Blood lipid markers are associated with hippocampal viscoelastic properties and memory in humans

Abstract

Age-related memory loss shares similar risk factors as cardiometabolic diseases including elevated serum triglycerides (TGs) and low-density lipoprotein cholesterol (LDL-C) and reduced high-density lipoprotein cholesterol (HDL-C). The mechanisms linking these aberrant blood lipids to memory loss are not completely understood but may be partially mediated by reduced integrity of the hippocampus (HC), the primary brain structure for encoding and recalling memories. In this study, we tested the hypothesis that blood lipid markers are independently associated with memory performance and HC viscoelasticity—a noninvasive measure of brain tissue microstructural integrity assessed by high-resolution magnetic resonance elastography (MRE). Twenty-six individuals across the adult lifespan were recruited (14 M/12 F; mean age: 42 ± 15 y; age range: 22–78 y) and serum lipid profiles were related to episodic memory and HC viscoelasticity. All subjects were generally healthy without clinically abnormal blood lipids or memory loss. Episodic memory was negatively associated with the TG/HDL-C ratio. HC viscoelasticity was negatively associated with serum TGs and the TG/HDL-C ratio, independent of age and in the absence of associations with HC volume. These data, although cross-sectional, suggest that subtle differences in blood lipid profiles in healthy adults may contribute to a reduction in memory function and HC tissue integrity.

Structure–Function Dissociations of Human Hippocampal Subfield Stiffness and Memory Performance

“…Eighty-eight participants were included from three different studies (age range: 23-81 years, M/F: 36/51); all participants completed identical one-hour MRI scanning protocols on a 3T Siemens Prisma MRI scanner. Subsets of these data have been previously reported (Delgorio et al, 2021;Sanjana et al, 2021). We confirmed MRE data quality for each participant in our sample, as quantified by octahedral shear strain signal-to-noise ratio (OSS-SNR), and all 88 participants had OSS-SNR values greater than the threshold of 3.0 necessary for stable property estimation (McGarry et al, 2011;Hannum et al, 2021).…”

Swimming training and Plantago psyllium ameliorate cognitive impairment and glucose tolerance in streptozotocin–nicotinamide-induced type 2 diabetic rats

“…The association between lipid profile elevation and brain function dysfunction has not yet been elucidated, but recently, it has been shown that an increase in lipid profile can partially reduce the integrity of the hippocampus, the primary brain structure for encoding and recalling memories. Hippocampus viscoelasticity is negatively associated with serum TG levels and the TG/HDL-C ratio [ 43 ]. In this regard, the results of this study showed that diabetes decreases the general locomotor activity and passive avoidance, and cognitive memory, but anxiolytic activity, despite an insignificant increase, was not affected by diabetes induction.…”

Insulin resistance-related features are associated with cognitive decline: a cross-sectional study in adult patients with type 1 diabetes

“…Other than the obesity parameters, dyslipidemia also showed an independent correlation with deteriorated cognitive function. Findings from general population suggest that even modest, preclinical changes in lipid metabolism may be sufficient to evoke changes to hippocampus structure and function, which is responsible for encoding and recalling memories [ 33 ]. And simvastatin and lovastatin are drugs that can potentially be used for the treatment of cognitive deficits [ 34 ].…”