While growing evidence suggests that there’s a link between blood iron levels and the development of Alzheimer’s disease, new research investigating the effects of an available iron-reducing drug has raised concerns about its use as a treatment for the condition.
With aging, iron deposits in different brain regions may impair normal cognitive functioning. Studies have found that iron plays a role in the development of Alzheimer’s disease, with excessive iron levels contributing to the deposition of beta-amyloid and the formation of tangles in the brain that promote neurodegeneration.
Because of this, medications that reduce iron overload by binding to iron, a process that’s called chelation, have received a good deal of attention as potential treatments for Alzheimer’s disease. However, new research examining the effects of one particular iron chelator medication on Alzheimer’s progression has raised alarm.
The study was a collaboration between Australian institutions, including the Florey Institute of Neuroscience and Mental Health (The Florey), the University of Melbourne, the University of New South Wales (UNSW), Monash University, Curtin University, The Queensland Brain Institute, the Commonwealth Scientific and Industrial Research Organization (CSIRO), and the University of Newcastle.
The researchers investigated the drug deferiprone, an iron chelator that is usually used to remove excess iron in people with certain blood disorders (thalassemia, sickle cell anemia) who have too much iron in their bodies because of repeated blood transfusions. The 12-month clinical trial was conducted on 81 patients over the age of 54 with mild cognitive impairment or early Alzheimer’s and confirmed amyloid deposits. Participants were randomized to receive either 15 mg/kg of oral deferiprone twice a day or a placebo. The primary outcome was improved cognitive functioning – memory, executive function, and attention – which the researchers assessed at baseline, six and 12 months. Secondary outcomes included a change in brain iron levels.
MRIs showed that, compared to patients in the placebo group, those treated with deferiprone had reduced iron levels in the hippocampus, a region of the brain that is heavily involved in memory. However, while it reduced iron levels in the brain, patients who received the drug showed accelerated cognitive decline overall, driven primarily by worsening performance on executive function tests. Executive functioning is the term given to the higher-level mental processes that enable us to make plans, focus our attention, remember, and juggle multiple tasks.
The researchers say that their trial findings suggest that lowering iron levels using deferiprone makes things worse for people with Alzheimer’s disease.
The study was published in the journal JAMA Neurology.
Source: Scimex