Download Sexual Dysfunction Is Common in the Morbidly Obese Male and

Sexual Dysfunction Is Common in the
Morbidly Obese Male and Improves after
Gastric Bypass Surgery
Ramsey M Dallal, MD, FACS, Arthur Chernoff, MD, Michael P O’Leary, MD, Jason A Smith, MD,
Justin D Braverman, MD, Brian B Quebbemann, MD, FACS
There has been limited research examining the mechanisms and epidemiology of sexual dysfunction in the morbidly obese. Our objectives were to measure sexual function in the morbidly
obese man before and after substantial weight loss induced by gastric bypass surgery.
STUDY DESIGN: All male patients in undergoing gastric bypass completed the Brief Male Sexual Function
Inventory (BSFI) before and after operation. BSFI scores were also compared with published
normative controls and analyzed for predictors of change. Mixed models were created to control
for age, diabetes, and hypertension.
RESULTS:
Ninety-seven men with a mean age of 48 years (range 19 to 75 years) and mean body mass index
of 51 kg/m2 (range 36 to 89 kg/m2) underwent gastric bypass surgery. On average, preoperative
morbidly obese patients reported a substantially greater degree of sexual dysfunction than did
published reference controls in all domains, p ⬍ 0.001. Increasing weight independently
predicted lower domain scores. Mean postoperative followup length was 19 months (range 6 to
45 months). On average, BSFI scores improved from preoperative levels by bivariate analysis in
all categories (means ⫾ SE): sexual drive (range 0 to 8), 3.9 ⫾ 0.3 to 5.3 ⫾ 0.3; erectile function (range 0 to 12), 6.4 ⫾ 0.5 to 8.9 ⫾ 0.5; ejaculatory function (range 0 to 8), 4.9 ⫾ 0.4 to
6.3 ⫾ 0.4; problem assessment (range 0 to 12), 7.4 ⫾ 0.5 to 9.6 ⫾ 0.5; and sexual satisfaction
(range 0 to 4), 1.6 ⫾ 0.2 to 2.3 ⫾ 0.2; all p ⬍ 0.01. On multivariable analysis, the amount of
weight loss independently predicted the degree of improvement in all BSFI domains, p ⬍ 0.05.
After an average 67% excess weight loss, BSFI scores in postoperative gastric bypass patients
approached those of the reference controls.
CONCLUSIONS: Men with morbid obesity commonly suffer from profound, but reversible sexual dysfunction.
(J Am Coll Surg 2008;207:859–864. © 2008 by the American College of Surgeons)
BACKGROUND:
ated with sexual dysfunction. Obesity is also a complex
endocrine disorder that may alter sexual function independently through perturbations in a variety of gender hormones. Research into the relationship of obesity and male
sexual dysfunction has been limited because few published
studies include patients with class III (morbid) obesity
(body mass index [BMI] ⱖ 40 kg/m2), and those few studies that prospectively examine the effect of weight loss on
sexual dysfunction have used weight loss methods that tend
to have only modest and inconsistent effects.
In the US, one-third of adult men are obese (BMI ⱖ 30
kg/m2) and 3% are morbidly obese.2 Gastric bypass surgery
is one of the few treatment options proved to induce substantial weight loss, increase life expectancy, and improve
numerous comorbidities of obesity such as type II diabetes
and hypertension.3-6 Male patients experiencing massive
weight loss after bariatric surgery provide an excellent opportunity to examine obesity-induced sexual dysfunction.
Male sexual dysfunction encompasses a spectrum of problems that include erectile dysfunction, lack of sexual interest or desire, and orgasm or ejaculatory dysfunction. The
incidence of sexual dysfunction increases with age and is
associated with several medical conditions such as diabetes,
tobacco abuse, metabolic syndrome, hypertension, cardiovascular disease, and obesity.1
Obesity seems to adversely affect male sexual function
indirectly by inducing many of the comorbidities associDisclosure Information: Nothing to disclose.
Received May 24, 2008; Revised July 29, 2008; Accepted August 5, 2008.
From the Department of Surgery (Dallal, Smith) and the the Division of
Endocrinology (Chernoff ), Albert Einstein Healthcare Network, Philadelphia, PA; the Department of Urology, Brigham and Women’s Hospital, Boston, MA (O’Leary); and CALSURG, Inc, Newport Beach, CA (Braverman,
Quebbemann).
Correspondence address: Ramsey M Dallal, MD, Department of Surgery,
Albert Einstein Healthcare Network, Philadelphia, PA 19027.
© 2008 by the American College of Surgeons
Published by Elsevier Inc.
859
ISSN 1072-7515/08/$34.00
doi:10.1016/j.jamcollsurg.2008.08.006
860
Dallal et al
Sexual Dysfunction in Men after Gastric Bypass
Here, we report our prospective analysis of male sexual
function before and after bariatric surgery. Our goal was to
measure the degree to which the morbidly obese male suffers from sexual dysfunction and to analyze the change in
sexual function after substantial weight loss.
METHODS
This study was conducted with institutional review board
approval. All male patients undergoing Roux-en-Y gastric
bypass between 2003 and 2007 were asked to give informed consent.
Assessment of sexual function
The previously validated Brief Male Sexual Inventory was
used to assess the multidimensional aspects of sexual function.7 The Brief Male Sexual Inventory (BSFI) consists of 11
questions comprising 5 sexual function domains: sexual drive
(2 items), erectile function (3 items), ejaculatory function
(2 items), sexual problem assessment (3 items), and sexual
satisfaction (1 item). All questions are scored on a scale
from 0 to 4, with domain scores equaling the sum of the
individual questions comprising the domain. Respondents
are asked to report their experience over the past 30 days.
Because the Brief Male Sexual Function Inventory validates
the spectrum of sexual activity, it does not generate a single
score. Rather, each domain is considered separately. The
ranges of domain scores are 0 to 8 for sexual drive, 0 to 12
for erectile function, 0 to 8 for ejaculatory function, 0 to 12
for sexual problem assessment, and 0 to 4 for overall satisfaction with gender life. Lower domain scores indicate impaired sexual function. The Brief Male Sexual Inventory
was obtained twice, once before surgery (during the initial
consultation, usually between 30 and 90 days before the
operation) and once after surgery (from patients with at
least 6 months followup). Repeat scoring was performed
once. Approximately 100 patients were eligible for the
study.
The Olmstead County Study of Urinary Symptoms and
Health Status among Men is a prospective cohort study
begun in 1989 and, as a part of the survey, subjects completed the Brief Male Sexual Function Inventory. The cohort was derived from an age-stratified, random sample
drawn from an enumeration of nearly all Caucasian male
Olmstead County, MN residents between the ages of 40
and 79 years old. Detailed results of the Brief Male Sexual
Function Inventory in this normative cohort have been
previously published and were used in this analysis.8-10
Statistical methods
The domain scores were not normally distributed. The
right and left censored scores were analyzed using multiva-
J Am Coll Surg
riable mixed Tobit models. The predictor variables examined included the continuous variables weight and age at
the time of operation. Binary predictor variables included
the presence or absence of treated diabetes or hypertension
at the time of each survey (defined as current treatment
with medications). Bivariate analysis was performed using
uncontrolled mixed Tobit models. Means are reported
⫾standard error. Percent excess weight loss was calculated
using published standards.11
RESULTS
Ninety-seven men with a mean age of 47.9 years (range 19
to 75 years) and mean initial BMI of 51.4 kg/m2 (range 36
to 89 kg/m2) underwent gastric bypass surgery. Preoperatively treated diabetes and hypertension were present in
51% and 70% of the patients, respectively. Forty-six percent of patients either were current smokers, or had reported any history of smoking. There were no deaths during the study period. Four patients refused to participate in
the study. The followup rate was 95%.
The rates of excess weight loss at 1 year and 2 years after
operation were 60% (range 21% to 115%) and 66% (range
41% to 93%), respectively. Mean BMI fell from 51.4
kg/m2 to 31.8 kg/m2 and mean weight dropped from 155
kg to 102 kg (342 lbs to 224 lbs). At a mean of 19 months
(range 6 to 45 months) after operation, the presence of
treated diabetes and hypertension decreased to 21% and
40%, respectively.
Baseline sexual function in the preoperative, morbidly
obese male was significantly lower than that in published
reference controls (p ⬍ 0.01) in each age group and domain (Table 1). Average postoperative BSFI scores significantly increased from preoperative levels in all domains in
uncontrolled models (Table 2); all p ⬍ 0.01. On multivariable analysis (Table 3), the amount of weight loss predicted the degree of improvement in all BSFI domains,
independent of the presence or improvement in diabetes or
hypertension, p ⬍ 0.001. Increasing weight adversely affects sexual performance whether it is assessed in the preoperative group comparison (the between effect that compares a patient against the group) or the postoperative
comparison (the within effect that compares a patient before and after surgery). The regression coefficients are negative, as presented in Table 3, indicating that as weight
increases, the domain scores for sexual function decrease.
The average BSFI domain scores in postoperative gastric
bypass patients approached or equaled the reference control group (Table 1). Only in two domains, overall sexual
satisfaction and ejaculatory function, and then only in the
oldest group of patients (60 to 69 years old) did scores not
reach the scores of the reference norms. There were too few
patients 70 years old or greater for meaningful analysis.
Vol. 207, No. 6, December 2008
Dallal et al
Sexual Dysfunction in Men after Gastric Bypass
861
Table 1. Mean Sexual Function Domain Score by Age Group and Cohort
Sexual function domain and
age groups
Sexual drive (score range 0–8)
Age, y
20–29
30–39
40–49
50–59
60–69
70–79
Erectile dysfunction (score range 0–12)
Age, y
20–29
30–39
40–49
50–59
60–69
70–79
Ejaculatory function (score range 0–8)
Age, y
20–29
30–39
40–49
50–59
60–69
70–79
Problem assessment (score range 0–12)
Age, y
20–29
30–39
40–49
50–59
60–69
70–79
Sexual satisfaction (score range 0–4)
Age, y
20–29
30–39
40–49
50–59
60–69
70–79
n
Reference
norms
n
Morbidly obese,
preoperative*
Morbidly obese,
postoperative
—
—
468
602
454
337
—
—
5.2 ⫾ 0.1
4.5 ⫾ 0.1
3.7 ⫾ 0.1
2.4 ⫾ 0.1
10
17
25
29
13
3
4.5 ⫾ 0.6
5.1 ⫾ 0.6
3.9 ⫾ 0.5
3.6 ⫾ 0.4
2.1 ⫾ 0.8
2.0 ⫾ 1.2
7.0 ⫾ 1.1
6.0 ⫾ 1.1
6.9 ⫾ 0.4†
4.7 ⫾ 0.4
4.0 ⫾ 0.5
4⫾0
—
—
468
550
447
337
—
—
9.8 ⫾ 0.1
8.8 ⫾ 0.1
6.5 ⫾ 0.2
3.3 ⫾ 0.2
10
17
25
29
13
3
8.3 ⫾ 1.0
8.8 ⫾ 1.0
6.5 ⫾ 0.9
6.2 ⫾ 0.8
2.0 ⫾ 1.2
3.7 ⫾ 2.3
12 ⫾ 1.7
9.4 ⫾ 1.7
11.0 ⫾ 0.4†
8.1 ⫾ 0.8
6.3 ⫾ 1.6
8.5 ⫾ 1.5
—
—
467
595
444
337
—
—
7.4 ⫾ 0.1
7.0 ⫾ 0.1
5.9 ⫾ 0.1
3.6 ⫾ 0.2
10
17
25
29
13
3
6.5 ⫾ 0.7
5.0 ⫾ 0.9
5.3 ⫾ 0.6
4.9 ⫾ 0.6
1.5 ⫾ 0.6
3 ⫾ 1.5
8.0 ⫾ 1.3
6.0 ⫾ 1.3
7.5 ⫾ 0.3
6.8 ⫾ 0.4
3.0 ⫾ 1.2†
6⫾2
—
—
467
595
444
337
—
—
10.7 ⫾ 0.1
9.9 ⫾ 0.1
8.6 ⫾ 0.2
7.7 ⫾ 0.2
10
17
25
29
13
3
9.3 ⫾ 1.0
8.3 ⫾ 1.3
7.3 ⫾ 0.9
6.7 ⫾ 0.9
5.5 ⫾ 1.6
7 ⫾ 2.1
—
—
465
591
447
337
—
—
2.6 ⫾ 0.1
2.6 ⫾ 0.1
2.3 ⫾ 0.1
2.1 ⫾ 0.1
10
17
25
29
13
3
2.3 ⫾ 0.5
2.2 ⫾ 0.4
1.5 ⫾ 0.3
1.2 ⫾ 0.3
1.2 ⫾ 0.4
2 ⫾ 0.6
12 ⫾ 1.9
9.4 ⫾ 1.9
11.4 ⫾ 0.3
9.4 ⫾ 0.8
6.8 ⫾ 2.1
9⫾3
2.0 ⫾ 1.1
2.6 ⫾ 0.9
2.6 ⫾ 0.5
2.1 ⫾ 0.3
1.7 ⫾ 0.4†
2.5 ⫾ 0.5
*All scores are significantly lower than reference norms, p ⬍ 0.01.
†
p ⬍ 0.05 relative to reference norms. Otherwise postoperative scores were not significantly different than norms.
DISCUSSION
This study is the first to examine male sexual function
using validated measures in a substantial number of morbidly obese patients. The average morbidly obese male suffers from profound sexual dysfunction. We estimate that a
man who is morbidly obese has the same degree of sexual
dysfunction as a nonobese man about 20 years older. Sexual
function improves substantially after gastric bypass surgery
to a level that reaches or approaches age-based norms.
Obesity has been previously associated with erectile dysfunction. In the Massachusetts Male Aging Study, the overall prevalence of erectile dysfunction was 17%, but it in-
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Dallal et al
Sexual Dysfunction in Men after Gastric Bypass
Table 2. Bivariate (Uncontrolled) Analysis
Sexual function
domain
Sex drive
Erection
Ejaculation
Problem assessment
Sexual satisfaction
J Am Coll Surg
Table 3. Multivariable Model
Preoperative
domain
score
Postoperative
domain score
p Value
3.9 ⫾ 0.3
6.4 ⫾ 0.5
4.9 ⫾ 0.4
7.4 ⫾ 0.5
1.6 ⫾ 0.2
5.3 ⫾ 0.3
8.9 ⫾ 0.5
6.3 ⫾ 0.4
9.6 ⫾ 0.5
2.3 ⫾ 0.2
⬍0.001
⬍0.001
⬍0.001
⬍0.001
0.002
Variable
creased to 45% in subjects with BMI values ⬎ 30 kg/m .
In the Health Professionals Follow-up Study, men with a
BMI ⬎ 28.7 kg/m2 had a 30% higher risk for erectile
dysfunction than those with a BMI ⬍ 23.2 kg/m2.13
The underlying mechanism of obesity-related sexual
dysfunction is likely multifactorial. There are high rates of
diabetes, metabolic syndrome, and hypertension in the
morbidly obese, and these comorbidities have been clearly
associated with sexual dysfunction. But this study suggests
that alterations in glucose metabolism or the presence of
cardiovascular disease may not be the primary cause. Abnormalities in gender hormone regulation and production
may also contribute to sexual dysfunction in men.14-16 Pasquali and colleagues16 examined 52 obese men with an
average BMI of 35 kg/m2 and found decreased free and
total serum testosterone concentrations and a decrease in
gender hormone binding globulin. Estrogen production
rates also increase with increasing obesity, possibly because
of aromatization of androgens by adipocytes.17 Alagna and
associates18 specifically measured sexual hormone changes
1 year after biliopancreatic diversion in 20 obese men. Although sexual function was not measured, significant improvement in sexual hormone levels (luteinizing hormone,
follicle-stimulating hormone, leptin, total testosterone,
and 17␤-estradiol) were noted. Whether body image, depression, and other psychogenic factors have an impact on
the sexual function of the morbidly obese is unclear.
Modest improvements in sexual function have been previously documented with nonsurgical weight loss therapies. In a randomized controlled trial of 110 obese men
(BMI ⬎ 30 kg/m2) who had erectile dysfunction and did
not have diabetes or hypertension, patients who ate a very
low calorie diet noted improvement in erectile function
with International Index of Erectile Dysfunction scores
that improved from 13.9 to 17. This improvement in erectile function was independently associated with a decrease
in BMI which, on average, decreased from 36.9 to 31.2
kg/m2.19 Others, however, have been unable to document
an improvement in erectile dysfunction with medical
weight loss programs.9 One randomized trial showed no
difference in sexual function in men with a BMI ⬎ 35
kg/m2 after an average 17 kg weight loss, even while doc2 12
Sex drive
Weight
Age
Diabetes (no versus yes)
Hypertension (no versus yes)
Erection
Weight
Age
Diabetes
Hypertension
Ejaculation
Weight
Age
Diabetes
Hypertension
Problem assessment
Weight
Age
Diabetes
Hypertension
Sexual satisfaction
Weight
Age
Diabetes
Hypertension
Regression
coefficient
p Value
⫺0.02
⫺0.06
⫺0.56
⫺0.78
0.001
0.01
NS
NS
⫺0.03
⫺0.13
⫺1.15
⫺4.00
0.003
0.009
NS
0.001
⫺0.02
⫺0.23
⫺1.62
⫺0.44
⬍0.001
⬍0.001
NS
NS
⫺0.02
⫺0.11
⫺3.3
⫺1.1
0.01
NS
0.03
NS
⫺0.005
⫺0.02
⫺1.2
⫺0.28
0.05
NS
0.02
NS
NS, not significant.
umenting improvements in testosterone and gender hormone binding globulin levels.20
Diabetes and hypertension were present preoperatively
in a high percentage of our patients. At an average of
19 months after operation, 60% of diabetic patients and
40% of hypertensive patients no longer required treatment
with medications. Whether short-term remission of these
typically long-standing comorbidities can improve sexual
function is unclear. For example, in the VA Cooperative
Study, men with type II diabetes were treated intensively,
resulting in an improvement of mean hemoglobin A1C values from 9.4% to 7.3%. Despite this, the prevalence of
erectile dysfunction, which was 51% at baseline, increased
to 73% during the 2 years of the study and was not significantly different from that in a conventionally treated control group.21
Improvement in sexual function should be a strong motivator for male patients to adopt a healthier life style.
Health care providers treating erectile dysfunction should
counsel patients in healthy eating and life style modification. But obesity is an extremely difficult disease to treat.
Commercial diet programs have been documented to have
Vol. 207, No. 6, December 2008
Dallal et al
poor longterm effectiveness22 and best medical therapy,
which includes intensive behavior modification, sibutramine, and nutritional education is expensive, poorly reimbursed, and results in only modest (average 12 kg) weight
loss.23 Despite these challenges, nonsurgical therapy for
obesity is the mainstay of therapy. Although bariatric surgery certainly has risks, it has been shown to improve life
expectancy, medical comorbidities, and quality of life. The
national mortality rate after bariatric surgery is approximately 0.2%.24 Although 30% of the eligible obese population is male, men represent only 20% of patients undergoing bariatric surgery. This under-representation likely
results from differing social pressures to achieve normal
weight between the genders.25,26 In addition, men who do
consider bariatric surgery typically have a higher BMI and
have more comorbidities than the average women seeking
surgery.27
There are some limitations to our analysis. We did not
analyze the severity or duration of diabetes or hypertension
as a function of domain scores. Nor did we examine testosterone and other hormone levels before and after weight
loss. Other objective measures of erectile function are also
available, but patient self-report is the current standard in
the study of male sexuality. Surgery-seeking morbidly
obese patients may have a greater degree of medical comorbidities and lower quality of life than morbidly obese patients not seeking bariatric surgery.28 So, the degree of sexual dysfunction in weight-loss-seeking men may be greater
than in individuals not seeking treatment. Another important consideration is that our patients may not be a random
sample of the male morbidly obese population.
Almost half of our patient population expressed some
previous history of tobacco abuse, but controlling for this
important variable proved difficult. Patients often stopped
and restarted tobacco use. Some were active tobacco users;
others had remote histories. The amount of tobacco products consumed over time also varied within patients. Some
individuals were successful at postoperative smoking cessation (which we actively encouraged); others renewed tobacco use at variable times after surgery. Because of the
complexity of tobacco behavior and limitations in our statistical power, we chose not to include this important predictor variable in our statistical model. Of note, our patients with a preoperative history of tobacco use did not
score differently in preoperative BSFI scores compared
with nonsmokers using a simple t-test (p ⬎ 0.10).
In conclusion, gastric bypass surgery, unlike nonsurgical
therapies for obesity, reliably induces substantial weight
loss in the majority of the morbidly obese. Studying patients undergoing gastric bypass offers an excellent oppor-
Sexual Dysfunction in Men after Gastric Bypass
863
tunity to understand the complications and pathophysiology of obesity and its numerous comorbidities. Obesity
clearly causes sexual dysfunction in men in a “dosedependent” fashion, and substantial weight loss normalizes
sexual function in the morbidly obese male. Sexual dysfunction should be considered one of the numerous potentially reversible complications of obesity.
Author Contributions
Study conception and design: Dallal, Quebbemann
Acquisition of data: Dallal, Smith, Braverman
Analysis and interpretation of data: Dallal, O’Leary
Drafting of manuscript: Dallal, Chernoff, O’Leary, Smith
Critical revision: Dallal, Chernoff, O’Leary, Smith
Acknowledgment: We thank Statistician Leonard Braitman,
PhD, Albert Einstein Health Care Network, Department of
Research, Philadelphia, PA.
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