Sex and gender differences in Lewy body dementia: a narrative review

Lewy body dementia (LBD), including Parkinson's disease dementia and dementia with Lewy bodies, is one of the most prevalent and burdensome type of dementias. Clinical diagnostic accuracy during life remains limited and there are currently only symptomatic therapy options without disease modification. However, recent advances in biomarkers and clinical trials are promising. Literature so far showed sex and gender differences in older adults without cognitive changes, people with all-cause dementia, Alzheimer's disease, and Parkinson's disease. While the number of studies in LBD are lower, understanding sex and gender differences and the underlying reasons can improve both diagnosis and treatment for LBD. Accordingly, the aim of this narrative review is to provide a summary of the literature for sex and gender differences in LBD. Majority of the studies for LBD investigating sex/gender differences so far focused on sex, with sex and gender terms being misused at times. Experiences of people in non-binary categories for sex or gender have yet to be investigated. While more research is needed, findings so far outline sex differences in prevalence, risk factors, biomarkers, symptoms, progression, treatment, daily life, and pathology for LBD. Sex-specific risk factors have also been reported, emphasizing the value of sex-stratified analyses and investigating female/male-specific factors such as sex hormones, menopause, and sex chromosomes. Lack of adequate research representation for females and women, as well as people from non-binary categories, is an important limitation that should be addressed to obtain more applicable findings in LBD.