The Clinical Study On Blood Lipid Parameters And Vascular Erectile Dysfunction

Erectile dysfunction(ED)is defined as the recurrent or persistent inability to attain and/or maintain a penile erection sufficient for satisfactory sexual performance.It was reported that 150 million were affected by some degree of ED in 1995 and the prevalence of ED will be increased to 322 million cases by end of 2025.The etiology of ED was complex involving of vascular,neurogenic,hormonal,psychogenic,iatrogenic,and anatomic causes.ED can be divided into three categories according to etiology:psychological,organic,and mixed.Organic ED accounts for more than half of all cases of ED.Vascular factors make more important impacts on organic ED because the penis has a particular vascular network.Found on vascular involvement,it was divided into three types including arteriogenic ED,venous leakage,and mixed ED.Among them,arteriogenic ED is the most common and most important.vascular endothelial dysfunction that occurs in atherosclerosis plays a pivotal role in arterial erectile dysfunction.Lipids,which include total cholesterol(TC),triglycerides(TG),low-density lipoprotein cholesterol(LDL-C)and high-density lipoprotein cholesterol(HDL-C),have received more attention in cardiovascular diseases(CVD),especially in atherosclerosis and endothelial dysfunction.LDL-C was regarded as one of the strongest predictors of atherosclerosis and endothelial dysfunction and decreasing LDL-C is essential to prevent and treat atherosclerosis.However,cardiovascular risk assessment and lipid management based on LDL-C has not fully considered the role of other lipids.Numerous studies have shown that other lipids,for instance HDL-C,are independently associated with CVD,through endothelial dysfunction and atherosclerosis.Recently the combination of lipid ratios,such as TC/HDL,TG/HDL,LDL/HDL,Non-HDL-C calculated as TC-(HDL-C),have been evaluated to improve risk assessment and prediction of cardiovascular events.Given that arteriogenic ED has the same pathogenesis as cardiovascular disease,we predicted that these lipids parameters might also be associated with arteriogenic ED.most previous studies were limited to the changes of blood lipids in ED patients when they already had clinically cardiovascular diseases.Recently,Yao et al performed a study comparing young men with ED with young men without ED and they found men with ED have increased systolic blood pressure,total cholesterol and triglyceride levels,although all these values were within normal ranges.This study suggests that many young men with ED might not have overt clinical CV disease but still have subclinical CV factors that predispose them to ED.Meanwhile,the notion of vascular ED and its potential relationships with other vascular system disorders make us speculate it might be linked to various lipids as a chronic vascular risk indicator.Therefore,the aim of the present study was to investigate the ability of the blood lipids parameters to predict the discrimination of arteriogenic erectile dysfunction in relative young men.ObjectiveThe aim of the study was to investigate the ability of the blood lipid parameters to predict the discrimination of arteriogenic erectile dysfunction(ED).Materials and methods1.Study subjects and inclusive and exclusive criteriawe prospectively examined the patients who attended in the Urology Department of the Second Hospital of Shandong University(Jinan,China)for erectile dysfunction between the period of March 2016 and March 2019.Each participant was required to finish the International Index of Erectile Function-5(IIEF-5)questionnaire19 and 260 people with an IIEF-5?21 were regarded as erectile dysfunction.Sixty healthy male volunteers which were sexually active,married,and age matched men with a score more than or equal to 26,from the Center of Health Management,were recruited in the same time.Only people between the ages of 20 to 50 years old were recruited,for limiting the influence of sub-clinical cardiovascular disease(CVD)on lipoproteins.Exclusion criteria:patients with diabetes or impairment of glucose,metabolic syndrome,malignant tumor,alcoholism,inflammatory conditions,pelvicsurgery or trauma,spinal cord injury,cardiovascular and/or hematologic diseases,psychogenic disorders,hormonal disorders(hyperprolactinemia,hypogonadism),cerebrovascular events,neurological disorders(multiple sclerosis and seizure),liver dysfunction,and the use of drugs known to influence the blood lipids.The study was approved by the Institutional Ethics Committee of the Second Hospital of Shandong University,and each participant signed informal consent before they participated in the study.2.study design260 patients and 60 healthy controls underwent a detailed clinical investigation including medical history and andrology physical examination,laboratory investigation,the ED patients was recorded NPT data,the patients with abnormal NPT results(n=216)were included and then they were examined by neurophysiological test.The neurophysiological test results were all normal.so the 216 patients were further tested by penile artery doppler ultrasound(pDUS).Data included intial blood flow,5-Min PSV,5-Min EDV,10-Min PSV and 10-Min EDV.The ED patients were divided into arteriogenic ED(n=87),venous ED(n=45)and non-vascular ED(n=84)3.Data collectionThe General information of the subjects,including age,International Index of Erectile Function([IIEF]5),nocturnal penile tumescence(NPT),penile color Doppler ultrasonography(pDUS)were recorded.Venous blood was collected and common clinical laboratory indicators,including FBG,TG,TC,LDL-C,HDL-C,estradiol,FSH,LH,PRL,progesterone,testosterone were measured and recorded.4.Statistical analysisStatistical analysis was performed with SPSS for Windows version 23(SPSS Inc.,Chicago,IL,USA).The Kolmogorov-Smirnov test was conducted to test whether the variables were normally distributed.All continuous sample data are expressed as the mean±standard deviation(SD),and categorical data are expressed as proportions.Differences between 3 groups were performed by one-way analysis of variance(ANOVA)if the variables were in accordance with ecological distribution and homogeneity;or the Kruskal-Wallis H test was performed.The Spearman correlation was conducted to analyse the relationship between lipids parameters and PSV or EDV.Receiver operating characteristic(ROC)analysis was applied to evaluate the diagnostic value of lipids parameters for arteriogenic ED patients.The relationship between 10-min PSV and lipids was analyzed by multivariate linear stepwise regression analysis in arteriogenic ED.All P values were two-tailed,and P values<0.05 were considered as statistically significant.Result1.Population Characteristics and Sex Hormone Comparison of Three GroupsWe evaluated a total number of 260 individuals with consecutive ED patients and 60 healthy volunteers(control group)were enrolled in this study.In the ED patients,44 patients who were normal in the NPT examination and 84 with pDUS results that demonstrated vascular which had no obvious abnormality or mixed vascular abnormalities were excluded.87 patients were identified as arteriogenic ED and 45 patients had venous leakage.The demographic and clinical characteristics of these three groups are presented in Table 1.There were no significant differences among these three groups in all parameters except for follicle-stimulating hormone(FSH).The mean FSH was 6.16±1.45mlU ml-1,6.15±1.42mlU ml-1,and 4.25±1.62mlU ml-1 for arteriogenic ED group,venous leakage group,and control groups,respectively(P<0.05).2.Comparison of lipid parameters in different groupsThere was a statistically significant difference in TC/HDL,LDL/HDL,HDL-C and LDL-C among these three groups(Table 2)(P=0.00,P=0.00,P=0.00,P=0.00,respectively).The Scheffe post hoc multiple comparison test demonstrated that LDL-C in the arteriogenic ED group was significantly higherthan in the venous leakage groups,and control groups,but there was no significant difference in the LDL-C between the venous leakage and control group.Multiple comparison of TC/HDL,LDL/HDL and HDL-C was performed using the Games-Howell test,TC/HDL,LDL/HDL was significantly higher in the arteriogenic ED group when compared with the venous leakage and control groups and HDL-C was significantly lower in the arteriogenic ED group when compared with the venous leakage and control,No statistically significant difference was observed between the venous leakage and control groups.There was no significant difference in TG,TC,TG/HDL and Non-HDL between the arteriogenic and venous ED group and control group.3.Correlation between lipids and vascular parameters in arteriogenic ED group and venous leakage group.Spearman correlation analyses were conducted to test correlation between penile vascular velocity and lipids parameters in the arteriogenic ED groups.TC/HDL,LDL/HDL,LDL-C had a negative effect on 10-min PSV(r=-0.347,P<0.01 VS r=-0.487,P<0.01 VS r=-0.330,P<0.01).HDL-C had a positive effect on 10-min PSV(r=0.471,P<0.01),but lipids parameters have no significant correlation with 5-min PSV,5-min EDV,or 10-min EDV(all P>0.05)and none of lipids significantly correlated 5-min PSV,10-min PSV,5-min EDV,or 10-min EDV in Venous leakage group(all P>0.05).4.Predictive effect of lipid parameters on arteriogenic EDROC regression analysis identified the following variables as predictive for arteriogenic ED;TC/HDL?3.73,as a cut off value(area under the curve[AUC]:0.720,95%CI:0.639-0.801)with a sensitivity of 56.3%and a specificity of 83.3%,LDL/HDL?2.01,as a cut off(AUC:0.737,95%CI:0.657-0.816)with a sensitivity:of 55.2%and specificity of 91.7%.7,HDL-C?1.25mmol/L,as a cut off value(AUC:0.791,95%Cl:0.719-0.863)with a sensitivity of 69%and specificity of 81.7%,LDL-C?2.41mmol/L as a cut off value(area under the curve[AUC]:0.641,95%Cl:0.552-0.730)with a sensitivity of 55.2%and a specificity of 76.7%.4.Linear regression analyses of lipid parameters and arteriogenic EDMultivariate linear stepwise regression analysis was performed to test the association between lipid parameters and 10-min PSV.Potential confounding variables including age,smoking,alcohol consumption,BMI,fasting blood glucose,systolic blood pressure and sex hormones were applied to models.After adjustment,LDL/HDL and HDL-C were the only variables to independently predict(P<0.01)10-min PSV.ConclusionsThese findings suggest that LDL/HDL and HDL-C might be powerful indicatorsto predict and diagnose arteriogenic ED.Lipid-lowing therapy should be considered for arteriogenic ED patients.