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Prevalence of sleep apnea in men with erectile dysfunction
PREVALENCE OF SLEEP APNEA IN MEN
W I T H E R E C T I L E DYSFUNCTION* GUVEN ACIK, B.A. ERDEM M. NARTER, M.D. ROBERT L. WILLIAMS, M.D.
MAX HIRSHKOWITZ, PH.D. ISMET KARACAN, M.D., D.Sc. MURAT O. ARCASOY, M.D.
From the Sleep Disorders and Research Center, Department of Psychiatry, Baylor College of Medieine, and Sleep Researeh Laboratory, Research Service, Veterans Affairs Medical Center, Houston, Texas
ABSTRACT--Sleep studies were performed on 1,025 patients complaining of erectile dysfunction. In addition to standard measures of sleep stage and nocturnal penile tumescence, respiratory activity was evaluated. The number of episodes of sleep apnea per hour (Apnea Index--AI) was calcu,:: lated for each patient. The overall prevalence of sleep apnea activity in this sample was: 43.8 percent with AI> 5; 27.9 percent with AI>_ 10; and 19.6 percent with AI> 15. These results confirm that sleep apnea activity is common in men with erectile dysfunction. This high prevalence also indicates that further study is needed to elucidate pathophysiology of erectile failure in men with sleep apnea.
Sleep apnea is the cessation of breathing for ten or more seconds during sleep.1 Clinieally significant sleep apnea is found in approximately 43 pereent of patients with hypersomnia and 6 pereent of patients with insomnia, z Guilleminault, van den Hoed, and Mitler a have reported that 48 pereent of men with sleep apnea have erectile dysfunction, ejaeulatory problems, and/or diminished libido. In a study of 15 men with erectile problems, Sehmidt and Wise4 were the first to note that men with erectile dysfunction have a high prevalenee of sleep apnea. Pressman et al. 5 eonfirmed this association and found sleep apnea in 9 of the 31 (29 % ) impotent men they studied in the sleep laboratory. At our laboratory we routinely perform noeturnal penile tumeseence (NPT) sleep studies on men with complaints of erectile dysfunction for *Supported in part by funds from the Veterans Affairs Medical Center and Baylor College of Medicine, Houston, Texas.
232
the purpose of making a differential diagnosis of impotence. Prior to 1983 we often recorded respiration and found it clinically useful for the interpretation of NPT tracings. The respiratory i; activity, however, was not systematically ana~ lyzed. In 1983 we began routine quantification of sleep apnea in every patient we evaluated for erectile dysfunction. In this report we attemp! to estimate the prevalence of sleep apnea among men with ereetile dysfunetion in a large population of patients. Material and Methods Between January 1983 and June 1987, multi: night polysomnography was performed on :~: 1,025 men with erectile complaints These slee~ )i studies included strain gauge recordings 0!i penile circumference change; thermistor re~i! ~ordings of nasal-oral airflow; eleetroencepha; ~; og aphie, eleetro-oeulographie, eleetroeardid'i graphic, and eleetromyographie aetivity; and~!i
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VOLUME XXXVI, NUMI3
in many eases, tracings of thoracic or abdominal movement. Penile buckling pressure (rigidity) was also measured for each patient during one or more of that patient's typical sleep-related erections. Patients ranged in age from twenty to eightytwo years (mean age, 54) and included both men with organic and non-organic erectile dysfunction. Of the total sample, 57 percent had organic erectile dysfunction with maximum penile rigidity below 550 g. The mean height was 70 in (SD = 3.5) and the mean weight was 187 pounds (SD = 31.4). In addition to erectile dysfunction, patients had an assortment of other medical, psychiatric, and psychologic conditions. Results The number of episodes of apnea per hour of Sleep (apnea index) was calculated for each patient. The overall mean apnea index was 9.56 (SD = 16.18) with the longest sleep apnea epiSode averaging 30.86 seconds (SD = 25.62). ;Table I shows the percentage of men within different age groups and the total for all patients i n each of four cumulative apnea index categories. The total number of patients in each age .group is also shown. In the majority of cases i~(58% ), significant sleep apnea (AI > 5) was not ';}:accompanied by complaints of difficulty initiat?!hg sleep, difficulty maintaining sleep, or pe!;,i'iods of excessive daytime sleepiness. Addi;~tionally, the mean apnea index for the organic i r o u p was 10.5 while the non-organic group ad an average of 8.3 apnea episodes per hour f sleep. This slightly higher index for men with hrganic erectile dysfunction is statistically significant (P = 0.02),
~
; , ~; ! i ¸
~i;i~;! ~!i~
TABLEI.
Apnea index distribution for impotent men* -Apnea Index N 0 >0 >5 >10
>15
42
33.3
66.7
23.8
14.3
7.1
i023~9 106 i0~49 165 ~0~59 349 i0.69 285 69 78 TOTALS 1,025
37.7 34.5 22.6 19.6 23.1 25.8
62.3 65.5 77.4 80.4 76.9 74.2
21.7 35.2 49.6 49.8 55.1 43.8
12.3 18.8 31.5 32.3 43.6 27.9
8.5 13.3 21.5 23.5 32.1 19.6
Percent within each age group and for total of impotent paents without apnea and in each of four cumulative apnea index ategories.
: ~OLOGY
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Comment The results of the present study confirm the previously reported findings of a high prevalence of sleep apnea among men with erectile dysfunction. 4,5 The data presented here are derived from a sample of more than 1,000 impotent men and indicate that erectile problems and sleep apnea are associated in all age groups. Moreover, the prevalence of sleep apnea increases dramatically with advancing age. The percentage of patients with ten or more apnea episodes per hour increases from 14.3 for men thirty years or younger to 43.6 for men seventy years or older. Pressman et al.5 demonstrated that the sleep disruption produced by sleep apnea can cause problems in the interpretation of NPT recordings. Therefore, polysomnographie information about sleep stages and respiratory activity should be recorded in conjunction with NPT when sleep studies are conducted on men with erectile complaints. This additional information will help avoid misinterpretations and thereby reduce misdiagnosis. We generally expect excessive sleepiness, sleep initiation, and/or sleep maintenance problems to accompany sleep apnea. This expectation is largely due to the fact that sleep apnea is most often found during diagnostic evaluations of patients with sleep problems or hypersomnia. It is noteworthy that in this population, mild to moderate sleep apnea occurs more often than not without a sleep/wake complaint. Consequently, clinicians cannot rely on symptoms to alert them to the presence of sleep-related respiratory dysfunction in patients with erectile dysfunction. Apnea-related erectile dysfunction is typically ascribed to the sleepiness and/or depression that may accompany sleep apnea. 6 While this is undoubtedly the ease in some patients, our findings do not support this explanation as a general rule. Less than half of the patients in whom we found sleep apnea had sleep/wake complaints. Additionally, the fact that more than half of the sample had organic erectile dysfunction makes it unlikely that impotence among men with sleep apnea principally derives from diminished libido induced by sleepiness or depression. Obesity is a known associate of sleep apneaJ Actuarial tables 8 of weights indicate that the average 70-in tall, fifty-four-year-old man weighs 175 lb. Therefore, in this sample, our patients are, on average, 12 lb overweight. In
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future analyses we will assess the interactions between sexual status, obesity, and sleep apnea. Finally, the pathophysiology of erection in patients with sleep apnea is currently unknown. Further study of the interrelationship between erectile failure and sleep apnea is needed. VAMC-Research Service 151 2002 Holcombe Boulevard Houston, Texas 77030 (DR. HIRSHKOWITZ) References 1. Guilleminault C, van den Hoed J, and Mitler MM: Clinical overview of the sleep apnea syndromes, in Guilleminault C and Dement WC: Sleep Apnea Syndromes, New York, 1978, Alan R. Liss, p 1.
234
2. Coleman RM, et ah Sleep-wake disorders based on a polysomnographic diagnosis. A national cooperative study, lAMA 247:997 (1982). 3. Guilleminault C, et ah Sleep apnea syndrome due to upper airway obstruction: a review of 25 cases, Arch Intern Med 137: 296 (1977). 4. Sehmidt HS, and Wise HA: Significance of impaired penile tumeseenee and associated polysomnographic abnormalities in the impotent patient, J Urol 126:348 (1981). 5. Pressman MR, et ah Problems in the interpretation of nocturnal penile tumescence studies: disruption of sleep by occult sleep disorders, J Urol 136:595 (1986). 6. Hudgel DW: Clinical manifestations of the sleep apnea syndrome, in Fletcher EC: Abnormalities of Respiration During Sleep, Orlando, 1986, Grune and Stratton, p 21. 7. Harman E, Wynne JW, Block AJ, and Molloy-Fisher L: Sleep-disordered breathing and oxygen desaturation in obese patients, Chest 79:256 (1981). 8. New weight standards for men and women, Star Bull 40:1 (1959).
UROLOGY
/
SEPTEMBER 1990 /
VOLU
E XKXVI,
W I T H E R E C T I L E DYSFUNCTION* GUVEN ACIK, B.A. ERDEM M. NARTER, M.D. ROBERT L. WILLIAMS, M.D.
MAX HIRSHKOWITZ, PH.D. ISMET KARACAN, M.D., D.Sc. MURAT O. ARCASOY, M.D.
From the Sleep Disorders and Research Center, Department of Psychiatry, Baylor College of Medieine, and Sleep Researeh Laboratory, Research Service, Veterans Affairs Medical Center, Houston, Texas
ABSTRACT--Sleep studies were performed on 1,025 patients complaining of erectile dysfunction. In addition to standard measures of sleep stage and nocturnal penile tumescence, respiratory activity was evaluated. The number of episodes of sleep apnea per hour (Apnea Index--AI) was calcu,:: lated for each patient. The overall prevalence of sleep apnea activity in this sample was: 43.8 percent with AI> 5; 27.9 percent with AI>_ 10; and 19.6 percent with AI> 15. These results confirm that sleep apnea activity is common in men with erectile dysfunction. This high prevalence also indicates that further study is needed to elucidate pathophysiology of erectile failure in men with sleep apnea.
Sleep apnea is the cessation of breathing for ten or more seconds during sleep.1 Clinieally significant sleep apnea is found in approximately 43 pereent of patients with hypersomnia and 6 pereent of patients with insomnia, z Guilleminault, van den Hoed, and Mitler a have reported that 48 pereent of men with sleep apnea have erectile dysfunction, ejaeulatory problems, and/or diminished libido. In a study of 15 men with erectile problems, Sehmidt and Wise4 were the first to note that men with erectile dysfunction have a high prevalenee of sleep apnea. Pressman et al. 5 eonfirmed this association and found sleep apnea in 9 of the 31 (29 % ) impotent men they studied in the sleep laboratory. At our laboratory we routinely perform noeturnal penile tumeseence (NPT) sleep studies on men with complaints of erectile dysfunction for *Supported in part by funds from the Veterans Affairs Medical Center and Baylor College of Medicine, Houston, Texas.
232
the purpose of making a differential diagnosis of impotence. Prior to 1983 we often recorded respiration and found it clinically useful for the interpretation of NPT tracings. The respiratory i; activity, however, was not systematically ana~ lyzed. In 1983 we began routine quantification of sleep apnea in every patient we evaluated for erectile dysfunction. In this report we attemp! to estimate the prevalence of sleep apnea among men with ereetile dysfunetion in a large population of patients. Material and Methods Between January 1983 and June 1987, multi: night polysomnography was performed on :~: 1,025 men with erectile complaints These slee~ )i studies included strain gauge recordings 0!i penile circumference change; thermistor re~i! ~ordings of nasal-oral airflow; eleetroencepha; ~; og aphie, eleetro-oeulographie, eleetroeardid'i graphic, and eleetromyographie aetivity; and~!i
UROLOGY
/
SEPTEMBER 1990
/
VOLUME XXXVI, NUMI3
in many eases, tracings of thoracic or abdominal movement. Penile buckling pressure (rigidity) was also measured for each patient during one or more of that patient's typical sleep-related erections. Patients ranged in age from twenty to eightytwo years (mean age, 54) and included both men with organic and non-organic erectile dysfunction. Of the total sample, 57 percent had organic erectile dysfunction with maximum penile rigidity below 550 g. The mean height was 70 in (SD = 3.5) and the mean weight was 187 pounds (SD = 31.4). In addition to erectile dysfunction, patients had an assortment of other medical, psychiatric, and psychologic conditions. Results The number of episodes of apnea per hour of Sleep (apnea index) was calculated for each patient. The overall mean apnea index was 9.56 (SD = 16.18) with the longest sleep apnea epiSode averaging 30.86 seconds (SD = 25.62). ;Table I shows the percentage of men within different age groups and the total for all patients i n each of four cumulative apnea index categories. The total number of patients in each age .group is also shown. In the majority of cases i~(58% ), significant sleep apnea (AI > 5) was not ';}:accompanied by complaints of difficulty initiat?!hg sleep, difficulty maintaining sleep, or pe!;,i'iods of excessive daytime sleepiness. Addi;~tionally, the mean apnea index for the organic i r o u p was 10.5 while the non-organic group ad an average of 8.3 apnea episodes per hour f sleep. This slightly higher index for men with hrganic erectile dysfunction is statistically significant (P = 0.02),
~
; , ~; ! i ¸
~i;i~;! ~!i~
TABLEI.
Apnea index distribution for impotent men* -Apnea Index N 0 >0 >5 >10
>15
42
33.3
66.7
23.8
14.3
7.1
i023~9 106 i0~49 165 ~0~59 349 i0.69 285 69 78 TOTALS 1,025
37.7 34.5 22.6 19.6 23.1 25.8
62.3 65.5 77.4 80.4 76.9 74.2
21.7 35.2 49.6 49.8 55.1 43.8
12.3 18.8 31.5 32.3 43.6 27.9
8.5 13.3 21.5 23.5 32.1 19.6
Percent within each age group and for total of impotent paents without apnea and in each of four cumulative apnea index ategories.
: ~OLOGY
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SEPTEMBER 1990
/
Comment The results of the present study confirm the previously reported findings of a high prevalence of sleep apnea among men with erectile dysfunction. 4,5 The data presented here are derived from a sample of more than 1,000 impotent men and indicate that erectile problems and sleep apnea are associated in all age groups. Moreover, the prevalence of sleep apnea increases dramatically with advancing age. The percentage of patients with ten or more apnea episodes per hour increases from 14.3 for men thirty years or younger to 43.6 for men seventy years or older. Pressman et al.5 demonstrated that the sleep disruption produced by sleep apnea can cause problems in the interpretation of NPT recordings. Therefore, polysomnographie information about sleep stages and respiratory activity should be recorded in conjunction with NPT when sleep studies are conducted on men with erectile complaints. This additional information will help avoid misinterpretations and thereby reduce misdiagnosis. We generally expect excessive sleepiness, sleep initiation, and/or sleep maintenance problems to accompany sleep apnea. This expectation is largely due to the fact that sleep apnea is most often found during diagnostic evaluations of patients with sleep problems or hypersomnia. It is noteworthy that in this population, mild to moderate sleep apnea occurs more often than not without a sleep/wake complaint. Consequently, clinicians cannot rely on symptoms to alert them to the presence of sleep-related respiratory dysfunction in patients with erectile dysfunction. Apnea-related erectile dysfunction is typically ascribed to the sleepiness and/or depression that may accompany sleep apnea. 6 While this is undoubtedly the ease in some patients, our findings do not support this explanation as a general rule. Less than half of the patients in whom we found sleep apnea had sleep/wake complaints. Additionally, the fact that more than half of the sample had organic erectile dysfunction makes it unlikely that impotence among men with sleep apnea principally derives from diminished libido induced by sleepiness or depression. Obesity is a known associate of sleep apneaJ Actuarial tables 8 of weights indicate that the average 70-in tall, fifty-four-year-old man weighs 175 lb. Therefore, in this sample, our patients are, on average, 12 lb overweight. In
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future analyses we will assess the interactions between sexual status, obesity, and sleep apnea. Finally, the pathophysiology of erection in patients with sleep apnea is currently unknown. Further study of the interrelationship between erectile failure and sleep apnea is needed. VAMC-Research Service 151 2002 Holcombe Boulevard Houston, Texas 77030 (DR. HIRSHKOWITZ) References 1. Guilleminault C, van den Hoed J, and Mitler MM: Clinical overview of the sleep apnea syndromes, in Guilleminault C and Dement WC: Sleep Apnea Syndromes, New York, 1978, Alan R. Liss, p 1.
234
2. Coleman RM, et ah Sleep-wake disorders based on a polysomnographic diagnosis. A national cooperative study, lAMA 247:997 (1982). 3. Guilleminault C, et ah Sleep apnea syndrome due to upper airway obstruction: a review of 25 cases, Arch Intern Med 137: 296 (1977). 4. Sehmidt HS, and Wise HA: Significance of impaired penile tumeseenee and associated polysomnographic abnormalities in the impotent patient, J Urol 126:348 (1981). 5. Pressman MR, et ah Problems in the interpretation of nocturnal penile tumescence studies: disruption of sleep by occult sleep disorders, J Urol 136:595 (1986). 6. Hudgel DW: Clinical manifestations of the sleep apnea syndrome, in Fletcher EC: Abnormalities of Respiration During Sleep, Orlando, 1986, Grune and Stratton, p 21. 7. Harman E, Wynne JW, Block AJ, and Molloy-Fisher L: Sleep-disordered breathing and oxygen desaturation in obese patients, Chest 79:256 (1981). 8. New weight standards for men and women, Star Bull 40:1 (1959).
UROLOGY
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SEPTEMBER 1990 /
VOLU
E XKXVI,