Indicators of stress and their association with frailty in the precontact Southwestern United States

Abstract

Physiological disturbances in early life have been shown to increase individual mortality risk and impact health in adulthood. This study examines frailty through analysis of lesion status of two commonly collected skeletal indicators of stress (cribra orbitalia [CO] and porotic hyperostosis [PH]) and their association with mortality risk in the precontact U.S. Southwest. Several predictions are addressed: (a) individuals with active skeletal lesions are the frailest; (b) individuals with healed lesions are the least frail; (c) CO lesions, regardless of status, are associated with increased mortality risk. Odds ratios and Kaplan-Meier survival analysis are used to examine the association between stress indicators and mortality in the U.S. Southwest. This study includes 335 individuals (75 females, 81 males, 20 adults of unknown sex, and 159 juveniles) from precontact New Mexico archaeological sites dating to A.D. 1,000-1,400. Active CO and PH lesions are associated with lower survivorship and greater mortality risk than healed or absent lesions. Only juvenile individuals have active CO and PH lesions, as is expected given their physiology. CO lesions in any state are associated with greater mortality risk and earlier ages of death. Individuals with active lesions are the frailest; while individuals with healed lesions are the least frail. CO and PH likely have different etiologies: CO lesions are associated with increased mortality risk and decreased individual longevity. These results indicate that CO's presence suggests a more severe underlying condition than PH lesions alone.