Lower tau levels may obscure early Alzheimer’s in black patients

  • Two large studies show an association between the Alzheimer's protein tau and the Alzheimer's gene APOE4, but the association varies across race and gender.

Data from 1,215 older adults, of whom 173 (14%) were African-American, has found that, although brain scans showed no significant differences between black and white participants, cerebrospinal fluid (CSF) showed significantly lower levels of the brain protein tau in African-Americans.

While both groups showed the same (expected) pattern of higher tau levels being associated with greater chance of cognitive impairment, the absolute amounts of tau protein were consistently lower in African-Americans.

However, when APOE status was taken into account, it was found that those who held the low-risk variants of the “Alzheimer’s gene” had similar levels of tau, regardless of race. It was only African-Americans with the APOE4 gene variant that showed lower levels of tau.

This suggests that the APOE4 risk factor has different effects in African-Americans compared to non-Hispanic white Americans, and points to the need for more investigation into how Alzheimer’s develops in various populations.

Interestingly, another study, using data from 1798 patients (of whom 1690 were white), found that there was a strong gender difference in the association between APOE status and tau levels in the CSF.

Previous research has shown that the link between APOE4 and Alzheimer's is stronger in women than men. This study points to a connection with tau levels, as there was no gender difference in the association between APOE and amyloid-beta levels, amyloid plaques, or tau tangles.

https://www.futurity.org/alzheimers-disease-black-patients-1951502/

Reference: 

Morris JC, Schindler SE, McCue LM, et al. Assessment of Racial Disparities in Biomarkers for Alzheimer Disease. JAMA Neurol. Published online January 07, 2019. doi:10.1001/jamaneurol.2018.4249

Hohman TJ, Dumitrescu L, Barnes LL, et al. Sex-Specific Association of Apolipoprotein E With Cerebrospinal Fluid Levels of Tau. JAMA Neurol. 2018;75(8):989–998. doi:10.1001/jamaneurol.2018.0821

 

Related News

A large, two-year study challenges the evidence that regular exercise helps prevent age-related cognitive decline.

A study involving 97 healthy older adults (65-89) has found that those with the “Alzheimer’s gene” (APOe4) who didn’t engage in much physical activity showed a decrease in hippocampal volume (3%) over 18 months.

An Indian study involving 648 dementia patients, of whom 391 were bilingual, has found that, overall, bilingual patients developed dementia 4.5 years later than the monolingual ones. There was no additional advantage to speaking more than two languages.

A study, involving 371 patients with mild cognitive impairment, has found that those with depressive symptoms had higher levels of amyloid-beta, particularly in the frontal cortex and the anterior and posterior

A study involving 206 spousal and adult children caregivers of dementia sufferers (mostly Alzheimer’s) has found that about 84% of caregivers reported a clinically significant burden. Three factors were significant contributors to the burden:

A study involving 254 people with dementia living at home has found that 99% of people with dementia and 97% of their caregivers had one or more unmet needs, 90% of which were safety-related.

A new U.S. study suggests that Alzheimer's disease and other dementias are markedly under-reported on death certificates and medical records. Death certificates tend to only provide an immediate cause, such as pneumonia, and don’t mention the underlying condition that provoked it.

It’s often argued that telling people that they carry genes increasing their risk of Alzheimer’s will simply upset them to no purpose. A new study challenges that idea.

11 new genetic susceptibility factors for Alzheimer’s identified

Understanding a protein's role in familial Alzheimer's disease

Pages

Subscribe to Latest newsSubscribe to Latest newsSubscribe to Latest health newsSubscribe to Latest news