- Unusually high or low hemoglobin levels may indicate an increased risk of dementia, according to the latest research.
- Low hemoglobin was associated with an increased risk of Alzheimer’s disease, while both high and low levels were linked to a higher risk of vascular dementia.
- Experts advise that, while hemoglobin levels do not directly cause dementia, they may reflect underlying conditions, such as iron deficiency, chronic kidney disease, and cardiovascular issues.
Unusually high or low hemoglobin levels could indicate an increased risk of dementia.
This is according to research presented in October at the 39th ECNP Congress in Munich and published in the Journal of Alzheimer’s Disease earlier in the year.
The aim of the study was to evaluate the potential link between hemoglobin levels and dementia risk among Korean adults. It also examined whether there was a stronger association in men or women.
The researchers analyzed data from 316,542 participants ages 40 years and over who had had a national health screening in 2004 to 2005, then monitored for dementia diagnoses for 15 years, until 2019.
They found that the highest and lowest hemoglobin levels were linked with an increased all-cause dementia risk. Certain groups were also more likely to experience either Alzheimer’s disease or vascular dementia.
In a press release, Hyun Soo Kim, PhD, study author and assistant professor at Dong-A University College of Medicine, Busan, South Korea, spoke about the importance of the research:
“Dementia is one of the fastest-growing health challenges in aging societies, and there are not many treatments and no cure. Identifying simple, accessible markers of future risk could help researchers and clinicians better understand how whole-body health relates to brain health over time.”
High and low hemoglobin suggest increased dementia risk
The researchers found that the individuals with the highest and lowest hemoglobin levels were most likely to receive a dementia diagnosis later on.
Participants were placed in one of 5 groups, ranging from the lowest hemoglobin levels to the highest.
Individuals in the group with the lowest hemoglobin levels were 16% more likely to develop dementia, while those with the highest hemoglobin levels had a 7% higher risk.
“The findings do not show that hemoglobin itself causes dementia, but suggest that abnormal hemoglobin levels may be a visible marker of wider physical vulnerability relevant to brain health,” Kim explained in the press release.
Medical News Today spoke with Dung Trinh, MD, internist, of MemorialCare Medical Group and Chief Medical Officer of Healthy Brain Clinic in Irvine, CA, to find out about the clinical significance of these findings.
“A 16% increase in dementia risk is certainly worth paying attention to, especially given how common low hemoglobin and anemia can be in older adults. However, it’s important to understand that we’re talking about a relative increase in risk, not an absolute 16% increase in someone’s chance of developing dementia,” explained Trinh, who was not involved in the study.
“This study followed more than 316,000 adults in South Korea and found that people with the lowest hemoglobin levels had a 16% higher adjusted hazard of developing dementia compared with those in the reference group. While this increase is relatively modest for any one individual, it could have meaningful implications at the population level,” he added.
“What I find particularly interesting is that hemoglobin is something we routinely measure with a simple blood test. This gives us another potential piece of information about a patient’s overall health and possibly their long-term brain health. However, we cannot conclude from this study that raising hemoglobin levels will prevent dementia.”
Increased risk of Alzheimer’s disease and vascular dementia
The risk of vascular dementia increased in individuals with either the highest or the lowest levels of hemoglobin, an increase of 18% and 19%, respectively.
However, the chance of Alzheimer’s disease only rose in individuals with lower hemoglobin levels, with an increased risk of 14%.
“There are some interesting biological explanations for this finding,” said Trinh.
“Hemoglobin is
He explained, “Both low and high hemoglobin levels could potentially contribute to vascular problems through different mechanisms. Low hemoglobin may compromise oxygen delivery, while high hemoglobin can increase blood viscosity and may be associated with a greater risk of blood clots and strokes.”
Trinh added that “
