Introduction

The prostate is a chestnut-shaped auxiliary genital gland located in the pelvis, below the bladder, surrounding the prostatic portion of the urethra1.

Benign prostatic hyperplasia (BPH), affecting the center of the per urethral glandular tissue2, is a chronic and complex disease that is progressive in many men3. It has been connected to unchecked glandular epithelium, smooth muscle, and connective tissue growth in the prostatic transition zone. The development of BPH glandular nodules initially begins to form in the periurethral region followed by an increment in size1.

The burden of BPH has been increasing from time to time, predominantly in low-income and middle-income countries4. BPH affects about 210 million males worldwide with the estimated risk of developing it over the next 30 years is 45%5 and 379,000 men over the age of 55 annually which made it the main reason for major surgery according to studies done in the United States6.

In adult men in the Sub-Saharan African region, urinary bladder outlet obstruction due to BPH is a common urological condition2. The incidence of BPH is increasing from 0.3% of men aged 45–49 years to 0.38% of men aged between 75 and 79 years with the respective prevalence rates of 2.7% and 24%7. The study in Japan revealed the prevalence of BPH in participants aged 70 and above as 25.2%5. Another study indicated prevalence of LUTS for ages between 50 and 79 as 56%, 80 to 89 years old as 70%, and men aged 90 or beyond as 90%6. Similarly, the prevalence of BPH is stated as 62.3% in western Africa8, 42.0% in Egypt1and 20% in Gondar Ethiopia9.

A growing body of evidence suggests that modifiable factors such as increasing prostate volume, obesity, diet, dyslipidemia, hormonal imbalance, hypertension, metabolic syndrome, alcohol, smoking, and aging contribute to the development of BPH6.

Evidence-based data is important to determine the magnitude of BPH and its associated factors. Finding detailed and up-to-date estimates of the illness burden of BPH in a particular study region is beneficial. Therefore, the current study aimed to assess the prevalence of BPH and associated factors among men visiting Wolaita Sodo University Comprehensive Specialized Hospital (WSUCSH).

Method and materials

Study setting

The study was conducted at WSUCSH in Wolaita Sodo town, located in Wolaita Zone, 154 km from Hawassa, the capital of Southern Ethiopia, and 329 km away from Addis Ababa, the capital of Ethiopia. The hospital provides general outpatient and inpatient services, including medical, surgical, pediatric, psychiatric, ophthalmic, emergency, gynecology, and obstetrics care. It serves approximately 3.5–5 million patients annually in Wolaita and the neighboring zones like Dawuro, Gamo, Gofa, and Kambata-Tambaro.

Study design and period

An institutional based cross-section design study was conducted from July 1 through August 31, 2022.

Source and study population

All male patients presented at Wolaita Sodo University Compressive Specialized Hospital were the source population. All male patients admitted to the urology ward with LUTS who fulfilled the inclusion criteria were the study population.

Eligibility criteria

All male patients aged 30 and above admitted to the urology department with LUTS were included in this study and Patients with confirmed cases of prostatic cancer, unconscious and unable to speak and those patients with confirmed mental disorders were excluded.

Sample size determination and sampling procedure

The sample size was calculated using a single population proportion formula considering the following assumptions: 95% confidence level with a margin of error (5%), using the anticipated population proportion of prevalence of BPH from the previous study conducted in Mekelle Hospital, Northern Ethiopia 33.4%10. The final sample size calculated after considering a 10% non-response rate was 376.

Hence, n = Z (1- α/2) 2 p (1-p).

d2.

n = (1.96)2 (0.334) (0.66) = (3.8416) (0.2224) = 342.

(0.05)2 0.0025.

Where n = required sample size.

Z = critical value for normal distribution at 95% confidence level which equals to 1.96 (z value at α = 0.05, two tailed).

Sample size = 342.

Expecting a 10% non-response rate, the final sample size calculated was 376.

Sampling procedure

Systematic random sampling was employed to select study participants. The total number of men patients who visited urology units (N) was estimated by considering the past 5 months’ case flow and reviewing the records which yielded a total of 1002 clients. Then the number of sampling intervals was determined by dividing the number of clients (N = 1002) by the estimated sample size (n = 376), and hence the sampling interval (k) was 3. The first sampling unit was selected by the lottery method, and then every 3rd unit was taken. To control the second visit of participants, the charts of those with appointments were kept in urology OPD separately.

Study variables

Dependent variables

Presence or absence of BPH.

Independent variables

Socio-demographic, Family history, and Metabolic syndrome factors and Behavioral and psychological related factors were used as predictors.

Operational definitions

BPH

diagnosed when a digital rectal examination revealed symmetrically enlarged, smooth, rubbery, movable rectal mucosa and a normal median sulcus detected8.

LUTS

refers to the typical aging male voiding and/or storage issues. Daytime frequency and nocturia are two examples of storage symptoms that occur during the storage phase of the bladder, while voiding symptoms occur during the voiding phase11.

International Prostate Symptom Score (I-PSS)

Questionnaires were utilized to rate the intensity of three storage symptoms (frequency, nocturia, and urgency) and four voiding symptoms (feeling of incomplete emptying, intermittency, straining, and a weak stream)12. Men with an IPSS score of 0 were classified as asymptomatic, those with values 1–7 as mildly symptomatic, and those with scores 8–35 as severely symptomatic8.

Bladder Outlet Obstruction (BOO)

is the generic term for all forms of obstruction to the bladder outlet (e.g., urethral stricture), including BPO12.

Hypertension

Men were regarded as having a history of hypertension if they were actively using medication to treat their hypertension or if their doctor had diagnosed them with the condition13.

Diabetes mellitus

Men are considered to have a history of diabetes mellitus if they are currently taking medicine to treat it or have been told by their doctor that they have diabetes, high blood sugar, or both13.

Body mass index (BMI)

defined as the body weight in kilograms divided by the height in square meters and categorized as normal weight (18.5–22.9 kg/m2), overweight (23–24.9 kg/m2), and obesity (> 25 kg/m2)9.

Smoking

was assessed during the interview, and men were classified according to their smoking habits as current, former, or never smokers14. A never smoker is someone who has never smoked in his life; a former smoker is someone who has been smoke-free for the past one month and a person who smokes every day or some days is classified as a current smoker15.

Alcohol intake

an individual who has never drunk alcohol in his life was considered as a never drinker, consumed two or more glasses weekly was considered as a current drinker, and has been alcohol-free for the past one month was considered as former drinker12.

Physical activity

Information about home, work, and leisure activities were combined to create the Psoriatic Arthritic Screening Evaluation (PASE) scores. The aggregate of all activities was used to calculate the total PASE score by multiplying either the amount of time (in hours per week) or involvement (i.e., yes or no) in each activity by experimentally obtained item weights. The PASE score might range from 0 to 400 or higher overall. The PASE score was divided into tertiles 0 to 40 (sedentary), 41 to 90 (mild physical activity), and more than 90 (moderate to intense activity)16.

Sexual dysfunction

The Arizona Sexual Experience Questionnaire (ASEX) is a 5-item rating scale that analyzes the four stages of sexual functioning, including sexual drive, arousal with sexual stimuli, penile erection, the ability to reach orgasm, and orgasm satisfaction. The total score goes from 5 to 30, with a score of 19 or higher suggesting sexual dysfunction. Scores of 4 or 5 were regarded as having no sexual dysfunction in that category for each domain17.

Sleeping time

defined as the total amount of time a person sleeps in 24 h. A person who sleeps 0–6 h per day is considered to have inadequate sleeping time, and 7 or more hours per day is considered to have adequate sleeping time18.

Fruit and vegetable consumption

the total amount of fruit and vegetables an individual consumes. Consumption of four servings per day is considered adequate, while consumption of less than four servings per day is considered inadequate19.

Co-morbidity

a medical term that describes the long-term or chronic existence of more than one disease or condition within the body at the same time20.

Data collection procedure and collection instrument

Data was collected using ODK collect survey tool through interviewer-administered questionnaire which was adapted from previous literatures and modified according to the current study objectives. The pre-tested questionnaires were translated into Amharic and back to English to ensure consistency in meaning. The questionnaire is divided into four sections. Part I: socio-demographic factors; Part II: family history and metabolic syndrome factors; Part III: behavioral and psychological-related factors; and Part IV: a digital rectal examination checklist.

Two data collectors and one supervisor were recruited for data collection and supervision respectively.

Data processing and analysis

The collected data was transferred from Open Data Kit (ODK) to Microsoft Excel 2010 and then completeness of data and cleaning were done and any error identified was corrected. Then the data was exported to SPSS version 25 for further analysis. The binary and multivariable logistic regressions were used. All variables with a p-value < 0.25 were taken into the multivariable model. Finally, the results of multivariable logistic regression analysis were presented to identify the independent effects of predictors on outcome variables. The factors with P < 0.05 were considered as having significant association with outcome variable and adjusted odd ratios with 95% Confidence Interval (CI) were used to measure a degree of association. A Hosmer - Lemeshow test was done to check for model fitness.

Data quality assurance

To maintain the quality of data, two data collectors and one supervisor were trained for three days about the purpose of the study, data collection tools, and ethical procedures. A pretest was conducted on 5% of the study participants out of the study area with similar population to assess the validity of the instrument. Each study subject was identified only by code and the collected data was kept secure by the principal investigator. Following data collection, data was stored in a secure location to maintain confidentiality. To maintain the quality of data senior medical doctors were participated to diagnosis BPH by digital rectal examination. Moreover, all the study participants were informed orally about the purpose and benefit of the study, along with their right to refuse or decline participation in the study at any time.

Results

Socio demographic characteristics of the participants

A total of 376 patients were interviewed in this study, with a response rate of 100%. One hundred twenty-six (33.5%) were aged between 50 and 59 years, and the mean age (SD) of the respondents was 55.06 ± 9.95 years. Protestants were predominant (51.3%) in religion and the majority of the respondents, 253 (67.3%) were Wolaita in ethnicity. Three hundred two (80.3%) of the respondents were married and in terms of educational attainment, 109 (29.0%) had completed college or higher, and 116 (30.9%) were government employees (Table 1).

Table 1 Socio demographic characteristics of men presented with LUTS at Wolaita Sodo University Comprehensive Specialized Hospital, South Ethiopia, 2022.
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Family history and metabolic syndrome-related factors

Among all study participants, 156 (41.5%) had no family history of BPH, and 108(31.5%) did not know about their family history of BPH. One hundred sixty-eight, (44.6%) of participants had normal Body Mass Index whereas overweight and obese participants were 115(30.7%) and 93 (24.7%) respectively. Of 119 (31.6%) of the respondents diagnosed with a chronic illness, 50 (42.8%) were hypertensive patients (Fig. 1).

Fig. 1
figure 1

Types of Metabolic related factors of respondents at Wolaita Sodo University Comprehensive Specialized Hospital, Southern Ethiopia, 2022. (n = 119).

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Behavioral and psychological-related factors

Nearly half of the participants (49.2%) were never drinkers, and 255 (67.82%) were never smokers. The majority of the respondents, 319 (84.8%) eat fruits with 242 (68.75%) having adequate fruit consumption. Regarding sleeping time, physical activity, and sexual dysfunction, two hundred forty-eight (65.95%) of the respondents had adequate sleeping time, 257 (68.4%) did moderate-to-intense physical activity and about 313 (83.2%) of the respondents had no sexual dysfunction (Table 2).

Table 2 Behavioral and psychological related factors of respondents among patients presented with LUTS at Wolaita Sodo University Comprehensive Specialized Hospital, Southern Ethiopia, 2022.
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The magnitude of benign prostatic hyperplasia

The magnitude of Benign Prostatic Hyperplasia among 376 patients was found to be 80 (21.3%; 95% CI: 17.3, 25.8) with 46 (57.5%) had severe BPH (Fig. 2).

Fig. 2
figure 2

Severity of Benign Prostatic Hyperplasia symptoms among male patients presented with LUTS at urology unit of Wolaita Sodo University Comprehensive Specialized Hospital, South Ethiopia, 2022.

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Factors associated with benign prostatic hyperplasia

In bivariate logistic regression, fruit consumption, vegetable consumption, physical activity, sleeping time, depression, BMI of respondents, sexual dysfunction, and family history of BPH were with p < 0.25. However, in multivariable logistic regression, vegetable consumption, fruit consumption, physical activity, sleeping time, and sexual dysfunction were significantly associated with BPH with p < 0.05.

Participants who had inadequate fruit consumption were twenty-one times more likely to develop BPH than participants who had adequate fruit consumption [(AOR = 21.06, 95% CI: (7.06, 27.53)]. Likewise, the odds of BPH among participants with inadequate vegetable consumption were seven times more likely to develop BPH than participants who had adequate vegetable consumption [(AOR = 7.57, 95% CI: (2.78, 20.60)]. Those participants who did moderate to intense [(AOR = 0.57, 95% CI: (0.19, 0.67)] and light physical activity [(AOR = 0.05, 95% CI: (0.01, 0.56)] were 43% and 95% less likely to develop BPH than who did sedentary physical activity respectively.

The odds of developing BPH increased by three times for the participants who had inadequate sleeping time than those who had adequate sleeping time [(AOR = 3.23, 95% CI: (1.18, 8.79)]. Similarly, the odds of developing BPH increased by seventeen times for the participants who had sexual dysfunction than those who had not [(AOR = 17.05, 95% CI: (4.82, 60.28)] (Table 3).

Table 3 Multi-variable logistic regression factors associated with BPH among patients presented with LUTS at Wolaita Sodo University Comprehensive Specialized Hospital, South Ethiopia, 2022. 1: reference category **=p-value < 0.05 (significantly associated), CI = Confidence Interval, AOR = Adjusted Odds Ratio.
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Discussion

The magnitude of benign prostatic hyperplasia in this study was found to be 21.3% (95% CI: 17.3, 25.8). This study finding is higher than previous studies done in China, 10.66%)21, and Turkey, 13.84%6.This might be due to the difference in living standards, socioeconomic status, and quality of health service provision. On the contrary, it is lower than the study done in Egypt, where the overall prevalence of benign prostatic hyperplasia using the IPSS questionnaire is 42.0%1, 62.3%8in West Africa, and 33.4%10 in Ethiopia. This might be due to the difference in sample size and the difference in the tools used to diagnose BPH.

Patients with inadequate sleep time were more likely to develop BPH compared to those with adequate sleep time. This is consistent with studies conducted in China22,23. This might be explained in terms of the Production of melatonin (sleep regulator hormone) which generally decreases with age. The older individuals show an increased lag from sunset to the onset of melatonin pulse and the middle of the sleep period 24 and this could be the reason why BPH presence was high among respondents with inadequate sleeping time.

Regarding sexual function, in the current study, prostate enlargement cases with sexual dysfunction were more frequent among BPH patients than those with normal sexual function. This evidence was supported with previous study findings in Ethiopia, Germany, and the United States of America on the relationship between sexual dysfunction and prostate enlargements25,26,27. There is a high relative risk of sexual dysfunction in individuals with BPH28. This might be due to the similarity of most studied participants were elderly patients and thus the amount of the hormone testosterone which controls sexual activity declines with age and may have an impact on prostatic growth27. Emerging research has suggested lack of testosterone may be a risk factor for BPH26.

The findings of the present study revealed that the practice of moderate to intense and light physical activities were factors that significantly decreased the risk of BPH. This result is similar to other cross-sectional studies done in Europe30,31,32,33. Patients who do moderate to intense and light physical activities were less likely to develop BPH as compared with those who did sedentary physical activity which is supported by the previous study conducted in Saudi Arabia.1 Besides, prostate enlargement is related to serum testosterone levels, which believed to fall with less physical activity1. Increasing physical activity to moderate levels reduces sympathetic nervous system activity at rest which generally controls prostate growth34. Thus, physical activity has a beneficial effect on BPH, which is in part mediated by diminished systemic sympathetic nervous system activity.

According to prior studies in Europe25,28and Mekelle, North Ethiopia10, inadequate intake of fruits and vegetables increased the risks of BPH, which is in line with the current study findings. This could be justified as fruits and vegetables contain significant amounts of antioxidants, polyphenols, vitamins, minerals, and fiber which might have a significant impact on the inflammatory pathways involved in the pathophysiology of benign prostatic hyperplasia and reduce prostate hyperplasia28.

Limitations of the study

Since the study was conducted in one hospital, the findings of the current study may not be generalized to the larger population and the study did not use ultrasound (imaging) which made it difficult to know the exact volume of the prostate and PSA test was not conducted to assess the possible risk of prostatic cancer. Since it is a cross sectional study design causality cannot be determined between outcome and independent variables.

Conclusion and recommendation

In this study, benign prostatic hyperplasia was found to be a highly prevalent disease among men. Sexual dysfunction, consumption of vegetables, consumption of fruits, practice of physical activity, and sleeping time were factors significantly associated with BPH.

Healthcare providers should do screening programs for all people in a higher-risk group to ensure the early presentation of benign prostatic hyperplasia and It is recommended that scholars to conduct further studies about benign prostatic hyperplasia. For the community, it is recommended to serve a high amount of fresh fruit and vegetables and do physical activity regularly. To determine causality between dependent and independent variables cohort or follow up study design is highly recommended.