Making the Most of Continuous Glucose Monitoring Gary Scheiner MS, CDE Owner & Clinical Director Integrated Diabetes Services LLC Wynnewood, PA Dean Type-1.

Making the Most of Continuous Glucose Monitoring

Gary Scheiner MS, CDEOwner & Clinical Director

Integrated Diabetes Services LLC

Wynnewood, PA

“Dean”

Type-1 University

www.type1university.com

Making the Most of Continuous Glucose Monitoring

1. What Information Is Available

2. How to Use Immediate Data

3. How to Use Intermediate Data

4. What Can Be Learned from Retrospective Analysis

5. Optimizing CGM System Performance

Sensor Daily Overlay

Report Options:Medtronic Carelink Personal

Sensor Overlay By

Meal

3

• Sensor tracing & BG entries

• Basal & bolus delivery

• Carbohydrate, exercise &

logbook entries

Daily Summary Layered Report:

Report Options:Medtronic Carelink Personal

4

• Avg, SD, Hi/Low

• # Hi/Low Excursions, AUC

• % Time above, below, within target range

Statistical Summary

Report Options:Medtronic Carelink Personal

5

Hourly Statsw/data table for each hour

Glucose TrendIncludes event entries

Report Options:DexCom DM3*

6

* Dexcom 7+ System not FDA approved for use in children under age 18 in the U.S.

BG Distribution% high, low, normal for each segment of the day

Modal DayCustomizable

date range

Report Options:DexCom DM3

7

Success Report

Report Options:DexCom DM3

16 Jan - 15 Apr 10 16 Apr - 15 Jul 10 ChangeA1c % 0.0 % 0.0 % N/A

Mean Glucose 191 164 -14 %

Standard Deviation 65 64 -2 %

% in Hypoglycemia (39-55 mg/dL)

0 1 N/A

% in Low (55-70 mg/dL) 1 3 200 %

% in Target (70-160 mg/dL) 33 48 45 %

% in High (160-240 mg/dL) 46 36 -22 %

% in Hyperglycemia (240-401 mg/dL)

20 12 -40 %

Days Sensor Used 22 91 314 %

12 am 1 am 2 am 3 am 4 am 5 am 6 am 7 am 8 am 9 am 10 am 11 am16 Jan - 15 Apr 10 206 199 204 208 206 198 179 169 166 172 181 19616 Apr - 15 Jul 10 165 167 170 168 163 156 148 147 152 164 175 176

Changes in control: week-to-week, month-to-month, or quarter-to-quarter

Breakdown by hour, with averages

8

Report Options:Freestyle Navigator/Copilot

Modal Day Report

Customizable by date range, day of week

Glucose Line Report

Stats Report

Broken down by phase of the day 9

Report Options:Freestyle Navigator/Copilot

Logbook Report(Sensor BG q10 minutes) 10

What Do We Get in Real Time?

Trends

Alerts

Numbers

Decision-Making Based on Trend Information

• Self-Care Choiceso To snack?o To check again soon?o To exercise?o To adjust insulin?

• Key Situationso Drivingo Sportso Testso Bedtime

Bolus AdjustmentBased on Trend Information

• BG Stable: Usual Bolus Dose

• BG Rising Gradually: bolus slightly*

• BG Rising Sharply: bolus modestly**

• BG Dropping Gradually: bolus slightly*

• BG Dropping Sharply: bolus modestly**

* Enough to offset 25 mg/dl (1.5 mmol/l)

** Enough to offset 50 mg/dl (3 mmol/l)

Immediate Info: Hypoglycemia Alerts

• Predictive Hypo Alert or Hypo Alert & recovering: Subtle Treatment • 50% of usual carbs

• Med-High G.I. food

• Hypo Alert & Dropping: Aggressive Treatment• Full or increased carbs

• High G.I. food

vs

Types of Alerts

• Hi/Low Alert: Cross specified high or low thresholds

• Predictive Alert: Anticipated crossing of high or low thresholds

• Rate of Change: Rapid rise or fall

The Value of Alerts:

Minimizing the DURATION and MAGNITUDE of BG Excursions

CGM Turns Mountains into Molehills

Uniform Response is Key!

1. Fingerstick

2. Act on the Fingerstick

Setting Alerts

• Hi/Low alert thresholds are not BG target ranges

• Balance need for alerts against “nuisance factor”

• Predictive alerts lose value the further the advance warning (keep below 10 min)

• Rate of FALL alerts helpful for long-term hypo prevention (>3 mg/dl/min) (.17)

LOW: 80 mg/dl (4.5 mmol)(90/5+ if hypo unaware)

HIGH: 300 mg/dL (18 mmol)(lower progressively toward 180/10)

NOT RECOMMENDED: Low 70 (4)NOT RECOMMENDED: High 140 (8)

Initial Hi/Low Alert Settings

Special Alert Settings

• Young children (higher, wider range)

• Hypoglycemia unawareness, high-risk professions (higher hypo setting)

• Pregnancy (lower, narrower range)

• HbA1c of 11.0% (higher initially)

The Numbers:Ballpark Estimates

+/- 20% if >80 (4.4)

+/- 20 mg/dl if <80 (+/- 1 mmol/l if < 4.4)

Can The Numbers Be Trusted?

• Not during first 1-2 cycles of using the system

• Not during the first 12-24 hrs after sensor insertion

• If BG Stable

• If Recent calibrations in-line

• If No recent alarms

Specific Insights to Derive(a purely retrospective journey)

CGM Data Analysis Tools

Hardware/Software

• Medtronic: – Internet Access to Carelink– Carelink USB Adapter

• Dexcom*: – PC, DM3 Software– Connector Cable

• Color Printer* Dexcom 7+ System not FDA approved for use in children under age 18 in the U.S.

Before You Analyze, Qualify. Before You Analyze, Qualify. • Were sufficient calibrations performed?

• Did the calibrations match the CGM data reasonably well?

• Was the data mostly continuous?

• Was the time/date set correctly?

26

Before You Analyze, Qualify. Before You Analyze, Qualify.

MAD = 28%

Abnormal Artifact

gaps & inaccuracy

27

1. Are bolus amounts appropriate?– Meal doses– Correction doses

2. How long do boluses work?

3. What is the magnitude of postprandial

spikes?

4. Is basal insulin holding BG steady?

Objectives-Based Analysis

5. Are asymptomatic lows occurring?– Are there rebounds from lows?– Are lows being over/under treated?

6. How does exercise affect BG?– Immediate– Delayed effects

7. Is amylin/GLP-1 doing the job?

Objectives-Based Analysis

8. How do various lifestyle events

affect BG?– Hi-Fat meals– Unusual foods– Stress– Illness– Work/School– Sex– Alcohol

Objectives-Based Analysis

Reports to Focus onReports to Focus on

• Summary Statistics

• Modal Day / Overlay Graphs

• Individual Day Details

31

These Are a Few of These Are a Few of My Favorite My Favorite

Stats… Stats…

Mean (avg) glucose

% Of Time Above, Below, Within Target Range

Standard Deviation

# Of High & Low Excursions Per Week

32

Case ExamplesCase Examples(the “retrospective journey”)

Case Study 1: The “Dark Side of the Moon”

• Type 2; using glargine and metformin• Fasting readings OK; HbA1c elevated

BG rising & staying high after meals. Consider meglitinide, exenatide, mealtime bolus insulin

BG rising & staying high after meals. Consider meglitinide, exenatide, mealtime bolus insulin

3 AM 6 AM

Glu

cose

(m

g/d

L)

400

300

200

100

0

9 AM 12 PM 3 PM 6 PM 9 PM

Case Study 2a: Fine-Tuning Meal/Correction Boluses

Breakfast and lunch doses

may be too low

Breakfast and lunch doses

may be too low

Dinner dose appears OK Dinner dose appears OK

Glu

cose

(m

g/d

L)

400

300

200

100

0

3 AM 6 AM 9 AM 12 PM 3 PM 6 PM 9 PM

Night-snack dose clearly insufficient

Night-snack dose clearly insufficient

• 34-y.o. pump user

Case Study 2b: Fine-Tuning Meal/Correction Boluses

Dropping low 2-3 hours after dinner.

Consider decreasing dinner bolus.

Dropping low 2-3 hours after dinner.

Consider decreasing dinner bolus.

• 5-year-old on MDI; levemir BID.

Case Study 2c: Fine-Tuning Meal/Correction Boluses

BG Rising 9pm-1am.

Consider structured night snacks with increased bolus amount.

BG Rising 9pm-1am.

Consider structured night snacks with increased bolus amount.

Teenager on a pump; stays up late.

Case Study 2d: Fine-Tuning Meal/Correction Boluses

• Pumper, dropping low after correcting for highs during the night

Corr.Bolus

Consider increasing nighttime correction factor / insulin sensitivity

Consider increasing nighttime correction factor / insulin sensitivity

Case Study 3a: Postprandial Analysis

• Young adult on MDI. • HbA1c are higher than expected based on SMBG• Tired and lethargic after meals

Significant postprandial spikes (300s). Consider pramlintide before meals.

Significant postprandial spikes (300s). Consider pramlintide before meals.

Glu

cose

(m

g/d

L)

400

300

200

100

Meal

Meal

MealMeal

Case Study 3b: Postprandial Analysis

• Pump user, usually bolusing right before eating. • Potatoes w/dinner most nights.

Spiking primarily after dinner.

Consider lower g.i. food or pre-bolusing.

Spiking primarily after dinner.

Consider lower g.i. food or pre-bolusing.

Case Study 3c: Postprandial Analysis

• Pump user, 6 months pregnant• Pre-bolusing (15-20 min) at most meals.

Spiking primarily after breakfast.

Consider “splitting” breakfast or walking post-bkfst.

Spiking primarily after breakfast.

Consider “splitting” breakfast or walking post-bkfst.

Case Study 4a: Basal Insulin Regulation

• Pump user, 6 months pregnant• Generally not eating (or bolusing) after 8pm.

BG rising 1am-6am.

Consider raising basal insulin 12am-5am.

BG rising 1am-6am.

Consider raising basal insulin 12am-5am.

Case Study 4b: Basal Insulin Regulation

Glu

cose

(m

g/d

L)

400

300

200

100

0

3 AM 6 AM 9 AM 12 PM 3 PM 6 PM 9 PM

Basal dose is likely too high. Consider reducing.Basal dose is likely too high. Consider reducing.

• Type 1 diabetes; using insulin glargine & MDI• History of morning lows• Snacking at night and not “covering” w/bolus

Case Study 4c: Basal Insulin Regulation

Glu

cose

(m

g/d

L)

400

300

200

100

0

BG dropping after bolus action completed. Consider reducing basal rates early morning & late afternoon.

BG dropping after bolus action completed. Consider reducing basal rates early morning & late afternoon.

• Pump user, frequent lows before breakfast and dinner.

Case Study 5: Determination of Insulin Action Curve

3-Hour Duration

5-HourDuration

4-Hour Duration

12am 3am 6am

Case Study 6: Detection of Silent Hypoglycemia

• Type1 college student; on pump

• Frequent fasting highs (9-10 AM). Wanted to raise overnight basal rates.

Dropping & rebounding during the night. Consider decreasing basal in early part of night.

Dropping & rebounding during the night. Consider decreasing basal in early part of night.

Case Study 7: Effectiveness of Pramlintide/Exenatide

• 15 mcg pramlintide

• 60 mcg pramlintide

Case Study 8: Response Curve to Different Food Types

Postprandial peak: cereal > oatmeal > yogurt

Postprandial peak: cereal > oatmeal > yogurt

CerealOatmealYogurt

Case Study 9: Immediate Responses to Unusual Events

• Type 1 diabetes; pump user

• 40 years old; athletic

• Handsome, excellent speaker

• Gets flat tire; eats 15g carbs to prepare for tire change

• Spare is flat too!!

STRESS CAN RAISE BLOOD GLUCOSE… A LOT!!!STRESS CAN RAISE BLOOD GLUCOSE… A LOT!!!

• Late for meetingG

luco

se

(mg

/dL

)

400

300

200

100

0

9 AM 12 PM 3 PM 6 PM 9 PM

Case Study 10a: Delayed Effects

Experiencing delayed-onset hypoglycemia from heavy workouts. Consider temp basal reduction.Experiencing delayed-onset hypoglycemia from

heavy workouts. Consider temp basal reduction.

• Pump user• Basal rates confirmed overnight• “yellow” night: light cardio workout prior evening• “Red” night: Lifting & cardio workout prior evening

Case Study 10b: Delayed Effects

Delayed rise from high-fat meals. Consider using temp basal increase.Delayed rise from high-fat meals.

Consider using temp basal increase.

Saturday Nights, Dinner Out

• Pump user• Normal fasting readings during the week, but high on

weekends

Your Turn!

• What conclusions might you draw?

• What recommendations would you give?

Your Turn!

• What conclusions might you draw?

• What recommendations would you give?

Optimizing CGM System Performance

• Calibration

• Sensor & Site Care

• Signal reception

• Ingredients for success

• Calibrate at times when blood glucose (BG) is stable (fasting, pre-meals)*

• Avoid calibrations during times of rapid glucose change*– Post meal

– UP or DOWN arrows are displayed

– In the period following a correction with food or insulin

– During exercise

* Not required w/Dexcom system

Optimal Calibration

• Calibrate before bedtime to avoid alarms during the night

• Use good SMBG technique– Proper coding

– Clean hands

– Sufficient blood sample

– Fresh strips

• USE FINGERSTICKS

• Enter the calibration immediately after the fingerstick (Dexcom, Medtronic systems)

Calibration

The Sensors• Storage

– Refrigeration preferred (but not required)

– OK to use 1-2 months past expiration

• Site Selection– “Fleshy” areas

– At least 2” Away from insulin infusion

– Avoid tight clothing areas, scars, bruises, lipoatrophy

– Rotate sites

The Sensors• Timing

– Allow adequate “wetting” time (Medtronic)– Put sensor in the night before connecting the transmitter

(Medtronic)

• Bleeding/Irritation– Slight bleeding OK

– Profuse bleeding: remove

– Remove introducer needle at proper angle

The Sensors• Adhesive

– Completely cover the Transmitter & Sensor (Navigator & Medtronic systems)

– Check sensor daily for loose tape

– Apply extra tape over sensor & transmitter if tape patch begins to “curl” around edges

• Site Irritation– Watch for redness, swelling, tenderness– Remove sensor with prolonged irritation (>1 hour)

Signal Reception• Heed transmitter ranges

– Medtronic: 6 ft.– Dexcom: 5 ft.– Navigator: 10 ft.

• Signals do not travel well through water

– Wear receiver on same side of body as sensor

• Keep receiver very close while charging (Dexcom)

• Charge transmitter fully every 6 days (Medtronic)

Ingredients For Success• Have the right expectations

• Wear the CGM at least 90% of the time

• Look at the monitor 10-20 times per day

• Do not over-react to the data; take IOB into account

• Adjust your therapy based on trends/patterns

• Calibrate appropriately

• Minimize “nuisance” alarms

Questions?