Continuous Glucose Monitoring

What is Continuous Glucose Monitoring ?

• Blood glucose meters measure glucose in your blood and glucose sensors measure glucose levels in the fluid around the cells

• They are not exactly the same numbers and that’s normal

• Traditional blood glucose monitoring with a meter looks at only one point in time

• The meter doesn’t tell you where you’ve really been or where you are going

• CGMs help understand glucose trends, rate and direction of change

• The results will give you information about what your blood sugar is doing at times when you don’t normally check

• You will learn how diet, exercise, medication and your lifestyle are affecting your blood sugars

• CGMS measures subcutaneous interstitial glucose levels

• CGMS continuously records on an average of every 5 minutes

• This technology will be crucial in developing a closed loop system

• The wearer can either see in “real time’ BG values or use retrospective data to download for analysis

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Glucose Measurement

Gluc

ose (

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12:00 a.m. Breakfast Lunch Dinner Bedtime

Target Range

Typical Daily Patient Log

CGM Measures Interstitial Glucose CGM devices measure interstitial glucose

• Interstitial glucose is related to blood glucose, but not exactly the same

• CGM glucose values typically lag behind BG values

– The lag time is related to the physiologic delay of the glucose transfer between blood and interstitial compartments

Interstitial fluid

Blood Vessel G

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2 Main Categories of CGM*

Professional CGM iPro2

• Owned by clinicians, offices, hospitals

• Episodic, intermittent use (3 days)

• “Blinded” or “masked” evaluation

• Retrospective review by providers

• Minimal training and set-up time

Personal CGM Revel , Dexcom, Guardian

• Owned by patients

• On-going use by patients

• Displays glucose values and alarms that allow for immediate therapeutic adjustments

• Continuous review of data by patients

• Requires patient education

* AACE CGM Task Force. “Statement by the American Association of Clinical Endocrinologists Consensus Panel on Continuous Glucose Monitoring.” Endocrine Practice. 2010; 16(5):730 – 744.

CGM Category Names & Definitions

Ownership Healthcare professionals, clinics, hospitals

Typically owned by patients

Length of wear

3 – 5 days per evaluation; Episodic, intermittent use

On-going use by patients

Display of glucose data “Blinded” or “masked” data to allow for unbiased assessment of glucose control

Continuously displays glucose values and provides alarms that allow for immediate therapeutic adjustments

Data analysis Retrospective review by providers “Real-time” review by patients

Patient Training Minimal training and set-up time Requires education on glucose level targets and alarm thresholds

Professional CGM Personal CGM

Personal CGM has 4 components • Glucose Sensor: − Inserted into subcutaneous tissue

• Transmitter: − Connects to sensor

• Insulin Pump: − Records and displays glucose data

• Software: − Personal and Pro − Organizes data into reports used for

glucose evaluation

Personal CGM System Components

See More Excursions with Professional CGM

Kaufman Study*

47 pediatrics (A1C > 8.0%), intensive insulin therapy

3-day CGM evaluation + SMBG

Compared highs and lows identified with CGM and SMBG

CGM revealed up to 7x more night-time excursions than SMBG

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Number of Glucose Excursions Identified

Overall Night-time

SMBG CGM

* Kaufman F, Gibson L, et. al. “A Pilot Study of the Continuous Glucose Monitoring System.” Diabetes Care. 2001; 24(12):2030 – 2034. §Adapted from Kaufman study.

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See More Hypoglycemia with Professional CGM

Munshi Study*

40 Elderly patients – mean age = 75 – 70% had type 2 diabetes – Avg. A1C = 9.3%

Patient distribution by therapy: – Insulin only = 35% – Insulin + Orals = 38% – Orals = 8%

3-day iPro evaluation + SMBG

93% of hypoglycemic episodes were unrecognized by SMBG or symptoms

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48%

30%

Patients Who Experienced Hypoglycemia (as detected by CGM)

Below 70 mg/dL

Below 50 mg/dL

Below 60 mg/dL

*Munshi M, Segal A, et. al. “Frequent Hypoglycemia Among Elderly Patients with Poor Glycemic Control.” Arch Intern Med. 2011; 171(4):362 – 364. §Adapted from Munshi study.

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See More Post-Meal Highs with Professional CGM

Boland Study*

56 type 1 children with satisfactory A1C2 and pre-meal glucose near target range

3-day CGM evaluation + SMBG

Evaluated peak post-meal glucose levels

* Boland E, Brandt C, et. al. “Limitations of Conventional Methods of Self-Monitoring of Blood Glucose.” Diabetes Care. 2001; 24(11):1858 -1862. 2) Average A1C of 7.7% ± 1.4%. 3) Post-meal target range of < 180 mg/dL. §Adapted from Boland study.

CGM revealed that 90% of peak post-meal glucose was above target range3

(~50% were > 300 mg/dL)

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% of Peak Post-Meal Glucose Over Target Range3

> 300 mg/dL

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Breakfast Lunch Dinner

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See More Data To Help Reduce Risk of Macrosomia

* Murphy HR, Rayman G, Lewis K, Kelly S, Johal B, Duffield K, Fowler D, Campbell PJ, Temple RC. “Effectiveness of Continuous Glucose Monitoring in Pregnant Women with Diabetes: Randomized Clinical Trial.” BMJ. 2008;337: a1680 §Adapted from Murphy study.

The use of supplementary CGM as an educational tool during pregnancy is associated with improved glycemic control and reduced risk of macrosomia.

Murphy Study*

71 pregnant women with T1 or T2

Two Arms: CGMS and Control

Lower A1C in third trimester with CGM

Reduced risk of macrosomia with CGM

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• Star 3 Clinical Trial-provides evidence to support

the use of CGMS-multicenter, Type 1 ages 7-70 4 times greater reduction in A1C No increase in severe hypoglycemia More usage-better control Early and sustained results

AACE Reviews Clinical Evidence on CGM

Professional CGM Personal CGM

Can reduce A1C in adult and pediatric patients with type 1 diabetes and A1C > 7.0%, without increasing hypoglycemia in adult and pediatric patients6,7

In adults and adolescents, more consistent use predicts successful A1C reductions7

Can reduce hypoglycemia in well-controlled adult and youth patients (A1C<7.0%) with type 1 diabetes, without increasing A1C8

Can identify undetected hyperglycemia in pregnant women – Professional CGM identified 94-390 minutes/day of undetected hyperglycemia in studies1,2,3

Effective in improving maternal glycemic control, infant birth weight, and macrosomia risk in women with type 1 or type 2 diabetes4,5

1 Jovanovic L. The role of continuous glucose monitoring in gestational diabetes mellitus. Diabetes Technol Ther. 2000;2(Suppl 1):S67-S71. 2 Yogev Y, Chen R, Ben-Haroush A, Phillip M, Jovanovic L, Hod M. Continuous glucose monitoring for the evaluation of gravid women with type 1 diabetes mellitus. Obstet Gynecol. 2003;101:633-638. 3 Chen R, Yogev Y, Ben-Haroush A, Jovanovic L, Hod M, Phillip M. Continuous glucose monitoring for the evaluation and improved control of gestational diabetes mellitus. J Matern Fetal Neonatal Med. 2003;14:256-260 4 Murphy HR, Rayman G, Duffield K, et al. Changes in the glycemic profilies of women with type 1 and type 2 diabetes during pregnancy. Diabetes Care. 2007;30:2785-2791. 5 Murphy HR, Rayman G, Lewis K, et al. Effectiveness of continuous glucose monitoring in pregnant women with diabetes:randomised clinical trial. BMJ. 2008;337:a1680.

6 Juvenile Diabetes Research Foundation Continuous Glucose Monitoring Study Group, Ramborlane WV, Beck RW, et al. Continuous glucose monitoring and intensive treatment of type 1 diabetes. N Engl J Med. 2008;359:1464-1476. 7 Chase HP, Beck RW, Xing D, et al. Continuous glucose monitoring in youth with type 1 diabetes: 23-month follow-up of the Juvenile Diabetes Research Foundation continuous glucose monitoring randomized trial. Diabetes Technol Ther. 2010;12:507-515. 8 Juvenile Diabetes Research Foundation Continuous Glucose Monitoring Study Group. The effect of continuous glucose monitoring in well-controlled type 1 diabetes. Diabetes Care. 2009;32:1378-1383.

AACE Consensus Statement on CGM 2010

AACE supports broad range of ideal candidates for Professional CGM*

Professional CGM Patient selection and usage: Patients with type 1 or type 2 diabetes who:

are not at their A1C target. have recurrent hypoglycemia or hypo unawareness.

All pregnant women with type 1 diabetes.

CGM may also facilitate treatment adherence for women with type 2 diabetes or insulin-requiring gestational diabetes.

Intermittent use may be useful for youth with type 1 diabetes who are changing their diabetes regimen or are experiencing nocturnal hypo, dawn phenomenon, hypo unawareness, or post-prandial hyperglycemia.

Recommended to use Professional CGM on an episodic basis.

* AACE CGM Task Force. “Statement by the American Association of Clinical Endocrinologists Consensus Panel on Continuous Glucose Monitoring.” Endocrine Practice. 2010; 16(5):730 – 744.

ADA 2010 Standards in Glucose Monitoring

• Three primary techniques to evaluate control-SMBG, A1C,CGM

• CGM in conjunction with intensive managment can be a useful tool to lower A1C in Adults w/Type 1

• Ongoing use may also be helpful in children, teens and younger adults

• CGM maybe a supplemental tool for SMBG • CGM may also be beneficial to maintain

glycemic control

• Success in lowering A1C correlates to an individual’s ongoing use of CGM

Ideal Candidates for CGM

Patient selection and usage: Patients with type 1 or type 2 diabetes who:

are not at their A1C target. have recurrent hypoglycemia or hypo unawareness.

All pregnant women with type 1 diabetes.

CGM may also facilitate treatment adherence for women with type 2 diabetes or insulin-requiring gestational diabetes.

Intermittent use may be useful for youth with type 1 diabetes who are changing their diabetes regimen or are experiencing nocturnal hypo, dawn phenomenon, hypo unawareness, or post-prandial hyperglycemia.

Recommended to use Professional CGM on an episodic basis.

Professional CGM

Ideal Candidates for CGM

Patients with type 1 diabetes with: Hypoglycemia unawareness or frequent hypoglycemia.

A1C above target or with excess glucose variability.

Requires lowering A1C without increased hypoglycemia.

During preconception and pregnancy.

Children and adolescents who have met A1C targets (<7.0%) and who may be highly motivated.

Youth with A1C levels ≥7.0% and are able to use the device on a near-daily basis. The following might be good candidates and a trial period of 2-4 weeks is recommended: Youth who frequently monitor their blood glucose levels.

Committed families of young children (younger than 8 years) especially if the patient is having problems with hypoglycemia.

Personal CGM

Other candidates

• Blood glucose variability • Gastroparesis • Insulin-requiring diabetes—with or without a pump • Behavior modification • Type 2 patients on intensive insulin therapy • Patients desiring more time in target range • Intermittent CGM with Type 2 DM

Insurance Coverage

• CMS Medicare Part B Coverage in Washington, Idaho, Oregon( CPT codes 95250 & 95251)

• Blue Cross of Washington/Idaho • Blue Shield • Medicaid • Aetna/US Healthcare • United Healthcare • Tri West • BCBS of Minnesota/Idaho

• Ameriben Solutions • BCBS of Illinois/Washington • Cigna Healthcare • All cover for different criteria, Types of Diabetes,

sensing allowed per year • Check each individual plan

Part 2

Expectations

• Tracking and trending/pattern management • Immediate feedback on diet, exercise and

medication • Reducing hypo/hyperglycemia • Help in understanding A1c, glucose variability • Increase time in target range • Assessing magnitude of glucose excursions

Expectations

• Ongoing use in reductions of A1C • CGM supports proactive rather than reactive

management • Can empower patients to optimize control and

improve well being

What Not To Expect From CGM

• Not a technology that can be used to dose insulin

• CGM can be used as an adjunct to glucose meter

• NOT a replacement for a glucose monitor • Not a device to put on and “forget” about • Not a system that replaces or substitutes for

existing diabetes management tools • It does not think for the patient!

Remember

• All CGMS must be calibrated using SMBG and all treatment decisions are based on the meter BG not the CGM BG due to “lag time”

• CGMS can be useful in improving glucose control

• CGMS is a trending device not a treatment device

Patient Teaching Points

Patient Training patPatei

Patient success includes:

• Practice using CGM • Experience learning how to

react to CGM feedback (highs, lows)

• Continuing education

• Follow-up − Addressing questions − Providing practical solutions − Encouragement

Success comes with time & experience

Greater Differences In BG & PSG

• Expect greater differences in BG & SG when glucose is changing rapidly, such as:

– After a meal, giving an insulin bolus or exercising or – When up or down arrows are showing on the pump

Teach patients to focus:

• Less on the actual sensor glucose number and…

• More on the glucose trend (direction / speed of glucose change)

• Balance the frequency of alerts and a patient’s tolerance for alerts with the value of the information they receive – Choose alerts that benefit patient’s control – Individualize each alert setting to match patient needs

• Utilize software reports and patient feedback to help with

decisions on adjusting CGM settings – Start adjustments within a few days of initialization

• BG & SG are not expected to match, but… − Typically the readings are reasonably close (15% to 20% variance)

BG and SG Rarely Match Exactly

The disparity of 15% to 20% is larger in higher readings:

• BG = 250 mg/dL (Range difference: 300 mg/dL to 200 mg/dL) • BG = 65 mg/dL (Range difference: 52 mg/dL to 86 mg/dL)

Calibrations are Required for CGM to Work

What is a calibration?

−Adjusting a measurement to match an industry reference or standard

How is CGM calibration done?

− 1st patient checks BG using glucose meter − Next, BG is entered into pump or receiver (manually or wirelessly) − Patient determines if BG reading should be used for calibration

Industry reference for measuring glucose: − BG Meters − YSI (Yellow Springs Instrument)

CGM is An Adjunctive Therapy to BG Readings

− Insulin bolus amount − Treatment of low glucose

Teach patients to always use a BG reading when:

• Determining any treatment decision

Strategies for Success at Initialization

Therefore, it is usually best to minimize alerts at first: • Allowing patients to become familiar with CGM, glucose trends

and how insulin, food and exercise affect glucose • Easing the patient into the CGM experience. This seems to

increase patient understanding, success and adoption of therapy

Set alert ranges wide at first Concept: Alert patients only when action is needed

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It is difficult to anticipate how an individual will react in response to alerts until they are actually experiencing them.

As patient’s knowledge and ability to interpret graphs increases: • Tighten alert ranges to allow patient to obtain full benefit of CGM • Turn additional alerts ON (one at a time) as needed

Timely follow-up in evaluating and adjusting alert settings is key.

Anticipating and Alleviating Patient Concerns

# 1 Patient Concern SG Does Not Match BG

Possible questions to ask…

• Are calibrations done at right times? −Are 2 down arrows showing when they calibrate? −Calibrating 3 to 4 times / day? −Calibrating on rise or fall? −Calibrating too frequently?

• Are BG meter readings done correctly? −Washing hands? Coding meter properly? Large enough

sample? • Remind patient: BG readings entered within 15 minutes of a previous

reading, will replace the earlier reading

# 1 Patient Concern continued

• Does patient understand “SG ≠ BG” concepts? −SG typically lags behind BG −Trending of glucose can be more relevant than actual

glucose value −A 10% to 20% difference is greater in high BG range

than in Low range

# 2 Patient Concern: Too Many Alerts!

Frequent alerts may be due to inappropriate alert settings or too many sensor alert features being used

− Check to see if alerts are applicable and if ranges are set appropriately − Make sure patient is referring to sensor alerts and not pump alerts

• e.g. low reservoir, low battery alerts • Questions to ask…

– Is patient taking action immediately after first alert? – Is the length of time before the repeat alert occurs too short? – Is the sensor taped correctly?

• Could the sensor be moving / pulling-out / electrode drying? − If sensor pulls out (>2 mm) the transmitter will shut off, and cause a “Lost

Sensor” alert

Key Take-Aways • Leave all alerts OFF, except Low Glucose, at first • Turn pertinent alerts on as understanding of CGM increases

– Allows patient to become aware of glucose fluctuations, trends, patterns – Allows patient to observe effects of food, insulin, and exercise – Helps prevent information overload

• Not all alerts and features “have” to be used!

– Select which features best meet individual needs – Customize settings based on patient feedback & history

• When first starting a feature - set alert ranges wide

– Tighten ranges gradually as patient obtains better control – Balance benefit of feedback from alerts & live data with frequency of alerts

• Helps to minimize alerts and alarm fatigue

The Future

• My Sentry(relay CGM info to a “hub”) • Animas Vibe(pump and CGM combo) • Paradigm Veo • Symphony tCGM(sensor above skin) • Apps for phones • Closed Loop system