Pain and Sex Hormones: A Review of Current Understanding

References

• Greenspan JD , CraftRM , LerescheLet al. Studying sex and gender differences in pain and analgesia: a consensus report . Pain132 ( Suppl. 1 ), S26 – S45 ( 2007 ).
   PubMed Web of Science ®Google Scholar
• Paller CJ , CampbellCM , EdwardsRR , DobsAS . Sex-based differences in pain perception and treatment . Pain Med.10 ( 2 ), 289 – 299 ( 2009 ).
   PubMed Web of Science ®Google Scholar
• Racine M , Tousignant-LaflammeY , KlodaLA , DionD , DupuisG , ChoiniereM . A systematic literature review of 10 years of research on sex/gender and experimental pain perception – part 1: are there really differences between women and men?Pain153 ( 3 ), 602 – 618 ( 2012 ).
   PubMed Web of Science ®Google Scholar
• Racine M , Tousignant-LaflammeY , KlodaLA , DionD , DupuisG , ChoiniereM . A systematic literature review of 10 years of research on sex/gender and pain perception – part 2: do biopsychosocial factors alter pain sensitivity differently in women and men?Pain153 ( 3 ), 619 – 635 ( 2012 ).
   PubMed Web of Science ®Google Scholar
• Riley JL III , RobinsonME , WiseEA , PriceD . A meta-analytic review of pain perception across the menstrual cycle . Pain81 ( 3 ), 225 – 235 ( 1999 ).
   PubMed Web of Science ®Google Scholar
• Blackburn-Munro G , Blackburn-MunroR . Pain in the brain: are hormones to blame?Trends Endocrinol. Metab.14 ( 1 ), 20 – 27 ( 2003 ).
   PubMed Web of Science ®Google Scholar
• Maleki N , LinnmanC , BrawnJ , BursteinR , BecerraL , BorsookD . Her versus his migraine: multiple sex differences in brain function and structure . Brain135 ( Pt 8 ), 2546 – 2559 ( 2012 ).
   PubMedGoogle Scholar
• Ruau D , LiuLY , ClarkJD , AngstMS , ButteAJ . Sex differences in reported pain across 11,000 patients captured in electronic medical records . J. Pain13 ( 3 ), 228 – 234 ( 2012 ).
   PubMed Web of Science ®Google Scholar
• Wager TD , AtlasLY , LindquistMA , RoyM , WooCW , KrossE . An fMRI-based neurologic signature of physical pain . N. Engl. J. Med.368 ( 15 ), 1388 – 1397 ( 2013 ).
   PubMed Web of Science ®Google Scholar
• Wiesenfeld-Hallin Z . Sex differences in pain perception . Gend. Med.2 ( 3 ), 137 – 145 ( 2005 ).
   PubMedGoogle Scholar
• Helmick CG , FelsonDT , LawrenceRCet al. Estimates of the prevalence of arthritis and other rheumatic conditions in the United States. Part I . Arthritis Rheum.58 ( 1 ), 15 – 25 ( 2008 ).
   PubMed Web of Science ®Google Scholar
• Lawrence RC , FelsonDT , HelmickCGet al. Estimates of the prevalence of arthritis and other rheumatic conditions in the United States. Part II . Arthritis Rheum.58 ( 1 ), 26 – 35 ( 2008 ).
   PubMed Web of Science ®Google Scholar
• Schuna AA . Autoimmune rheumatic diseases in women . J. Am. Pharm. Assoc. (Wash.)42 ( 4 ), 612 – 623 ( 2002 ).
   PubMedGoogle Scholar
• Verhaak PF , KerssensJJ , DekkerJ , SorbiMJ , BensingJM . Prevalence of chronic benign pain disorder among adults: a review of the literature . Pain77 ( 3 ), 231 – 239 ( 1998 ).
   PubMed Web of Science ®Google Scholar
• Bartley EJ , FillingimRB . Sex differences in pain: a brief review of clinical and experimental findings . Br. J. Anaesth.111 ( 1 ), 52 – 58 ( 2013 ).
   PubMed Web of Science ®Google Scholar
• Kowalczyk WJ , SullivanMA , EvansSM , BisagaAM , VosburgSK , ComerSD . Sex differences and hormonal influences on response to mechanical pressure pain in humans . J. Pain11 ( 4 ), 330 – 342 ( 2010 ).
   PubMed Web of Science ®Google Scholar
• Martin VT . Ovarian hormones and pain response: a review of clinical and basic science studies . Gend. Med.6 , Part 2 , 168 – 192 ( 2009 ).
   PubMedGoogle Scholar
• Popescu A , LerescheL , TrueloveEL , DrangsholtMT . Gender differences in pain modulation by diffuse noxious inhibitory controls: a systematic review . Pain150 ( 2 ), 309 – 318 ( 2010 ).
   PubMed Web of Science ®Google Scholar
• Traub RJ , JiY . Sex differences and hormonal modulation of deep tissue pain . Front. Neuroendocrinol.34 ( 4 ), 350 – 366 ( 2013 ).
   PubMed Web of Science ®Google Scholar
• Gaumond I , ArsenaultP , MarchandS . The role of sex hormones on formalin-induced nociceptive responses . Brain Res.958 ( 1 ), 139 – 145 ( 2002 ).
   PubMed Web of Science ®Google Scholar
• Fillingim RB , NessTJ . Sex-related hormonal influences on pain and analgesic responses . Neurosci. Biobehav. Rev.24 ( 4 ), 485 – 501 ( 2000 ).
   PubMed Web of Science ®Google Scholar
• Amandusson Å , BlomqvistA . Estrogenic influences in pain processing . Front. Neuroendocrinol.34 ( 4 ), 329 – 349 ( 2013 ).
   PubMed Web of Science ®Google Scholar
• Kuba T , Quinones-JenabV . The role of female gonadal hormones in behavioral sex differences in persistent and chronic pain: clinical versus preclinical studies . Brain Res. Bull.66 ( 3 ), 179 – 188 ( 2005 ).
   PubMed Web of Science ®Google Scholar
• Aloisi AM . Gonadal hormones and sex differences in pain reactivity . Clin. J. Pain19 ( 3 ), 168 – 174 ( 2003 ).
   PubMed Web of Science ®Google Scholar
• Craft RM . Modulation of pain by estrogens . Pain132 ( Suppl. 1 ), S3 – S12 ( 2007 ).
   PubMedGoogle Scholar
• Kawata M . Roles of steroid hormones and their receptors in structural organization in the nervous system . Neurosci. Res.24 ( 1 ), 1 – 46 ( 1995 ).
   PubMed Web of Science ®Google Scholar
• Marcus DA . Interrelationships of neurochemicals, estrogen, and recurring headache . Pain62 ( 2 ), 129 – 139 ( 1995 ).
   PubMed Web of Science ®Google Scholar
• Sanoja R , CerveroF . Estrogen-dependent changes in visceral afferent sensitivity . Auton. Neurosci.153 ( 1–2 ), 84 – 89 ( 2010 ).
   PubMed Web of Science ®Google Scholar
• Smith MD , JonesLS , WilsonMA . Sex differences in hippocampal slice excitability: role of testosterone . Neuroscience109 ( 3 ), 517 – 530 ( 2002 ).
   PubMed Web of Science ®Google Scholar
• Smith MJ , AdamsLF , SchmidtPJ , RubinowDR , WassermannEM . Effects of ovarian hormones on human cortical excitability . Ann. Neurol.51 ( 5 ), 599 – 603 ( 2002 ).
   PubMed Web of Science ®Google Scholar
• Vincent K , WarnabyC , StaggCJ , MooreJ , KennedyS , TraceyI . Brain imaging reveals that engagement of descending inhibitory pain pathways in healthy women in a low endogenous estradiol state varies with testosterone . Pain154 ( 4 ), 515 – 524 ( 2013 ).
   PubMed Web of Science ®Google Scholar
• Menstrual Cycle . https://commons.wikimedia.org/wiki/File:MenstrualCycle2_en.svg .
   Google Scholar
• Micevych PE , KellyMJ . Membrane estrogen receptor regulation of hypothalamic function . Neuroendocrinology96 ( 2 ), 103 – 110 ( 2012 ).
   PubMed Web of Science ®Google Scholar
• Soltysik K , CzekajP . Membrane estrogen receptors - is it an alternative way of estrogen action?J. Physiol. Pharmacol.64 ( 2 ), 129 – 142 ( 2013 ).
   PubMed Web of Science ®Google Scholar
• Bereiter DA , CioffiJL , BereiterDF . Oestrogen receptor-immunoreactive neurons in the trigeminal sensory system of male and cycling female rats . Arch. Oral Biol.50 ( 11 ), 971 – 979 ( 2005 ).
   PubMed Web of Science ®Google Scholar
• Chaban VV , MicevychPE . Estrogen receptor-alpha mediates estradiol attenuation of ATP-induced Ca2+ signaling in mouse dorsal root ganglion neurons . J. Neurosci. Res.81 ( 1 ), 31 – 37 ( 2005 ).
   PubMed Web of Science ®Google Scholar
• Shughrue PJ , LaneMV , MerchenthalerI . Comparative distribution of estrogen receptor-alpha and -beta mRNA in the rat central nervous system . J. Comp. Neurol.388 ( 4 ), 507 – 525 ( 1997 ).
   PubMed Web of Science ®Google Scholar
• Simerly RB , ChangC , MuramatsuM , SwansonLW . Distribution of androgen and estrogen receptor mRNA-containing cells in the rat brain: an in situ hybridization study . J. Comp. Neurol.294 ( 1 ), 76 – 95 ( 1990 ).
   PubMed Web of Science ®Google Scholar
• Aloisi AM , BonifaziM . Sex hormones, central nervous system and pain . Horm. Behav.50 ( 1 ), 1 – 7 ( 2006 ).
   PubMed Web of Science ®Google Scholar
• Brown TJ , ScherzB , HochbergRB , MacluskyNJ . Regulation of estrogen receptor concentrations in the rat brain: effects of sustained androgen and estrogen exposure . Neuroendocrinology63 ( 1 ), 53 – 60 ( 1996 ).
   PubMed Web of Science ®Google Scholar
• Cairns BE , GazeraniP . Sex-related differences in pain . Maturitas63 ( 4 ), 292 – 296 ( 2009 ).
   PubMed Web of Science ®Google Scholar
• Relieving Pain in America: a Blueprint for Transforming Prevention, Care, Education, and Research . National Academy of Sciences , Washington, DC, USA ( 2011 ).
   Google Scholar
• Fillingim RB , KingCD , Ribeiro-DasilvaMC , Rahim-WilliamsB , RileyJL3rd . Sex, gender, and pain: a review of recent clinical and experimental findings . J. Pain10 ( 5 ), 447 – 485 ( 2009 ).
   PubMed Web of Science ®Google Scholar
• Hurley RW , AdamsMC . Sex, gender, and pain: an overview of a complex field . Anesth. Analg.107 ( 1 ), 309 – 317 ( 2008 ).
   PubMed Web of Science ®Google Scholar
• Manson JE . Pain: sex differences and implications for treatment . Metabolism59 ( Suppl. 1 ), S16 – S20 ( 2010 ).
   PubMedGoogle Scholar
• Hassan S , MuereA , EinsteinG . Ovarian hormones and chronic pain: a comprehensive review . Pain155 ( 12 ), 2448 – 2460 ( 2014 ).
   PubMed Web of Science ®Google Scholar
• Rezaii T , HirschbergAL , CarlströmK , ErnbergM . the influence of menstrual phases on pain modulation in healthy women . J. Pain13 ( 7 ), 646 – 655 ( 2012 ).
   PubMed Web of Science ®Google Scholar
• Ring C , Veldhuijzen Van ZantenJJCS , KavussanuM . Effects of sex, phase of the menstrual cycle and gonadal hormones on pain in healthy humans . Biol. Psychol.81 ( 3 ), 189 – 191 ( 2009 ).
   PubMed Web of Science ®Google Scholar
• Veldhuijzen DS , KeaserML , TraubDS , ZhuoJ , GullapalliRP , GreenspanJD . The role of circulating sex hormones in menstrual cycle-dependent modulation of pain-related brain activation . Pain154 ( 4 ), 548 – 559 ( 2013 ).
   PubMed Web of Science ®Google Scholar
• Craft RM . Modulation of pain by estrogens . Pain132 ( Suppl. 1 ), S3 – 12 ( 2007 ).
   PubMedGoogle Scholar
• MacGregor EA . “Menstrual” migraine: towards a definition . Cephalalgia16 ( 1 ), 11 – 21 ( 1996 ).
   PubMed Web of Science ®Google Scholar
• Macgregor EA , HackshawA . Prevalence of migraine on each day of the natural menstrual cycle . Neurology63 ( 2 ), 351 – 353 ( 2004 ).
   PubMed Web of Science ®Google Scholar
• Martin VT , WernkeS , MandellKet al. Defining the relationship between ovarian hormones and migraine headache . Headache45 ( 9 ), 1190 – 1201 ( 2005 ).
   PubMed Web of Science ®Google Scholar
• Granella F , SancesG , AllaisGet al. Characteristics of menstrual and nonmenstrual attacks in women with menstrually related migraine referred to headache centres . Cephalalgia24 ( 9 ), 707 – 716 ( 2004 ).
   PubMed Web of Science ®Google Scholar
• Brandes JL . The influence of estrogen on migraine: a systematic review . JAMA295 ( 15 ), 1824 – 1830 ( 2006 ).
   PubMed Web of Science ®Google Scholar
• Cairns BE . The influence of gender and sex steroids on craniofacial nociception . Headache47 ( 2 ), 319 – 324 ( 2007 ).
   PubMed Web of Science ®Google Scholar
• MacGregor EA , FrithA , EllisJ , AspinallL , HackshawA . Incidence of migraine relative to menstrual cycle phases of rising and falling estrogen . Neurology67 ( 12 ), 2154 – 2158 ( 2006 ).
   PubMed Web of Science ®Google Scholar
• Ripa P , OrnelloR , DeganDet al. Migraine in menopausal women: a systematic review . Int. J. Womens Health7 , 773 – 782 ( 2015 ).
   PubMed Web of Science ®Google Scholar
• Neri I , GranellaF , NappiR , ManzoniGC , FacchinettiF , GenazzaniAR . Characteristics of headache at menopause: a clinico-epidemiologic study . Maturitas17 ( 1 ), 31 – 37 ( 1993 ).
   PubMed Web of Science ®Google Scholar
• Oh K , JungKY , ChoiJY , SeoWK , ParkKW . Headaches in middle-aged women during menopausal transition: a headache clinic-based study . Eur. Neurol.68 ( 2 ), 79 – 83 ( 2012 ).
   PubMed Web of Science ®Google Scholar
• Marcus DA . Estrogen and tension-type headache . Curr. Pain Headache Rep.5 ( 5 ), 449 – 453 ( 2001 ).
   PubMedGoogle Scholar
• Rasmussen BK . Migraine and tension-type headache in a general population: precipitating factors, female hormones, sleep pattern and relation to lifestyle . Pain53 ( 1 ), 65 – 72 ( 1993 ).
   PubMed Web of Science ®Google Scholar
• Unruh AM . Gender variations in clinical pain experience . Pain65 ( 2–3 ), 123 – 167 ( 1996 ).
   PubMed Web of Science ®Google Scholar
• Scharff L , TurkDC , MarcusDA . Triggers of headache episodes and coping responses of headache diagnostic groups . Headache35 ( 7 ), 397 – 403 ( 1995 ).
   PubMed Web of Science ®Google Scholar
• MacFarlane TV , BlinkhornA , WorthingtonHV , DaviesRM , MacFarlaneGJ . Sex hormonal factors and chronic widespread pain: a population study among women . Rheumatology (Oxford)41 ( 4 ), 454 – 457 ( 2002 ).
   PubMed Web of Science ®Google Scholar
• Pamuk ON , CakirN . The variation in chronic widespread pain and other symptoms in fibromyalgia patients. The effects of menses and menopause . Clin. Exp. Rheumatol.23 ( 6 ), 778 – 782 ( 2005 ).
   PubMed Web of Science ®Google Scholar
• Leresche L , ManclL , ShermanJJ , GandaraB , DworkinSF . Changes in temporomandibular pain and other symptoms across the menstrual cycle . Pain106 ( 3 ), 253 – 261 ( 2003 ).
   PubMed Web of Science ®Google Scholar
• Dao TT , KnightK , Ton-ThatV . Modulation of myofascial pain by the reproductive hormones: a preliminary report . J. Prosthet. Dent.79 ( 6 ), 663 – 670 ( 1998 ).
   PubMed Web of Science ®Google Scholar
• Wise EA , RileyJL3rd , RobinsonME . Clinical pain perception and hormone replacement therapy in postmenopausal women experiencing orofacial pain . Clin. J. Pain16 ( 2 ), 121 – 126 ( 2000 ).
   PubMed Web of Science ®Google Scholar
• Leresche L , SaundersK , Von KorffMR , BarlowW , DworkinSF . Use of exogenous hormones and risk of temporomandibular disorder pain . Pain69 ( 1–2 ), 153 – 160 ( 1997 ).
   PubMed Web of Science ®Google Scholar
• Buckwalter JA , LappinDR . The disproportionate impact of chronic arthralgia and arthritis among women . Clin. Orthop. Relat. Res. ( 372 ), 159 – 168 ( 2000 ).
   PubMed Web of Science ®Google Scholar
• Kuiper S , Van GestelAM , SwinkelsHL , De BooTM , Da SilvaJA , Van RielPL . Influence of sex, age, and menopausal state on the course of early rheumatoid arthritis . J. Rheumatol.28 ( 8 ), 1809 – 1816 ( 2001 ).
   PubMed Web of Science ®Google Scholar
• Cirillo DJ , WallaceRB , WuL , YoodRA . Effect of hormone therapy on risk of hip and knee joint replacement in the Women’s Health Initiative . Arthritis Rheum.54 ( 10 ), 3194 – 3204 ( 2006 ).
   PubMed Web of Science ®Google Scholar
• Jorgensen C , PicotMC , BolognaC , SanyJ . Oral contraception, parity, breast feeding, and severity of rheumatoid arthritis . Ann. Rheum. Dis.55 ( 2 ), 94 – 98 ( 1996 ).
   PubMed Web of Science ®Google Scholar
• Tengstrand B , CarlstromK , Fellander-TsaiL , HafstromI . Abnormal levels of serum dehydroepiandrosterone, estrone, and estradiol in men with rheumatoid arthritis: high correlation between serum estradiol and current degree of inflammation . J. Rheumatol.30 ( 11 ), 2338 – 2343 ( 2003 ).
   PubMed Web of Science ®Google Scholar
• Cutolo M , CapellinoS , MontagnaPet al. New roles for estrogens in rheumatoid arthritis . Clin. Exp. Rheumatol.21 ( 6 ), 687 – 690 ( 2003 ).
   PubMed Web of Science ®Google Scholar
• Cutolo M , SulliA , CapellinoSet al. Sex hormones influence on the immune system: basic and clinical aspects in autoimmunity . Lupus13 ( 9 ), 635 – 638 ( 2004 ).
   PubMed Web of Science ®Google Scholar
• Castagnetta LA , CarrubaG , GranataOMet al. Increased estrogen formation and estrogen to androgen ratio in the synovial fluid of patients with rheumatoid arthritis . J. Rheumatol.30 ( 12 ), 2597 – 2605 ( 2003 ).
   PubMed Web of Science ®Google Scholar
• Capellino S , MontagnaP , VillaggioB , CutoloM . [Effects of estrogen peripheral metabolism in rheumatoid arthritis] . Reumatismo57 ( 2 ), 78 – 82 ( 2005 ).
   PubMedGoogle Scholar
• Schmidt M , WeidlerC , NaumannH , AndersS , ScholmerichJ , StraubRH . Androgen conversion in osteoarthritis and rheumatoid arthritis synoviocytes – androstenedione and testosterone inhibit estrogen formation and favor production of more potent 5alpha-reduced androgens . Arthritis Res. Ther.7 ( 5 ), R938 – 948 ( 2005 ).
   PubMed Web of Science ®Google Scholar
• Cutolo M . Sex and rheumatoid arthritis: mouse model versus human disease . Arthritis Rheum.56 ( 1 ), 1 – 3 ( 2007 ).
   PubMedGoogle Scholar
• Tsang A , Von KorffM , LeeSet al. Common chronic pain conditions in developed and developing countries: gender and age differences and comorbidity with depression-anxiety disorders . J. Pain9 ( 10 ), 883 – 891 ( 2008 ).
   PubMed Web of Science ®Google Scholar
• Smith BH , ElliottAM , ChambersWA , SmithWC , HannafordPC , PennyK . The impact of chronic pain in the community . Fam. Pract.18 ( 3 ), 292 – 299 ( 2001 ).
   PubMed Web of Science ®Google Scholar
• Torrance N , SmithBH , BennettMI , LeeAJ . The epidemiology of chronic pain of predominantly neuropathic origin. Results from a general population survey . J. Pain7 ( 4 ), 281 – 289 ( 2006 ).
   PubMed Web of Science ®Google Scholar
• Leboeuf-Yde C , NielsenJ , KyvikKO , FejerR , HartvigsenJ . Pain in the lumbar, thoracic or cervical regions: do age and gender matter? A population-based study of 34,902 Danish twins 20–71 years of age . BMC Musculoskelet. Disord.10 , 39 ( 2009 ).
   PubMed Web of Science ®Google Scholar
• Webb R , BrammahT , LuntM , UrwinM , AllisonT , SymmonsD . Prevalence and predictors of intense, chronic, and disabling neck and back pain in the UK general population . Spine (Phila Pa 1976)28 ( 11 ), 1195 – 1202 ( 2003 ).
   PubMed Web of Science ®Google Scholar
• Balter JE , MolnerJL , KohrtWM , MalufKS . Mechanical pain sensitivity and the severity of chronic neck pain and disability are not modulated across the menstrual cycle . J. Pain14 ( 11 ), 1450 – 1459 ( 2013 ).
   PubMed Web of Science ®Google Scholar
• Ihlebaek C , HanssonTH , LaerumEet al. Prevalence of low back pain and sickness absence: a “borderline” study in Norway and Sweden . Scand. J. Public Health34 ( 5 ), 555 – 558 ( 2006 ).
   PubMed Web of Science ®Google Scholar
• Oksuz E . Prevalence, risk factors, and preference-based health states of low back pain in a Turkish population . Spine (Phila Pa 1976)31 ( 25 ), E968 – 972 ( 2006 ).
   PubMed Web of Science ®Google Scholar
• Adera T , DeyoRA , DonatelleRJ . Premature menopause and low back pain. A population-based study . Ann. Epidemiol.4 ( 5 ), 416 – 422 ( 1994 ).
   PubMedGoogle Scholar
• Brynhildsen JO , HammarJ , HammarML . Does the menstrual cycle and use of oral contraceptives influence the risk of low back pain? A prospective study among female soccer players . Scand. J. Med. Sci. Sports7 ( 6 ), 348 – 353 ( 1997 ).
   PubMed Web of Science ®Google Scholar
• Schneider S , RandollD , BuchnerM . Why do women have back pain more than men? A representative prevalence study in the federal republic of Germany . Clin. J. Pain22 ( 8 ), 738 – 747 ( 2006 ).
   PubMed Web of Science ®Google Scholar
• Lovgren M , TishelmanC , SprangersM , KoyiH , HambergK . Symptoms and problems with functioning among women and men with inoperable lung cancer – a longitudinal study . Lung Cancer60 ( 1 ), 113 – 124 ( 2008 ).
   PubMed Web of Science ®Google Scholar
• Turk DC , OkifujiA . Does sex make a difference in the prescription of treatments and the adaptation to chronic pain by cancer and non-cancer patients?Pain82 ( 2 ), 139 – 148 ( 1999 ).
   PubMed Web of Science ®Google Scholar
• Katz N , MazerNA . The impact of opioids on the endocrine system . Clin. J. Pain25 ( 2 ), 170 – 175 ( 2009 ).
   PubMed Web of Science ®Google Scholar
• Vuong C , Van UumSH , O’DellLE , LutfyK , FriedmanTC . The effects of opioids and opioid analogs on animal and human endocrine systems . Endocr. Rev.31 ( 1 ), 98 – 132 ( 2010 ).
   PubMed Web of Science ®Google Scholar
• Aloisi AM , BuonocoreM , MerloLet al. Chronic pain therapy and hypothalamic-pituitary-adrenal axis impairment . Psychoneuroendocrinology36 ( 7 ), 1032 – 1039 ( 2011 ).
   PubMed Web of Science ®Google Scholar
• Bodnar RJ , KestB . Sex differences in opioid analgesia, hyperalgesia, tolerance and withdrawal: central mechanisms of action and roles of gonadal hormones . Horm. Behav.58 ( 1 ), 72 – 81 ( 2010 ).
   PubMed Web of Science ®Google Scholar
• Fillingim RB , GearRW . Sex differences in opioid analgesia: clinical and experimental findings . Eur. J. Pain8 ( 5 ), 413 – 425 ( 2004 ).
   PubMed Web of Science ®Google Scholar
• Niesters M , DahanA , KestBet al. Do sex differences exist in opioid analgesia? A systematic review and meta-analysis of human experimental and clinical studies . Pain151 ( 1 ), 61 – 68 ( 2010 ).
   PubMed Web of Science ®Google Scholar
• Abs R , VerhelstJ , MaeyaertJet al. Endocrine consequences of long-term intrathecal administration of opioids . J. Clin. Endocrinol. Metab.85 ( 6 ), 2215 – 2222 ( 2000 ).
   PubMed Web of Science ®Google Scholar
• Daniell HW . Opioid endocrinopathy in women consuming prescribed sustained-action opioids for control of nonmalignant pain . J. Pain9 ( 1 ), 28 – 36 ( 2008 ).
   PubMed Web of Science ®Google Scholar
• Fraser LA , MorrisonD , Morley-ForsterPet al. Oral opioids for chronic non-cancer pain: higher prevalence of hypogonadism in men than in women . Exp. Clin. Endocrinol. Diabetes117 ( 1 ), 38 – 43 ( 2009 ).
   PubMed Web of Science ®Google Scholar
• Aloisi AM , BachioccoV , CostantinoAet al. Cross-sex hormone administration changes pain in transsexual women and men . Pain132 ( Suppl. 1 ), S60 – S67 ( 2007 ).
   PubMed Web of Science ®Google Scholar
• Paulson PE , MinoshimaS , MorrowTJ , CaseyKL . Gender differences in pain perception and patterns of cerebral activation during noxious heat stimulation in humans . Pain76 ( 1–2 ), 223 – 229 ( 1998 ).
   PubMed Web of Science ®Google Scholar