title: Temporomandibular disorder and optimism: relationships to ischemic pain sensitivity and interleukin-6.
abstract: The current study examined patients with temporomandibular disorders (TMD) (n=20) and pain-free controls (n=28) under stress and relaxation conditions. Interleukin-6 (IL-6), norepinephrine and epinephrine (NE and E) were measured both before and during each of two conditions: a non-stressful relaxation period and a speech stressor. Ischemic pain sensitivity was also assessed after each of these conditions. Optimism (Life Orientation Test (LOT)), which has been associated with better outcomes in relationship to health and disease, was also evaluated in relationship to ischemic pain tolerance and unpleasantness ratings as well as to IL-6 levels under the two conditions. Regression analysis determined the unique contribution of each predictor and the interaction between Optimism and Group (TMD versus controls) after controlling for gender and blood pressure. During stress, IL-6 levels appeared to parallel NE with only controls displaying significant increases. After controlling for depressed mood, TMD patients as a whole showed a significantly blunted response in IL-6 levels produced during stress as compared to controls (beta=0.31*). Although TMD subjects as a whole did not show the expected greater pain sensitivity to the ischemic task, those displaying a less optimistic style did exhibit lower pain tolerance times (beta=-0.61*) and higher pain unpleasantness ratings (beta=0.48*), compared with low optimism controls and high optimism TMD patients. Less optimistic TMD patients also had higher NE and IL-6 levels during stress than other TMD patients, while optimism was unrelated to responses in controls (*P<0.05).
authors.affiliation: Dental Research Center, School of Dentistry, Medical Research Building A, University of North Carolina, CB #7175, Chapel Hill, NC 27599-7455, USA.
authors.forename: Nancy L
authors.initials: NL
authors.lastname: Costello
authors.forename: Edith E
authors.initials: EE
authors.lastname: Bragdon
authors.forename: Kathleen C
authors.initials: KC
authors.lastname: Light
authors.forename: Asgeir
authors.initials: A
authors.lastname: Sigurdsson
authors.forename: Shelley
authors.initials: S
authors.lastname: Bunting
authors.forename: Karen
authors.initials: K
authors.lastname: Grewen
authors.forename: William
authors.initials: W
authors.lastname: Maixner
mesh_terms: D000328:Adult; D001290:Attitude; D002395:Catecholamines / Q000097:blood; D005260:Female; D005542:Forearm; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D007511:Ischemia / Q000503:physiopathology / Q000523:psychology; D008297:Male; D010146:Pain / Q000503:physiopathology* / Q000523:psychology*; D017288:Pain Threshold / Q000502:physiology / Q000523:psychology; D011601:Psychophysics; D012044:Regression Analysis; D013060:Speech; D013312:Stress, Physiological / Q000503:physiopathology; D013705:Temporomandibular Joint Disorders / Q000503:physiopathology* / Q000523:psychology*
chemical_list: D002395:Catecholamines; D015850:Interleukin-6