Insulin to Treat AD-A Parable

A new study in the Archives of Neurology reports the possibility that inhaled insulin could slow memory decline and improve function in persons suffering from Alzheimer’s Disease (AD). However, caution is warranted because the double blind, Randomized Control Trial was small (N=104), follow up was short (4 months), and the clinical meaning of the improvements identified are unclear. Insulin disregulation is associated with AD in ways that are not entirely clear, but the study did not identify adverse effects or systematic safety concerns whose ruling out are a key part of phase II clinical trials, so further study is warranted.

Some of the media coverage heralded a “dramatic new development” while others stuck more closely to the measured words of the study

“Although we achieved statistical significance for our primary outcome measure, the observed effects were small in absolute terms, and thus their clinical significance is unclear.”

Why the inclination to overstate the study? AD is emblematic of the increased longevity of the U.S. population; persons who used to die of heart disease in their 50s or 60s are now surviving into their 70s, 80s or 90s and the risk of developing AD roughly doubles with each 5 years of survival beyond age 65. How will we address AD, which is now noted as the 6th leading cause of death when it wouldn’t have even been found in the official cause of death statistics 30 years ago? The preferred way is of course a pill, or an inhaled medication to make the disease vanish. I would love for such a medicine to be found, but more likely, success–it if comes–will be denominated in months of slight improvement.

Since a magic bullet cure is unlikely, we should systematically be asking how long term care should be insured, as such care is inevitable for anyone who develops AD. And 7 in 10 persons living to age 65 will use some LTC, with Medicaid paying for 43% of the total LTC spending in our country. Developing new insurance options that make planning for LTC a normal part of being a young adult are needed, and would seem to be something persons of all political stripes would be for. The CLASS provisions of the ACA are one attempt, but they need to be tweaked, most likely through an initial underwriting process at sign up that could make the program self sustaining. However, instead of working through the policy problems, CLASS is a political football with one side seeking a scalp and the other afraid to acknowledge that there are problems with these provisions of the ACA.

Clinging to hope for a magic bullet that will likely never come, while failing to engage in the (imperfect) policy making needed to provide the LTC that the baby boomers will need is truly a parable of our time.

About Don Taylor
Professor of Public Policy at Duke University (with appointments in Business, Nursing, Community and Family Medicine, and the Duke Clinical Research Institute). I am one of the founding faculty of the Margolis Center for Health Policy, and currently serve as Chair of Duke's University Priorities Committee (UPC). My research focuses on improving care for persons who are dying, and I am co-PI of a CMMI award in Community Based Palliative Care. I teach both undergrads and grad students at Duke. On twitter @donaldhtaylorjr

2 Responses to Insulin to Treat AD-A Parable

  1. “How will we address AD, which is now noted as the 6th leading cause of death when it wouldn’t have even been found in the official cause of death statistics 30 years ago?”

    This is, of course, a very good question. But…

    Something seems wrong here. Changes in overall life expectancy are largely driven by changes in infant mortality, I thought. Yep, here it is. In the US, the elderly only get one extra year every 10 years, as opposed to (from memory) 2.5 years per decade overall over the 20th century. (I see Japan is an outlier, yet again.)

    http://www.ssa.gov/legislation/SenSubCommAging030603_charts.pdf

    So if AD doubles every extra 5 years, but the elderly population is living at most 3 years longer than it was 30 years ago, this doesn’t add up to as major a change as we’re seeing. The eldery population is, of course, increasing rapidly, but AD occurrence per unit population (even unit elderly population) shouldn’t be changing that fast. I think.

    • Don Taylor says:

      @David Littleboy
      AD going from not in the mix to 6th leading does not represent a true increase from 0; there is detection bias as well as coding issues (meaning how you assign underlying cause v. contributing). In the mid-to late 1980s it was decided that AD/dementia was not “old age” but a disorder no matter the age. Hence, it came to be added as COD eventually, but the same biologic process occurred for folks in the early 1980s, just coded differently. The increase is cases due to longer life span is true, but the coding dynamics overstates the increase. There is some evidence that even since coding changed and people paid more attention that prevalence has risen, but there are sill issues of detection bias. I will link a paper later here I did on prevalence increases by race.

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