The Barker hypothesis confirmed: association of low birth weight with all-cause natural deaths in young adult life in a remote Australian Aboriginal community

Abstract

Barkeret al. proposed that low birth weight predisposes to higher death rates in adult life. We previously confirmed this fact in a cohort of young adults who were born in a remote Australian Aboriginal community between 1956 and 1985. We now present data in these same people with four more years of follow-up and a greater number of deaths. The fates of participants were documented from age 15 years until death, start of dialysis, or until the end of 2010 and causes of death were derived from clinic narratives and dialysis records. Rates of natural deaths were compared by birth cohorts and birth weight, and hazard ratios were calculated using Cox proportional hazards methods, by birth weight and adjusted for birth cohort and sex. Over follow-up of 19,661 person-years, 61 people died of natural causes between age 15 and the censor date. Low birth weights (<2.5 kg) were associated with higher rates of natural death, with HR (95% CI) 1.76 (1.1–2.9,P=0.03), after adjustment for year of birth and sex. The effect was particularly prominent for deaths at <41 years of age, and with deaths from respiratory conditions/sepsis and unusual causes. A predisposing effect of low birth weight on adult deaths was confirmed. This phenomenon, occurring in the context of dramatically improved survivals of lower birth weight infants and children since the early 1960s, helps explain the current epidemic of chronic disease in Aboriginal people. Birth weights continue to improve, so excess deaths from this source should progressively be minimized.