Metabolic syndrome is associated worsened erectile function in patients undergoing TURP due to benign prostatic hyperplasia

Abstract

Introduction

Transurethral resection of the prostate (TURP) is the gold standard method for surgical treatment of benign prostatic hyperplasia (BPH). So, the complications of TURP is important, in which erectile dysfunction is the most important. The aim of the present study is to evaluate erectile dysfunction in patients undergoing TURP treatment for BPH and investigate the correlation between metabolic syndrome and erectile dysfunction.

Materials and methods

This study included 120 patients who underwent surgery for BPH at Beylikdüzü State Hospital and Okmeydani Training and Research Hospital. IIEF-5 form was administered to the patients before the surgery and six months after the surgery. The Student’s t-test, Wilcoxon, and chi-square test were used in the statistical analysis.

Results

The patients were investigated by IIEF-5 scoring into three groups (severe, moderate, and non-ED (erectyl disfunction)-mild). The statistical analysis of IIEF-5 form administered to 120 patients who underwent surgery did not show any significant difference before surgery and six months after surgery (p > 0.05). Metabolic syndrome and erectile dysfunction correlation were examined, and a significant correlation was obtained between metabolic syndrome and severe erectile dysfunction (p < 0.05).

Conclusions

IIEF-5 results administered before and after surgery showed no significant difference. The study showed that patients with metabolic syndrome have a higher probability of having erectile dysfunction after TURP compared to patients without metabolic syndrome. Moreover, post-surgery, patients with metabolic syndrome seemed to be affected negatively regarding erectile dysfunction compared to patients with no metabolic syndrome.

Keywords:

• Benign prostatic hyperplasia (BPH)
• erectile dysfunction
• metabolic syndrome
• TURP

Introduction

Benign prostatic hyperplasia (BPH) is one of the most common diseases in the world. Lower urinary tract symptoms (LUTS) of BPH is increased with age, occur in 15 to 60% of males aged above 40 years, and 80% in men aged above 60 years [1,2].

Patients with severe LUTS that are non-responsive to medical treatment are operated. There are many alternative treatment methods for BPH. However, Transurethral Resection of Prostate (TURP) is still the gold standard method. TURP is one of the most performed surgical procedure in the world [3,4]. Therefore, the complications of this procedure on patients is significant. Post-op in early stages, bleeding, post-operative catheterization, prostate capsule perforation are observed whereas, in later stages, many complications such as urethral narrowness, retrograde ejaculation are observed. Erectile dysfunction is the most important and anticipated complication. Some studies suggested that TURP causes erectile dysfunction [5,6]. However, some research conducted lately showed the treatment of LUTS also helped in eliminating erectile dysfunction [7,8]. IIEF-5 (The International Index of Erectile Function) questionnaire form is frequently used for erectile dysfunction evaluation. Thus, in our study, the IIEF-5 form was used both before surgery and post-op sixth month. The effect of TURP on erectile dysfunction was investigated by comparing the findings.

Metabolic syndrome (MetS) consist of components such as fasting glucose level or the existence of diabetes, hypertension, increased waist circumference, and dyslipidemia and is diagnosed by the presence of at least three of these components. Studies demonstrate a close correlation between MetS and erectile dysfunction [9,10]. The present study aims to investigate the effects of the MetS in patients treated for BPH with TURP method.

Materials and methods

This study was conducted at Okmeydanı Training and Research Hospital after obtaining Ethics Committee approval, reference number 429, dated May 14 2016. This study included 120 patients who were administered TURP treatment in Beylikduzu State Hospital and Okmeydanı Training and Research Hospital between August 2016 and July 2018. Patients with prostatitis, patients who received 5-alpha-reductase inhibitor affecting PSA levels, and those with urethral stenosis or a history of surgery due to the lower urinary tract were excluded from the study. Patients underwent a routine rectal examination, PSA measurement, uroflowmetry, ultrasonography, and urinary culture before surgery. The patients’ demographic data are considered as age, gender, weight, body mass index (BMI), additional sicknesses, the existence of hypertension and diabetes, and also the existence of hypertension and MetS. Patients were administered TURP treatment. IIEF-5 form was performed to the patients before the surgery and at six months after the surgery, the possible change in erectile dysfunction was examined. The existence of metabolic syndrome and pre-op and post-op erectile dysfunction variations in patients with MetS was investigated. International Diabetes Foundation (IDF) 2005 criteria were used for metabolic syndrome diagnosis [9].

• Abdominal obesity (Waist circumference: In European, in men ≥94 cm, in women ≥80 cm) and at least two of following

• Tryglycerides ≥150 mg/dl

• HDL: In men <40 mg/dl, in women <50 mg/dl

• Blood pressure ≥130/85 mmHg

The SPSS 15.0 (SPSS for Windows, 15.0, SPSS Inc., Chicago, IL) software package was used for the statistical analysis. In the analysis of quantitative data, variables with normal distribution were analyzed using a paired sample Student’s t-test, and variables without a normal distribution were analyzed with a Wilcoxon test. A Chi-square test was used for the analysis of qualitative data. A p value less than 0.05 was considered statistically significant.

Results

The study included 120 patients. Patients’ age and body mass index is recorded and hypertension, diabetes mellitus, and the existence of Mets is investigated. 32 patients had Mets and 98 did not have.

Demographic data of the patients are summarized in Table 1.

Table 1. Demographic data of the patients.

Parameters n = 120	Number
Age (mean ± SD)	64.95 ± 8.2
Presence of MS	32 (26.7%)
BMI (kg/m^2 ± SD)	28.0 ± 4.5
Hypertension (%)	38 (31.7%)
Diabetes mellitus (%)	29 (24.2%)

The patients were separated via IIEF-5 scoring into three groups as severe, moderate, and non-ED-mild. The value of patient numbers classified as severe erectile dysfunction was 32 pre-op and 23 post-op, with a no significant difference (p > 0.05). The value of patient numbers classified as moderate erectile dysfunction was 51 pre-op and 64 post-op, with a no significant difference (p > 0.05). The value of patient numbers classified as non-ED-mild erectile dysfunction was 37 pre-op and 33 post-op, with no significant difference (p > 0.05). The study obtained no significant difference in pre-op and post-op erectile dysfunction parameters in any patient groups.

IIEF-5 data of patients are evaluated in Table 2.

Table 2. IIEF-5 parameters.

IIEF-5 erectile dysfunction rate	Pre-op patient number	Post-op patient number	p Value
Severe	32	23	0.22
Moderate	51	64	0.12
Non-ED-Mild	37	33	0.89

Also, all patients’ pre-op and post-op IIEF-5 values were compared numerically. Mean pre-op score was 12.5 ± 6 compared to post-op IIEF-5 score was 13.4 ± 5, there was no statistically significant difference with p values 0.19.

Mean numerical values of IIEF-5 scoring are shown in Table 3.

Table 3. IIEF-5 pre-op and post-op mean numeric values (120 patients).

	Pre-op average value	Post-op average value	p Value
Mean IIEF-5 score	12.5 ± 6	13.4 ± 5.1	0.19

Metabolic syndrome and IIEF-5 correlation was also investigated in this study. IIEF-5 was investigated in three groups. Number of patients with severe erectile dysfunction was 16 in 32 patients who had metabolic syndrome and also 16 in 98 patients who did not have metabolic syndrome, which was statistically significant (p < 0.05). Number of patients with moderate erectile dysfunction was 10 in patients who had metabolic syndrome and also 41 in patients who did not have metabolic syndrome, which was statistically not significant (p > 0.05). Number of patients with severe erectile dysfunction was six in patients who had metabolic syndrome and also 31 in patients who did not have metabolic syndrome, which was statistically not significant (p > 0.05).

Number of patients with metabolic syndrome in the present study, conducted with 120 patients, was 32. The study discovered correlation between severe erectile dysfunction and metabolic syndrome, which is detailed in Table 4.

Table 4. Erectile dysfunction rate regarding metabolic syndrome and IIEF-5 parameters.

IIEF-5 erectile dysfunction rate	Patients with metabolic syndrome (32)	Patients without metabolic syndrome (98)	p Value
Severe	16	16	0.003
Moderate	9	41	0.22
Non-mild	7	31	0.19

Discussion

Benign prostatic hyperplasia is one of the most common and in daily urology practice, the most frequently encountered diseases around the world. Surgeries for BPH treatment are among the most commonly administered surgical applications. Thus, TURP complications, especially erectile dysfunction, are crucial. In this study, erectile dysfunction in patients administered TURP treatment, and the effects of metabolic syndrome on erectile dysfunction were investigated.

Various studies have been conducted regarding erectile dysfunction. Some studies have findings to support erectile dysfunction improvement post-op, and also some suggest otherwise. Certain authors, with 5-alfa reductase inhibitors, began being administered as medical treatment, claimed that elimination of LUTS would also be useful in erectile dysfunction treatment. The surgical treatment is claimed to have a positive effect on erectile dysfunction [11].

Pavone et al. [12] conducted a study on 264 patients who underwent surgery for BPH treatment. The study was conducted in two separate hospitals in Italy between 2008 and 2012 retrospectively. The IIEF-5 form was administered in patients for pre-op and post-op erectile dysfunction evaluation, as well as a questionnaire for retrograde ejaculation. Patients were separated into three groups as an excellent erectile function, mild-medium ED, and complete ED. In the study, contrary to ejaculation disorders, TURP treatment did not have any significant influence on the advancement of erectile dysfunction. The study conducted by Reşorlu et al. [13] in Turkey included 80 patients who were administered transvezical prostatectomy. Patients were evaluated with IIEF-5 form, pre-op, and post-op. Severe hypertension, history of diabetes, and coronary artery disease are observed in patients with post-op erectile dysfunction disease. The similarity of this study and the present study is the small fraction of the participants, especially patients with risk factors, decline in sexual functions is obtained and in some patients, with improved life quality, improvement of sexual functions is observed. However, evaluating the study as a whole, no significant difference in erectile function is observed. The ratio of retrograde ejaculation is calculated 90% [13]. The study to evaluate the effects of TURP treatment on sexual functions conducted by Muntener et al. [14] included 644 patients and also shows supporting results.

On the other hand, the study reported in Germany by Poulakis et al. [15] included 500 patients and aimed to investigate TURP and erectile dysfunction correlation in postoperative sixth-month erectile function evaluation. Erectile dysfunction improvement was observed in 12% of the patients. Intraoperative capsular perforation and diabetes mellitus were remarked as the most crucial factor in erectile dysfunction deterioration.

Favilla et al. [16] reported a study including 178 patients who were administered TURP for BPH treatment. Sexual functions were evaluated by IIEF-5 scoring. Risk factors such as age, dyslipidemia, hypertension, and diabetes had been observed post operation throughout 12 months. Age occurred to be the only statistically significant risk factor. The risk of erectile dysfunction deterioration after TURP treatment was shown to be higher on patients over 65 contrary to patients under 65 years of age. Other risk factors, dyslipidemia, hypertension, or diabetes, were observed to have no significant effect on erectile dysfunction deterioration post-op TURP.

In our study, the evaluation of pre-op and post-op group results did not show any statistically significant difference. The recovery of ED in 20 patients was associated with quality of life improvements. Excessive comorbidities were observed in 15 patients with deteriorating ED. Many studies have been conducted regarding BPH surgery. Various results have been observed in the relevant literature. The present study indicates consistent results with studies conducted in the last few years.

The studies about erectile dysfunction, both socially and scientifically, are among the most anticipated topics around the world. The correlation between erectile dysfunction and LUTS is one of the most crucial components of this topic. Vallencien et al. [17] reported a comprehensive study. The study included 1274 patients, and erectile dysfunction was remarked to deteriorate with age. Moreover, a strong correlation between erectile dysfunction symptoms and excess LUTS was observed.

Metabolic syndrome is one of the most common diseases of the century. Therefore, it is one of the most critical topics in studies conducted. The correlation between metabolic syndrome and oncologic diseases such as prostate cancer, urinary cancer, renal cancer as well as the correlation between metabolic syndrome and functional diseases were examined. Thus, many studies were reported to evaluate the correlation between erectile dysfunction and metabolic syndrome [18]. The results of decreased nitric oxide synthesis production, Rho kinase activity related to endothelial dysfunction caused by metabolic syndrome are considered to form the basis of metabolic syndrome and erectile dysfunction correlation. However, in the present study, the correlation between metabolic syndrome and erectile function is evaluated. Also, the correlation between metabolic syndrome and erectile function in patients who underwent surgery for BPH treatment is evaluated.

The study conducted by Esposito et al. [19] consisted of 100 metabolic syndrome patients and 100 people control group. The IIEF scoring, CRP, and endothelial function scoring were investigated in the study. Low endothelial function and IIEF scoring and high CRP were observed in metabolic syndrome patients. Another study investigating the correlation between metabolic syndrome and erectile dysfunction is conducted by Kupelian et al. [20]. The study included 928 male patients, and erectile dysfunction was argued to be a symptom in metabolic syndrome diagnosis. Metabolic syndrome improvement was observed in 293 of the patients, 56 of the patients also showing erectile dysfunction. The results were evaluated, and an impressive result was obtained. The existence of erectile dysfunction in patients who had body mass index lower than 25 was claimed to be predictive for metabolic syndrome. A significant correlation between metabolic syndrome and erectile dysfunction was obtained in another study. Also, metabolic syndrome criteria, fasting glucose level, waist circumference and hypertension, were separately investigated and significant correlation with erectile dysfunction was obtained. The study was conducted by Bal et al. [21], including 393 urology patients.

In another study conducted by Balcı et al. [22] in Turkey, 400 patients aged over 50 with erectile dysfunction were included, and the correlation between metabolic syndrome and erectile dysfunction was examined. The study consisted of two different metabolic syndrome evaluation systems. The ratio of erectile dysfunction occurrence was concluded to be higher in metabolic syndrome patients. Among metabolic syndrome criteria, fasting glucose was remarked to be correlated with acute erectile dysfunction.

Thirty-two of 120 patients had metabolic syndrome in the present study. Erectile dysfunction was classified into three groups as non-ED-mild, moderate, and severe. A significant correlation between erectile dysfunction and metabolic syndrome was found by comparing preoperative IIEF-5 scores of metabolic syndrome patients to patients who did not have metabolic syndrome. The classified three groups were investigated separately, and no significant correlation was found in non-mild ED or moderate ED groups. However, significant correlation with metabolic syndrome was obtained in severe ED group. Post-op TURP treatment, 14 of the 15 patients with decreased IIEF-5 scores having metabolic syndrome and patients with increased IIEF-5 scores not having metabolic syndrome was significant. Therefore, the present study obtained a significant correlation between erectile dysfunction and metabolic syndrome and patients should be informed comprehensively before TURP treatment, and the probability of deteriorating erectile dysfunction complaints is considered to be higher in these patients.

Limitations

The present study is fractional, and the cause and effect correlation between metabolic syndrome and post-op TURP treatment ED is not definitive. However, some crucial data were obtained. Especially old aged patients included had trouble in understanding some of the complex questions in IIEF-5 form, and so the option that best corresponded to their response was considered the correct answer, which was a bias factor. The small number of patients in each three separated group can affect the efficiency of the statistical analysis so widespread, well-designed studies including more participants are needed.

Conclusions

In the study, pre-op and post-op erectile dysfunction and the correlation between metabolic syndrome and erectile dysfunction in patients who were administered TURP treatment for BPH was evaluated. The IIEF-5 scores suggest that erectile dysfunction in not affected after treatment. The ratio of erectile dysfunction in patients with metabolic syndrome is observed to be higher than the patients who did not have metabolic syndrome. Also, erectile dysfunction of metabolic syndrome patients is observed to be more effected than erectile dysfunction in the rest of the patients, respectively. Thus, the study suggests symptomatic patients can benefit from TURP treatment without having an effect on erectile dysfunction. It is thought that metabolic syndrome patients should be informed clearly about the higher possibility of post operational erectile dysfunction compared to normal patients. Properly designed, prospective, and randomized studies on larger cohorts of patients are required to confirm the results of the present study.

Disclosure statement

No potential conflict of interest was reported by the authors.