Cognitive decline in Alzheimer’s disease predicted by patient’s age, sex and irregular heart rate

Older age, female gender, irregular heart rhythms and daily activity levels can help predict how much cognitive function Alzheimer’s patients will decline and how dependent they will be on their caregivers over the next two years.

The findings suggest new ways to predict cognitive decline in patients and that caregivers should be considered in treatment plans. Liane Kaufmann of the Ernst von Bergmann Clinic in Potsdam, Germany, Josef Marksteiner of Hall General Hospital, Austria, and colleagues present the findings in the open-access journal PLOS ONE August 14, 2024.

Alzheimer’s disease affects between 50 and 70 percent of patients diagnosed with dementia. To understand which patient characteristics might best predict cognitive decline in these patients, the authors of this study followed an initial cohort of 500 Austrian patients with probable and possible Alzheimer’s disease for two years.

After taking into account the patients’ medical histories, including heart disease, atrial fibrillation and diabetes, the researchers tracked cognitive function, activities of daily living, depression, pain and neuropsychiatric symptoms over a two-year period. The researchers also assessed the burden on the patients’ caregivers.

All patients experienced significant cognitive decline over the two-year period, associated with decreased activities of daily living and increased dependence on their caregivers. Age, female gender, difficulty performing daily activities, and depression were predictors of cognitive decline at each time point.

Older age, female gender, inability to perform daily activities, and history of atrial fibrillation (rapid, arrhythmic contractions of the upper chambers of the heart) predicted the most severe cognitive decline after two years. Changes in cognitive function were strongly associated with increased caregiver burden.

The study had a high dropout rate and also did not control for lifestyle variables such as physical activity, smoking or alcohol consumption. However, the authors believe their findings suggest that a combination of demographic data (such as age and gender) as well as measures of daily functioning and medical history could help predict cognitive decline, and that caregiver workload should also be an important factor in diagnosing and treating patients with Alzheimer’s disease.

The authors add: “Results from our large prospective study of patients with early-onset Alzheimer’s dementia (AD) identify a combination of older age, female sex, atrial fibrillation (above and beyond other somatic risk factors), poor activities of daily living, and depressive symptomatology as important (and partially modifiable) risk factors for cognitive decline.

“Furthermore, our results reveal strong correlations between caregiver workload and various patient-related measures. Thus, we propose that clinical management of early-stage Alzheimer’s disease should be targeted at the patient-caregiver dyad (instead of focusing solely on the patient).”