Age at death and linear enamel hypoplasias: testing the effects of childhood stress and adult socioeconomic circumstances in premature mortality.

OBJECTIVE

The aim of this study was to test the association between linear enamel hypolasias and adult socioeconomic circumstances with age at death in a modern skeletal sample of known age. Specifically, this study wishes to test whether there is a relationship between early life stressors, environmental quality in adult life and premature mortality.

METHODS

The presence/absence of LEH and the number of LEH episodes were recorded in 113 adult males from the Lisbon identified skeletal collection. The association between LEH and age was quantified using linear regression and binary logistic regression models, calculating crude and adjusted linear regression coefficients and odds ratios. The models were adjusted for year of birth, socioeconomic and migration status, and cause of death.

RESULTS

The presence and number of LEH were related to premature mortality. Individuals expressing at least one enamel defect survived 9.0 years less or were 2.5 times more likely to die before 53 years of age compared to individuals with no LEH. However, when controlling for the confounding factors considered, the association between LEH and age became nonsignificant.

CONCLUSIONS

The results indicate that although early life stressors, identified as LEH, seem strongly associated with premature mortality, adulthood socioeconomic circumstances accounts for most of the decreased longevity. This suggests that either macroscopically identified LEH in the permanent canine do not measure stressors early in life, or that a cumulative adversity model is a more adequate explanation.