Saturday, August 11, 2012

hospital sleep and diagnosing diabetes

I have time to read the journals so you don't have to. I wanted to recap two really interesting articles in the most recent Annals for people who might not get a chance to read them.

The first is kind of a geeky article about diagnosing diabetes. I'm not sure why, but I have always found this a really interesting issue. The lab test used for monitoring one's sugar level is the a1c. When exposed to sugar, red blood cells do this little chemical reaction and by looking at how much of the chemical reaction has happened to the average red blood cell, you get a good idea of the average sugar level over the lifetime of the red blood cell. Red blood cells last about three months on average so the a1c is an indicator of what your average sugar has been over the past three months. Diabetics monitor their sugar at a particular moment in time to figure out what to do with their meds on a day to day basis, but doctors monitor the a1c to see how the person is doing overall.

When I was a resident, officially, one could not diagnose diabetes by checking an a1c, only by catching or inducing an elevated sugar. The a1c could only confirm diabetes and then monitor it. This was largely a historical thing (I think) and struck those of us who trained in the late 90's/early 2000's as dopey and lead to lots of glucose tolerance tests which require several blood draws, drinking a disgusting sugar load, two hours of time and, I bet, more money than an a1c, but I digress. A few years ago, the definition changed and we could diagnose diabetes with an a1c, but the level of a1c that was high enough to call diabetes was not really clearly defined. Most people said 6.5, but there was a lot of controversy about how strictly diabetes should be controlled--some studies said that some patients whose sugars were controlled to normal levels actually did worse than similar patients who were allowed to have slightly higher sugars. Maybe we were now in the position of telling people that their a1c was 6.7 so they had diabetes, but that their a1c was about at goal so we didn't need to do anything differently. Complicating the whole picture is that there may have been some evidence that treating "pre-diabetes" like diabetes delayed the onset of diabetes so some doctors treated their pre-diabetic patients. (There was also some thought that treating pre-diabetics with diabetes medicines postponed their diagnosis of diabetes because it lowered their sugars and that's how you diagnose diabetes so it's a bit of a recursive loop.) Are you getting the idea that it is a messy situation?

Enter more confusion. You may know that African Americans tend to have higher a1c's for the same level of sugars and so there has been some thought that the a1c used for diagnosing an African American person with diabetes should be a little bit higher than the a1c level used for a person who was not African American. Is this clear? I hope so, because here is the payoff: this recent article in Annals looked at a1c's and rates of early diabetes complications sorted by African American / not African American. They found that African Americans have a higher rate of this one particular complication for the same a1c level, making their suggestion be that African Americans should actually be diagnosed at a lower level of a1c. Whoa, huh? I think the whole issue of what's real (diabetes as a construct) and what are the outcomes we care about (complications) is really interesting. I really enjoy thinking about the relationship between where one diagnoses diabetes and rates of false and true positives. The fact that one can subdivide patient groups and get different sorts of answers is an extra interesting spin on the whole puzzle. OK, geeky.

hospital sleep article

OK, you didn't read all that self indulgent drivel about diabetes, did you? Good, don't waste your time. This is really interesting. Also in Annals, they recruited 12 healthy young people and then deliberately disrupted their sleep with typical hospital sounds. Guess what? typical hospital sounds at typical hospital volumes were disruptive. There is an older study that monitored patients in a CCU during a period of bad acoustics and then changed the ceiling tiles and did it again. Their results showed that "adverse acoustic environments are associated with higher pulse amplitude at night and elevated use of beta blockers. the patient group exposed to the unimproved acoustic environment also demonstrated higher rates of rehospitalization and poorer ratings of quality of care." Some things to make the environment quieter are so easy and of course better sleep leads to better outcomes. Wow! Now that it's been pointed out to me, I'm surprised that every hospital doesn't have a Better Sleep Committee working on these issues.

1 comment:

  1. I thought both articles were interesting! Then again, I'm kind of geeky about reading medical articles sometimes though I don't read the journals. I just read the magazines in the waiting rooms as I wait to see doctors or stuff people post of Facebook. Fortunately, I have the training in statistics and study design to understand what is pure garbage and what is probably a well-designed study so reading stuff on Facebook is usually dismissed before I finish the article.