Bulletin Board
Results of a study published recently in The Journals of Gerontology Series A Biological Sciences and Medical Sciences indicate that a single dose of methylphenidate (MPH), a drug commonly used to treat attention deficit hyperactivity disorder and narcolepsy, may improve gait function in the elderly.
Falls are the leading cause of hip fracture and accidental death in the elderly. As we age, the risk of falling increases. This is mostly due to age-related deterioration in balance and gait; however, both balance and gait can also be limited by the simultaneous performance of a motor or cognitive task. Using previous studies on the link between MPH and gait and mobility in the elderly as a starting point, the researchers from Ben-Gurion University of the Negev (Beer Sheva, Israel) examined the effects of a single dose (10 mg) of MPH on postural stability and gait in 30 healthy older adults (mean age: 74.9 ± 5.6 years). Using a randomized controlled double-blind study, the participants were assessed in four task conditions (single task, standing still; dual task, standing still performing a memory task; single task, narrow base walking; and dual task, narrow base walking, performing concurrent cognitive tasks).
They found that there was a reduced number of step errors and step error rate in both single and dual tasks, with no equivalent improvement in postural stability, in participants who had received a single dose of MPH. Furthermore, none of the participants experienced any adverse events to the drug treatment.
Itshak Melzer, from Ben-Gurion University‘s Schwartz Movement Analysis and Rehabilitation Laboratory was enthusiastic about the study outcome: “Our results add to a growing body of evidence showing that MPH may have a role as a therapeutic option for improving gait and reducing fall risk in older adults. This is especially true in real-life situations, where the requirement to walk commonly occurs under more complicated, dual task circumstances with cognitive attention focused elsewhere (e.g., watching traffic and talking) and not on performing a specific motor task. The enhanced attention that comes about as a result of MPH may lead to improved balance control during walking, especially in dual task conditions. Our findings that MPH improves gait can be explained not just by its effect of attentional improvements, but also by indications that it has a direct influence on areas of the brain that deal with motor and balance control.”
However, despite these promising results, the authors highlight that the results cannot be generalized to extremely weak or institutionalized elderly individuals because their small sample was taken from a defined, relatively healthy, community-based population.
– Written by Natasha Leeson
Sources: Shorer Z, Bachner Y, Guy T, Melzer I. Effect of single dose methylphenidate on walking and postural stability under single- and dual-task conditions in older adults – a double-blind randomized control trial. J. Gerontol. A Biol. Sci. Med. Sci. doi:10.1093/gerona/glt035 (2013) (Epub ahead of print); Ben-Gurion University of the Negev press release: http://in.bgu.ac.il/en/Pages/news/adhd_fall.aspx
A new international study, published recently in Annals of Emergency Medicine, reports that the needs of the elderly are not being met in emergency departments and, consequently, clinical protocols for treating the elderly in emergency departments should be amended.
In this report, the researchers studied the presence of geriatric syndromes in elderly patients (aged 75 years and older) in 13 emergency departments, in seven countries (Australia, Belgium, Canada, Germany, Iceland, India and Sweden). A total of 2282 patients were recruited, of whom 78% that arrived at emergency departments were dependent in activities of daily living, had fallen in the past 90 days or had cognitive problems.
John Hirdes, from the University of Waterloo‘s School of Public Health and Health Systems (ON, CA), explained: “The majority of older patients attending emergency departments are frail and dependent on others for help. They have distinct and often complex needs. Traditional emergency departments are not equipped for geriatric assessment and intervention because they were designed and staffed to respond to severe acute illnesses and injuries. When you bring an already frail person into a chaotic hospital environment like an emergency department, the risk for misdiagnosis or inadequate care is high. There often aren‘t the trained specialists available, so geriatric conditions like delirium can be misdiagnosed as dementia.”
– Written by Natasha Leeson
Sources: Gray LC, Peel NM, Costa AP et al. Profiles of older patients in the emergency department: findings from the interRAI Multinational Emergency Department Study. Ann. Emerg. Med. doi:10.1016/j.annemergmed.2013.05.008 (2013) (Epub ahead of print); University of Waterloo press release: http://uwaterloo.ca/news/news/emergency-rooms-failing-meet-seniors-needs
There is little literature regarding dual antiplatelet therapy in older versus younger patients with acute coronary syndromes. In a study recently published in Circulation that sought to rectify this, a team of researchers found that elderly patients treated with the smaller dose of prasugrel presented no greater risk of bleeding problems when compared with individuals prescribed 75-mg dose of clopidogrel, the more common treatment for this condition.
Deciding the optimal dosages of medications for elderly heart patients is challenging. Matthew Roe, associate professor of medicine at Duke Medicine (NC, USA), explained: “As people live longer throughout the world, it‘s increasingly important to establish appropriate treatments for conditions such as acute coronary syndromes that commonly occur later in life. These patients are very vulnerable to side effects, including bleeding, if therapies are not properly dosed. Additionally, existing practice guidelines have few specific recommendations for older patients with acute coronary syndromes as little evidence has been accrued from prior clinical trials in this population.”
In this study, 9326 acute coronary syndrome patients from the TRILOGY ACS trial (n = 7243 for individuals <75 years of age and n = 2083 for individuals ≥75 years of age) were randomized to receive either prasugrel (10 mg/day; 5 mg/d for those ≥75 or <75 years of age and <60 kg in weight) or clopidogrel (75 mg/day) plus aspirin for ≤30 months. In study participants ≥75 years of age, the primary end point rates (cardiovascular death, stroke or myocardial infarction) and thrombolysis in myocardial infarction major bleeding were similar with reduced-dose prasugrel and clopidogrel.
Coauthor Magnus Ohman, professor of medicine at Duke, added: “The findings from our study indicate how difficult it is to identify the right dose of anticlotting medications for the elderly to improve outcomes after a heart attack. While a lower dose seemed intuitive, it was safe but not more effective. Future dedicated studies need to continue to find the right therapies for the vulnerable elderly patients.”
– Written by Natasha Leeson
Sources: Roe MT, Goodman SG, Ohman EM et al. Elderly patients with acute coronary syndromes managed without revascularization: insights into the safety of long-term dual antiplatelet therapy with reduced-dose prasugrel versus standard-dose clopidogrel. Circulation 128(8), 823–833 (2013); Duke Medicine press release: www.dukehealth.org/health_library/news/drug-dosing-for-older-heart-patients-should-differ
A recent study, published in Genome Biology, may have provided valuable information moving us one step closer to the use of a blood test in Alzheimer‘s disease (AD) diagnosis. Using miRNA as a blood-based biomarker, Leidinger and colleagues (Saarland University, Saarbrücken, Germany and Siemens Healthcare, Erlangen, Germany) have reportedly distinguished those with AD from controls, but also from other CNS illnesses.
Biomarkers are an invaluable tool in both diagnosis and prognosis for many diseases, but a reliable and accurate biomarker for AD has, as yet, eluded us. A concrete diagnosis of AD is difficult to achieve, if a blood test could distinguish AD from other cognitive impairments, it would be a very desirable diagnostic tool.
The researchers at Saarland University compared blood samples from 48 AD patients with those of 22 controls who were unaffected. By applying next-generation sequencing to miRNA, the authors identified 140 miRNAs whose expression levels changed in the AD individuals. Out of the miRNAs with a higher abundance, the research group selected 12 for quantitative real-time PCR analysis in a larger investigation of 202 blood samples.
Using this 12 miRNA panel, Leidinger and colleagues were able to distinguish individuals with AD from the controls with 93% accuracy, 95% specificity and 92% sensitivity. Other CNS illnesses were also represented in the 202 samples as the symptoms of AD and other cognitive disorders can often overlap. Samples of mild cognitive impairment, multiple sclerosis, Parkinson‘s disease, depression, bipolar disorder and schizophrenia were included. Across these other neurological diseases, AD could be differentiated to accuracies between 74 and 78%, the accuracies distinguishing the other neurological conditions from controls were even higher.
This research further highlights the importance of miRNAs suggested in previous studies. Interestingly, two of the miRNAs in the panel are known to be involved in the processing of APP, a known contributor to AD, so further investigation into this may shed light on some of the processes leading to AD generation. This research holds promise for the field of AD, with the prospect of a cheap and noninvasive method of distinguishing the disease being very appealing.
The future of this research could take many forms. The authors acknowledge that additional work is needed to determine whether these miRNAs could be used as a reliable diagnostic tool, and that one future direction may be in investigating whether these miRNAs are affected by current treatments used in AD.
– Written by Elizabeth Webb
Source: Leidinger P, Backes C, Deutscher S et al. A blood based 12-miRNA signature of Alzheimer disease patients. Genome Biol. 14(7), R78 (2013).
A Group Health Research Institute and University of Washington (WA, USA) collaborative study published in the New England Journal of Medicine has reported results implicating blood sugar levels as a factor in the development of dementia.
The Adult Changes in Thought study was a longitudinal cohort study with one of its primary strengths being that combined data were collected at any interim appointment a participant attended with Group Health Research Institute. This led to a large number of results available for analysis. In total, there were 2067 individuals without dementia involved across a number of years (mean follow-up time being 6.8 years). The cohort presented a mean age of 76 years, were a mix of both men and women, and a proportion of participants also had diabetes. By taking into account all of these factors, Paul Crane and colleagues (University of Washington) were able to study the relationship between blood sugar level, diabetes status and dementia prevalence.
Results demonstrated that, in those without diabetes, a higher average blood glucose level in the 5 years preceding dementia onset correlated with an increased risk of dementia development. Furthermore, this occurred incrementally with no minimal glucose level that reduced dementia risk. This was also the case in those affected by diabetes. The risk of developing dementia was 40% higher in individuals with a glucose level of 190 mg/dl compared with those with a glucose level of 160 mg/dl.
The authors concluded that a higher blood glucose level may be a risk factor for dementia, irrespective of whether individuals suffer from a glucose-associated disorder, in this case diabetes. Although the Adult Changes in Thought study carefully observed blood glucose levels, it did not manipulate them. The next question will be whether lowering blood glucose levels will reduce an individual‘s risk of developing dementia.
– Written by Elizabeth Webb
Source: Crane PK, Walker R, Hubbard RA et al. Glucose levels and risk of dementia. N. Engl. J. Med. 369(6), 540–548 (2013).
