Relationship Between Oxidative Stress and Detrussor Overactivity: A Case Control Study Murat Keske1*, Bahri Gök2, Kemal Ener3, Muhammet Fuat Özcan4, Asım Özayar4, Emrah Okulu4, Salim Neşelioğlu5, Serdar Çakmak6, Erem Asil4, Mustafa Aldemir4, Özcan Erel7 Purpose: We analyzed the role of oxidative stress in detrusor overactivity (DO) by measuring serum total antiox- idant capacity (TAC), total oxidant status (TOS), binding capacity of exogenous cobalt to human albumin (IMA), serum advanced oxidation protein products (AOPP), paraoxonase (PON), and arylesterase. Materials and Methods: The study included 38 female patients diagnosed with DO and 29 healthy female subjects forming the control group. Serum total antioxidant capacity (TAC), total oxidant status (TOS), binding capacity of exogenous cobalt to human albumin (IMA), serum advanced oxidation protein products (AOPP), paraoxonase (PON), and arylesterase were analyzed. The results of serum TAC, TOS, IMA, AOPP, PON, and arylesterase of the subjects in both groups were compared. Results: There was no difference between the groups in terms of age. When compared to the control group, serum TAC and IMA levels were statisticaly lower (P < 0.001) and higher (P = 0.003), respectively. However, TOS, AOPP, PON, arylesterase levels were similar in both groups ( P > 0.05 ). Conclusion: There seems to be an association between DO and oxidative damage according our results, this can be measured by analyzing TAC and IMA in this patient group. Keywords: detrusor overactivity; hypoxia; ischemia; oxidative stress; total antioxidant capacity INTRODUCTION Detrusor overactivity (DO) is a common distressing condition with an unknown etiology that affects both genders.(1,2) Many pathophysiological mechanisms that could cause this condition have been investigated, including oxidative damage and free radicals originat- ing from decreased blood flow, ischemia, and hypoxia. (3–5) It has been proposed that free oxygen radicals are involved in this pathophysiological process. Oxidative stress damages the muscarinic receptor-linked signaling system and affects detrusor muscle contractions.(6,7) The resulting hypoxia and pelvic ischemia increases the fre- quency of spontaneous bladder contractions.(8,9) Since separate measurements of different antioxidant and oxidant molecules are not efficient in terms of cost and time, total antioxidant capacity and total oxidant status (TAC and TOS, respectively)(10,11) can be eval- uated in order to demonstrate the individual effects of these molecules. The binding capacity of exogenous cobalt to human albumin (IMA), serum advanced ox- idation protein products (AOPP), paraoxonase (PON), 1Kayseri City Hospital, Department of Urology, Kayseri, Turkey. 2Yildirim Beyazit University, School of Medicine, Ankara Ataturk Training and Research Hospital, Department of Urology, Ankara, Turkey. 3Umraniye Training and Research Hospital, Department of Urology, Istanbul, Turkey. 4Ankara Ataturk Training and Research Hospital, Department of Urology, Ankara, Turkey. 5Ankara Ataturk Training and Research Hospital, Department of Biochemistry, Ankara, Turkey. 6Ordu University Training and Research Hospital, Department of Urology, Ordu, Turkey. 7Yildirim Beyazit University, School of Medicine, Ankara Ataturk Training and Research Hospital, Department of Biochemistry, Ankara, Turkey. *Correspondence: Department of Urology, Kayseri City Hospital, Kayseri, 38080, Turkey. Tel: +90 5426620882, E-mail: muratkeske@yahoo.co.uk. Received February 2019 & Accepted July 2019 and arylesterase are the best known and most frequently studied antioxidant molecules.(12–18) To the best of our knowledge, there are no studies in the literature focusing on the association of these bio- markers with DO. In the current study, the levels of se- rum TAC, TOS, PON, arylesterase, AOPP, and IMA of DO patients and healthy controls were investigated and compared. Based on these results, this study presents the characteristics of a preliminary report analyzing the role of ischemia-related oxidative stress in DO. MATERIALS AND METHODS This study was approved by the institutional review board, and patients’ consent for the use of their infor- mation was taken in writing. The study group consisted of 38 female patients admitted to the Ankara Ataturk Training and Research Hospital Urology outpatient clinic between March 2017 and October 2018 and diag- nosed for the first time with DO and 29 healthy female subjects forming the control group. In the DO group, the patients had complaints regarding an increase in FEMALE UROLOGY Urology Journal/Vol 16 No. 4/ July-August 2019/ pp. 371-374. [DOI: http://dx.doi.org/10.22037/uj.v0i0.5090] daytime ( >9 times/day ) and nighttime urinary fre- quency, urgency, and urge incontinence. In order to eliminate other diseases presenting with idiopathic overactive bladder in the differential diagnosis of DO, an overall physical examination, urinalysis, routine biochemical analysis, and detailed laboratory tests, in- cluding a urine culture, were performed. Additionally, blood samples were obtained after overnight fasting in order to evaluate oxidative stress status and antioxidant parameters. Samples were drawn from the median cu- bital vein into blood tubes and immediately stored on ice at 4°C. Serum was separated from the cells by cen- trifugation at 1000 g for 10 min and then analyzed. In patients with an increase in urinary frequency, urgency, or urge incontinence, urodynamic analyses were done, and those that were diagnosed with DO were included in the study. Patients were excluded from the study if they were using alcohol, tobacco, taking any medica- tion(s), or had systemic diseases since these factors can affect oxidative status. For patients in the DO group , oral solifenacin succinate treatment was started at a dai- ly dose of 10 mg. Measurement methods of PON, arylesterase, TOS, TAC, AOPP, and IMA were performed in the same manner that was described in our previous study.(19) Statistical analysis The sample size of this study was determined using a power analysis. G-Power software was used in this analysis. The power of the study was calculated as 86% when groups 1 and 2 consisted of 38 and 29 par- ticipants, respectively. The normal distribution of the oxidative stress biomarkers was evaluated by the Kol- mogorov-Smirnov test. Mean ± standard deviations and median (25%–75% quartile) were used for descriptive statistics. Student’s t- and Mann Whitney U tests were used for statistical analyses. The data were analyzed by using SPSS for windows (version 25.00). RESULTS Table 1 summarizes the comparison of oxidative pa- rameters between patients with detrusor overactivity and healthy controls. There was no difference between the DO and control groups in terms of age. No statisti- cally significant differences were observed between the two groups in terms of the PON (P = 0.934), TOS (P = 0.109), ARES (P = 0.662), and AOPP (P = 0.641) levels. When compared to the control group, TAC was significantly lower (P < 0.001), and IMA was signifi- cantly higher (P = 0.003) in the DO group. DISCUSSION Reactive oxygen radicals are produced during the final stages of metabolic and physiological processes. During these processes, harmful oxidative reactions, which are counteracted or detoxified by enzymatic and non-en- zymatic oxidative mechanisms, can develop. When an increase in oxidant agents and decrease in antioxidants cannot be prevented, an imbalance occurs between the oxidants and antioxidants, resulting in oxidative stress, which has been shown to be responsible for more than a hundred of diseases.(19) Current evidence suggests that oxidative stress plays an important role in the pathogen- esis of urinary dysfunction.(20) The prevalence of lower urinary tract symptoms (LUTS) in both genders increases with age. It has been suggested that the arterial occlusive disease, which can lead to chronic bladder ischemia and oxidative dam- age, has a role in the pathogenesis of lower urinary tract dysfunction, including DO.(21,22) Using a rabbit model, Azadzoi et al. investigated the association be- tween LUTS and atherosclerotic vascular risk factors and showed that pelvic ischemia caused smooth muscle alterations and denervation in the prostate, penis, and urinary bladder.(23) These smooth muscle alterations and denervation induces the frequency of spontaneous blad- der contractions and results in DO. Similarly, Nomiya et al.(22) investigated the effects of chronic bladder is- chemia on voiding behavior and bladder function in rats and reported a significant increase in the rats’ urination frequency via cystometric evaluations. The authors concluded that atherosclerosis-induced chronic bladder ischemia could facilitate the voiding reflex, which is defined as DO. In our study, we tried to find an asso- ciation between DO and oxidative stress by analyzing biomarkers rather than doing histological evaluations. Malona et al.(3) reported that oxidative stress was high- Table 1. The comparison of oxidative parameters between patients with detrusor overactivity and healthy controls. Group N Mean ± S.D P-value ( Student T test) Age C 29 42.7 ± 10.6 0.531 DO 38 44.6 ± 14.8 TAC C 29 2.1 ± 0.216 < 0.001 DO 38 1.8 ± 0.199 TOS C 29 4.1 ± 1.46 0.109 DO 38 4.7 ± 1.77 ARES C 29 189.7 ± 55.7 0.662 DO 38 184.6 ± 39.2 AOPP C 29 138.9 ± 46.0 0.641 DO 38 134.4 ± 32.6 IMA C 29 0.530 ± 0.117 0.003 DO 38 0.614 ± 0.106 Median(25%-75% Quartel) P values ( Mann Whitney U Test) PON C 29 158.6(91.1-280.8) 0.934 DO 38 144.1(91.6-249.5) Abbreviations: C, Control group; DO, Detrusor Overactivity group; TAC, Total Antioxidant capacity; TOS, Total Oxidant Status; ARES, Arylesterase; AOPP, Serum advanced oxidation protein products; IMA, Binding capacity of exogenous cobalt to human albumin; PON, Paraoxonase; Oxidative stress and detrussor overactivity-Keske et al. Vol 16 No 04 July-August 2019 372 er in the bladder strips of the rats in which in vitro ischemia/reperfusion had been applied and that blad- der dysfunction occurred due to oxidative damage. In another study, serum IMA levels were found to have increased in ischemia-induced oxidative stress. The au- thors also suggested that the IMA levels increase as a result of endothelial and extracellular hypoxia, acido- sis, free radical damage, and free iron and copper ions. (17) Therefore, IMA was proposed as a marker indicat- ing ischemia.(17) Similarly, in the current study, serum IMA levels were found to be higher in the DO group compared to healthy subjects, which support the con- clusions of previous studies in which serum IMA levels were used as a marker of ischemia. These studies also support the hypothesis that ischemia is an important factor in the etiology of DO. To date, there are no studies attempting to find an an- swer to the association between DO and oxidative stress in humans. The studies were performed in animal models, including rabbits and rats. In 2011, Lin et. al. reported that there was a significant decrease in plas- ma TAC levels in rabbits having partial bladder outlet obstruction. However, our study included patients with DO, such as the aforementioned group, and we found that TAC levels were statistically lower in patients hav- ing DO when compared to healthy subjects.(24) The concentrations of many antioxidants can be meas- ured separately using complicated laboratory tech- niques, which are time-consuming, labor-intensive, and not cost-effective. Since this is not practical in routine practice, and the antioxidant effects of these molecules are additive, a commonly used alternative is the TAC measurement. Using a serum TAC analysis, the im- balance between oxidants and antioxidants in diseases and the overall oxidative status of the subjects can be clearly demonstrated. In the current study, TAC levels were found to be reduced in the DO group compared to the healthy subject group. This supports the association between oxidative stress and DO. Despite the considerable amount of research in this area, the etiology of DO has not yet been clearly identi- fied. However, in this study, the mechanism of hypox- ia-induced oxidative damage seems to be prominent. Currently, the most effective therapy for DO consists of anticholinergic drugs.(25) Identifying the role of is- chemia-induced oxidative stress in the etiopathogene- sis of DO can contribute to development of alternative treatment options for the disease, such as eliminating the need for lifetime use of medication. There are several limitations to this study. First of all, our study was a case control study and based on a small sample size. We think that the level of evidence in the study increased since it was designed in a randomized prospective manner, and the finding of oxidative stress was supported by histopathological evaluation. 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