NEUROLOGY
risk, few have tested specific intervention programmes and it’s positive to see new trials in this important area. “This small trial suggested that benefits may only be apparent while someone is actively engaged in an exercise programme, which will need following up in longer studies. The brain only accounts for 2% of our body weight but uses 20% of our oxygen supply, showing just how much oxygen needs to circulate around the brain to keep it working well. “With limited treatment options for people with memory decline or dementia, it’s important to explore a range of possible therapeutic approaches. Clinical trials such as this one are the best way to investigate the potential benefit of any medication or intervention, and the results will help to build a clearer picture of the potential of such an approach. Physical activity does not necessarily mean running marathons, but can involve a brisk regular walk with friends as part of a normal daily routine for people of any age.”7
Studies have also explored whether potential environmental factors may alter the risk of dementia. Researchers recently performed a systematic search of studies that had looked at environmental factors and dementia risk, and found 60 that were eligible for inclusion in the new analysis. The authors reported moderate associations with factors such as tobacco smoke, pesticides, solvents and vitamin D deficiency, although they acknowledged that firm evidence to link these factors directly with dementia are still lacking.8
In addition to the known lifestyle and environmental factors, other risks are also being identified. New research has highlighted a possible link between a prostate cancer treatment called androgen deprivation therapy (ADT) and the risk of
dementia. Androgens are a group of male hormones that includes testosterone. These hormones play a number of important roles in the body but can also stimulate the growth of prostate cancer cells in those affected by the disease. Androgen deprivation therapy blocks the effect of androgens on prostate cancer cells and is one treatment approach doctors may use to tackle the disease.9 Previous research by the authors suggested a link between ADT and Alzheimer’s disease, the most common cause of dementia. Dementia can be caused by a number of different diseases and this study broadened the analysis to see whether the therapy might be associated with a risk of all types of dementia.
The researchers reviewed the medical records of 9,272 men with prostate cancer, including 1,826 who had received ADT, taking into account established dementia risk factors such as age and cardiovascular health. The team found that, five years on from a diagnosis of prostate cancer, patients who didn’t receive ADT had a 3.5% risk of developing dementia compared to a 7.9% risk for those who did receive the therapy. Patients who received the treatment for at least a year showed the highest increased risk of developing dementia. The researchers suggested some possible causes for a link between ADT and dementia risk, highlighting that blocking androgens could affect the health and growth of nerve cells in the brain.9 Dr Laura Phipps explained: “This study is
part of an active area of research into the role that sex hormones like testosterone could be playing in the brain in dementia. Studies like this, which take advantage of the rich data held in medical records, can be very useful for highlighting trends and potential risk factors for further research. “While these results suggest a link between androgen deprivation therapy and
Hip fracture risk and dementia
The hip fracture risk factors are generally similar among those with and without Alzheimer’s disease, according to a recent study from the University of Eastern Finland. However, the incidence of hip fracture is higher among those with Alzheimer’s disease, regardless of other characteristics. Alzheimer’s disease itself appears to be such a significant risk factor for hip fracture that the relative impact of other risk factors is considerably smaller among those with Alzheimer’s disease. Older persons, men, and those with mental and behavioural disorders or using antipsychotics or antidepressants had a higher hip fracture risk both among persons with and without Alzheimer’s disease, but the relative risk increase was higher among persons without Alzheimer’s disease. Stroke, diabetes, active cancer treatment, and the use of proton pump
inhibitors, antiepileptics or opioids were associated with a higher hip fracture risk only in those without Alzheimer’s disease. The findings are based on the MEDALZ
study, including all community-dwellers of Finland who received a clinically verified diagnosis of Alzheimer’s disease in 2005- 2011 and had no history of previous hip fracture (N=67,072) and a matched cohort of persons without Alzheimer’s disease. Previously, many risk factors for hip fracture, including dementia, had been identified. It was not known whether the same factors predict hip fracture risk in persons with and without Alzheimer’s disease, which is the most common form of dementia. However, it is known that the consequences of hip fracture are even more devastating for a person with dementia. The new findings underline the importance of developing and implementing preventive
38 I
WWW.CLINICALSERVICESJOURNAL.COM
interventions that are suitable for persons with dementia. Different preventive interventions such as exercise, medications, home safety assessment and modification interventions, as well as medication reviews have already been proposed but few studies have explored the applicability of these measures to persons with dementia. Regular assessments of medication are one feasible approach, as an association was found between various medications and hip fracture risk.
Reference
1 Anna-Maija Tolppanen, Heidi Taipale, Antti Tanskanen, Jari Tiihonen, Sirpa Hartikainen: Comparison of predictors of hip fracture and mortality after hip fracture in community-dwellers with and without Alzheimer’s disease – exposure-matched cohort study. BMC Geriatrics (2016) 16:204. DOI 10.1186/s12877-016-0383-2
FEBRUARY 2017
an increased risk of dementia, they do not show that ADT is definitely causing this increased risk. We need to better understand the impact of sex hormones in the brain in diseases like Alzheimer’s to delve deeper into the possible reasons for this link.”9 Other recent insights have focused on the role of calcium supplements in potentially elevating risk. Researchers from the University of Gothenburg in Sweden have found that the use of calcium supplements is associated with an increased risk of dementia in women with increased cardiovascular risk.10 In this observational study, the
researchers followed a group of 700 women for five years. The women did not have dementia at the start of the study, and the researchers recorded the number using calcium supplements as well as how many went on to develop dementia. They assessed dementia using standard tests of memory and thinking skills and also took measurements of the volunteers’ cardiovascular health. Information about the dose of calcium taken by the participants was not available but the recommended daily dose of calcium in Sweden is 1000mg/day. The participants also had a brain scan to help researchers identify signs of vascular disease in the brain. During the five-year study period, 59 women (8%) developed dementia. Of the 98 women taking calcium supplements, 14 (14%) went on to develop dementia while of the 602 women not taking supplements, only 45 (7.5%), developed dementia.10 Research has shown that the risk of dementia, particularly vascular dementia, is increased by high blood pressure and cholesterol levels, being overweight, smoking, a lack of physical activity, diabetes and history of stroke. When the history of stroke was taken into consideration in this study, only women taking calcium
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64
