Abstract

Background: Alzheimer Disease (AD), the most common form of dementia, is a progressive and irreversible neurodegenerative disorder. Promising preventative strategies includes identification of potential modifiable risk factors for AD that could help identify individual who are at risk of AD. This study focuses on identifying biochemical factors associated with non- familial AD.
Methods: One hundred and ten individuals which included 55 AD patients and 55 healthy controls were recruited for the study. Patients clinically diagnosed by a neurologist as AD and controls with no clinical or family history of any neurological disease were subjected to Mini-Mental State Examination (MMSE) were evaluated for fourteen relevant biochemical markers using commercial kits. MDR analysis was carried out which is considered a basic machine learning tool for understanding the role of interaction and combination of the factors towards the outcome. PCA is performed to support the MDR interpretation. Through clustering analysis the probably causative factors towards the disease can be identified.
Results: MDR analysis revealed that the overall best fit model included 10 factors which had a maximal testing accuracy of 61%, cross-validation consistency of 8/10. PCA analysis has further reduced the factors to Iron, TSAT, HDL, VitB12, FA, and Hcy which are important in disease initiation/progression. Apart from the cases, 9% of the controls who had lower MMSE also had low Iron, TSAT, HDL, VitB12, FA, and high Hcy.
Conclusion: As per the results obtained, we would suggest a medical practice where, screening individuals above the age of 55 years with both MMSE and selected biochemical parameters (Iron, TSAT, HDL, VitB12, FA, and Hcy) should be carried out to identify those at risk of developing AD. Higher risk individuals can be suggested for modifications in diet/life style, enhancing certain nutritional components which may constitute promising strategies in postponing, slowing, and/or preventing cognitive decline in AD.

Keywords: Alzheimer disease; Folic acid; Vitamin B12; High-density-lipoprotein