Awwww, sniff, sniff! AlzGadfly admits he was rooting for intranasal insulin to have some positive effect in Alzheimer’s Disease (AD) or MCI. The early results (2012) from a pilot study at a local VA hospital were encouraging. Then a press release from the AAIC19 last year was encouraging. But last month, the most definitive report so far (of SNIFF, Study of Nasal Insulin to Fight Forgetfulness) showed no positive effects on cognition or function, and there was marginal shrinkage of certain brain areas on MRI (JAMA Neurology June 2020). Perhaps it was OK we couldn’t enroll in 2012, because the investigator moved across the country.
The study was a bit complicated; the first intranasal delivery device, used in earlier positive pilot studies, was found to be unreliable, so the investigators replaced it. This led to having two cohorts in an double-blind placebo controlled multi-institutional trial, also featuring an open-label period, imaging and CSF examination. They had more than twice the number of subjects (289) than the initial pilot, used “intention to treat” (i.e. standard) methods of testing and analysis, but the hypothesis in this study was reportedly null (sadly, it didn’t work).
Another null hypothesis: Aspirin did not prevent cognitive decline in a large study with almost 20,000 subjects randomized. AlzGadfly liked the scope and ambition of this one! Double-blind placebo controlled, mostly subjects in Australia and some in the US, followed for almost five years. The study dose, 100 mg, is not really baby aspirin, which is usually 80 mg in the US. It was disappointing as a result, but it seemed like an admirable effort, and part of the nature of honest clinical science. Nice to see it published.
Worth mentioning, and providing links, for those interested:
- A meta-analysis study that blood pressure control may help in prevention; they imply (perhaps) that they could tease out that BP meds themselves don’t improve test performance, but BP control seems to help prevent dementia. There were a number of caveats; they did not recommend a certain BP target.
- Sleep duration may help (?) a person’s PET scans. Out of 855 subjects in Japan wearing wrist sensors, 118 developed MCI, >5-1/2 hours seems better for less PET amyloid, but it was also associated with less PET glucose use. Total sleep time showed more effect on scans than total steps taken or conversation time.
- Do alcoholic drinks may help? Although the WHO Dementia risk reduction guidelines suggest otherwise, a published study of almost 20,000 self-reported low-moderate drinkers (women <8 drinks, men <14 drinks/week) shows that AlzGadfly needs another one.