Alzheimer's Cure by 2025: An Unnecessary Goal?

Contributed by: Dennis Fortier, President, Medical Care Corporation

The National Alzheimer's Prevention Act, signed into law one year ago, calls for a national strategy for defeating this terrible disease. A late-stage draft of the strategy sets a goal to develop a cure by the year 2025.  While many have suggested a timeline with more urgency, say by 2020, others have suggested that this timeline is too ambitious.

On the one hand, given our still poor understanding of the disease, coupled with a dismal track record of success for pipeline drugs over the past decade, it seems unlikely that a cure could be developed prior to 2025.  In fact, against the backrop of recent evidence, it may well take longer than that.

On the other hand, we could stop short of a cure and still have great success.  For example, many chronic diseases like diabetes and hypertension have no cure, but we have effective treatments, and we manage those diseases with high efficacy.  It is likely that new drugs, developed well before 2025, will give us greater treatment benefits for patients with Alzheimer's.

Perhaps of greater importance is the fact that we already have approved therapies that can significantly slow Alzheimer's disease progression.  However, since we commonly detect the disease too late and intervene only after massive brain damage has occurred, the perception among physicians is that treatment is unhelpful.  This nihilistic perception actually perpetuates the cycle of late intervention because, believing that there is no treatment, many MDs don't look for early signs Alzheimer's.

In this regard, a key element to an effective national Alzheimer's strategy would be to update physicians about the benefits of early detection and equip them with the tools and training to proactively monitor the cognitive health of their patients.  When a cure is developed, that will be great.  But in the meantime, we can find the disease early and treat it as effectively as possible with robust therapy (drugs, diet, physical exercise, control of diabetes and hypertension, intellectual stimulation, social engagement, and caregiver education).  Such a comprehensive approach has been shown to significantly delay disease progression in a meaningful percentage of early-stage patients.

Memory Loss More Common in Men?

Contributed by: Dennis Fortier, President, Medical Care Corporation

There is much press this week about a study published in Neurology that measured the incidence of mild cognitive impairment (MCI) in an aging population.

MCI is a subtle loss of thinking ability, such as impaired memory or judgment, that is not severe enough to interfere with the person's normal activities of living.  The study showed about a 20% incidence rate which is squarely in line with previous estimates.

The press has been largely focused on the fact that, in this study, men between the ages of 70 and 89 years had a higher incidence of MCI than women of the same age.  This is probably true.  It is also probably easy to explain.

MCI is not a disease, it is merely a descriptor term for a certain level of cognitive impairment.  It refers to the degree of impairment that falls between normal cognition and the severe loss of function that we call dementia.  Asking "why" a person has MCI is a whole different question with a host of common answers including depression, thyroid disease, stroke, sleep disorder, Alzheimer's disease, and anxiety, to name just a few.  

The question of "why" a person has MCI was not adressed in this study, but may shed some important light on the observed gender differences.  For example, sleep disorders and certain cardiovascular conditions, like hypertension and stroke, are common causes of MCI and are somewhat more prevalent among men than women.  Clearly, conditions that impair memory and are also more common in men, could fully explain the observed gender differences in this study.  In that respect, these results are hardly surprising and, in fact, make perfect sense.

It would be truly worthy of a media frenzy if researchers controlled for each cause of MCI and still found that one gender was more susceptible than the other.  But despite many misleading headlines, that was not the case in this study.

Can Genetic Risk for Alzheimer's be Reduced?

Contributed by: Dennis Fortier, President, Medical Care Corporation

As genetic testing has become more commonplace in medicine, we have all seen frequent examples of overstatement, where writers and speakers confuse "higher risk" with "absolute certainty".  This has been an especially maddening component of arguments against testing for the APOe4 gene associated with increased risk for Alzheimer's disease.

A great many of these faulty arguments state that learning about a genetic risk for an incurable disease is pointless.  (I have refuted that argument many times but that is not the point of this post).  This week, research published in Archives of Neurology strengthens the case for genetic testing.

In a study from the University of Washington in St. Louis, more than 200 participants aged 45 to 88 reported on their physical exercise habits and submitted to spinal fluid measures or PET scans to determine the amount of accumulated amyloid protein in their brains. They also had their APOe4 status checked and researchers found that, among those who carried the APOe4 gene, regular exercisers had less amyloid load than sedentary members of the group.  Interestingly, this was not the case among the APOe4 non-carriers.

This was a small study and needs replication before we can conclude that physical exercise staves off amyloid accumulation in those with genetic risks for AD.  However, the study has a very intuitive finding and gives credence to a much larger body of work showing that good cardiovascular health may reduce the risk of Alzheimer's disease.

The suggestion from this study is very significant.  It could be that genetic risk for AD (usually considered to be an unmodifiable risk), could possibly be reduced by physical exercise.  If so, it will put a whole new spin on those old arguments against genetic testing.