This FAQ on blood glucose monitoring is borrowed, with permission, from the Internet newsgroup, misc.health.diabetes. It is copied here
Last-modified: 13 April 1996
Changes: Expand comments about free meters (24 Mar)
Add section on high morning bg, from Charles Coughran (13 April)
Subject: READ THIS FIRST
Copyright 1993-1996 by Edward Reid. Re-use beyond the fair use provisions of copyright law and convention requires the author's permission.
Advice given in m.h.d is *never* medical advice. That includes this FAQ. Never substitute advice from the net for a physician's care. Diabetes is a
critical health topic and you should always consult your physician or personally understand the ramifications before taking any therapeutic action based on advice found here or elsewhere on the net.
Subject: Table of Contents
INTRODUCTION (found in all parts)
READ THIS FIRST
Table of Contents
GENERAL (found in part 1)
Where's the FAQ?
What's this newsgroup like?
Abuse of the newsgroup
The newsgroup charter
Newsgroup posting guidelines
What is glucose?
What does "bG" mean?
What are mmol/L?
How do I convert between mmol/L and mg/dl?
What is c-peptide?
What do c-peptide levels mean?
What's type 1 and type 2 diabetes?
Is it OK to discuss diabetes insipidus here? What is it?
How about discussing hypoglycemia?
BLOOD GLUCOSE MONITORING (found in part 2)
How accurate is my meter?
Ouch! The cost of blood glucose measurement strips hurts my wallet!
What do meters cost?
Comparing blood glucose meters
How can I download data from my One Touch II?
How can I download data from my Glucometer (tm)?
Other recordkeeping software
I've heard of a non-invasive bG meter -- the Dream Beam?
What's HbA1c and what's it mean?
Why is my morning bg high? What are dawn phenomenon, rebound, and Somogyi effect?
TREATMENT (found in part 3)
My diabetic father isn't taking care of himself. What can I do?
Managing adolescence, including the adult forms
So-and-so eats sugar! Isn't that poison for diabetics?
Travelling with insulin
Injectors: Syringe and lancet reuse and disposal
Type 1 cures -- beta cell implants
Type 1 cures -- pancreas transplants
Type 2 cures -- not even a dream
What's a glycemic index? How can I get a GI table for foods?
Should I take a chromium supplement?
I beat my wife! (and other aspects of hypoglycemia) (not yet written)
Does falling blood glucose feel like hypoglycemia?
Alcohol and diabetes
Necrobiosis lipoidica diabeticorum
Has anybody heard of frozen shoulder (adhesive capsulitis)?
What is pycnogenol? Where and how is it sold?
What claims do the sales pitches make for pycnogenol?
What's the real published scientific knowledge about pycnogenol?
How reliable is the literature cited by the pycnogenol ads?
What's the bottom line on pycnogenol?
SOURCES (found in part 4)
Online resources: diabetes-related newsgroups
Online resources: diabetes-related mailing lists
Online resources: commercial services
Online resources: FTP
Online resources: World Wide Web
Online resources: other
Where can I mail order XYZ?
How can I contact the American Diabetes Association (ADA) ?
How can I contact the Juvenile Diabetes Foundation (JDF) ?
How can I contact the British Diabetic Association (BDA) ?
How can I contact the Canadian Diabetes Association (CDA) ?
What about diabetes organizations outside North America?
How can I contact the United Network for Organ Sharing (UNOS)?
Could you recommend some good reading?
RESEARCH (found in part 5)
What is the DCCT? What are the results?
More details about the DCCT
DCCT philosophy: what did it really show?
IN CLOSING (found in all parts)
Who did this?
Subject: How accurate is my meter?
bG (blood glucose) meters are not as accurate as the readings you get from
them imply. For example, you might think that 108 means 108 mg/dl, not 107 or
109. But in fact all meters made for home use have at least a 10-15% error
under ideal conditions. Thus you should interpret "108" as "probably between
100 and 120". (See above for conversion to mmol/L.) This is a random error
and will not be consistent from one determination to the next. You cannot
expect to get exactly the same reading from two checks done one after the
other, nor from two meters using the same blood sample.
This is generally considered acceptable because variations in this range will
not make a major difference in treatment decisions. For example, the
difference between 100 and 120 may make no difference in how you treat
yourself, or at most might make a difference of one unit of insulin. With
present technology, more accurate meters would be much more expensive. This
expense is only justified in research work, where such accuracy might detect
small trends which could go undetected with less accurate measurements.
This discussion applies to ideal conditions. The error may be increased by
poor or missing calibration, temperatures outside the intended range,
outdated strips, improper technique, poor timing, insufficient sample size,
contamination, and probably other factors. Contamination is especially
serious since it can happen so easily and is likely to result in an overdose
of insulin. Glucose is found in fruits, juices, sodas, and many other foods.
Even a smidgen can seriously alter a reading.
When comparing meter readings with lab results, also note that plasma readings
are 15% higher than whole blood, and that capillary blood gives different
readings from venous blood.
Visually read strips are slightly less accurate than meters, with an error
rate around 20-25%.
For some meters, strips are available from manufacturers other than the meter
manufacturer. Some m.h.d. readers have compared the strips side-by-side and
found those from one manufacturer to read consistently lower than the strips
from another. The differences are not likely to make a significant difference
in your treatment, but are large enough to be noticeable and possibly
confusing. For this reason it is not a good idea to change strip
manufacturers without comparing the readings from one with the readings from
I've seen no such direct comparison of meters, but the possibility exists that
some meters might read consistently lower than others. Be careful when
By "error rate" I mean twice the standard deviation from the mean. An error
rate of 15% says that about 97% of the readings will be within 15% of the
Subject: Ouch! The cost of blood glucose measurement strips hurts my wallet!
The cost of blood glucose measurement strips is a complex interaction of R&D
costs, manufacturing costs, marketing strategy, insurance practices, and
undoubtedly other factors. You can ask on the net if you want; you'll get
lots of comments but no answers.
There are a couple of ways of reducing the cost of blood glucose monitoring.
One is to seek out the best price for the strips; large stores such as FEDCO
often have good prices, as do some mail order suppliers (see mail order
A second way is to use visually read strips (Chemstrip bG and a couple of
lesser known brands) and cut them in half or even in thirds. Do the cutting
carefully with a pair of strong, *clean* scissors, and get the strips back
into the vial as quickly as possible. There have been reports that some
manufacturers claim this procedure will cause problems, but those who have
used the technique report that it works well. Visually read strips are
slightly less accurate than meters.
Do *not* cut strips when using them in meters. The results will be totally
Most discussion on m.h.d of the cost of blood glucose measurement strips has
centered on the US. I'm not sure why, though a good guess is that differences
in health care systems and national policies make this issue more critical to
the individual patient in the US. There is no dearth of non-US participants
Subject: What do meters cost?
The flip side of expensive blood glucose measurement strips is that the
manufacturers virtually (and sometimes literally) give away the meters to
hook you on their strips. Don't pay full price for a meter; look for
discounts, rebates, and giveaways. For example, as of this writing I'm
looking at a catalog that shows a Glucometer 3 for US$45, with a US$30
manufacturer's rebate *and* a US$30 trade-in allowance if you already have a
competing meter -- which means you make US$15. There are similar deals on
But make sure you consider the cost of strips as well as the cost of meters,
and find out which your insurance will pay for. The most fully featured
meters, such as the One Touch II, don't have such widely advertised deals,
though you can probably find ways of getting them at discount.
If you have insurance that pays for strips but not for the meter, you should
not have to pay anything for the meter. If it's worth the time to you, call
the meter manufacturers' customer service departments or the mail order
outfits (see "Where can I mail order XYZ?" in part 4, Sources). They will
find a way to get you the meter for free.
As with strips, this discussion of costs applies to the US, and there has
been little discussion of meter costs outside the US on m.h.d., probably
because fewer tradeoffs are available in most countries. An Australian
correspondent notes a much narrower choice and higher cost of meters there,
but subsidized (pardon, subsidised) measurement strips. In Britain, strips
are covered by the National Health Service, but meters may be expensive.
Elsewhere? Please post.
Subject: Comparing blood glucose meters
This section is courtesy of Lyle Hodgson , who found the
chart published by Hospital Center Pharmacy, got permission to reproduce it,
and entered and formatted the data. Take it, Lyle.
The following Blood Glucose Monitor Comparison Chart is published by the
Hospital Center Pharmacy (433 Brookline Ave. Boston MA 02215; reprinted here
with permission). After I mentioned it a couple weeks ago, Ed encouraged me
to seek the permission to post it and helped in figuring out how to format it
into 80 columns, which was hell since the original was an 8.5x14" landscape
with 8-point text.
Note that I haven't edited anything more than to patch in some grammar where
it was lacking and to abbreviate the hell out of everything. I don't know
what a Privacy Option is; whether the Previous Test, Last Test, and Latest
Test under "Memory" are all the same thing; whether the cassette available
from the Diascan manufacturer is Audio or Video; or the sizes of most of
Hope you find this chart as informative as I found the hard copy. You can get
your own hard copy of the original for free by calling the Hospital Center
Pharmacy yourself, 1-800-824-2401.
Ctrl Soln = Control Solutions.
Trng Cass = training cassette available. A=audio, V=video.
Power Srce= power source (wow): NR=non-replaceable
Mem = memory. Number of results stored. D/T=date and time also
Wrty = length of warranty.
Product Name/ Range Time Ctrl Trng Power
Manufacturer mg/dl (sec) Soln Cass? Srce Mem Wrty
Accuchek III/ 20- 120 Lo/Hi A,V 9V 20, 2 yr
Boehringer- 500 alka- D/T
Rejects inadequate sample, must wipe and time. Displays date&time.
Companion2 20- 20 Lo/Hi Video 3V NR 10 4 yr
Sensor/ 600 lith
Largest display of readings. No wiping, blotting, or timing; auto
start. Easy strip insertion. No cleaning.
Diascan-S 10- 90 Norm/ Yes 6V J 10 2 yr
Meter/ Home 600 Elev/ cell
The only smearable strip. Must wipe and time. Large easy-to-read
display. Privacy option.
Exactech 40- 30 Hi/Lo Video NR last 4 yr
Companion 450 lith
One-button operation. No wiping, blotting, or timing.
Glucometer3/ 20- 60 Norm A,V mem: 300, 3 yr
Miles/Ames 500 NR; D/T
Alarm clock, meter, & logbook. Privacy option.
One Touch II/ 0- 45 Norm A,V 6V J 250 3 yr
Lifescan 600 cell
No wiping, timing, or blotting. Signals when meter must be
One Touch 0- 45 Norm Audio 6V J prev 3 yr
Basic/ 600 cell
Pen2 20- 20 Hi/Lo Video NR 10 4 yr
Sensor/ 600 lith
Largest display of readings. No wiping, blotting, or timing; auto
start. Easy strip insertion. No cleaning.
Tracer II/ 40- 120 Hi/Lo Video two 10 2 yr
Boehringer- 400 3V
Pocket-sized monitor, smallest strip needs less blood.
Ultra/ 0- 45 Lo/ Video four 2 2 yr
Home Diag- 600 Mid/ 1.5V
nostics Hi "N"
No timing, wiping, blotting; automatic temperatures; correction.
Large easy-to-read display.
Accucheck 20- 15- Lo/ Video 6V 30 3 yr
Easy/ 500 60 Mid/ alka
Boehringer- Hi line
Easy calibration; small drop of blood needed. No wiping, blotting.
Glucometer 40- 60 Hi/ Video two latest 5 yr
Elite/ 500 Norm 3V
No wiping or timing. Strip draws up amount of blood needed.
*PARTNER 10- 90 Norm/ Audio "J" 10 2 yr
Visually 600 Elev/ cell
Home Diag. Elev
Shoulder strap, durable carry case, extra battery, smearable
strip. Large display earpiece. Privacy option.
CheckMate/ 40- 60- Norm None two 40+ lifetime
Cascade 400 90 3V D/T of pur-
Medical lith chaser
Built-in lancing device, 4 programmable alarms. Strips are
individually foil wrapped.
Lyle, happy with her Companion2 thanks
Subject: How can I download data from my One Touch II?
You can get a cable to hook the One Touch II to a PC from the meter
manufacturer, LifeScan. The cable includes some electronics, not just a
cable, so you probably don't want to make your own. In the US the cable is
free. Elsewhere, LifeScan lets each international office set its own policy
on cable distribution, and some are charging substantial fees. North American
telephone numbers are:
+1 408 263 9789
elsewhere (If you have trouble locating a phone number for your
international office, let me know. If this problem is
recurrent, we will add the list of offices here.)
LifeScan provides some software for downloading the data. According to a
recent posting, it is minimal download software, and you must use other
software (for example, a spreadsheet) for analysis.
Vic Abell's freeware TOUCH2 (described below), by contrast, downloads and
analyzes data and has received rave reviews from its users for its analysis
features. And Vic posts update announcements to misc.health.diabetes.
There is a shareware Windows program called Diabetics Assistant which
downloads from the One Touch II, saves the data in a file, and provides
various analysis and display facilities. I haven't heard from anyone who has
used this program. I know it is available on America Online.
See also the mention of OTVIEW under "Other recordkeeping software", below.
No comparable Macintosh software is known to be available. However,
downloading the raw data using a basic telecom program (such as Kermit or
ZTerm) is feasible. The meter responds to basic simple commands. LifeScan
will send you a list of the commands and responses. Call and ask for the
protocol specification, or FTP it from Vic Abell (see below).
Info from Vic Abell :
TOUCH2 is Vic Abell's freeware MS-DOS/PC application for downloading and
analyzing data from the LifeScan One Touch 2 blood glucose meter. TOUCH2
interfaces to the RS-232 data port of the One Touch 2, downloads the data on
command, and provides a variety of analytical displays. It's available via
anonymous ftp from vic.cc.purdue.edu (18.104.22.168) in /pub/touch2.zip or
/pub/touch2.tar.gz, with information in /pub/touch2.README. When ftp asks for
a password, you must provide your valid email address of the standard form
The protocol specification is available from the same site, same directory,
If you do not have ftp access, you can get a copy of a TOUCH2
distribution by email by sending an email letter to:
In the body of the letter put:
connect vic.cc.purdue.edu anonymous
If you want touch2.tar.gz or lifescan.ot2 instead, put its name in place of
touch2.zip in the "get" directive. Multiple "get"s are allowed.
must be in the standard form email@example.com. If you
want btoa encoding instead of uuencoding, replace the "uuencode" line with
"btoa". If you can't receive email messages of 100K bytes, change the
"chunksize" line. Be patient; the server sometimes takes two or three days to
process the backlog, and recently up to a week.
Using the World Wide Web, enter the URL
Subject: How can I download data from my Glucometer (tm)?
Miles Inc, makers of the Glucometer M/M+ blood glucose meters, sells a
program called Glucofacts+ DMS which
-- downloads and analyzes data from the meters
-- stores the data in files
-- produces quite a variety of statistical reports and graphs
on screen or printed
-- runs under MS-DOS only
-- supports only the Glucometer M and M+
-- requires a nonstandard cable which is supplied with the software
-- uses a proprietary interface (unlike Lifescan, Miles will not provide the
specifications of the interface)
-- does not provide for manual entry of data
-- a Data-Link Modem available separately provides the capability
of transferring data directly from the meter to a PC at the
physician's office, for those lacking a home PC.
-- can upload the data to the doctor's office (a Data-Link Module provides
standalone capability for users without a PC)
-- is *not* available in a demo version
Chris Trippel of Miles will answer questions
unofficially and can email copies of a very good description, about 7K long,
of Glucofacts+ DMS. You can also get information and place orders by calling
1-800-348-8100. If ordering, ask for Lloyd Bane, ask for product code 5044B,
and provide the serial number from your meter.
Subject: Other recordkeeping software
Michael Wolfe is maintaining a software review
panel that is posted in conjunction with this FAQ. New and udpated software
information is mostly going into that panel, so look there for more up to
I searched the PC and Macintosh software libraries on America Online using
the key 'diabetes' and came up with programs running under MS-DOS, Windows
and Macintosh (HyperCard) for blood glucose recordkeeping. Prices range from
free to $30. The Control Diabetes program from Nutrisoft has received
favorable mention in m.h.d; I haven't seen any of the others mentioned. The
Diabetics Assistant can download from a One Touch II.
CompuServe has software in the Diabetes Forum.
_Diabetes Forecast_, from the ADA, carries some advertisements for commercial
software. I don't know anything about the packages advertised.
OTVIEW is a shareware PC DOS or Windows program to download and report data
from a One Touch II, as well as managing other operational features of the
meter. It's available on the Demon ftp site (see below) and elsewhere. For
more information, contact the author, Tom McKeever, at Tom.McKeever@mit.com.
Demon Internet Services is generously providing FTP space for software and
information related to diabetes on ftp.demon.co.uk, directory /pub/diabetes.
See the sections on Online Resources for details. From the WWW:
Subject: I've heard of a non-invasive bG meter -- the Dream Beam?
***The following information is incomplete, as another company has introduced
a non-invasive meter for about $8000. It has been discussed in the
newsgroup. Rumors of other non-invasive (and "non-evasive") meters abound.
I won't be trying to keep this section up to date until the situation
There is at least one development project in hot pursuit of a bG monitor
which operates by shining light through flesh (through the thumbnail in one
case) and analyzing the light that passes through. Glucose doesn't affect
light much differently from many other substances in the body, so this is not
an easy task. Some field trials have been done, but the developers have a way
to go to reach acceptable accuracy. A successful product is far from
guaranteed, and may be several years away if it arrives at all.
One estimate is that such a meter might cost about US$1000. Assuming the
per-check cost is zero, this would pay for itself in 1-2 years for many
patients. Look for the insurance companies to throw up some roadblock to
achieving these savings, at least in the US.
Subject: What's HbA1c and what's it mean?
Hb = hemoglobin, the compound in the red blood cells that transports oxygen.
A1c is a specific subtype. (The 1 is actually a subscript to the A, and the c
is a subscript to the 1.) Glucose binds slowly but irreversibly to
hemoglobin, forming a stable sub-sub-type which is only eliminated by the
normal recycling of the red blood cells, which have a lifetime of about 90
days. In non-diabetic persons, the formation and destruction reach a steady
state with about 3.0% to 6.5% of the hemoglobin being the A1c subsubtype.
Since most diabetics have a higher average blood glucose (bG) level than
non-diabetics, the steady state level is higher in diabetics. The HbA1c level
thus is an indication of the average bG level over the past 90 days or so.
Interpreting HbA1c values is tricky because several different lab
measurements have been introduced over the last 15 years, measuring slightly
different subtypes with different limits for normal values and thus different
interpretive scales. All are still in use in some places. When you get a lab
result, be sure to look at what the lab considers to be the normal range.
Most discussion of HbA1c values in m.h.d appears to be based on the most
recent lab measurement, where the normal range is approximately 3-6.5%.
Subject: Why is my morning bg high? What are dawn phenomenon, rebound,
and Somogyi effect?
This section is written by Charles Coughran .
There are three main causes of high morning fasting bg. In decreasing order of
probability they are insufficient insulin, dawn phenomenon, and Somogyi
effect (aka rebound). Insufficient or waning insulin is simple. If the
effective duration of intermediate or long acting insulin ends sometime
during the night, the relative level of circulating insulin will be too low,
and your blood sugars will rise.
Dawn phenomenon refers to increased glucose production and insulin resistance
brought on by the release of counterregulatory hormones in the early morning
hours near waking. It happens in normal people as well as in diabetics; in
nondiabetics it shows up as measurably increased insulin secretion around
dawn. Dawn phenomenon is variable in strength both within the population and
over time in individuals. It can show up as either high fasting glucose
levels or an increased insulin requirement to cover breakfast compared to
equivalent meals at other times of day.
Somogyi effect refers to a rebound in bg after nocturnal hypoglycemia which
occurs during sleep with the patient not experiencing any symptoms. The
hypoglycemia triggers the release of counterregulatory hormones. Somgoyi
effect appears to be less prevalent than previously thought. While it does
occur, some episodes of hyperglycemia following hypoglycemia are actually
waning insulin levels following an insulin peak with medium acting insulin.
This can be difficult to sort out.
The best way to sort it out is to test every couple of hours from bedtime to
If your bg rises all, or much of the night, it is a lack of circulating
If it is stable all night, but rises sharply sometime before you wake in
the morning, it is dawn phenomenon.
If your bg declines to the point of a hypoglycemic reaction, it is
*possibly* Somogyi effect.
You may have to test on several nights to nail the problem. Once you have
figured out the problem you and your doctor can discuss changes in your
insulin regimen to correct it. The answer depends critically on your
Mayer Davidson, in _Diabetes Mellitus: Diagnosis and Treatment_ p 252 in the
3rd edition) says that Somogyi effect rarely causes fasting hyperglycemia,
and cites studies.
Subject: Who did this?
Edward Reid firstname.lastname@example.org
PO Box 378 email@example.com
Greensboro FL 32330
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