Correlations between SHBG, Sex Hormones, Inflammation, and Neurocognitive Decline in Alzheimer's Disease:A Retrospective Study

Abstract

Background: Alzheimer's Disease (AD) is characterized by a progressive neurodegenerative process leading to cognitive decline and functional impairment. Endocrine factors, particularly sex hormones and their binding proteins, play a critical role in AD pathophysiology. Understanding the relationship between these factors and AD is essential for developing targeted interventions.

Objective: To investigate the potential links between sex hormone binding globulin (SHBG) levels, sex hormone profiles, inflammatory markers, and neurocognitive decline in patients with AD.

Methods: A retrospective case-control investigation was conducted with 110 AD patients who were admitted to our hospital from January 2021 to December 2023, and the patients were classified into either a mild neurocognitive impairment group (n=59) or a moderate to severe neurocognitive impairment group (n=51) according to their cognitive function. Correlation and regression analyses were conducted to examine relationships between variable factors.

Results: The study revealed a significant neurocognitive decline in AD patients with lower Mini-- Mental State Examination (MMSE) and higher AD Assessment Scale-Cognitive Subscale (ADAS- Cog) scores in the moderate to severe neurocognitive impairment group compared to the mild neurocognitive impairment group. Additionally, the moderate to severe neurocognitive impairment group significantly increased for SHBG, estradiol, progesterone inflammatory markers [C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β)). It decreased for follicle-stimulating hormone (FSH) and luteinizing hormone (LH)]. Moreover, significant positive correlations were found between SHBG levels and ADAS-Cog scores, and significant negative correlations were found between SHBG levels and MMSE scores. FSH showed significant negative correlations with the MMSE score, while certain inflammatory markers demonstrated significant correlations with neurocognitive abilities. The correlation between sex hormones and inflammatory factors is weak. FSH, LH, SHBG, CRP, IL-6, TNF-α, and IL-1β are risk factors for neurocognitive impairment, while E2 and P are protective factors.

Conclusion: The study provides evidence of significant correlations between SHBG levels, sex hormone profiles, inflammatory markers, and neurocognitive decline in AD patients.

Keywords: Alzheimer's disease; Correlation analysis; inflammation; neurocognitive abilities; retrospective.; serum hormone binding globulin levels.