Background: To investigate the association between infant mortality at time of birth and mortality from various causes of death in adulthood in men and women.
Methods: Linked mortality study based on mortality records for 1996 and 1997 and on 1996 population census data of the Region of Madrid (Spain). Deaths from five cancer sites and from five chronic diseases were estimated for 1 224 894 people aged 35-74 years residing in the Region of Madrid who were born elsewhere in Spain.
Results: A gradient in mortality by infant mortality quartile was seen for mortality from stomach cancer, colon cancer, diabetes mellitus and chronic liver disease in men, and for stomach cancer, ischaemic heart disease and chronic liver disease in women. The association was positive for stomach cancer and negative for all other causes. The relative mortality rates adjusted for age and adult socioeconomic factors for men belonging to infant mortality quartiles 3 and 4 (highest) versus those belonging to quartiles 1 and 2 as baseline were 1.06 (95% CI : 0.75-1.56) for stomach cancer, 0.67 (95% CI : 0.47-0.95) for colon cancer, 0.59 (95% CI : 0.35- 1.00) for diabetes mellitus, and 0.70 (95% CI : 0.49-0.99) for chronic heart disease. The relative mortality rates for women were 2.06 (95% CI : 1.09-3.88) for stomach cancer, 0.58 (95% CI : 0.41-0.80) for ischaemic heart disease, and 0.44 (95% CI : 0.27-0.70) for chronic liver disease.
Conclusion: Higher infant mortality at time of birth is associated with adult mortality from diabetes mellitus and colon cancer in men, from ischaemic heart disease in women, and from stomach cancer and chronic liver disease in both sexes. These results most likely reflect adverse living conditions and/or nutritional deprivation in childhood.