Sorry for my voice.  I've been pretty sick this week.  I'm part of a weekly gaming group.  Most of the time it's role-playing games.  Other board games come into play as well.  Most of the participants are doctors.  We have a group text that we officially use to schedule gaming night,  but unofficially, it's the way that we share news stories about medicine that drive us insane.  It's unfortunate that this gaming group group text, which is seriously one of the most qualified, educated, and thought-provoking (?~0:26) that only eight people in the world get access to, can't be more widely shared, but today, we're gonna go over some of those crazy new stories and why you shouldn't believe every headline you read.  That's the topic of this week's Healthcare Triage.

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Here's the one that got this episode going.  From Reuters, "Sleeping in on weekends may help reduce diabetes risk".  That headline is based on a study published in Diabetes Care.  That study took 19 healthy, young, lean men and for four nights, they were allowed to sleep for up to 8.5 hours.  On four other nights, they were only allowed 4.5 hours in bed, followed by up to 12 hours in bed, and then 10 hours in bed.  

They found that insulin sensitivity was reduced by a relative, not absolute, 23% after sleep deprivation and that this resolved somewhat after recovery sleep.  You'll notice I said nothing about diabetes.  Nothing about women.  Nothing about older people.  Nothing about long-term effects, and when a lot of us think about sleeping in on the weekend, it's not after getting only 4.5 hours all week, so almost none of this applies to real life, yet, "Sleeping on weekends may help reduce diabetes risk."  

Many of you wrote to me angrily after my Upshot piece and Healthcare Triage episodes on artificial sweeteners.  You cited many, many headlines that showed that consuming artificial sweeteners led to diabetes.  Almost of all them were based on a Nature study entitled "Artificial sweeteners induce glucose intolerance by altering the gut microbiota." 

The manuscript described many experiments.  First, researchers showed that mice fed aspartame, sucralose, or saccharin had a higher blood glucose levels than mice who were fed just water or sugar.  Second, they showed that if they sterilized the guts of mice or cleared out their microbiomes and then did bacterial transplants from mice who were fed artificial sweeteners, those mice with the new bacteria had higher blood sugar levels than those who got transplants from mice fed sugar.  Third, they showed that people who use artificial sweeteners have different levels of certain kinds of bacteria in their guts than those who don't.  The final study involved seven people, five men and two women.  They were healthy people who didn't use artificial sweeteners.  They were given the FDA's maximum allowable amount of saccharine for six days.  Four of the seven developed, quoting, "abnormal glucose responses," and three didn't.  The four people who developed this also showed changes in the levels of bacteria in their guts.  

So what we have are two mice studies, one relatively small cross-sectional analysis of people that can establish causality and didn't appear to control for anything other than BMI, and a final prospective study of seven people followed for a week.  I think that the results of that manuscript are worthy of follow-up and further research, but they don't merit inclusion as to what we can and can't say artificial sweeteners do to humans in practice.  With so few participants, it's hard to discuss validity at all.

There are also a lot of holes here.  No one knows how the artificial sweeteners affect the bacteria in the gut.  No one knows why the three different artificial sweeteners resulted in similar changes when they're completely different molecules, and no one really knows how the interplay between bacteria in the gut or the microbiome affects health.  There are some interesting theories, but they're nowhere near conclusive.  

Here's one from NOVA about a year ago, and they should know better.  "Scientists finally prove why cold weather makes you sick."  Lots of you took this opportunity to e-mail me that I was wrong in our cold weather myths episode when I said this wasn't true.  It's still not, regardless of what those headlines say.

News stories this time were based on a press release from a paper entitled "Temperature dependant innate defense against the common cold virus limits viral replication of warm temperature in mouse airway cells."  So let's unpack this study.  

They took mouse airway epithelial cells in the lab and infected them with rhinovirus.  They then checked to see how well the virus was able to replicate itself in those cells in the lab at both 37 degrees Celsius and 33 degrees Celsius, which is 98.6 Fahrenheit versus 91.4 Fahrenheit.  

Neither of those is cold weather.  That's the difference between the temperature in the core of your body and the temperature in your nose likely.  'Cause it's colder in your nostrils than deep in your body, and it turns out that rhinovirus replicates better in your nostrils than in the core of your body.  It prefers a balmy 91.4 degrees to a toasty 98.6.  It's cells.  Of mice.  In the lab.  In controlled environments.  Measuring only viral replication.  At temperatures nowhere near what we'd define as cold.  This is not proof in any way that cold weather makes it more likely for you to catch a cold.  

A few months later, The Daily Mail ruined my day with this headline: "Popular sleep remedies and hay fever pills increase the risk of Alzheimer's by more than 50%" but the study this is based on was from JAMA Internal Medicine, "Cumulative use of strong anticholinergics and incident dementia, a prospective cohort study."  

Researchers followed 3,400 participants, who were 65 years of age or older, for an average of seven years.  They were interested in seeing if the use of anticholinergic drugs, especially really chronic use, was associated with an increased risk of dementia or Alzheimer's.  The top line results were that those who used anticholinergic drugs had a significantly increased risk, hazard ratio of 1.5, of dementia if they had at least 1095 standard daily doses of these drugs.  

That's where the 'more than 50% increased risk' comes from.  Well, let's unpack.  That's a relative risk increase.  What's the actual risk increase?  That's hard to tease out, because they don't report the actual rates of Alzheimer's or dementia in the two groups in the study, only the number of incidents per person (?~6:04) of follow-up.

For instance, you can tell from table three than in the high users of these drugs, there were 184 cases of dementia for 4,022 person years of follow up, or 0.46 cases per 10 person years versus 136 cases for 5,618 person years of follow up in users who never used the drugs or 0.24 cases per 10 person years, but that's before adjustment and these drugs are not all the same.  Some of them are for serious problems.  In fact, more than half of the people in the trial who were high users of anticholergics were on antidepressants, not Benadryl.  

We also can't forget that these are all people over the age of 65.  That's a very different population than the 40-some year old women, which is what my wife and many of our friends on Facebook, were considering.  

That's not even what I want to stress the most.  There are trade-offs.  I imagine that many of the people in this study were taking antidepressants because they were depressed.  I hope that they were receiving the benefit from those drugs.  Some were for bladder control issues and I imagine the drugs benefit those people, too, but if you only focus on the harms, you'd never consider any therapies at all, and that's what headlines often do.  You need to go deeper.  Hopefully Healthcare Triage helps.

Healthcare Triage is supported in part by viewers like you through patreon.com, a service that allows you to support the show through a monthly donation.  Your support makes this show bigger and better.  We'd especially like to thank our research associate Joe Sevits and thank our surgeon admiral, Sam.  More information can be found at patreon.com/healthcaretriage.  

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