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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- 862 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. REFERENCES 1. McVary KT. Clinical practice. Erectile dysfunction. N Engl J Med 2007;357:2472–2481. 2. Ogden CL, Carroll MD, Curtin LR, et al. Prevalence of overweight and obesity in the United States, 1999–2004. JAMA 2006;295:1549–1555. 3. Adams TD, Gress RE, Smith SC, et al. Long-term mortality after gastric bypass surgery. N Engl J Med 2007;357:753– 761. 4. Schauer PR, Burguera B, Ikramuddin S, et al. Effect of laparoscopic Roux-en-Y gastric bypass on type 2 diabetes mellitus. Ann Surg 2003;238:467–484, discussion 484–485. 5. 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