Jason's Log

Updated ABSI Calculator

Based on user feedback, I've now updated the ABSI online calculator. This version will now display the smoothed average value for your age and gender, as well as the standard deviation. According to the original article, an ABSI value that was greater than one unit of standard deviation above the average indcated a significantly increased mortality rate.

A Body Shape Index (ABSI) online calculator

A paper published recently in PLoS One - "A New Body Shape Index Predicts Mortality Hazard Independently of Body Mass Index" - describes a new approach for assessing mortality rates based on a few, simple body measurements. It expands and improves upon the BMI - Body Mass Index - which has been used for years as the basis for a clinical definition of obesity.

The paper describes the new formula, but does not provide an online calculator for the new measure - ABSI - A Body Shape Index. So I decided to implement a simple online ABSI calculator, which you can access here:

http://absi-calc.appspot.com/

The best way to evaluate your ABSI value to the general population is to view the larger version of Figure 1a from the article. The chart in the top-left corner shows the mean ABSI values by age and gender. Using that chart, you can compare yourself to the US average values.

My score - 0.071 - which puts me comfortably below the mean for men in their early 40s <whew>

 

 

Blood glucose, carbohydrates, and me

This story starts about two weeks ago with an early afternoon visit to my optometrist for an annual eye exam. I've been myopic in both eyes since the fifth grade, and have worn glasses full time since my freshman year in college. For the last 10 years, my prescription has remained relatively stable - about -3.25 diopters in my right eye and -4.25 diopters in my left.

As I am sitting in the exam chair on that Wednesday afternoon, the doctor configures the lens system for my current prescription, and asks me to read the letters projected on the wall. I can only read the largest row, and only barely. "Really?" he asks. "Really," I reply.

"That is your current prescription - that's what was used in the glasses you wear currently," said Dr. Froumis. I insisted the letters were quite blurry. After 10 minutes of adjusting, it was determined that each of my eyes had become one full diopter more myopic since my last visit.

"That rate of change, in both eyes, is what you might expect to see in a rapidly growing teenager, but not in an adult with a 10 year history of stable vision," he said. "Oh, and I see you have a family history of diabetes. That's not good."

As it turns out, high levels of circulating blood sugar are know to distend the lenses in the human eye, increasing the level of myopia. I insist that I am not currently diabetic (which I am not), and that I eat a rigorously - almost ridiculously - strict sugar and starch-less diet. Dr. Froumis recommended I see my primary care physician to have my blood glucose levels checked.

I managed to make a late morning appointment for the very next day. The nurse used a standard glucose meter to take a quick measurement in the office. The result was 98mg/dL, which was at the high end of the 'normal range' (70-100 is normal, 101-125 is elevated, fasting glucose above 125 is considered diabetic). The doctor insisted that I was not diabetic, but he could not think of another reason for the sudden change in vision.

Deciding to take matters into my own hands - which is exactly what you'd expect me to do - I ordered an Accu-Chek Aviva testing kit from Amazon.com (Blood glucose meter, lancets, test strips, and lancing device). It arrived on a Thursday.

When I woke up just after 6am on Friday, I took my first reading after 12 hours of no food: 96mg/dL. This is as close to a 'fasting blood glucose' level as I am likely to get.

This felt a bit high, but not dangerously high. So I got up, ate breakfast (3 eggs plust 60g of protein powder mix) - all protein and fat, zero carbohydrates, for a total calorie count just under 500kcal. I then went to the gym, came home for coffee and measured again at around 8:30am. This time, the value came back with 95mg/dL. It had actually decreased by 1 point.

After that it was off to the office. My lunch boxes for the day were 250kcals of steamed green beans and fresh spinach. No oil, no dressing, no nothing. Just veggies.

I ate the first veggie box at 12 noon on Friday. I then waited the recommended 1-2 hours, and measured again at 1:28pm. I was expecting to see only a slight rise, to perhaps 110 or 115mg/dL. The actual value? 138mg/dL.

At the same time, I measured two co-workers. One had a lunch of a burger, fries and coke. His reading? 110mg/dL. The other had a few slices of pizza and a coke. His reading? 105mg/dL. Me with my 250kcal portion of veggies? 138mg/dL.

WHAT THE FUCK?!

An hour and a half after the other portion of veggies - another 250kcal of green beans and spinach, and the reading was up to 122mg/dL.

And yet, the measurements continued. Just before dinner that evening at 6pm, I measured again - 104mg/dL. For dinner that night, it was all fat and protein again - 500kcal of eggs and protein powder. An hour and a half later? Down to 96mg/dL.

CONTROL MEASUREMENTS COMPLETE.

The real experimentation began on Saturday morning. Wanting to prove that it was the small amount of complex carbohydrates in my veggie boxes that had sent the value skyward on Friday, I decided to make Saturday a very high calorie, zero carbohydrate day.

Woke up at 6am. Reading was 108mg/dL. Ate 3 eggs, 80g protein powder mixed with a two fistfuls of brazil nuts and two tablespoons of coconut oil, with a dash of stevia. Went the gym. Measured again at 8:27am - 99mg/dL.

Continued measuring every two hours throughout the day on Saturday. The value never went above 99mg/dL, and by 7:30pm it had fallen back to 96mg/dL. Over the course of the day I had consumed at least 3500kcal of fat and protein. Nary a drop of carbohydrate. The blood glucose remained remarkably constant.

What does this mean for me?

I am fairly sure that my genetic predisposition to Type 2 diabetes (runs in the family, very strongly, on my Mom's side) has resulted in either a loss of insulin production (causing blood sugars to accumulate and remain in the blood longer then they ought to) or a lack of sensitivity to insulin (causing the same symptoms).

To be honest, I'm not sure what the long term plan is. I suppose I could transition to a very low-carbohydrate diet in order to prevent my glucose levels from ever spiking into the danger zone. Or I could talk to my doctor about long-term medications, which I am very reluctant to consider.

Or perhaps my genetics will get the better of me in the end. Perhaps I should just resign myself to the inevitable onset of Type 2 diabetes, and enjoy all the sugary snacks I can before the onset. Probably not a wise choice.

 Conclusions?

First, this may help to explain the sudden change in vision. I had visited the optometrist at 1:15pm - just after eating one of my 250kcal steamed veggie boxes consisting primarily of carrots and sugar snap peas. Given my reaction (95 to 138) to green beans and spinach, I suspect the lunch I had eaten just prior to that visit had my glucose levels well above 140mg/dL. Blood sugar levels need to be very high to cause myopia according to this article, but this may be a possible explanation.

My plan it to schedule a follow-up visit to the optometrist at around 9/10am after my protein/fat-only breakfast. If my hypothesis is correct, my vision should be back to normal.

I'll post those results as soon as I have them.

Tracking changes in percent body fat over time

I am a strong proponent of measuring percent bodyfat instead of body weight for tracking progress towards fitness and body shape goals. Although there are many different techniques for measuring body fat - each with its own benefits and limitations - it can be cumbersome to track progress over time.

For measurements at home, which I do once per week, I use an Accu-Measure caliper. Although I have a fairly good memory, it can be tough to remember the exact measurement value from the previous week. So today it dawned on me that this could be made much easier by just taking a photo of the calipers immediately after measuring using my phone.

First, I installed the DropBox app for Android (available for iPhone too) on my phone. I created a new folder on my dropbox account named 'bodyfat'.

I then took a quick photo of the current measurement. Once I had a good (clear/focused) photo, I pressed the 'Share' button on the phone. I selected the 'Dropbox' option on the sharing menu, and saved the photo to my 'bodyfat' folder.

The photos are all tagged with the date/time automatically when you take the picture, so you can easily review the history of changes. Here is the photo from my measurement this morning:

I don't really care what the actual values are, as long as they are going in the right direction - not up - and by keeping a photo log of each measurement, I can quickly tell where the numers are headed.

 

Hydrocortisone solved my sweat-induced burning skin irritation problem

UPDATE 2011-07-08: Based on additional research I've done into the long term use of topical corticosteroids, I have stopped using it to treat my irritation problem. Instead, I've decided to pickup a few extra Hydryx Workout Towels in order to soak up the sweat before it gets a chance to cause problems.

Every time sweat or perspiration appears on my forehead, it is followed within minutes by a fairly uncomfortable burning sensation. Nothing dibilitating or severe, but incredibly consistent:

Engage in sweat-inducing level of physical activity -> start sweating -> burning sensation on forehead and temples.

The burning sensation persists for the duration of the activity, and about 30 minutes afterward. To make matters worse, these episodes often lead to the appearance of acne in the same areas by the next morning. Because of this, I often avoid strenously aerobic gym routines or any activity that starts me sweating.

Only recently did it occur to me that I may not be the only person on the planet to suffer from this condition. Sure enough, a few Google searches turned up quite a few reports of similar symptoms. Duh. A few of those posts indicated that it could be an (auto-immune?) inflammation reaction - either induced by the sweat liquid or the heat that accompanies it. 

So the next morning I grabbed a tube of cortisol/hydrocortisone (generic "1% Anti-itch cream") from the medicine cabinet and smeared a small amount on my forehead and temples before heading to the gym. I made sure that the workout included some high-intensity invterval training, which will always get the sweat flowing. 

Sure enough - there was no burning. No irritation. No acne eruption the next morning. I've been using this regimen for about a week now, and have not experienced the burning or irriation in that time. Problem solved? I sure hope so. I'll follow up in a few weeks if the treatment is still working.

The College Course I Dream of Teaching

I was saddened by the results reported in this study of critical thinking skills of college students. Apparently, the ability to use logic and apply reason to modern problems is not on the syllabus at most univesities.

To remedy this in some small way, I would love to talk a local community college into allowing me to teach the following course to all incoming freshman students:

How to Think Like a Geek:

• Correlation is not causation
• Science is a process, not a collection of facts
• A 100% increase in a very small number is still a very small number

I'm guessing I wouldn't get many students to sign-up, but it would be fun to try.

The National Ignition Facility is Actually Cerebro

Reading an article today on the accomplishments of the National Ignition Facility, I was somehow struck by the similarity in the design of the NIF and the Cerebro chamber, featured in the X-Men movies. Putting the images side-by-side shows just how strikingly similar they are:

 

Hmm - controlled nuclear fusion or mutant detection. You be the judge!

New Scientist Magazine: Making it as hard as possible to buy their product

I really do enjoy many of the articles available on-line from the British science mag New Scientist. I have no desire to subscribe to a printed edition - I know I won't read the paper version, and don't want it. So I attempted to find an 'on-line only' subscription.

Nope. Nada. Nuthin. 

In order to gain unlimited access to the on-line articles, you must subscribe to the printed edition. So instead of allowing me to just pay them money for on-line access, they lose an on-line reader. Too bad. So sad.

A discovery about my circadian rhythms

With a solid month of sleep data now captured (using my Zeo Sleep Coach), I've been able to tease out an important contributor to how rested I feel when I wake up in the morning.

I had initially assumed that my body would allow me to sleep enough hours each night in order for it to fully recuperate. In other words, if I go to bed late I figured that my body would just sleep in a bit longer and wake me up a bit later. But based on the recordings from my Zeo, this turned out to not be the case at all. In fact, no matter how late I went to bed, my body would just 'wake up' at right around 6am the next morning. 

So even if I went to bed very late - 2am for example - I would still wake up around 6am. Of course, I didn't feel well rested, but I was never able to go back to sleep. Once the eyes were open, they stayed that way.

That told me that if I wanted to feel more rested in the mornings, that my only realistic option was to go to bed earlier. So that is what I did - adjusted by bedtime to 10pm, no exceptions. Sure enough, I still woke up just about 6am, but I felt much better rested. 

The results of adjusting my bed time to 10pm are shown in the chart below. I made the shift on Thursday, 8/27. Notice how my total sleep time jumped by over an hour? I could definitely feel the difference:

A bit of research into why this might be the case lead me to this article: Differential rescue of light- and food-entrainable circadian rhythms. In the study, the scientists show how circadian rhythms are strongly influenced by feeding/meal times. As it turns out, I eat dinner very consistently at 6pm each night. So my speculation is that my circadian clock says "Jason - you will wake up 12 hours after your last meal, no matter how much time you spent sleeping." 

Although I'm not sure meal time dictates my wakeup time completely, it sure does seem to be a strongly contributing factor.

Sleep Stats: Plenty of REM, too little Z

I've now collected nearly two weeks of sleep data with the Zeo, and the results so far are mildly encouraging. During this entire period I did not consume any caffeine after 3pm, and I ate nothing after 7pm each day. That seems to help. In addition, I only go to bed when I feel sleepy - eyes drooping, yawning - instead of trying to force an artificial sleep schedule on my brain stem.

Here is the overview for the month - showing that I get slightly under 6 hours of sleep, on average, each night:

Here is the breakdown, with comparisons to others in my age bracket. On the minus side, I seem to be getting less total sleep than most (by almost an hour), but I do get quite a bit more REM sleep. Does that compensate? Not sure...

Some secondary statistics here - showing that I tend to fall asleep quite quickly (6 minutes). It also shows that I am something of a night owl, going to bed after midnight on a regular basis. But at least I am consistent!

Here is the chart of my total amount of sleep:

Here is my time in REM sleep:

The data collection will continue - although I'm not yet ready to make any radical changes or look for some pathology in these results. I'm mostly just fascinated by the data.