Plasma cholesterol in Alzheimer's disease and frontotemporal dementia

The relationship between the apolipoprotein E (APOE)-ε4 allele, triglyceride (TG) level, and cholesterol level and an increased risk of developing Alzheimer's disease (AD) has been well established, but their relationship with behavioral-variant frontotemporal dementia (bvFTD) is not well-known.

The levels of TGs, total cholesterol (TC), low-density lipoprotein (LDL), and high-density lipoprotein were measured in bvFTD and AD patients and in normal controls (NCs). DNA was extracted, and APOE was genotyped.

The APOE-ε4 allele frequency was higher in the AD group than in the NC group, but no difference was found between the AD and the bvFTD groups. The bvFTD group had higher LDL than the AD group, and significant differences were also found for the cholesterol level in the dementia groups compared with the NC group. Elevated LDL level was positively correlated with appetite and eating score in the bvFTD group. Compared with the AD patients and NCs without the APOE-ε4 allele, those with the APOE-ε4 allele had higher TC, but its correlation with the bvFTD group was absent.

The bvFTD and the AD groups had higher cholesterol levels. The APOE-ε4 allele and eating behavior might modify lipid metabolism in dementia. TG and cholesterol analyses may offer a new opportunity for targeted treatments.