Lactation, female hormones and age-related macular degeneration: the Tromsø Study

Some risk factors for age-related macular degeneration (AMD) have been shown to act differently in women and men. The present study aims to investigate this disparity by examining associations between female hormones, reproductive history and AMD.

Women aged 65-87 years were invited to this cross-sectional, population-based study in Norway. Participants underwent physical examination, retinal photography, answered questionnaires and had blood samples taken.

The sample included 1512 women, of whom 48 (3.2%) had late AMD and 378 (25%) had large drusen >125 μm phenotype. Length of breast feeding per child was significantly associated with late AMD (OR per month 0.80, 95% CI 0.68 to 0.94) in multivariable regression analysis. We observed no associations between late AMD or drusen >125 μm and contraceptives, oral hormonal replacement therapy, parity, age at first childbirth, age of menarche, age of menopause, number of menstruating years or the reason for menopause.

Longer duration of lactation was associated with lower frequency of maternal late AMD when controlled for confounders. Other reproductive factors and hormone replacement therapy were not significantly associated with AMD.