodes of acute urinary retention (AUR), prediction of the outcome of trial without catheter after AUR, and the future need of BPE-related surgery. Partial ligation of the urethra in some animal studies has demonstrated an increase in bladder weight due to increased BWT. Detrusor hypertrophy is characterized by increased deposition of collagen and muscle hypertrophy at the microscopic level and by reduction of the intermediate cell junctions.
PV is usually measured using transrectal and transabdominal ultrasounds. However, the most widely used modality for the estimation of PV in our center is transabdominal ultrasound. Transabdominal ultrasound is easy to perform and provides a reliable measurement of PV and its intravesical protrusion as well as the PVR and BWT. Several formulas exist for the calculation of PV. The most widely accepted formula for TRUS volume measurements is the prolate ellipsoid volume formula. This formula assumes that the gland conforms to an ideal geometric shape of an ellipse (π/6 × transverse diameter × AP diameter × longitudinal diameter). The longitudinal dimension is measured in the sagittal plane just off the midline because the bladder neck may obscure the cephalad extent of the gland.
Therefore, this study was designed to determine the relationship between IPSS and ultrasound parameters.
| Methods|| |
This study included 150 patients referred to our urology outpatient clinic for LUTS due to BPE. These patients had normal prostate-specific antigen (PSA) and with no prior treatment for LUTS.
Those excluded from the study were patients with previous treatment for benign prostatic hyperplasia (BPH) and prostate cancer, patients with elevated PSA or abnormal digital rectal examination or imaging, and patients with associated neurological or endocrine disease. Moreover, excluded were patients with suspected bladder pathologies such as stones or tumor, suspected urethral stenosis or stricture disease, and patients taking medications interfering with urination such as anticholinergic.
Informed consent was taken from each patient concerning the study. A thorough history was obtained to get a clear understanding of the patient's complaints, including type of symptoms (urgency, frequency, urge incontinence, pain, other voiding and storage symptoms), severity and duration of symptoms, bother associated with the symptoms as stated above, previous therapies, and relevant medical comorbidities which could have an impact on their management. They were also asked to fill the IPSS questionnaire to determine their symptom severity. The educated patients were able to fill the questionnaires themselves, while the illiterates were assisted in filling the IPSS questionnaires. A complete physical examination was done to support the diagnosis of bladder outlet obstruction (BOO) due to BPE.
All patients had an abdominopelvic ultrasound done by a single examiner to determine the PV, BWT, and PVR urine.
Assessment of lower urinary tract symptoms
The patients who presented to us in the urology clinic were asked to fill the IPSS form. This was evaluated to assess the severity of urological symptoms in these patients. These LUTS were assessed by the IPSS questionnaire, which consists of voiding and storage symptoms. The QoL or Bother Score (BS) question of the IPSS was used to assess the bothersomeness of the symptoms for all patients.
For analysis of the LUTS determinants, IPSS was categorized into mild symptoms which is the score between 0 and 7, moderate which is between 8 and 19, and severe symptom which is also between 20 and 35. The assessment of the impact of LUTS on the QoL was done using BS section of the questionnaire. BS 0–3 was regarded as good QoL, while BS 4–6 was regarded as a poor QoL.
Estimation of prostate volume, bladder wall thickness, and postvoid residual volume
The PV, BWT, and PVR were estimated by ultrasound scan, using Toshiba Nemino XG (Osaka Japan). This was done using a 3.5 MHz to 7.5 MHz curved linear array probe, depending on the size of the patient. The prostate scan was done in each patient with a full bladder in the ultrasound room by a consultant radiologist at the radiology department. We considered a bladder urine volume of at least 250 ml as a full bladder, proposed by Oelke et al. The PV was estimated with the patient in a supine position. Each patient drank about 500 ml of water 1 h before the scan to ensure a full bladder, which aided adequate prostate visualization and increased the accuracy of the measurements taken for the PV. The probe was angled approximately 30° caudal using the bladder as a window. The bladder was compressed slightly to ensure that the inferior portion of the prostate was not obscured by the shadow artifact from the base of the bladder. The prostate dimensions were taken and the PV was calculated by multiplying the height, length in the sagittal plane, and width in the axial plane by 0.52. This is the prolate ellipsoid formula.
The BWT was determined at full bladder capacity. A bladder volume of at least 250 ml was considered as a full bladder, because beyond this volume, there was no change in BWT with further filling. The bladder was scanned using a 3.5 MHz probe to measure inner bladder dimensions. A 7.5 MHz probe was used to measure the BWT at the anterior wall, dome, right and left lateral walls, and at the trigone, taking the average of three points for each section at about 1 cm apart. The bladder wall was identified by the central hypoechoic layer, which represents the detrusor layer and the inner and outer thin hyperechoic layers, which represent the mucosa, submucosa, and subserosal tissues, respectively.
Patients were asked to void after estimating the PV and BWT. Within 10 min of termination of voiding, the PVR value was computed using the same machine with a 3.5 MHz hand-held probe using the formula π/6 × width × height × depth. Values >50 ml were considered abnormal.
All answered questionnaires and investigation results were coded before analysis. The determinant variable was the IPSS including the subscore components, in patients with BPE, while the outcome variables in the correlation were PV, BWT, and PVR. The subscores include the storage symptoms component of IPSS, voiding symptoms component of IPSS, and the QoL score. Analysis also included the age groups. The results of all these were correlated with the PV, BWT, and PVR. The data were analyzed using a multipurpose computer statistical program, Statistical Package for the Social Sciences Version 22 (IBM, SPSS, Chicago, IL, USA). Results were expressed using tables and charts where necessary. The data were subjected to linear regression. Pearson's correlation was used to assess correlation where applicable. P < 0.05 was considered statistically significant for all tests.
| Results|| |
A total of 150 men diagnosed with BPE were included in the study. Patient demographics are described in [Table 1].
The peak age incidence was between 61 and 70 years. Patients in the sixth and seventh decades of life made up 41.3% of the study population. The majority of the patients (85%) were over 50 years old.
[Table 2] shows the distribution of symptom severity as classified into mild, moderate, and severe symptoms.
The most common category of symptom severity was moderate scores. Fifteen patients had mild symptoms. Other details are contained in [Table 2]. Thirteen patients (8.7%) had a storage symptoms subscore of 15, while 9 patients (6%) had voiding symptoms subscore of 20. Only one patient (0.7%) recorded a total IPSS of 35. Most patients (32%) were unhappy about their urinary QoL. This was followed by mixed feelings by 39 patients (26%) if allowed to live the rest of their lives the same way it was before presentation. Only four patients were delighted with their QoL regarding their urinary function.
PV ranged from 12 to 312.9 ml with a mean of 71.96 ± 48.75 ml. The most common range of PV was found in both 10–49 ml and 50–89 ml, respectively. This occurred in 38.67% in each of these groups of patients. Twenty-two percent of patients had a PV >90 ml.
[Figure 1] depicts the distribution of PV of all patients in this study.
The BWT ranged from 1.7 mm to 20.0 mm with a mean of 4.63 ± 1.99 mm.
The BWT was then grouped into those with a thickness of 5 mm and below and those whose thickness was more than 5 mm. A significant BWT (>5 mm) was seen among 48 (32%) patients.
The PVR volume ranged from 1 ml to 310 ml with a mean of 48.01 ± 59.17 ml.
There was a statistically significant correlation between IPSS and age (r = 0.159; P = 0.05). Correlation of symptom score with the ultrasound parameters is as shown in [Table 3].
|Table 3: Pearson's correlation coefficients and their significance for total International Prostate Symptom Score|
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There was no correlation between the storage symptom score and PV, BWT, and PVR. Values are outlined in [Table 4]. The relationship between the voiding symptom score and the ultrasound parameters showed a statistically significant correlation with BWT (r = 0.255; P = 0.002). It confirmed no correlation with other parameters as shown in [Table 5]. The correlations of QoL score with PV (r = 0.014; P = 0.862), BWT (r = 0.003; P = 0.974), and PVR (r = 0.104; P = 0.207) were weak. The scatter plot of the relationship between the total IPSS and the BWT is shown in [Figure 2], while that of voiding symptoms and BWT is illustrated in [Figure 3].
|Table 4: Pearson's correlation coefficients and their significance for storage symptoms|
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|Figure 2: Scatter diagram of regression of total IPSS on BWT. IPSS = International Prostate Symptom Score, BWT = Bladder wall thickness|
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|Figure 3: Scatter diagram of regression of voiding symptoms on BWT. BWT = Bladder wall thickness|
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| Discussion|| |
Benign prostate enlargement is a common urological condition which is intimately related to aging. In this study, the age range and mean age were similar to those reported in several other similar earlier studies.,,,,, This finding corroborates the observation from earlier studies that the prevalence of LUTS due to BPE is an aging problem.
In Nigeria, the burden of benign prostate enlargement has a significant impact on the health care of the people. IPSS is generally used as the main instrument for measuring the severity of LUTS. The mean total IPSS of 17.58 ± 7.7 in this study is very similar and comparable to that of Ezz el Din et al. who documented a mean of 17 ± 7. This showed that the majority of the patients had moderate symptoms requiring treatment. A similar study by Oranusi et al. also showed that patients with moderate symptoms dominated their patient population. Our mean total IPSS was slightly lower than the 18.81 and 19.1 reported by Pethiyagoda et al. and Steele et al., respectively. The mean storage symptoms was 8.62 ± 3.9 and voiding symptoms was 8.95 ± 5.64, unlike Trumbeckas et al. who documented 7.6 ± 3.3 and 10.5 ± 5.0 in their work. In this study, we documented a slightly higher number of patients with voiding symptoms compared to storage symptoms, likewise Agrawal et al. who also found higher number with voiding symptoms. Furthermore, most patients in this study also experienced moderate symptoms (49.3%). This finding is also similar to that of other similar studies too.,,
The mean QoL score in this study was also similar to the findings in other studies., This shows that most patients who have moderate to severe LUTS will mostly experience poor QoL if there are no therapeutic interventions to alleviate or eradicate their symptoms.
PV is the most extensively studied risk factor for disease progression in BPE. It has been found that men with a PV of ≥30 ml are more likely to have moderate-to-severe LUTS (3.5-fold increase), decreased flow rates (2.5-fold increase), and urinary retention (three-to four-fold increase) than are men with a PV <30 ml. PV information has, therefore, become increasingly important because it strongly predicts BPH-related morbidities such as AUR and the need for surgery. The mean PV in this work is slightly higher compared to the mean PVs reported from other studies.,,, This could be ascribed to the genetic predisposition associated with larger PV in blacks.
The rationale behind the use of BWT as a determinant of BOO comes from several studies describing detrusor hypertrophy as a consistent outcome of infravesical obstruction in animal models., In our series, there is a lower mean BWT compared to some other studies,, but the finding from this study was similar to the 4.54 ± 1.1 documented by Manieri et al. Manieri et al. reported a cutoff value of BWT in men with BPE of 5 mm as a good predictor of subvesical obstruction. In this study, 68% had BWT of < 5 mm while 32% had over 5 mm thickness, which is similar to the 34% with over 5 mm thickness documented in their study. The mean PV in their study was 38.11 ± 27.11 ml which is lower than our mean PV. This is in support of the fact that there is no correlation between PV and severity of LUTS. However, their mean total IPSS was 14.91 ± 6.93 which is comparable to our mean total IPSS. The PVR ranged from 1 ml to 310 ml with a mean of 48.01 ± 59.17 ml compared to 76.5 ± 88 documented by Trumbeckas et al. in their study.
Concerning the correlation of total IPSS with PV, there is a lot of variation in the findings of most authors. In this study, correlating total IPSS with PV showed a weak but not statistically significant correlation. Jacobsen et al. and Overland et al. also found a modest correlation but rather a strong statistical significance (r = 0.176, P < 0.001) between IPSS and PV. Franciosi et al. also documented a positive but weak correlation between PV and IPSS (r = 0.15; P = 0.02), while Pethiyagoda et al. documented a strong positive correlation between PV and IPSS, (r = 0.223; P < 0.003). We observed that they used larger sample sizes in their work. The large sample sizes may have contributed to the improved level of significance of their positive correlation. However, some other investigators found no correlation between IPSS and PV.,,, There is a poor correlation between storage symptoms and PV and no correlation between voiding symptoms and PV. This is similar to what Agrawal et al. found in their study, (r = 0.166; P = 0.099) for storage and (r = 0.159; P = 0.113) for voiding symptoms.
There was no correlation between the QoL score and PV (r = 0.014; P = 0.862) and between QoL score and BWT (r = 0.003; P = 0.974). The correlation between QoL and PVR was weak (r = 0.104; P = 0.207). The possible explanation for this poor correlation is that enlargement may be associated with a prominent median lobe, which may cause a ball-valve effect on the bladder neck worsening obstruction. Another reason for this may be related to the multifactorial factors involved in the development of LUTS. Therefore, the occurrence of progressive changes in the urinary bladder with aging, which occur at the same time as histopathological alterations of the prostate that may contribute to the LUTS.
This study demonstrated a statistically significant positive correlation between the IPSS and BWT in this study (r = 0.174; P = 0.033). This finding is very similar to that from the study done by Aganovic et al. (r = 0.17; P = 0.08); however, their finding was not statistically significant. This may be explained by their smaller study population of 111 participants. Similarly, a weak correlation was found between IPSS and PVR (r = 0.118; P = 0.151). This corroborated the work of Bosch et al. who also documented a weak correlation at r = 0.25, which was statistically significant. They used a larger sample size in their study, which might have accounted for this result. In this study, there was no correlation between storage symptoms and BWT (r = −0.021; P = 0.803). However, there was a positive statistically significant correlation between voiding symptoms and BWT (r = 0.255; P = 0.002). This indicates that BWT is a good predictor of the severity of LUTS due to BPE. Moreover, the correlation between storage and voiding symptoms with PVR was poor.
To our surprise, very few studies have correlated storage and voiding symptoms with these ultrasound parameters. Finally, the findings of this positive correlation between IPSS and BWT and between voiding symptoms and BWT, including findings by some other studies, may emphasize the significance of BWT as an indispensable sonographic parameter in the evaluation of patients with LUTS/BPE.
| Conclusion|| |
IPSS demonstrated a weak positive correlation with PV. There was no correlation between symptom severity score components (storage and voiding symptoms) and PV. There was no statistically significant relationship between the QoL score and sonographic parameters. We observed a statistically significant correlation between IPSS and BWT. There was an inverse relationship between storage symptoms and BWT. Correlation between voiding symptoms and BWT was positive and statistically significant. Symptom severity scores including its components had a weak correlation with PVR.
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Conflicts of interest
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[Figure 1], [Figure 2], [Figure 3]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]