Introduction:
Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by a progressive decline in memory and cognitive abilities. The monocyte/HDL-C ratio (MHR) has emerged as a new marker of inflammation in recent years. The purpose of this research was to examine MHR alterations in AD and to assess its feasibility as a straightforward and easily computable biomarker for evaluating the severity of the disease.

Material and methods:
A retrospective case-control study was conducted with 101 patients with AD and 81 age and sex-matched controls from the hospital records. AD was diagnosed according to the National Institute of Neurological and Communicative Disorders and Stroke/Alzheimer’s Disease and Related Disorders Association (NINCDS-ADRDA) criteria. The hospital’s electronic patient record data between September 2021 and April 2022 were screened.

Results:
Individuals diagnosed as having AD were classified into three subgroups based on the progression of the disease: mild, moderate, and severe. MHR was higher in the moderate and severe dementia subgroups compared with the controls according to subgroup analysis (p = 0.013). An increase in MHR was found in patients with AD. The multivariate logistic regression analysis model revealed that a one-unit increase in MHR resulted in a 1.081-fold increase in the risk of AD (OR = 1.081, 95% CI: [1.005–1.162]; p = 0.035).

Conclusions:
High MHR values could not be used as a diagnostic test for AD. Instead, because it negatively correlates with MMSE, it could be a good index reflecting increased AD risk and disease severity.