title: Cigarette smoking, stress-induced analgesia and pain perception in men and women.
abstract: This study examined gender differences in smoking-related analgesia and stress-induced analgesia (SIA), as a function of pain modality. Forty men (20 smokers, 20 nonsmokers) and 37 women (17 smokers) were tested twice for pain sensitivity to tourniquet ischemia, thermal heat, and cold pressor tests; once following mental stress and once following rest control, counterbalancing order. Cardiovascular and neuroendocrine responses to mental stress were also examined. While expected gender differences in pain sensitivity were observed, women smokers had greater threshold and tolerance times to ischemic pain than women nonsmokers (P<0.05) when pain testing followed rest. Male smokers had greater threshold and tolerance to cold pressor pain than male nonsmokers (P<0.05) after both rest and stress. Only women showed evidence for SIA, since women nonsmokers demonstrated greater ischemic pain threshold and tolerance following mental stress versus rest (P<0.05), and all women reported lower thermal heat pain unpleasantness after stress versus rest (P=0.05). Only nonsmokers showed expected inverse relationships between sympathetic and hypothalamic-pituitary-adrenal (HPA) axis reactivity measures and sensitivity to pain. Smokers showed evidence for blunted HPA-axis function at rest and stress. These results indicate that analgesia related to both being a smoker and stress is influenced by gender and pain modality. The reduced pain perception in smokers and absence of relationships between endogenous pain regulatory mechanisms and pain sensitivity may reflect a maladaptive response to chronic smoking.
authors.affiliation: Department of Psychiatry, University of North Carolina at Chapel Hill, CB #7175, Medical Research Bldg A, Chapel Hill, NC 27599-7175, USA Department of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
authors.forename: Susan S
authors.initials: SS
authors.lastname: Girdler
authors.forename: William
authors.initials: W
authors.lastname: Maixner
authors.forename: Herman A
authors.initials: HA
authors.lastname: Naftel
authors.forename: Paul W
authors.initials: PW
authors.lastname: Stewart
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: Moretz
authors.forename: Kathleen C
authors.initials: KC
authors.lastname: Light
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000097:blood; D000328:Adult; D001794:Blood Pressure; D003080:Cold Temperature; D005260:Female; D006339:Heart Rate; D006358:Hot Temperature; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007511:Ischemia / Q000150:complications; D008297:Male; D009538:Nicotine / Q000097:blood; D009619:Nociceptors / Q000502:physiology; D009638:Norepinephrine / Q000097:blood; D017288:Pain Threshold / Q000502:physiology* / Q000523:psychology*; D010465:Perception / Q000502:physiology; D012727:Sex Characteristics; D012907:Smoking / Q000503:physiopathology* / Q000523:psychology; D013315:Stress, Psychological / Q000503:physiopathology* / Q000523:psychology; D013375:Substance Withdrawal Syndrome / Q000503:physiopathology; D001615:beta-Endorphin / Q000097:blood
chemical_list: D001615:beta-Endorphin; D009538:Nicotine; D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone; D009638:Norepinephrine