Sex differences for clinical correlates of substantia nigra neuron loss and Lewy body pathology

Abstract

AbstractBackgroundLewy body pathology staging and substantia nigra neuron loss levels are associated with clinical features in Lewy body dementia (LBD). Compared to women, neocortical Lewy body pathology is more common and co‐pathologies are less common in men. Clinical features of people with limbic and neocortical Lewy body also differ based on sex, although sex differences for additional Lewy body pathology stages or nigral neuron loss are unclear.MethodData was obtained from the National Alzheimer’s Coordinating Center Uniform Data Set (UDS) and Neuropathology Data Set for UDS visits conducted between September 2005 and August 2019. Analysis included 31 women and 62 men from 25 AD Research Centers with Lewy body pathology and substantia nigra neuron loss data, excluding those with other neuropathologic diagnoses including moderate/severe Alzheimer’s disease. Linear models assessed the sex differences for clinical associations of nigral neuron loss level and Lewy body pathology staging controlling for age at last visit.ResultWomen were older at last visit and at death, had less years of education than men (Table 1). Men were more likely to have a clinical LBD diagnosis, had cognitive decline at a younger age, worse dementia at last visit, and higher levels of Lewy body pathology staging and nigral neuron loss. Higher Lewy body pathology stage was associated with more nigral neuron loss more for men compared to women (Table 2). Higher Lewy body pathology stage and greater degrees of nigral neuron loss were associated with more severe dementia and behavioral symptoms and a higher likelihood for a clinical Lewy body diagnosis in men compared to women.ConclusionLewy body pathology staging and the level of substantia nigra neuron loss may be worse for men compared to women. These data also suggest that Lewy body pathology and nigral neuron loss affect men more severely than women in terms of dementia severity and behavioral profiles associated with LBD. The blunted clinical manifestations of these pathological features in women add to the difficulty in accurate diagnosis and future work on the reasons for women’s resilience to these pathological features is needed.