Body size at birth and age‐related macular degeneration in old age

Abstract

Purpose: To study associations between body size at birth and age-relatedmacular degeneration (AMD) in old age. Methods: The study sample consists of 1497 community-dwelling individuals(56.1% women) aged 67–89 years with birth data and retinal data collectedtwice in old age 5 years apart. Birth data (weight, length, birth order) wereextracted from original birth records. Digital retinal photographs were graded todetermine AMD status. Data on covariates were collected at the baselinephysical examination in old age. Multivariable regression analyses were used tostudy the association between birth data and AMD adjusting for knownconfounding factors, including birth year cohort effects. Results: The prevalence and 5-year incidence of any AMD were 33.1% and 17.0%,respectively.Menandwomenbornin1930–1936 were significantly leaner and slightlylonger at birth compared to those in earlier birth cohorts. There were no consistentassociations between weight, length or ponderal index (PI) at birth and AMD in oldage even when stratified by birth cohort. Age-related macular degeneration (AMD)prevalence (39.8%) and 5-year incidence (28.6%) were highest in individuals whowere in the highest quartile of PI at birth and who were obese in old age. Conclusion: Body size at birth was not consistently associated with AMD in oldage, suggesting that intrauterine growth might have little direct importance in thedevelopment of AMD in old age. It is possible that some yet unknown factorsrelated to larger size at birth and obesity in old age may explain differences in theprevalence and incidence of AMD in the ageing population.