COGNITIVE PERFORMANCE IN RELATION TO SYSTEMIC AND BRAIN IRON AT PERIMENOPAUSE

Abstract

For females from infancy through the reproductive years, low levels of systemic iron have been linked to deficits in cognitive performance. However, this relationship has not been widely assessed in women before and after the menopausal transition, and the two studies that do exist have drawn contradictory conclusions. This transition is important as, with the cessation of menses, women no longer lose blood and thus iron monthly, resulting in an increased potential for iron to accumulate in tissue, including brain tissue. It is known that iron accumulates in the brain across the lifespan and that accumulation has negative consequences for brain structure, brain function, and cognitive performance. However, the studies that have demonstrated these relationships provide no data on the relationship between systemic iron levels and brain iron levels. And the two studies mentioned above provided no data on brain iron deposits. Thus, there are no data to link systemic iron, brain iron, and cognitive performance in perimenopausal women. The present work sought to address two questions. First, does cognitive performance in women at the menopausal transition vary with systemic iron levels? Second, do variations in systemic levels correlate with variations in brain iron levels? The present study used a cross-sectional design to provide an exploratory assessment of these relationships. Women at the earliest and latest stages of menopause were assessed in three ways. Blood iron levels were measured using standard clinical laboratory assays. Brain iron levels were measured using structural magnetic resonance imaging (MRI). Cognitive performance was assessed using a set of measures targeting learning and memory, including working memory. Results indicated a positive relationship with the iron measures and cognition, although age was not a good indicator of cognitive performance. No evidence of a relationship was detected between systemic iron and brain iron, indicating the need for further research on this topic.