The disease-causing protein tau seems to accumulate faster in women than men. This is shown by a study from Lund University’s strategic research area MultiPark and Skåne University Hospital. The study was recently published in the scientific journal Brain.
Around 100,000 Swedes suffer from Alzheimer’s disease, which is the most common form of dementia. More women than men suffer from memory problems due to Alzheimer’s. Tau and beta-amyloid are two proteins that clump together and accumulate in patients’ brains as the disease progresses. How fast this accumulation goes can be important for the development of the disease.
The accumulation of tau is faster in patients who already have a pathological concentration of beta-amyloid. These are individuals who are already in the early stages of the disease, but who have sometimes not been diagnosed yet. Now, researchers at Lund University have discovered that tau accumulates faster in women, even after they have taken into account the patients’ age and the levels of tau that the patients had at the first measurement. Together with data from three similar studies in the United States, 209 women and 210 men have been examined on several occasions.
– The individual variation in tau levels is large, but in the temporal lobe, which is a central area for Alzheimer’s, the accumulation rate is 75% higher on average for women as a group compared to men, “explains Ruben Smith, specialist at Skåne University Hospital and associate professor of neurology at Lunds university.
Our study gives strong indications that the faster spread of tau means that more women than men suffer from dementia due to Alzheimer’s.
Both men and women are equally affected by the early stages of the disease when the beta-amyloid protein accumulates. Here, the researchers have not found any differences between the sexes. It is only when the protein tau accumulates that memory problems arise and here the researchers found gender differences.
– The next step will be to clarify why the accumulation is faster in women, “says Sebastian Palmqvist, neurologist at Skåne University Hospital, associate professor at Lund University and the researcher behind the cognitive assessments of patients.
The reasons behind the higher rate of accumulation in women
The causes behind the higher rate of accumulation in women have not been investigated in this study. But the difference between the sexes could, according to the researchers, be due to different prevalence of other diseases that can affect the course. Other factors that can differ between the sexes are the levels of hormones and molecules that promote the growth of nerve cells and the degree of inflammation in the brain.
Markers linked to inflammation in the brain can be analyzed in the new BIOFINDER-2 project *. The new study offers more biomarkers and more detailed information on how Alzheimer’s can be linked to other diseases in patients.
– Our study gives strong indications that the faster spread of tau means that more women than men suffer from dementia due to Alzheimer’s. Future experimental studies will be important to understand why this is so, ”continues Oskar Hansson, who is primarily responsible for the study. Oskar Hansson is a professor of neurology at the unit for clinical memory research at Lund University and chief physician at Skåne University Hospital.
The recently published study is the result of a successful collaboration between various research leaders within MultiPark. In addition, the network has supported the brain imaging infrastructures needed for the investigations to be carried out. Since half of all MultiPark’s research leaders conduct molecular research, it would be possible to experimentally investigate the causes behind the clinical findings.
The scientific article “ The accumulation rate of tau aggregates is higher in females and younger amyloid-positive subjects ”
was published in Brain , Volume 143, Issue 12, December 2020, Pages 3805–381.
The study has been funded with the support of: the Swedish Research Council, the Knut and Alice Wallenberg Foundation, the Marianne and Marcus Wallenberg Foundation. The strategic research area MultiPark at Lund University, the Alzheimer’s Foundation, the Brain Foundation, the Parkinson’s Foundation, The Parkinson Research Foundation, Skåne University Hospital, the Faculty of Medicine, Region Skåne ALF funds.
Featured image: In a clinical study, researchers have found that the disease-causing protein tau accumulates faster in women than in men. To the left is shown pathological uptake of how the protein tau in the brain (red). To the right healthy brain. Photo: Ruben Smith.
Provided by Lund University