The moderating effect of age on the association between homocysteine levels, third ventricular width and cognitive function in Parkinson’s disease

Abstract

Objectives: This study aimed to explore the moderating effect of age on the relationships between homocysteine (Hcy) levels and cognitive function, as well as between third ventricular (V3) width and cognitive function in patients with Parkinson’s disease (PD).

Methods: We enrolled 237 PD patients and categorized them into two groups based on Montreal Cognitive Assessment (MoCA) scores: 65 patients with normal cognition (PDNC) and 172 patients with cognitive impairment (PDCI). All subjects underwent transcranial sonography and laboratory analysis to measure V3 width and Hcy levels, respectively.

Results: Multiple regression analysis with interaction terms revealed significant moderating effects of age on both Hcy-cognition (p < 0.001) and V3-cognition (p = 0.005) relationships. Simple slope analysis demonstrated that the negative impacts of both V3 width and Hcy levels on cognitive function intensified with advancing age (V3: β = -0.654 in younger patients vs. β = -1.260 in older patients; Hcy: β = -0.082 in younger patients vs. β = -0.531 in older patients). No significant interaction was observed between V3 width and Hcy levels on cognitive function (p = 0.074).

Conclusions: Age significantly moderated the relationships between V3 width, Hcy levels, and cognitive function in PD patients, with older patients showing greater cognitive vulnerability to elevated Hcy and ventricular enlargement.