Forty percent of dementia cases could be prevented or delayed by targeting 12 risk factors throughout life
July 30, 2020
Science Daily/University of Southern California - Health Sciences
Modifying 12 risk factors over a lifetime could delay or prevent 40% of dementia cases, according to an updated report by the Lancet Commission on dementia prevention, intervention and care presented at the Alzheimer's Association International Conference (AAIC 2020).
Twenty-eight world-leading dementia experts added three new risk factors in the new report -- excessive alcohol intake and head injury in mid-life and air pollution in later life. These are in addition to nine factors previously identified by the commission in 2017: less education early in life; mid-life hearing loss, hypertension and obesity; and smoking, depression, social isolation, physical inactivity and diabetes later in life (65 and up).
"We are learning that tactics to avoid dementia begin early and continue throughout life, so it's never too early or too late to take action," says commission member and AAIC presenter Lon Schneider, MD, co-director of the USC Alzheimer Disease Research Center's clinical core and professor of psychiatry and the behavioral sciences and neurology at the Keck School of Medicine of USC.
Dementia affects some 50 million people globally, a number that is expected to more than triple by 2050, particularly in low- and middle-income countries where approximately two-thirds of people with dementia live, according to the report. Women are also more likely to develop dementia than men.
However, in certain countries, such as the United States, England and France, the proportion of older people with dementia has fallen, probably in part due to lifestyle changes, demonstrating the possibility of reducing dementia through preventative measures, Schneider says.
Schneider and commission members recommend that policymakers and individuals adopt the following interventions:
Aim to maintain systolic blood pressure of 130 mm Hg or less from the age of 40.
Encourage use of hearing aids for hearing loss and reduce hearing loss by protecting ears from high noise levels.
Reduce exposure to air pollution and second-hand tobacco smoke.
Prevent head injury (particularly by targeting high-risk occupations).
Limit alcohol intake to no more than 21 units per week (one unit of alcohol equals 10 ml or 8 g pure alcohol).
Stop smoking and support others to stop smoking.
Provide all children with primary and secondary education.
Lead an active life into mid-life and possibly later life.
Reduce obesity and the linked condition of diabetes.
The report also advocates for holistic, individualized and evidenced-based care for patients with dementia, who typically have more hospitalizations for conditions that are potentially manageable at home and are at greater risk for COVID-19. In addition, it recommends providing interventions for family caregivers who are at risk for depression and anxiety.
The commission members conducted a thorough investigation of all the best evidence in the field, including systematic literature reviews, meta-analyses and individual studies, to reach their conclusions.
https://www.sciencedaily.com/releases/2020/07/200730123651.htm
Apathy not depression helps to predict dementia
July 13, 2020
Science Daily/University of Cambridge
Apathy offers an important early warning sign of dementia in individuals with cerebrovascular disease, but depression does not, new research led by the University of Cambridge suggests.
Depression is often thought to be a risk factor for dementia but this may be because some depression scales used by clinicians and researchers partially assess apathy, say scientists from the universities of Cambridge, King's College London, Radboud and Oxford.
The study, published on 11 July in the Journal of Neurology, Neurosurgery & Psychiatry is the first to examine the relationships between apathy, depression, and dementia in individuals with cerebral small vessel disease (SVD). SVD may occur in one out of three elderly individuals, causes about a quarter of all strokes, and is the most common cause of vascular dementia.
The team studied two independent cohorts of SVD patients, one from the UK and the other from the Netherlands.* Across both cohorts, they found that individuals with higher baseline apathy, as well as those with increasing apathy over time, had a greater risk of dementia. In contrast, neither baseline depression nor change in depression had any detectable influence on dementia risk.
These findings were consistent despite variation in the severity of participants' symptoms, suggesting that they could be generalised across a broad spectrum of SVD cases. The relationship between apathy and dementia remained after controlling for other well-established risk factors for dementia including age, education, and cognition.
Lead author, Jonathan Tay, from Cambridge's Department of Clinical Neurosciences said: "There has been a lot of conflicting research on the association between late-life depression and dementia. Our study suggests that may partially be due to common clinical depression scales not distinguishing between depression and apathy."
Apathy, defined as a reduction in 'goal-directed behaviour', is a common neuropsychiatric symptom in SVD, and is distinct from depression, which is another symptom in SVD. Although there is some symptomatic overlap between the two, previous MRI research linked apathy, but not depression, with white matter network damage in SVD.
Jonathan Tay said: "Continued monitoring of apathy may be used to assess changes in dementia risk and inform diagnosis. Individuals identified as having high apathy, or increasing apathy over time, could be sent for more detailed clinical examinations, or be recommended for treatment."
Over 450 participants -- all with MRI-confirmed SVD -- recruited from three hospitals in South London and Radboud University's Neurology Department in the Netherlands, were assessed for apathy, depression and dementia over several years.
In the UK cohort, nearly 20% of participants developed dementia, while 11% in the Netherlands cohort did, likely due to the more severe burden of SVD in the UK cohort. In both datasets, patients who later developed dementia showed higher apathy, but similar levels of depression at baseline, compared to patients who did not.
The study provides the basis for further research, including the mechanisms that link apathy, vascular cognitive impairment, and dementia. Recent MRI work suggests that similar white matter networks underlie motivation and cognitive function in SVD. Cerebrovascular disease, which can be caused by hypertension and diabetes, can lead to network damage, resulting in an early form of dementia, presenting with apathy and cognitive deficits. Over time, SVD-related pathology increases, which is paralleled by increasing cognitive and motivational impairment, eventually becoming severe enough to meet criteria for a dementia state.
Jonathan Tay says: "This implies that apathy is not a risk factor for dementia per se, but rather an early symptom of white matter network damage. Understanding these relationships better could have major implications for the diagnosis and treatment of patients in the future."
https://www.sciencedaily.com/releases/2020/07/200713120022.htm