Feeling Cold, pt. 2 - effect of insulin on body temp

As you may recall, I recently started doing some data recording of my basal body temperature at waking and before bed. Through that data, it was pretty obvious that my core body temperature (CBT) is more than a bit lower than the normal 98.6 degrees (F). I have consistently run 96.5. Having established my initial baseline for my A-B-A data set test for my upcoming experiments on increasing my own CBT, I was doing some Google-research when I stumbled upon a preview of an article to be published this coming October in the medical journal, Diabetes.

The article is entitled "Insulin Causes Hyperthermia by Direct Inhibition of Warm-Sensitive Neurons." The objective of the research was to examine the role of the metabolic signal insulin in the control of core body temperature. The findings demonstrated that insulin can directly modulate hypothalamic neurons that regulate thermogenesis and CBT which indicated that insulin plays an important role in coupling metabolism and thermoregulation at the level of anterior hypothalamus. Since I myself don't have a subscription to the Diabetes medical journal nor feel like spending $45 to read something I probably can't understand in the first place, I'll just assume they are correct until one of you readers points me to contrary medical research.

According to a summary medical article on Medical News Today "New Link Discovered Between Core Body Temperature and Insulin," while much research has been conducted on insulin since its discovery in the 1920s, this is the first time the hormone has been connected to the fundamental process of temperature regulation:

The scientists found that when insulin was injected directly into a specific area of the brain in rodents, core body temperature rose, metabolism increased, and brown adipose (fat) tissue was activated to release heat. The research team also found that these effects were dose-dependent - up to a point, the more insulin, the more these metabolic measures rose.

"Scientists have known for many years that insulin is involved in glucose regulation in tissues outside the brain," said Scripps Research neurobiologist Manuel Sanchez-Alavez, who was first author of the new paper with Bartfai lab colleagues Iustin V. Tabarean and Olivia Osborn (now at the University of California, San Diego). "The connection to temperature regulation in the brain is new."

...

In work coordinated by Osborn to characterize these neurons and their transcriptome (all of the messenger RNA molecules in a cell, which reflect the genes being expressed), the team noticed something unexpected - a messenger RNA for an insulin receptor.

"We were surprised to find the insulin receptor," said Tabarean. "The insulin receptor is very well documented in the pancreas and in other peripheral tissues. But in the brain, it was not clear and we definitely did not know about its existence in warm-sensitive neurons."

The article goes on to explain the methodology, then draws some conclusions:

The authors note that while their new paper illuminates a key piece of the puzzle of the body's metabolic processes, it also raises many intriguing questions: How does insulin get to the brain's preoptic area - does it cross the blood-brain barrier or is it produced locally? Are diabetics, who are insensitive to insulin in peripheral tissues, still sensitive to insulin in the brain; if so, could this dichotomy be used in the development of a new therapy? Could scientists find a way to use these new insights to increase energy expenditure for the purpose of weight loss?

Unlike the rodents in the medical tests, I'm not really in much of a position to stick a syringe into my brain and inject a bit of humalog to see what happens. So, I thought I'd ask for volunteers. Just kidding!

It does, however, give me an idea for an experiment to try: determining the effect deprivation of all insulin from my system would have on my CBT. Given the above, would my CBT actually be lower if I had, say, 24 hours of no insulin whatsoever? It would be a pretty simple test to complete, perhaps at my next scheduled site change. Don't worry, I'd couple it with a complete fast as well so my blood sugar levels shouldn't rise too high... that in and of itself would be pretty interesting to know as well: what is the rising rate of one's blood sugar if nothing is ingested?

As always, please don't try this at home. I don't mind screwing up my own body processes in the name of science, but I don't want to worry that I'm messing with your own. But, if you do decide to give it a try, don't hesitate to share the data!

Beware the Forgotten Bolus...

On my iPod Diabetes Pilot app, my glucose readings are color-coded so I can immediately tell how I am doing. Black readings are in the desired range, blue are lows and reds are for those infernal highs. I was in the black all of yesterday (even with Mexican for lunch!) then ended the evening and early morning in the red. Why?

I was a victim of the forgotten bolus.

What is the forgotten bolus, you ask? Actually, if you ask that you probably aren't a diabetic. All real diabetics have experienced the forgotten bolus, when they get so caught up in the moment that they actually forget that they have diabetes and neglect to bolus.* Believe it or not, it actually sometimes happens. In my case it occurred at my daughter's birthday party at her favorite restaurant, Famous Dave's BBQ.

Here's how I was attacked by the forgotten bolus. We sat down at the restaurant and I decided what to eat. I decided upon the BBQ pork sandwich, a diet Coke and some baked beans. I knew the baked beans were going to throw a complication into the mix, but I was ready for the challenge. I dutifully input all my info into my trusty little iPod app and it calculated the total to be 94 carbs. I input that into my pump and pushed the magic ACT button and it told me that I needed 13.4 units of insulin.

Because of prior experience, I knew that sometimes the food took a bit longer than expected to arrive, so I refrained from giving myself the bolus at that time. Then she opened her birthday gifts and suddenly the food arrived, we hurried to clear the table and set about enjoying a nice meal, complete with a birthday sundae for the girl.

Things went so well I didn't even notice that I had forgotten to bolus. A few hours later, about 8:30pm, I tested at a whopping 311! I figured that I had woefully underestimated the amount of BBQ sauce I had used--that or perhaps that diet Coke wasn't really a diet Coke--and gave myself the recommended 9.5 units of insulin. Two hours later: 345. 345? how could my blood sugar have gone up in two hours? Unless....

That was when I checked and realized that I had become a victim of the forgotten bolus. The insulin units I gave myself at 10:30pm wasn't enough, which prompted another round at 2:40am (238, 5.9 units) until the morning arrived at a cool blue 70. A bit lower than I would have liked, but I wasn't going to complain and could certainly use the difference to offset twelve hours or so of being too high.

Gee, if I'm already forgetting stuff at this age, what will I be like when I am really old? Like at, say, 50?!

:-)


* Not to be confused with the neglected bolus, which occurs when you know you really should bolus for something and you decline to do so out of laziness.

Letter to a New Diabetic: Leg Cramps

Dear Concerned:

I, too, have had the (un)pleasant experience of waking in the middle of the night mid-scream and in tears from the knotting pain of a cramp in the calf. Unfortunately, until you manage to get your blood glucose levels down to an acceptable level you will continue to be plagued by these nocturnal visitors.


Assuming for discussion purposes that you haven't been intensely exercising, the most probably cause of your leg cramps are due to dehydration or an electrolyte imbalance. If you haven't noticed, one of the ways that your body rids itself of excess blood sugar is to try and pee it out. If you aren't careful to take more water in, you can easily find yourself dehydrated. This is known to accentuate muscle fatigue, which some people think can result in abnormal neural activity whereby certain muscles get the signal to contract but not relax.

Another frequent cause of leg cramps is an imbalance in your electrolytes. Whether this is due to all the urination or caused by a lack of sufficient intake from the outset, the result is painful just the same. If you aren't regularly taking a multivitamin AND mineral supplement each day, you need to be. You should also have your physician order a complete blood work-up on you. That will tell you if you are deficient in calcium, potassium, magnesium,Vitamin D or other vital nutrients. (Note: unless you are farming and eating your own organic produce, have eggs from the chickens running around your backyard and raise and slaughter your own livestock, it's a safe bet that you aren't getting all the requisite nutrients you need from the food items you are purchasing from the grocery store.)

However, none of this is of much solace at three in the morning when you are hopping around on one foot, trying not to wake everyone else up as you sob from the pain. Things to try include eating a banana (potassium) or chewing a couple of Tums (calcium). More general suggestions can be found in this article over at roadbikerider.com on cramps.

Hope this helps,

Niko

Static Electricity + Pump = Trouble

I stumbled upon a nice blog (The Life of a Diabetic) which had an interesting post about attending to your diabetes when you are attending a conference. Well worth a read if you ever find yourself having to go on the road for a while. I added a few suggestions of my own, and while doing so recalled an event earlier this year which I thought I'd repost here.

In short, I was at a conference about three hours away from home and inclement weather caused me to have to stay in a hotel rather than return home as originally planned. Due to the low temperature and bone dry air, the static electricity in the room was incredible. Sparks literally lit up the dark room every time I moved the sheets, myself, anything. Shortly thereafter, I noticed that my pump was dead. A brick. After much button mashing and trying to get it restarted I gave up and tried Minimed. I learned then that the static had fried the pump and despite some various techniques to restart it (e.g. remove the battery for a few hours), they sent me a replacement. Thank goodness for warranties.

I hadn't given much thought to the effect of static electricity on insulin pumps, but it makes complete sense. I can remember when walking across a carpet in winter would be create enough static to erase the contents of a floppy disk. Sometimes when I get out of our minivan and close the door I get a small shock of static. From some of the google results I found, this appears to be a pretty common problem.

In addition to weather, I've noticed a lot of static on the plastic slides at the playground where my kids play. The event has evidently been studied, but I couldn't figure out how to access the article to read it. Something you probably should be aware of if you are the parent of a kid with a pump.

To freak yourself out more about static electricity, what it is and how to get rid of it (buy a humidifier!), check out this article on Static Electricity and People. I found it positively shocking!!

(hehe, I couldn't resist such an electrifying opportunity! )

Diabetic Datamining

Being a diabetic athlete means a dedication to trial and error. Every diabetic athlete I have ever met or read about is a meticulous record-keeper and is in his or her own way a scientist, continuously experimenting on his or her body to find the best combination of insulin, food, stress, exercise. The crazy thing is that the combination keeps changing and it is highly personalized, so there has to be a willingness to continuously revamp, re-evaluate, re-organize. Having diabetes and being committed to performance requires a degree of mental flexibility that deserves recognition and celebration. It is symbolic of what all of us as humans have to do to perform at high levels.

Mari Ruddy, from An Invitation to Ride

I'd like to talk a bit about Diabetic Datamining. Diabetic Datamining is the art and science of

Feeling cold?

The other day I stumbled upon an interesting article entitled "Chronic Fatigue Syndrome and Low Body Temperature" by Dr. David Jernigan of Hansa Center for Optimum Health. He is of the opinion that a low body temperature creates a "happy home for viruses and chronic infections, and is a sign of degeneration and gradual cellular death." As the body’s core temperature decreases all cellular energy also decreases thereby leading to profound and chronic fatigue that is not relieved by sleep. In his article he also summarizes the effect a cold body core temperature has on the circulation system, including peripheral circulation problems and cravings for high sugar based foods to increase the body's heat production. As you probably know, these are two issues every diabetic has to deal with on a daily basis.

According to Dr. Jernigan, it is essential to monitor and graph your core body temperature upon awakening but before getting out of bed and sometime between 8 and 10 pm. Evidently the healthy body has daily temperature fluctuations (diurnal) with the coolest temperature upon awakening in the morning hours of 6-8 a.m. and the warmest being in the evening between 8-10 p.m. There should be a difference between the morning and evening temperature, in a healthy person, of at least 0.9° F (0.5° C).

The core body temperature is the temperature taken under the tongue. After doing some research (okay, okay, after Googleing a bit) it appears that it is best to use a digital basal thermometer as they record much smaller temperature changes than an ordinary thermometer. As for the temperature you want to see, Dr. Jernigan maintains the optimal core body temperature is 98.6-99.6°F, with 98.6° F being the minimum.

So, today as part of my continued life-logging project, I am off to purchase a basal thermometer. I've already gone online and purchased an iPod app for tracking blood temperature. I settled on BT Monitor.

- - -
6/13 Just a followup comment - my core morning temp turned out to be 96.5! That is more than 2 degrees colder than it is supposed to be. Hmm...

Random thought at 2:30 am

When I was young, from as early as I can recall up to high school, I would often spend a Saturday night at my grandmother's house. Each night before bed she would give me a bowl of cereal "so I wouldn't feel hungry during the night." There was little chance of that actually happening since hunger and an Italian grandmother are two words seldom used in the same sentence, but it meant a lot to her and I certainly wasn't complaining. No doubt that is one of the reasons why I was always a bit overweight. Nothing like a bowl full of Frosted Flakes before bed.

I was reminded of this at 2:30am this morning, as I write this entry. I just woke up with a low of 60 and decided I needed to treat it with more than some glucose tabs. So now I'm enjoying a bowl of Life cereal in the middle of the night. Why? At 11:30 pm I was at 68 and had taken 3 tabs and dropped my basal rate to 0.5 for an hour. But that evidently wasn't enough to bring my BG back up. It must have been those damn homemade coconut macaroons I had earlier in the evening; I must have over covered for them. Anyone have any idea how many carbs in a homemade chocolate covered coconut macaroon?!