title: Sex-specific impact of early-life adversity on chronic pain: a large population-based study in Japan.
abstract: BACKGROUND
  Responses to early-life adversity may differ by sex. We investigated the sex-specific impact of early-life adversity on chronic pain, chronic multisite pain, and somatizing tendency with chronic pain.
  
  
  METHODS
  We examined 4229 respondents aged 20-79 years who participated in the Pain Associated Cross-Sectional Epidemiological Survey in Japan. Outcomes were: 1) chronic pain prevalence, 2) multisite pain (≥3 sites) prevalence, and 3) multiple somatic symptoms (≥3 symptoms) among respondents with chronic pain related to the presence or absence of early-life adversity. Multivariable-adjusted odds ratios (ORs) were calculated with 95% confidence intervals using a logistic regression model including age, smoking status, exercise routine, sleep time, body mass index, household expenditure, and the full distribution of scores on the Mental Health Inventory-5. We further adjusted for pain intensity when we analyzed the data for respondents with chronic pain.
  
  
  RESULTS
  The prevalence of chronic pain was higher among respondents reporting the presence of early-life adversity compared with those reporting its absence, with multivariable ORs of 1.62 (1.22-2.15,p<0.01) in men and 1.47 (1.13-1.90,p<0.01) in women. Among women with chronic pain, early-life adversity was associated with multisite pain and multiple somatic symptoms; multivariable ORs were 1.78 (1.22-2.60,p<0.01) for multisite pain and 1.89 (1.27-2.83,p<0.01) for ≥3 somatic symptoms. No associations were observed between early-life adversity and chronic multisite pain or multiple somatic symptoms among men with chronic pain.
  
  
  CONCLUSIONS
  Early-life adversity may be linked to a higher prevalence of chronic pain among both sexes and to multisite pain and somatizing tendency among women with chronic pain.
authors.affiliation: Public Health, Department of Social Medicine, Osaka University Graduate School of Medicine, Suita, Osaka; Center for Pain Management, Osaka University Hospital, Suita, Osaka.
authors.forename: Keiko
authors.initials: K
authors.lastname: Yamada
authors.affiliation: Department of Medical Research and Management for Musculoskeletal Pain, 22nd Century Medical and Research Center, Faculty of Medicine, The University of Tokyo, Tokyo; Japan Labour Health & Welfare Organization, Tokyo.
authors.forename: Ko
authors.initials: K
authors.lastname: Matsudaira
authors.affiliation: Public Health, Department of Social Medicine, Osaka University Graduate School of Medicine, Suita, Osaka; Hyogo Institute for Traumatic Stress, Kobe.
authors.forename: Eizaburo
authors.initials: E
authors.lastname: Tanaka
authors.affiliation: Department of Medical Research and Management for Musculoskeletal Pain, 22nd Century Medical and Research Center, Faculty of Medicine, The University of Tokyo, Tokyo.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Oka
authors.affiliation: Department of Medical Research and Management for Musculoskeletal Pain, 22nd Century Medical and Research Center, Faculty of Medicine, The University of Tokyo, Tokyo; Department of Prosthetics & Orthotics and Assistive Technology, Faculty of Medical Technology, Niigata University of Health and Welfare, Niigata, Japan.
authors.forename: Junji
authors.initials: J
authors.lastname: Katsuhira
authors.affiliation: Public Health, Department of Social Medicine, Osaka University Graduate School of Medicine, Suita, Osaka.
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Iso
keywords: chronic pain; disaster; early-life adversity; sex characteristics; somatoform disorders