Postmenopausal sarcopenia and Alzheimer's disease: The interplay of mitochondria, insulin resistance, and myokines

As life expectancy increases, cognitive impairments such as Alzheimer's disease (AD) create serious problems for older adults. Women regardless of ethnicity and age group, are disproportionately affected, accounting for two-thirds of AD cases, with post-menopausal women representing over 60 % of those affected. Sarcopenia, defined by gradual reduction of skeletal muscle mass, strength, and activities, is increasingly correlated with an elevated risk of cognitive decline in post-menopausal women. Menopause-related hormonal decline (particularly estrogen loss) and aging contribute to sarcopenia, characterized by muscle mitochondrial dysfunction, oxidative stress, and insulin resistance. This sarcopenia-driven reduction in muscle mass and functional capacity further reduces the production of myokines (e.g., BDNF, irisin), impairing neuronal proliferation, adult neurogenesis, and spatial learning/memory. These pathophysiological changes show a contributing link between sarcopenia and AD progression in post-menopausal women. This review is unique in that it discusses the triangular interplay between menopause, sarcopenia, and AD, offering an integrated mechanistic framework that links hormonal decline, muscle loss, and neurodegeneration. We aim to clarify the pathophysiological causes behind the muscle-brain axis and suggest viable treatment approaches to slow down sarcopenia and cognitive deterioration in postmenopausal women based on current evidence. The formulation of targeted strategies for enhancing the quality of life and lessening healthcare expenditures in this expanding population depends on the advancement of understanding this complex interconnection between menopause, sarcopenia and cognition.