Gender differences in sexual dysfunctions among individuals with obesity
Cinzia Niolu1,2, Emanuela Bianciardi1, Alberto Siracusano1,2
1. Psychiatric Chair, Department of Systems Medicine, University of Rome “Tor Vergata”, Rome, Italy;
2. Psychiatry and Clinical Psychology Unit, Department of Neurosciences, Fondazione Policlinico “Tor Vergata”, Rome, Italy.
Summary. Obesity, defined as a Body Mass Index ≥30, is a growing global epidemic with adverse short and long-term complications impacting subjective well-being, physical health, mental health and sexual function. Sexual disorders have become a feature of growing interest in the obesity field and are critically related to the quality of life. Fat storage and metabolism differ considerably between men and women. Therefore, the relationship between obesity and sexual functioning may be gender-specific. Although there is a link between either obesity and sexual dysfunction or surgical and diet-induced weight loss and improved sexual function, the improvement may not be dependent on the amount of weight loss only. Sexual dysfunction in obese patients may be a consequence of obesity itself, psychiatric and somatic comorbidities, and the use of certain medications such as anti-hypertensive drugs. These issues are also influenced by gender differences. This paper reviews the most common sexual dysfunctions in women and men, citing the possible putative mechanisms. Given that sexual disorders greatly affect quality of life, it is mandatory that clinicians involved in obesity management gain specific knowledge with the aim of detecting gender-specific sexual dysfunctions and planning appropriate therapeutic strategies.
Key words: obesity, gender, sexual dysfunction, psychiatric comorbidities.
Differenze di genere nelle disfunzioni sessuali degli individui con obesità
Riassunto. L’obesità è definita da un Indice di Massa Corporea ≥30. A livello mondiale, la sua prevalenza è diventata un fenomeno talmente diffuso e allarmante da raggiungere le dimensioni di una vera e propria pandemia. Le conseguenze negative nel breve e nel lungo termine hanno un impatto sul benessere soggettivo, sulla salute fisica e mentale e sul funzionamento sessuale. I meccanismi di accumulo e metabolismo lipidico sono diversi tra uomini e donne. È ragionevole quindi ipotizzare che esistano delle differenze sesso-specifiche che mediano la relazione esistente tra l’obesità e i disturbi sessuali. Nonostante sia stata dimostrata un’associazione sia tra l’obesità e le disfunzioni sessuali, sia tra la perdita di peso in eccesso e il miglioramento della funzione sessuale, il peso non è il solo elemento determinante. I cambiamenti ormonali, le comorbilità mediche e psichiatriche dell’obesità differiscono tra uomini e donne e sono tutti fattori implicati nella genesi dei disturbi sessuali. Questo lavoro passa in rassegna i disturbi sessuali più diffusi negli uomini e nelle donne con obesità, elencando i possibili meccanismi eziopatogenetici. Poiché le disfunzioni sessuali compromettono grandemente la qualità della vita, è necessario, per chi si occupa di obesità, acquisire le conoscenze specifiche e utilizzare gli strumenti più idonei per individuare questi disturbi e pianificare un trattamento, tenendo conto delle differenze tra i due sessi.
Parole chiave: obesità, genere, disturbi sessuali, comorbilità psichiatriche.
Obesity and sexual dysfunctions
In the European Union, 50.1% of the adult population is overweight or obese. The worldwide prevalence of obesity has almost doubled from 6.4% in 1980 to 12.0% in 2008. Half of this rise has occurred in the last fifteen years1. It is estimated that almost 1.5 billion individuals were overweight in 20152.
Obesity is an increasing global epidemic with adverse short and long-term complications impacting subjective well-being, physical health, mental health and sexual function. Sexual disorders have become a feature of growing interest in the obesity field and are critically related to quality of life.
Fat storage and metabolism differ considerably between men and women3. Moreover, it has been demonstrated that gender is a determinant of weight loss after bariatric surgery and non-surgical weight-loss programs4,5. Therefore, the relationship between obesity and sexual function may be gender-specific.
The World Health Organization (WHO) debated the definition of “sexual dysfunction,” declaring that it is a problematic term6. The International Classification of Diseases describes human sexual dysfunction as “the various ways in which an individual is unable to participate in a sexual relationship as he or she would wish.” Masters and Johnson proposed a framework leading to the concept that sexual disorders were referred to the four phases of human sexual response: excitement, plateau, orgasm, and resolution7. Afterwards, Kaplan included the notion of “desire” and restricted the phases of sexual response to three: desire, arousal and orgasm8. According to these theoretical constructs the past Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) classified sexual dysfunctions on the basis of each of these phases. This model gave the assumption that sexual response is linear, but it was argued that the sexuality of women is more complex and nonlinear9. Therefore, in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5; American Psychiatric Association, 2013) sexual disorder diagnostic criteria were revised (Table 1).
Sexual dysfunction in obese patients may be a consequence of obesity itself (e.g., hormonal changes), psychiatric and somatic comorbidities, and the use of some medications such as anti-hypertensive drugs. These entire issues are also influenced by gender differences.
Among individuals with obesity (Body Mass Index ≥30 kg/m2) sexual dysfunctions have been reported with a prevalence of 7-22% in women and 5-21% in men10.
The actual diffusion of sexual disorders could even be higher given that clinicians often do not ask and underestimate their prevalence as much as the repercussions on the patient’s quality of life. Sexuality is often a disregarded issue by mental health practitioners, and some psychiatrists may not know enough about this topic or feel embarrassed. In contrast, most patients, when asked, are encouraged to discuss sexual problems.
The assessment of sexual function is complicated by the different topics that are relevant to each gender. Indeed, the several psychometric instruments that are used for diagnosis were developed for both genders. The most widely used validated instruments that are gender-specific are the Female Sexual Function Index (FSFI), Sexual Quality of Life-Female questionnaire (SQOL-F), Brief Sexual Function Inventory (BSFI), and International Index of Erectile Function (Table 2).
Finally, gender is one of the characteristics involved in the doctor-patient relationship, including in the framework of weight loss counseling11. Patients may experience different feelings and barriers according to the gender of clinicians. Physicians seem to be more likely to encourage weight loss and make specific reference to weight problems during the interaction with women than with men, with a similar body mass index12.
Sexual dysfunctions in women with obesity
Among women with obesity sexual pain, arousal problems, and low desire have often been reported. Although some researchers have demonstrated that obese women were less sexually active than those with normal weight13, it has been shown that obese women were more likely to report ever having male sexual intercourse (P <0.001), regardless of age14. Moreover, a European survey reported that obese women had a higher number of unintended pregnancies15. Studies examining the relationships between sexual function and obesity in women are scarce, and their results are questionable. Divergent results of the research studies could be due to a number of factors, among which the heterogeneity of instruments used to assess sexual function. Hormonal profiles including the increase of androgens determined by excess body fat, polycystic ovary syndrome, urinary incontinences, menopause, psychiatric disorders such as major depression, binge eating disorders or other feeding disorders associated with body image disturbances, and a history of trauma have been explored as putative mechanisms. It has been shown that female obese patients had poorer sexual function than normal weight women, with a more serious psychological impairment in those with binge eating disorder16,17.
Emotional eating is a type of maladaptive eating behavior that is more frequent in women than in men18. Emotional eating has been defined as “the tendency to eat in response to emotional distress (described as a range of negative, and for some authors positive, emotions) and during stressful life situations.” It is a psychological underlying construct that is related to binge eating, and other maladaptive eating patterns like grazing, nibbling, and “uncontrolled” eating which are prevalent among obese individuals19. Emotional eating shares with sexuality neurobiological pathways involving the endogenous opioid system20. It has been documented that emotional eating was a primary psychological determinant of sexual dysfunctions in obese women, resulting in impaired sexual desire, arousal, lubrication, orgasm, and satisfaction21.
Major depression is a common disorder among individuals with obesity. It is well known that the prevalence of depression is almost double in women compared with men.
Depressive symptoms and drugs used in their treatment are frequently associated with sexual dysfunctions22.
Body image is a multidimensional theoretical construct, which indicates the subjective mental representation of one’s own body. Body image includes: the mental perception of one’s own shape of the body; the cognition and emotional state related to the body, which is an attitudinal skill; and the behavioral component, which refers to a person’s involvement in behaviors related to body shape, such as nutrition, fitness, or not wearing tight-fitting clothing.
Body dissatisfaction can be considered as the discrepancy between one’s current and stated ideal weight. Numerous studies have found that women have less body esteem than men23. Since adolescence, women display a cognitive vulnerability in the body image domain that may facilitate the development of negative psychological consequences24.
Body image disorders are prevalent across eating disorders and obesity.
Up to 74% of patients with obesity have body shape concerns and a distorted view of their body image. Moreover, body image is poorer among female bariatric surgery candidates compared to those participating in weight loss programs, and non-obese controls25. A survey including both men and women found that body dissatisfaction was greater in women who perceived themselves as being overweight with men easily evaluating themselves as strong rather than fat26.
Body shape dissatisfaction can inhibit sexual intercourse that is a situation particularly involving the own body. In obese women, greater body image satisfaction has been related with more frequent and pleasant sexual experiences, pursuit of a wider range of sexual activities, not avoiding being seen naked, and feeling of being sexually desirable27.
Sexual dysfunctions in men with obesity
Among men, erectile dysfunction, hypoactive sexual desire disorder and premature ejaculation are prevalent.
Males with obesity often report detrimental changes in sexual function and impaired sexual satisfaction. Epidemiological studies suggest that erectile dysfunction is the most common sexual dysfunction. According to the hypothesis of a cause-and-effect mechanism, prospective studies have suggested an association between obesity and subsequent occurrence of erectile dysfunction, with an increased risk of 70-95% compared to normal-weight individuals28. Cross-sectional studies from various countries, with large population samples of men, showed that erectile dysfunction developed more often in men with obesity than in normal weight men29.
Several pathogenic mechanisms linking obesity and erectile dysfunction have been reported. Concentrations of testosterone and its carrier protein, sex hormone-binding globulin (SHBG), decrease with increasing BMI, with a stronger association in men with abdominal obesity30. Prevalence of low testosterone levels in obese men range from 20 to 64% depending on the characteristics of the population, age and on whether total or free circulating testosterone was measured31.
Testosterone is the leading sex hormone in men, and it plays a crucial role either in libido or in sexual function. Lower testosterone levels can cause low sexual desire. Androgen deficiency can directly affect erectile dysfunction. Despite the clear association between lower testosterone and obesity, the causal directionality of this observed link is still uncertain.
Low testosterone levels in obese men have been associated with increased estrogen production by the adipose tissue, insulin resistance, and low-grade systemic inflammatory process (C-reactive protein values). Leptin levels are higher in obese individuals, negatively correlating with testosterone values. Sleep apnea, which is a common comorbidity of obesity, has been associated with decreased testosterone levels32. Despite the demonstrated decrease of testosterone level, in these subjects the actual efficacy of testosterone replacement treatment for erectile dysfunction is controversial. Lifestyle interventions aimed at eliminating the multiple metabolic risk factors seem to be the most favorable approach.
Individuals with obesity showed higher levels of proinflammatory cytokines (interleukin-6, interleukin-8, and interleukin-18) and markers of inflammation such as the C-reactive protein. A large body of evidence indicates that obesity is an inflammatory state that influences endothelial function, and it may contribute to the increased risk of thrombotic accidents. It is widely accepted that erectile dysfunction shares a common vascular mechanism with atherosclerosis. Indeed, a diagnosis of erectile dysfunction may be an alarming signal of a developing coronary heart disease.
Indirectly, obesity contributes to erectile dysfunction through the presence of medical comorbidities, namely: high blood pressure, diabetes, and high cholesterol. Atherosclerotic damage on penile arteries induced by lipid disorders and hypertension can reduce blood flow in and out of the penis, compromising the beginning and maintenance of an erection33.
Moreover, obese individuals are often insulin-resistant and therefore endothelial response to insulin is altered leading to vasoconstriction, which can possibly contribute to impaired erection34. The use of antihypertensive drugs and antidiabetic agents, such as metformin and thiazolidinediones, can induce sexual dysfunction35,36.
Compared to women, men are more likely to engage in problem drinking, and to develop alcohol-related disorders. It has been reported that almost one third of patients pursuing weight loss surgery had a lifetime history of any substance use disorder, including alcohol abuse37. In addition, after bariatric surgery an increasing use of alcohol38 has been observed.
Among sexually active men, high alcohol consumption was previously associated with various sexual dysfunctions, including erectile dysfunction39. Alcohol use disorder was found to be more prevalent in obese individuals with binge eating disorder40.
In a study of bariatric surgery candidates, men with dysfunctional sexual behavior showed lower impairment of psychosocial function and quality of life than women41.
Furthermore, a recent review clearly showed that men with sexual disorders are less predisposed to ask for help than women42. Accordingly, women’s sexual difficulties are more prevalent in clinical studies compared to population studies where men reported higher sexual dysfunctions.
The relationship between obesity and sexual function is a multifactorial interplay. Sexuality in obese people may be jeopardized by weight-related comorbidities, as well as by reproductive hormones, many environmental factors and psychiatric influences.
For instance, the same phases of sexual behavior are comparable to eating behavior. Indeed, the refractory period after ejaculation may correspond to satiety after a meal, and the rhythmicity of vaginal thrusting is similar to chewing food.
Many studies have explored the link of eating disorders and sexual dysfunction, whereas the literature of gender differences in sexual dysfunction among obese patients is lacking.
The papers that we have reviewed point to hormonal, metabolic, and psychiatric characteristics differentiating men and women with obesity and sexual disorders. In particular, in women sexual dysfunctions seem to be related to the motivational interface of sexuality, the so-called libido, with studies reporting a higher rate of psychiatric issues in women than men, such as body image concerns, history of trauma, depression, and eating disorders. On the other hand, one of the most common sexual dysfunctions in obese men is erectile dysfunction, which is essential for coitus, representing the consummatory part of sexuality. Among obese men, erectile dysfunction has been more frequently linked to vascular impairment and androgen deficiency.
In conclusion, sexual dysfunctions are prevalent and complex disorders among subjects with obesity, which can result in considerable personal distress and adversely affect individual’s health and quality of life.
Although a link has been found between either obesity and sexual dysfunction or surgical and diet-induced weight loss and improved sexual function, the improvement may not be dependent on the amount of weight loss43. Nevertheless, highlighting the advantages of weight loss, some people may be encouraged to lose their weight in excess.
Further research is needed to explore whether medical and psychological factors, including body image disorders and depression, play a mediating role in the amelioration of sexual dysfunction after weight loss.
In particular, in obese women, sexual function is an understudied issue. We believe that sexuality must be fully addressed by clinicians by asking open and targeted questions in the initial screening and during counseling provided with weight loss programs.
Given the multidisciplinary approach to obesity, it is mandatory that general practitioners, endocrinologists, nutritionists, surgeons as well as psychiatrists detect and evaluate sexual disorders with the aim of addressing the possible causes and therapeutic options.
Finally, sexual life is a determinant of subjective well-being and mental health, overcoming the reproductive instinct and determining “a significant individual distress” (according to DSM-5 criteria). Researchers should further address the impact of sexual dysfunctions on the quality of life, clarifying the differences between women and men.
Conflict of interest statement: the Authors declare no potential conflits of interest or any financial or personal relationships with other people or organizations that could inappropriately bias conduct and findings of this study.
1. Scully T. Public health: Society at large. Nature 2014; 508 (7496): S50-1.
2. World Health Organization. Global health risks: mortality and burden of disease attributable to selected major risks, 2009. http://www.who.int/healthinfo/global_burden_disease/GlobalHealthRisks_report_full.pdf .
3. Löfgren P, Hoffstedt J, RydénM, et al. Major gender differences in the lipolytic capacity of abdominal subcutaneous fat cells in obesity observed before and after long-term weight reduction. J Clin Endocrinol Metab 2002; 87(2):764-71.
4. Perrone F, Bianciardi E, Benavoli D, et al. Gender influence on long-term weight loss and comorbidities after laparoscopic sleeve gastrectomy and Roux-en-Y gastric bypass: a prospective study with a 5-year follow-up. Obes Surg 2016; 26(2): 276-81.
5. Bhogal MS, Langford R. Gender differences in weight loss; evidence from a NHS weight management service. Public Health 2014; 128(9): 811-3.
6. World Health Organisation. Measuring sexual health: conceptual and practical considerations and related indicators, 2010.
7. Masters WH, Johnson, VE. Human sexual response. Boston: Little, Brown and Company, 1966.
8. Kaplan HS. Disorders of Sexual Desire and Other New Concepts and Techniques in Sex Therapy. New York, NY: Brunner/Hazel Publications, 1979.
9. DeFeo J. Understanding sexual, paraphilic, and gender dysphoria disorders in DSM-5. J Child Sex Abus 2015; 24(2): 210-15.
10. Pinderhughes CA, Grace EB, Reyna LJ. Psychiatric disorders and sexual functioning. Am J Psychiatry 1972;128: 1276-83.
11. Dutton GR, Herman KG, Tan F, et al. Patient and physician characteristics associated with the provision of weight loss counseling in primary care. Obes Res Clin Pract 2014; 8(2): e123-30.
12. Anderson C, Peterson CB, Fletcher L, Mitchell JE, Thuras P, Crow SJ. Weight loss and gender: an examination of physician attitudes. Obes Res 2001; 9(4):257-63.
13. Nagelkerke NJ, Bernsen RM, Sgaier SK, Jha P. Body mass index, sexual behaviour, and sexually transmitted infections: an analysis using the NHANES 1999-2000 data. BMC Public Health 2006; 6:199.
14. Kaneshiro B, Jensen JT, Carlson NE, Harvey SM, Nichols MD, Edelman AB. Body mass index and sexual behavior. Obstet Gynecol 2008; 112: 586-92.
15. Bajos N, Wellings K, Laborde C, Moreau C; CSF Group. Sexuality and obesity, a gender perspective: results from French national random probability survey of sexual behaviours. BMJ 2010; 340:c2573.
16. Wilfley DE, Wilson GT, Agras WS. The clinical significance of binge eating disorder. Int J Eat Disord 2003; 34 Suppl:S96-106.
17. Lewer M, Nasrawi N, Schroeder D, Vocks S. Body image disturbance in binge eating disorder: a comparison of obese patients with and without binge eating disorder regarding the cognitive, behavioral and perceptual component of body image. Eat Weight Disord 2016; 21(1): 115-25.
18. Gade H, Rosenvinge JH, Hjelmesæth J, Friborg O. Psychological correlates to dysfunctional eating patterns among morbidly obese patients accepted for bariatric surgery. Obesity Facts 2014; 7: 111-9.
19. Leehr EJ, Krohmer K, Schag K, Dresler T, Zipfel S, Giel KE. Emotion regulation model in binge eating disorder and obesity--a systematic review. Neurosci Biobehav Rev 2015; 49: 125-34.
20. Bodnar RJ. Endogenous opiates and behavior: 2014. Peptides 2016; 75:18-70.
21. Castellini G, Mannucci E, Mazzei C, et al. Sexual function in obese women with and without binge eating disorder. J Sex Med 2010; 7(12): 3969-78.
22. Kennedy SH, Rizvi S. Sexual dysfunction, depression, and the impact of antidepressants. J Clin Psychopharmacol 2009; 29: 157-64.
23. Polce-Lynch M, Myers B, Kliewer W, Kilmartin C. Adolescent self-esteem and gender: Exploring relations to sexual harassment, body image, media influence, and emotional expression. Journal of Youth and Adolescence 2001; 30: 225-44.
24. Hyde JS, Mezulis AH, Abramson LY. The ABCs of depression: integrating affective, biological, and cognitive models to explain the emergence of the gender difference in depression. Psychological Review 2008; 115 (2): 291-313.
25. Wimmelmann CL, Dela F, Mortensen EL. Psychological predictors of weight loss after bariatric surgery: a review of the recent research. Obes Res Clin Pract 2014; 8(4):e299-313.
26. Wardle J, Johnson F. Weight and dieting: Examining levels of weight concern in British adults. Int J Obes Relat Metab Disord 2002; 26, 1144-9.
27. Kolotkin RL, Crosby RD, Gress RE, Hunt SC, Engel SG, Adams TD. Health and health-related quality of life: differences between men and women who seek gastric bypass surgery. Surg Obes Relat Dis 2008; 4(5):651-8.
28. Esposito K, Giugliano D. Obesity, the metabolic syndrome, and sexual dysfunction in men. Clin Pharmacol Ther 2011; 90(1): 169-73.
29. Bacon CG, Mittleman MA, Kawachi I, Giovannucci E, Glasser DB, Rimm EB. Sexual function in men older than 50 years of age: results from the health professionals follow-up study. Ann Intern Med 2003; 139: 161-8.
30. Brand JS, Rovers MM, Yeap BB et al. Testosterone, sex hormone-binding globulin and the metabolic syndrome in men: an individual participant data meta-analysis of observational studies. PLoS One 2014; 9(7): e100409.
31. Kalyani RR, Dobs AS. Androgen deficiency, diabetes, and the metabolic syndrome in men. Curr Opin Endocrinol Diabetes Obes 2007; 14, 226-34.
32. Rao SR, Kini S, Tamler R. Sex hormones and bariatric surgery in men. Gend Med 2011; 8(5): 300-11.
33. Walczak MK, Lokhandwala N, Hodge MB, Guay AT. Prevalence of cardiovascular risk factors in erectile dysfunction. J Gend Specif Med 2002; 5(6): 19-24.
34. Stehouwer CD, Henry RM, Ferreira I. Arterial stiffness in diabetes and the metabolic syndrome: A pathway to cardiovascular disease. Diabetologia 2008; 51:527-39.
35. Al Khaja KA, Sequeira RP, Alkhaja AK, Damanhori AH. Antihypertensive Drugs and Male Sexual Dysfunction: A Review of Adult Hypertension Guideline Recommendations. J Cardiovasc Pharmacol Ther 2016; 21(3): 233-44.
36. Borges R, Temido P, Sousa L, et al. Metabolic syndrome and sexual (dys)function. J Sex Med 2009; 6: 2958-75.
37. Kalarchian MA, Marcus MD, Levine MD, et al. Psychiatric disorders among bariatric surgery candidates: relationship to obesity and functional health status. Am J Psychiatry 2007; 164:328-34.
38. Heinberg LJ, Ashton K, Coughlin J. Alcohol and bariatric surgery: review and suggested recommendations for assessment and management. Surg Obes Relat Dis 2012; 8(3): 357-63.
39. Christensen BS, Grønbaek M, Pedersen BV, Graugaard C, Frisch M. Associations of unhealthy lifestyle factors with sexual inactivity and sexual dysfunctions in Denmark. J Sex Med 2011; 8(7): 1903-16.
40. Wiedemann AA, Saules KK, Ivezaj V. Emergence of new onset substance use disorders among post-weight loss surgery patients. Clin Obes 2013; 3(6): 194-201.
41. Sarwer DB, Spitzer JC, WaddenTA, et al. Sexual functioning and sex hormones in persons with extreme obesity and seeking surgical and non surgical weight loss. Surg Obes Relat Dis 2013; 9:997-1007.
42. Kolotkin RL, Crosby RD, Williams GR. Health-related quality of life varies among obese subgroups. Obes Res 2012; 10(8): 748-56.
43. Bond DS, Wing RR, Vithiananthan S, et al. Significant resolution of female sexual dysfunction after bariatric surgery. Surg Obes Relat Dis 2011; 7(1): 1-7.