Insulin

Insulin comes in many forms and brands.  All types of insulin sold in the U.S. are either synthetic human insulin or insulin analogs.  Synthetic human insulin is designed to exactly match the structure of naturally occurring human insulin.   Insulin analogs, on the other hand, have minor structural differences that are designed to give you the same effect as human insulin, but with more predictable absorption rates.  Animal insulins are still available in other countries and can be imported into the U.S.

How It Works

Insulin is categorized into different types based on four variables:

Onset – How long it takes to start working

Duration – How long its effects last

Peak – How quickly it reaches maximum impact

Concentration – In the U.S. insulin is only available in concentrations of 100 units per milliliter (U-100); however, in other countries, varying concentrations are available.  Be sure to take this into consideration if you are traveling abroad.

*Times for onset, duration and peak shown above are estimates and are provided only to give you an idea of how each type of insulin varies from one another. Always use the information provided with your product. This information, along with your doctor’s guidance, will enable you to best optimize your blood glucose control.  It is also important to note that times can vary from person to person and based on different conditions (i.e. during times of illness, exercise, stress, etc.). These times can also vary from manufacturer to manufacturer.

Insulin users can use these different types of insulin in combination to manage their blood sugar levels.  However, there are also pre-mixed forms of insulin that can allow you to achieve the effects of combined insulin usage. Pre-mixed insulins consist of a mixture of rapid-acting and intermediate-acting insulin; the percentage of each is indicated by the numbers following the brand name.  For example Humalog® Mix 75/25 is a mixture of 75% rapid-acting and 25% intermediate-acting insulins.

*Times for onset, duration and peak shown above are estimates and are provided only to give you an idea of how each type of insulin varies from one another. Always use the information provided with your product. This information, along with your doctor’s guidance, will enable you to best optimize your blood glucose control.  It is also important to note that times can vary from person to person, based on different conditions (i.e. during times of illness, exercise, stress, etc.), and site of injection (e.g. arm, leg, stomach, etc.). These times can also vary from manufacturer to manufacturer.

Pumps

Insulin pumps help you manage your diabetes by eliminating the need to inject insulin throughout the day.  Pumps deliver rapid-acting insulin to your body 24 hours a day via a catheter placed underneath the skin.  They deliver three different types of doses:

• Basal
• Bolus
• Correction or supplemental

Basal is intended to be background coverage, while boluses and correction doses are used when quick impact is needed, i.e. blood glucose corrections and for meals.

You will program your pump to deliver basal doses of insulin throughout the day.  These are used to keep your blood sugar levels within a normal range between meals and during the night; these doses are usually programmed for different levels at different times of the day.

When you eat, you will use buttons on the pump to administer an extra dose, or bolus, of insulin to cover the carbohydrates you consume.

Pumps also allow you to give yourself a correction or supplemental dose of insulin if your blood sugar is too high.

Where Do You Put It?

You can keep your insulin pump just about anywhere!  They make special cases for pumps, and they can be attached nearly anywhere: a belt, waistband, underwear, bra, or pocket, are just a few ideas.  When you sleep, you can lay it next to you in bed, or attach it to a pillow, blanket, or sheet.

When you shower or bathe, you will also need somewhere to put your pump.  Most insulin pumps are water resistant, but it’s still not a good idea to hold it directly under water.  Thankfully, insulin pumps have a disconnect port, making them easy to take off when you shower, bathe, or swim.

What about when you’re exercising?  Usually, you can easily wear your pump on an armband or waistband; women can even try taping it to their sports bra!  However, depending on your sport, it may be dangerous to wear the pump while exercising – if you fall on it, it could damage the pump, or worse, cause an injury.  If you want to play it safe, you can disconnect the pump while exercising.

Disconnecting Your Pump

Whenever you disconnect your pump, remember that you will not be getting any insulin!  The American Diabetes Association makes the following precautions and recommendations for times when your pump is disconnected:

1. If you disconnect your pump while it is delivering a bolus, this bolus will not be resumed when you reconnect.
2. Depending on how long you are disconnected, you may need to inject insulin boluses to cover the insulin you will miss.
3. Do not go longer than 1-2 hours without insulin. However, DO NOT inject insulin without first checking your blood sugar.

Check your blood sugar level at least every 3-4 hours.¹

Advantages of Pumps

• Eliminate the need for insulin injections
• If used properly, pumps often improve A1Cs
• Usually reduce large swings in blood sugar levels
• Eliminate unpredictable effects of intermediate- and long-acting insulin

Disadvantages of Pumps

• May cause weight gain
• Can cause diabetic ketoacidosis (DKA) if the catheter comes out and you don’t realize it
• Cost
• May be uncomfortable to be attached to a pump most of the day

Whether you decide to manually inject insulin or use a pump is up to you and your personal preferences. Good glucose control can be achieved by either method. The choice is yours and no matter which way you decide to go, the good news is that we are very lucky to have these options available to us!

References:

2015, March 9. American Diabetes Association. “How Do Insulin Pumps Work?” American Diabetes Association. http://www.diabetes.org/living-with-diabetes/treatment-and-care/medication/insulin/how-do-insulin-pumps-work.html

Testers

There is no getting around it; testing your blood sugar frequently is absolutely essential to controlling your blood sugar levels.  Diabetics test by using a device that measures the amount of glucose in the blood, using a finger prick to draw a blood sample, which is then placed on a test strip inserted into the device.  These devices go by many different names, from glucose tester, glucose meter, glucometer, or just plain tester.  While they go by many names, there are even more types and brands of testers to choose from.  We’re lucky to live in an age where medical advancements have led us to blood glucose testers that are faster, smaller, and more accurate than ever!  However, with so many options, picking out the glucose tester that will work best for you can appear to be a daunting task.  What should you look for in a glucose tester?

Accuracy –

The whole point of testing is to get an accurate measure of your blood sugar levels, right?  So you’ll want to make sure you are satisfied with the accuracy of your tester.  The current FDA standard for accuracy for testers is as follows:

For readings greater than or equal to 75 mg/dl, 95% of test results must be within +/- 20 percent of the actual blood sugar level.¹ For example, if your actual blood sugar is 120 mg/dl, a tester could give you a reading of anywhere between 96 mg/dl and 144 mg/dl and meet the FDA’s standards.

For readings below 75 mg/dl, 95% of test results must be within +/- 15 points of the actual blood sugar level.¹ For example, if your actual blood sugar is 65 mg/dl, a tester could give you a reading of anywhere between 50 mg/dl and 80 mg/dl and meet the FDA’s standards.

So, any tester on the market should be at least this accurate.  Consumers Reports rates the accuracy of many of the leading testers.

You can help maximize the quality of each test by ensuring that your hands are clean and dry (substances like sugar and even dirt can affect your test’s accuracy).  The quality of your test strips and factors like altitude, temperature, and whether or not you are dehydrated can all also have an impact on your test’s accuracy.

Cost of Both the Machine and Strips –

These little machines can typically run you anywhere from $10 to $50.  But it’s not just the price of the unit you need to consider.  You can’t use your fancy new machine without test strips, and you’re going to need a lot of these little guys if you test as often as you should.  Test strips run anywhere from $39 to $129 for a 100-count bottle.  If you test at least 5 times a day (and we recommend more), at $129/bottle, that’s going to cost you $129 every 20 days or about $2300/year! Research how much the test strips are going to cost you for the machine you’re eyeballing; you might find that it makes more sense to opt for one with less expensive test strips.

Testing Speed –

This might not seem that important, but when you’re testing as often as you will need to, those few extra seconds start to add up and the slower testers can become a real inconvenience.  Testers range in speed from three seconds at the fast end to sixty seconds at the slow end.

Amount of Blood Required –

If you dislike pricking your finger, or find the process painful or difficult because you have a hard time getting blood out of your fingertips, this could be a big factor for you.  Different testers require different amounts of blood to get accurate readings, so look for one that doesn’t need much, especially if you anticipate you will have difficulty getting large drops of blood out of your fingertips. This will help you reduce the likelihood that you will need to re-prick your finger to draw more blood.

Memory –

Testers can now store data from your tests, making it easier for you to track your levels over a longer period of time and get a better feel for how you’ve been managing your blood sugar overall.  Some can hold up to over one thousand records and some can give you an average of your results over seven, fourteen, or thirty days.  Others can even plug into your computer via a USB cord, allowing you to download your results on to your computer.  We recommend that your meter have some form of memory capability so that you can see how your levels have fluctuated on a day-to-day basis.  This is also useful for keeping track of how meals and different activities affect your blood sugar levels.

Size –

This is based on personal preferences and needs.  Do you need to test discreetly in public places?  Do you want something that you can easily carry in your purse or knapsack?  Do you need larger buttons and screen readings to operate the machine properly?  These are all questions to consider when looking at the size of a tester.  A sleek, compact little tester might sound appealing, but if your vision is impaired, this will probably not be ideal for you.  If being able to test discreetly in public or easily carry the tester in your purse is important to you, you might want to opt to spend a little more money on a compact tester.

The bottom line is that testing is the single most important thing you can do to put blood sugar control on your side.  You will be using your tester very often (hopefully at least 5 times per day or more), so make sure you pick a device that is trustworthy, affordable, and that you will be comfortable using.

CGMs

Continuous glucose monitors (also known as CGMs, RTCGs, or RT-CGMs) are a relatively new (they’ve only been approved by the FDA for less than ten years) form of blood sugar monitoring technology that allow the user to receive nearly continuous updates of their blood sugar levels (most displaying blood sugar levels at 1-, 5-, or 10-minute intervals), without the traditional “finger-stick” method.  They can also sound an alarm to alert you if your blood sugar falls below or rises above a normal range.

Recent studies have shown that use of continuous glucose monitors have a positive impact on blood sugar control in adult diabetics, without increasing the occurrence of hypoglycemia.² Some studies have shown evidence that CGMs can help lower A1Cs and reduce incidences of hypoglycemia in users.³ The coolest part about these gizmos is that they allow you to see trends in your daily blood sugar levels; using a CGM can tell you whether your blood sugar is rising or falling.  When you use a traditional tester, you only have one reading, which doesn’t show you whether your blood sugar is on the rise or falling fast.

However, CGMs cannot completely replace the use of traditional testers, and should be used in conjunction with traditional testing methods.  If your CGM alerts you that your blood sugar is too high or too low, you should verify the reading using a traditional test.  Here is a quick synopsis of how CGMs work:

• You place a disposable glucose sensor just under your skin. These sensors are good for a few days before they have to be replaced.
• The sensor links to a transmitter, which communicates to a receiver.
• The receiver is worn like a pager. It receives information from the sensor (via the transmitter) and displays glucose levels continuously.  It also monitors rising and falling trends.

Drawbacks to CGMs:

Lag Time –

While traditional testers measure blood glucose levels and therefore don’t typically experience much of a lag time, CGMs measure glucose levels in the interstitial fluid, which has been estimated to lag anywhere from 4 to 26 minutes behind actual blood glucose levels⁴, though most reports seem to suggest a typical lag time of 5 minutes, and sometimes up to 10 – 15 minutes. This isn’t a big deal if blood sugars are relatively stable, but if your blood sugar is crashing, this could be a problem, as your CGM might still show you are in the normal range!  That’s why it is important to test using a traditional tester if you are experiencing any symptoms of a low or high.

Calibration –

The sensor must be calibrated at least twice per day (recommended 3-4 times per day) to maintain accuracy.  Calibration requires the user to test their blood sugar using the traditional “finger-stick” method, and enter the reading in to the CGM.

Sensor Replacement –

The disposable sensors implanted under the skin must be replaced every 3 to 7 days (depending on the make and model of your CGM).  Accuracy of your readings may be compromised if you wear your sensor longer than the recommended period of time.

Receiver Lifetime –

The receivers themselves may last anywhere from 6 months to 2 years.

Cost –

Receivers cost upwards of $1000.  Add this to the cost of replacing the sensor (which run from about $300-$400 for a 6-pack) every 5 or so days, and you’ve got yourself a pretty hefty monetary investment.

The manufacturers of these relatively new devices will undoubtedly work out these kinks eventually as they work to make continuous glucose testing as accurate, efficient, and easy as possible.

• References
  1. Wahowiak, Lindsey. “Blood Glucose Meters 2014: Will Meters Be More Accurate? And Getting the Most from What You Have.” Diabetes Forecast. 2014. Web. http://www.diabetesforecast.org/2014/Jan/blood-glucose-meters-2014.html
  2. Hoeks, LB, Greven, WL, deValk, HW. Real-time continuous glucose monitoring system for treatment of diabetes: a systematic review. Diabetic Medicine [Internet]. 2011 April [cited 2012 July 26];28(4):386-94. Department of Internal Medicine, University Medical Centre Utrecht, Utrecht, the Netherlands. doi: 10.1111/j.1464-5491.2010.03177.x. Available from: http://www.ncbi.nlm.nih.gov/pubmed/21392060
  3. Hsin-Chieh, Y, Brown, TT, Maruthur, N, Ranasinghe, P, Berger, Z, Suh, YD, Wilson, LM, Haberl, EB, Brick, J, Bass, EB, Golden, SH. (2012, July). Comparative effectiveness and safety of methods of insulin delivery and glucose monitoring for diabetes mellitus: a systematic review and meta-analysis. Annals of Internal Medicine. [Internet]. 2012 July 10 [cited 2012 July 26] Available from: http://annals.org/article.aspx?articleid=1215793
  4. Burge, Mark R., Stephen Mitchell, Alison Sawyer, and David S. Schade. “Continuous Glucose Monitoring: The Future of Diabetes Management.” Diabetes Spectrum 2: 112-119. American Diabetes Association. Apr. 2008. Web. doi: 10.2337/diaspect.21.2.112 http://spectrum.diabetesjournals.org/content/21/2/112.full