¹Department of Urology, Kyoto Prefectural University of Medicine, Kyoto, Japan

²Department of Urology, Toujinkai Hospital, Kyoto, Japan

³Department of Urology, Kyoto First Red-Cross Hospital, Kyoto, Japan

⁴Department of Urology, Nishijin Hospital, Kyoto, Japan

⁵Department of Urology, Keio University, School of Medicine, Tokyo, Japan

Correspondence to: Y Mizutani, Department of Urology, Kyoto Prefectural University of Medicine, Kawaramachi-Hirokoji, Kyoto, 602-8566, Japan. E-mail: ymizutan@koto.kpu-m.ac.jp

In order to evaluate the erectile function in male renal failure patients treated with hemodialysis (HD), we investigated the International Index of Erectile Function (IIEF) in patients and healthy controls. The subjects were 174 male patients treated with HD, of whom 43 had diabetes mellitus (DM) and the remaining 131 patients did not have DM. The controls were 1133 healthy males. We evaluated the prevalence of erectile dysfunction (ED) using the erectile function (EF) score, which is one of the five domains of the IIEF, in each age group (upto 39 y old, 40-49 y old, 50-59 y old, 60-69 y old). The severity of ED was classified into five categories using EF in each age group. The univariate logistic regression analysis and multiple variate analysis of IIEF in HD patients were performed. The prevalence of ED in HD patients was significantly higher than that in the controls in each age group. The severity of ED in HD patients was also significantly higher than that in the controls in each age group. In the logistic regression analysis and multiple variate analysis of IIEF in HD patients, DM and age were significant risk factors on sexual dysfunction. ED was more prevalent in male renal failure patients treated with HD than in the controls. In the patient group, ED was more prevalent in older DM patients.

International Journal of Impotence Research (2002) 14, 172-177. doi:10.1038/sj.ijir.3900854

erectile dysfunction; chronic renal failure; hemodialysis; IIEF

Introduction

Erectile dysfunction (ED) is a common complication of chronic renal failure.¹ In a study of dialysis patients, 79% and 61% of males complained of sexual dysfunction and erectile dysfunction, respectively, following uremia and the onset of regular dialysis therapy.² In another study, in 53 males with chronic renal failure, erectile disorders occurred in 41.5% and 64.2% before and after hemodialysis (HD),³ respectively. Abram et al reported that 20% of 32 married, male dialysis patients had no decrease in sexual functioning after the onset of kidney disease or the instigation of dialysis, 45% had reduced sexual potency after the onset of kidney disease, and the other 35% after beginning dialysis.⁴ In these reports, the different methods were used for the evaluation of ED. Recently, Rosen et al reported the International Index of Erectile Dysfunction (IIEF).⁵ The IIEF has been shown to be a cross-culturally and psychometrically valid measure of male ED. The IIEF is a brief, reliable, and valid self-administered questionnaire of 15 items. The IIEF has high sensitivity and specificity for evaluating the effects of treatment in patients with ED of broadspectrum etiology. In order to evaluate the erectile function in male renal failure patients treated with HD, we examined the difference of IIEF questionnaire between the patients and healthy controls.

Patients and methods

Patients

The subjects were 174 male patients treated with HD, of whom 43 had diabetes mellitus (DM) and the remaining 131 patients did not. The age ranged from 22 to 69-y-old (mean 56.1±9.6). The controls were 1133 healthy males, aged from 23 to 69-y-old (mean 45.3±12.6). They consisted of employees of 10 pharmaceutical companies and their fathers, who responded to the IIEF questionnaire.⁶

Questionnaire

We used the Japanese version of the IIEF.⁷ The IIEF questionnaire was self-administered in their homes. One hundred and seventy-four out of the 242 male dialysis patients whom were given the IIEF questionnaire responded (response rate; 71.9%). The IIEF questionnaire includes 15 items related to male sexual activity organized into five domains (EF, erectile function; OF, orgasmic function; SD, sexual desire; IS, intercourse satisfaction; OS, overall satisfaction).⁵

In this study, ED was diagnosed when EF was less than 26.⁸ We evaluated the prevalence of ED by the score of EF in each age group (up to 39-y-old: 11 HD patients and 452 controls; 40-49-y-old; 29 HD patients and 262 controls; 50-59-y-old; 62 HD patients and 192 controls; 60-69-y-old; 72 HD patients and 227 controls). The severity of ED was classified into five categories in each age group:⁸ no ED (EF score: 26-30), mild (EF score: 22-25), mild to moderate (EF score: 17-21), moderate (EF score: 11-16), and severe (EF score: 6-10).

Statistical analysis

The comparison of the prevalence and the severity between the HD patients and controls was performed using the chi-square test. In controls and HD patients, the relationship between the score of each domain and age was analyzed by simple regression analysis. The comparison of the five separate domains between the HD patients and controls was performed using the Mann-Whitney U-test for each age.

In the HD patients, the univariate logistic regression analysis was performed on the five domains of IIEF versus age, smoking, alcohol consumption, blood pressure, ischemic heart disease, DM, anemia and the overall times of HD. Age group was divided by median (58-y-old). When the level of hemoglobin (Hb) was less than 10 mg/dl, the patient had an anemia. The overall times of HD was divided by median (630 times). The multiple variate analysis was performed on the five domains of IIEF versus age, smoking, alcohol consumption, blood pressure, ischemic heart disease, DM, the level of hemoglobin and the overall times of HD.

Statistical significance was set at P<0.05 in all analyses.

Results

Prevalence and severity of ED

The prevalence of ED in HD patients at the age of less than 40-y-old, 40-49-y-old, 50-59-y-old and 60-69-y-old was 36.4%, 82.8%, 88.7% and 93.1%, respectively. The prevalence of ED in controls for the same age groups was 30.1%, 29.4%, 44.8% and 70.0%, respectively. The prevalence of ED in HD patients was significantly higher than that in controls at each age group (Table 1).

The severity of ED in HD patients and controls is shown in Table 2. In the severity of ED in HD patients at the age of 40-49-y-old, the prevalence of severe, moderate and mild to moderate were significantly higher than those in controls. At the age of over 50-y-old and less than 40-y-old, the prevalence of severe in HD patients was significantly higher than that in controls. Altogether, the percentage of severe ED in HD patients was higher than in the controls at each age group (P<0.05).

The relationship between IIEF and age

The score of each domain of IIEF inversely correlated with age in HD patients, but modestly (Figure 1A-E). The average score of all domains in HD patients was significantly lower than that in controls over the age of 40 y (Table 3).

The relationship between five domains of IIEF and various lifestyle factors

The univariate logistic regression analysis was performed on the five domains of IIEF versus aging, smoking, alcohol consumption, blood pressure, ischemic heart disease, DM, Hb and the overall times of HD (Table 4). Aging and DM were risk factors for all five domains. EF in the patients with alcohol consumption was relatively higher than for those without alcohol consumption (P=0.053). SD in the patients with alcohol consumption was significantly higher than for those without alcohol consumption. Smoking, high blood pressure, ischemic heart disease, Hb and the overall times of HD were not risk factors in HD patients.

The multiple variate analysis was also performed on the five domains of IIEF versus age, smoking, alcohol consumption, blood pressure, ischemic heart disease, DM, anemia and the overall times of HD. In the four domains (EF, OF, SD and IS), aging was an independent risk factor (Table 5). In EF, OF and OS, DM was an independent risk factor. Interestingly, alcohol consumption enhanced SD.

Discussion

ED is a common complication of chronic renal failure. In three previous studies of dialysis patients, 45-64.2% of men had ED.^2,3,4 Although Rodger et al described that the incidence of ED in patients with renal failure increased with age, they did not show the data.² Other papers did not comment on the relationships between age and ED in male renal failure patients. In this study, the prevalence of ED in HD patients was evaluated in four groups divided according to age. The prevalence of ED in HD patients was extremely higher than that in controls in each age group. In the Massachusetts Male Aging Study (MMAS), the prevalence of ED was strongly associated with age.⁹ These findings demonstrated that the prevalence of ED in HD patients was also associated with age.

The severity of ED in HD male patients has not been previously reported. In this study, the degree of ED in HD patients was significantly more severe than that in controls in each age group.

Age is thought to be the most important causative factor for ED. In EF, the average scores of HD patients were significantly lower than that of controls over 40-y-old. The score of EF was decreased with age in HD patients as well as controls. In the remaining four domains, the average scores of HD patients were also significantly lower than that of controls over 40-y-old.

The role of lifestyle factors such as smoking or alcohol consumption in sexual dysfunction was also reported.^9,10,11 In our results, smoking was not a risk factor in sexual dysfunction with hemodialysis condition. In the male hemodialysis patients with alcohol consumption, the average score of SD was higher than that without alcohol consumption. Since alcohol disinhibits psychological sexual arousal and suppresses physiological responding,¹² alcohol consumption may increase SD in male HD patients.

In MMAS, the risk of ED was increased with heart disease and hypertension.⁹ In the Japanese population, Marumo et al reported that hypertension and heart disease were putative risk factors for ED.⁶ Because most of the dialysis patients had hypertension and heart disease, hypertension and heart disease were not independent risk factors in dialysis patients in this study.

DM is the most common causative disease of chronic renal insufficiency. Jungers et al reported that the patients with vascular renal disease and diabetic nephropathy were 22.5% and 20.6%, respectively, in the 1155 patients accepted on maintenance dialysis in 1998.¹³ In MMAS, the risk of ED was increased with DM.⁹ In a Japanese study, Marumo et al reported that DM was a risk factor for ED.⁶ In this study, DM is an independent risk factor of ED in male HD patients. DM is thought to be a risk factor of ED, not only in the general population but also in dialysis patients.

Renal anemia may partially participate in the pathogenesis of sexual dysfunction.¹⁴ In our present study, renal anemia was not an independent risk factor of sexual dysfunction in the male HD patients. Erythropoietin therapy has been shown to improve sexual function in the male dialysis patients, with a direct effect upon endocrine function, as well as anemia.¹⁴ Erythropoietin therapy was performed on 81% of HD patients in this study.

Overall times of dialysis was not also a risk factor in this study. Rodger et al also reported that the incidence of ED was not related to the duration of dialysis.²

The present study demonstrated that ED was more prevalent in patients treated with HD than in the controls. In addition, aging and DM have been considered to be putative risk factors for ED in HD patients. These findings suggest that the IIEF may be suitable for assessing epidemiology of ED.

Acknowledgements

We gratefully acknowledge to Dr M Maegawa and Dr M Kondo for assistance to cooperation of IIEF questionnaire of male dialysis patients.

Some of the results in this paper were presented at the third Asian and Oceanic Congress of Andrology held in Tokyo, Japan in May 2000.

1 Marumo K, Murai M. Epidemiology of erectile dysfunction. In: Kim YC, Tan HM (ed). ASPIR Book on Erectile Dysfunction The Asia-Pacific Society for Impotence Research (ASPIR). 1999; pp. 15-26.

2 Rodger RS et al. Prevalence and pathogenesis of impotence in one hundred uremic men. Uremia Invest 1984; 8: 89-96. MEDLINE

3 Breza J, Reznicek J, Pribylincova V, Zvara P. Erectile dysfunctions in patients treated with hemodialysis and kidney transplantation. Bratisl Lek Listy 1993; 94: 489-493. MEDLINE

4 Abram HS, Hester LR, Sheridan WF, Epstein GM. Sexual functioning in patients with chronic renal failure. J Nerv Ment Dis 1975; 160: 220-226. MEDLINE

5 Rosen RC et al. The international index of erectile function (IIEF): a multidimensional scale for assessment of erectile dysfunction. Urology 1997; 49: 822-830. Article MEDLINE

6 Marumo K, Nagatsuma K, Murai M. Effect of aging and diseases on male sexual function associated by the international index of erectile function. Jpn J Urol 1999; 90: 911-919.

7 Shirai M et al. Japanese validation of the international index of erectile function (IIEF). Impotence 1999; 14: 1-28.

8 Cappelleri JC et al. Diagnostic evaluation of the erectile function domain of the international index of erectile function. Urology 1999; 54: 346-351. Article MEDLINE

9 Feldman HA et al. Construction of surrigate variable for impotence in the Massachusetts Male Aging Study. J Clin Epidemiol 1994; 47: 457-467. MEDLINE

10 Mannino DM, Klevence RM, Flanders WD. Cigarette smoking: an independent risk factor for impotence? Am J Epidemiol 1994; 140: 1003-1008. MEDLINE

11 Whalley LJ. Sexual adjusment of male alcoholics. Acta Phychiatr Scand 1978; 58: 281-298.

12 Crowe LC, George WH. Alcohol and human sexuality: review and integration. Psychol Bull 1989; 105: 374-386. MEDLINE

13 Jungers P et al. Incidence of end-stage renal disease in Ile de France: a prospective epidemiological survey. Presse Med 2000; 29: 589-592. MEDLINE

14 Lawrence IG et al. Erythropoietin and sexual dysfunction. Nephrol Dial Transplant 1997; 12: 741-747. MEDLINE

Figure 1 Figures show the relationship between age and five domains of IIEF in HD patients. Each domain, erectile function (EF), orgasmic function (OF), sexual desire (SD), intercourse satisfaction (IS) and overall satisfaction (OS) was decreased with aging. (A) EF, (B) OF, (C) SD, (D) IS, (E) OS.

Table 1 The prevalence of ED in controls and HD patients

Table 2 The severity of ED in controls and HD patients

Table 3 The average score of five domains of IIEF

Table 4 Univariate logistic regression analyses in the HD patients

Table 5 Multiple variate analyses in the HD patients