High-density lipoprotein cholesterol and cognitive function in patients undergoing hemodialysis

Cognitive impairment is highly prevalent among older adults receiving maintenance hemodialysis; however, its pathophysiology is multifactorial and poorly understood. Evidence linking the lipid-profile components to cognitive function in patients undergoing hemodialysis remains limited. To address this evidence gap, we evaluated the associations between serum lipid-profile components and global cognitive function.

We conducted an exploratory cross-sectional study of patients aged ≥ 65 years receiving maintenance hemodialysis at seven dialysis centers in Japan. Serum high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglyceride (TG) levels were measured immediately before the first hemodialysis session of the week. Global cognitive function was assessed using the Montreal Cognitive Assessment (MoCA) and the Mini-Mental State Examination (MMSE). Multivariate linear regression analyses were performed, adjusting for clinical comorbidities and markers of nutritional status, inflammation, and dialysis adequacy.

Among 265 participants (median age, 74 years; 67.6% male), higher serum HDL-C levels were independently associated with higher MoCA scores (fully adjusted model: β = 0.06; 95% confidence interval, 0.03-0.10; P < 0.001) and MMSE scores (β = 0.03; 95% confidence interval, 0.01-0.06; P = 0.031). In contrast, the serum LDL-C and TG levels showed no significant associations with either cognitive assessment.

Higher serum HDL-C levels were associated with better global cognitive function in older patients undergoing hemodialysis, whereas the LDL-C and TG levels were not significantly related to cognitive scores.