title: Multisystem dysregulation and bone strength: findings from the study of midlife in the United States.
abstract: BACKGROUND
  Accumulated dysregulation across multiple physiological systems, or allostatic load (AL), has been proposed as the biological pathway from psychosocial adversity to poor health.
  
  
  OBJECTIVE
  The objective of the study was to examine whether AL, constructed using biomarkers and medication data from seven systems (sympathetic, parasympathetic, hypothalamic-pituitary-adrenal axis, cardiovascular regulation, inflammation, and lipid and glucose metabolism), is associated with lower bone strength in a national sample.
  
  
  METHODS
  This was a cross-sectional study.
  
  
  METHODS
  Seven hundred three community-dwelling men and women from the Study of Midlife in the United States participated in the study.
  
  
  METHODS
  Bone mineral density (BMD) was measured in the femoral neck and lumbar spine. Femoral neck BMD was combined with bone size and body size to create composite indices of femoral neck strength relative to load in three failure modes: compression, bending, and impact.
  
  
  RESULTS
  In mixed-effects linear regression controlling for clustering within families and adjusted for age, gender, race/ethnicity, body mass index, menopausal transition stage, childhood socioeconomic status, adult finances, education level, and study center, each SD increment in AL score was associated with between 0.10 and 0.11 SD decrements in lumbar spine BMD and each of the three composite strength indices (all values of P < .05). Gender modified the association of AL only with femoral neck BMD; each SD increment in AL score was associated with 0.21 SD decrement in femoral neck BMD in men (P < .01) but not in women.
  
  
  CONCLUSIONS
  Accumulation of dysregulation across systems was modestly associated with lower bone strength. This study adds to the accumulating evidence that multisystem dysregulation, or AL, predicts a variety of adverse health outcomes.
authors: Geriatric Research Education and Clinical Center (T.M.), Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California 90073; Divisions of Geriatrics (T.M., A.S.K., S.M., G.A.G., T.E.S.), David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California 90095; General Internal Medicine and Health Services Research (C.J.C.), David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California 90024; and Osteoporosis Clinical Center and Research Program (N.B.), University of Wisconsin-Madison, Madison, Wisconsin 53705.
authors: Takahiro
authors: T
authors: Mori
authors: Arun S
authors: AS
authors: Karlamangla
authors: Sharon Stein
authors: SS
authors: Merkin
authors: Carolyn J
authors: CJ
authors: Crandall
authors: Neil
authors: N
authors: Binkley
authors: Gail A
authors: GA
authors: Greendale
authors: Teresa E
authors: TE
authors: Seeman
mesh_terms: D000328:Adult; D000368:Aged; D052636:Allostasis / Q000502:physiology*; D015519:Bone Density / Q000502:physiology*; D003430:Cross-Sectional Studies; D004522:Educational Status; D005260:Female; D005272:Femur Neck / Q000000981:diagnostic imaging*; D006304:Health Status; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011859:Radiography; D012923:Social Class; D014481:United States