Journal Article

Early life exposure to the 1918 influenza Pandemic and old-age mortality by cause of death

Abstract

OBJECTIVES To analyze how early exposure to the 1918 Pandemic is associated with old-age mortality by cause of death. METHODS We analyze the National Health Interview Surveys (N=81,571, follow-up 1989-2006,43,808 deaths) using year and quarter of birth to assess timing of Pandemic exposure. We use Cox proportional and Fine-Gray competing hazard models for all-cause and cause-specific mortality, respectively. RESULTS Cohorts born during pandemic peaks have excess all-cause mortality due to increased non-cancer mortality. We find evidence for a trade-off between non-cancer and cancer causes: cohorts with high non-cancer mortality have low cancer mortality, and vice versa. CONCLUSION Early disease exposure increases old-age mortality through non-cancer causes, which include respiratory and cardiovascular diseases, and may trigger a trade-off in the risk for cancer and non-cancer causes. Potential mechanisms include inflammation or apoptosis. The findings contribute to our understanding of the causes of death behind the early disease exposure-later mortality association. The cancer/non-cancer trade-off is potentially important for understanding the mechanisms behind these associations.