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

2. Making the Most of Continuous Glucose Monitoring
What Information Is Available
How to Use Immediate Data
How to Use Intermediate Data
What Can Be Learned from Retrospective Analysis
Optimizing CGM System Performance

3. Medtronic Carelink Personal
Report Options:
Medtronic Carelink Personal
Sensor Daily Overlay
Sensor Overlay By Meal

4. Medtronic Carelink Personal
Report Options:
Medtronic Carelink Personal
Daily Summary Layered Report:
Sensor tracing & BG entries
Basal & bolus delivery
Carbohydrate, exercise & logbook entries

5. Medtronic Carelink Personal
Report Options:
Medtronic Carelink Personal
Statistical Summary
Avg, SD, Hi/Low
# Hi/Low Excursions, AUC
% Time above, below, within target range

6. Report Options: DexCom DM3*
Hourly Stats
w/data table for each hour
Glucose Trend
Includes event entries
* Dexcom 7+ System not FDA approved for use in children under age 18 in the U.S.

7. Report Options: DexCom DM3
BG Distribution
% high, low, normal for each segment of the day
Modal Day
Customizable date range

8. Report Options: DexCom DM3
16 Jan - 15 Apr 10
16 Apr - 15 Jul 10
Change
A1c %
0.0 %
N/A
Mean Glucose
191
164
-14 %
Standard Deviation 65 64
-2 %
% in Hypoglycemia (39-55 mg/dL) 1
% in Low (55-70 mg/dL) 3
200 %
% in Target ( mg/dL) 33 48
45 %
% in High ( mg/dL) 46 36
-22 %
% in Hyperglycemia ( mg/dL) 20 12
-40 %
Days Sensor Used 22 91
314 %
Success
Report
Changes in control: week-to-week,
month-to-month, or quarter-to-quarter
Breakdown by hour, with averages
12 am
1 am
2 am
3 am
4 am
5 am
6 am
7 am
8 am
9 am
10 am
11 am
16 Jan - 15 Apr 10
206
199
204
208
198
179
169
166
172
181
196
16 Apr - 15 Jul 10
165
167
170
168
163
156
148
147
152
164
175
176

9. 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

10. Report Options: Freestyle Navigator/Copilot
Logbook Report
(Sensor BG q10 minutes)

11. What Do We Get in Real Time?
Trends
Alerts
Numbers

12. Decision-Making Based on Trend Information
Self-Care Choices
To snack?
To check again soon?
To exercise?
To adjust insulin?
Key Situations
Driving
Sports
Tests
Bedtime
Third, REAL-Time Trend Arrows.
One arrow up or down indicates a change of 1-2 mg/dl/min in the last 20 minutes.
Two arrows up or down indicate a change of more than 2 mg/dl/min in the last 20 minutes.
Arrows are only displayed if there has been at least a 1 mg/dl/min change in the last 20 minutes.
Patients should think about where glucose may be in 20 minutes if it continues at the same rate.

13. Bolus Adjustment Based 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)
Third, REAL-Time Trend Arrows.
One arrow up or down indicates a change of 1-2 mg/dl/min in the last 20 minutes.
Two arrows up or down indicate a change of more than 2 mg/dl/min in the last 20 minutes.
Arrows are only displayed if there has been at least a 1 mg/dl/min change in the last 20 minutes.
Patients should think about where glucose may be in 20 minutes if it continues at the same rate. 13

14. 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
Third, REAL-Time Trend Arrows.
One arrow up or down indicates a change of 1-2 mg/dl/min in the last 20 minutes.
Two arrows up or down indicate a change of more than 2 mg/dl/min in the last 20 minutes.
Arrows are only displayed if there has been at least a 1 mg/dl/min change in the last 20 minutes.
Patients should think about where glucose may be in 20 minutes if it continues at the same rate. 14

15. 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

16. The Value of Alerts: Minimizing the DURATION and MAGNITUDE of BG Excursions

17. CGM Turns Mountains into Molehills

18. Uniform Response is Key!
Fingerstick
Act on the Fingerstick

19. 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)

20. Initial Hi/Low Alert Settings
LOW: 80 mg/dl (4.5 mmol)
(90/5+ if hypo unaware)
HIGH: 300 mg/dL (18 mmol)
(lower progressively toward 180/10)
It is Medtronic’s recommendation that the starting alert setting on initiation should be a low of 80 mg/dL and a high of 240 mg/dL. It is important that patients do not confuse these alert settings with blood glucose targets. For instance, the low threshold of 70 might mean that the patient would miss hypoglycemia in the 60 or 50 range, or a high setting of 140 would mean that the patient would unnecessarily get alarms when glucose was in the normal range of 120 or multiple alarms when the glucose was in the 160 range.
NOT RECOMMENDED: Low 70 (4)
NOT RECOMMENDED: High 140 (8)

21. 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)

22. The Numbers: Ballpark Estimates
+/- 20% if >80 (4.4)
+/- 20 mg/dl if <80 (+/- 1 mmol/l if < 4.4)
Third, REAL-Time Trend Arrows.
One arrow up or down indicates a change of 1-2 mg/dl/min in the last 20 minutes.
Two arrows up or down indicate a change of more than 2 mg/dl/min in the last 20 minutes.
Arrows are only displayed if there has been at least a 1 mg/dl/min change in the last 20 minutes.
Patients should think about where glucose may be in 20 minutes if it continues at the same rate. 22

23. Can The Numbers Be Trusted?
Not during first 1-2 cycles of using the system
Not during the first hrs after sensor insertion
If BG Stable
If Recent calibrations in-line
If No recent alarms
Third, REAL-Time Trend Arrows.
One arrow up or down indicates a change of 1-2 mg/dl/min in the last 20 minutes.
Two arrows up or down indicate a change of more than 2 mg/dl/min in the last 20 minutes.
Arrows are only displayed if there has been at least a 1 mg/dl/min change in the last 20 minutes.
Patients should think about where glucose may be in 20 minutes if it continues at the same rate. 23

24. Specific Insights to Derive
(a purely retrospective journey)

25. 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.

26. 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?

27. Before You Analyze, Qualify.
MAD = 28%
gaps & inaccuracy
Abnormal Artifact

28. Objectives-Based Analysis
Are bolus amounts appropriate?
Meal doses
Correction doses
How long do boluses work?
What is the magnitude of postprandial spikes?
Is basal insulin holding BG steady?

29. Objectives-Based Analysis
Are asymptomatic lows occurring?
Are there rebounds from lows?
Are lows being over/under treated?
How does exercise affect BG?
Immediate
Delayed effects
Is amylin/GLP-1 doing the job?

30. Objectives-Based Analysis
How do various lifestyle events affect BG?
Hi-Fat meals
Unusual foods
Stress
Illness
Work/School
Sex
Alcohol

31. Reports to Focus on Summary Statistics Modal Day / Overlay Graphs
Individual Day Details
                                                

32. These Are a Few of My Favorite Stats…
Mean (avg) glucose
% Of Time Above, Below, Within Target Range
Standard Deviation
# Of High & Low Excursions Per Week

33. (the “retrospective journey”)
Case Examples
(the “retrospective journey”)

34. Case Study 1: The “Dark Side of the Moon”
Type 2; using glargine and metformin
Fasting readings OK; HbA1c elevated
Glucose (mg/dL)
400
300
200
100
3 AM AM
9 AM PM PM PM PM
BG rising & staying high after meals.
Consider meglitinide, exenatide, mealtime bolus insulin

35. Case Study 2a: Fine-Tuning Meal/Correction Boluses
34-y.o. pump user
Glucose (mg/dL)
400
300
200
100
3 AM AM AM PM PM PM PM
Breakfast and lunch doses may be too low
Dinner dose appears OK
Night-snack dose clearly insufficient

36. Case Study 2b: Fine-Tuning Meal/Correction Boluses
5-year-old on MDI; levemir BID.
Dropping low 2-3 hours after dinner.
Consider decreasing dinner bolus.

37. Case Study 2c: Fine-Tuning Meal/Correction Boluses
Teenager on a pump; stays up late.
BG Rising 9pm-1am.
Consider structured night snacks with increased bolus amount.

38. 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

39. 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.
Glucose (mg/dL)
400
300
200
100
Meal

40. 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.

41. 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.

42. 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.

43. Case Study 4b: Basal Insulin Regulation
Type 1 diabetes; using insulin glargine & MDI
History of morning lows
Snacking at night and not “covering” w/bolus
Glucose (mg/dL)
400
300
200
100
3 AM AM AM PM PM PM PM
Basal dose is likely too high. Consider reducing.

44. Case Study 4c: Basal Insulin Regulation
Pump user, frequent lows before breakfast and dinner.
Glucose (mg/dL)
400
300
200
100
BG dropping after bolus action completed. Consider reducing basal rates early morning & late afternoon.

45. Case Study 5: Determination of Insulin Action Curve
12am am am
3-Hour Duration
4-Hour Duration
5-Hour Duration

46. 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.

47. Case Study 7: Effectiveness of Pramlintide/Exenatide
15 mcg pramlintide
60 mcg pramlintide

48. Case Study 8: Response Curve to Different Food Types
Cereal
Oatmeal
Yogurt
Postprandial peak:
cereal > oatmeal > yogurt

49. Case Study 9: Immediate Responses to Unusual Events
Type 1 diabetes; pump user
40 years old; athletic
Handsome, excellent speaker
Glucose (mg/dL)
400
300
200
100
Late for meeting
Gets flat tire; eats 15g carbs to prepare for tire change
Spare is flat too!!
9 AM 12 PM 3 PM 6 PM 9 PM
STRESS CAN RAISE BLOOD GLUCOSE… A LOT!!!

50. Case Study 10a: Delayed Effects
Pump user
Basal rates confirmed overnight
“yellow” night: light cardio workout prior evening
“Red” night: Lifting & cardio workout prior evening
Experiencing delayed-onset hypoglycemia from heavy workouts. Consider temp basal reduction.

51. Case Study 10b: Delayed Effects
Pump user
Normal fasting readings during the week, but high on weekends
Saturday Nights, Dinner Out
Delayed rise from high-fat meals.
Consider using temp basal increase.

52. Your Turn! What conclusions might you draw?
What recommendations would you give? 52

53. Your Turn! What conclusions might you draw?
In clinics that have utilized the MiniMed Paradigm REAL-Time System in studies, certain experiences can be gained. An analysis of patients who did well experienced benefits from using it continuously or at least 90 percent of the time. Patients who have experience with insulin pump therapy seemed to benefit more than those who were new to pump therapy and therefore still learning how to optimize their insulin pump usage. Patients who looked at it frequently, almost times per day, but did not overreact to the data. Patients who had their CareLink data examined by the healthcare team, and with the help of the healthcare team, looked at trends and patterns and responses of glucose to insulin and made changes in carbohydrate to insulin ratios and basal rates. Patients who used the Bolus Wizard calculator did best and avoided hypoglycemia. It can also be said to the contrary that a lot has been learned from patients who do not benefit as much of the time: patients who did not wear the sensor at least 50 percent of the time; patients who did not trust the readings, and therefore did not look at the sensor; and patients who became extremely frustrated with nuisance alarms, causing them to stop using the sensor.
So patient behavior during wearing CGM is also a key factor to achieve a better outcome.
What conclusions might you draw?
What recommendations would you give? 53

54. Optimizing CGM System Performance
Calibration
Sensor & Site Care
Signal reception
Ingredients for success 54

55. Optimal Calibration
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
The best time to calibrate is when the blood glucose (BG) is stable — before meals or at bedtime—for then it is less likely that rapid changes in BG are going to take place.
NOTE: When the BG is rapidly changing and a patient attempts to calibrate with a “single point in time” BG fingerstick reading, there may be enough of a change taking place to cause a calibration error to occur. If 2 calibration errors occur in a row, the glucose sensor can no longer be used and must be replaced. For this reason, patients should try not to calibrate within 2 hours after a meal or when 2 UP or DOWN arrows are displayed beside the current glucose reading on the insulin pump screen.
The continuous glucose monitoring system must be calibrated a minimum of every 12 hours. However, 3 to 4 times a day is preferred. If calibration is not done every 12 hours, the insulin pump screen will stop displaying sensor glucose readings until a fingerstick BG value is entered
Remind your patient to calibrate before going to sleep to prevent a METER BG NOW alarm from sounding during sleep hours

56. 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)
The best time to calibrate is when the blood glucose (BG) is stable — before meals or at bedtime—for then it is less likely that rapid changes in BG are going to take place.
NOTE: When the BG is rapidly changing and a patient attempts to calibrate with a “single point in time” BG fingerstick reading, there may be enough of a change taking place to cause a calibration error to occur. If 2 calibration errors occur in a row, the glucose sensor can no longer be used and must be replaced. For this reason, patients should try not to calibrate within 2 hours after a meal or when 2 UP or DOWN arrows are displayed beside the current glucose reading on the insulin pump screen.
The continuous glucose monitoring system must be calibrated a minimum of every 12 hours. However, 3 to 4 times a day is preferred. If calibration is not done every 12 hours, the insulin pump screen will stop displaying sensor glucose readings until a fingerstick BG value is entered
Remind your patient to calibrate before going to sleep to prevent a METER BG NOW alarm from sounding during sleep hours 56

57. The Sensors Storage Site Selection
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

58. The Sensors Timing Bleeding/Irritation
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

59. The Sensors Adhesive Site Irritation
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)

60. 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)
                   
In clinics that have utilized the MiniMed Paradigm REAL-Time System in studies, certain experiences can be gained. An analysis of patients who did well experienced benefits from using it continuously or at least 90 percent of the time. Patients who have experience with insulin pump therapy seemed to benefit more than those who were new to pump therapy and therefore still learning how to optimize their insulin pump usage. Patients who looked at it frequently, almost times per day, but did not overreact to the data. Patients who had their CareLink data examined by the healthcare team, and with the help of the healthcare team, looked at trends and patterns and responses of glucose to insulin and made changes in carbohydrate to insulin ratios and basal rates. Patients who used the Bolus Wizard calculator did best and avoided hypoglycemia. It can also be said to the contrary that a lot has been learned from patients who do not benefit as much of the time: patients who did not wear the sensor at least 50 percent of the time; patients who did not trust the readings, and therefore did not look at the sensor; and patients who became extremely frustrated with nuisance alarms, causing them to stop using the sensor.
So patient behavior during wearing CGM is also a key factor to achieve a better outcome.

61. Ingredients For Success
Have the right expectations
Wear the CGM at least 90% of the time
Look at the monitor 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
In clinics that have utilized the MiniMed Paradigm REAL-Time System in studies, certain experiences can be gained. An analysis of patients who did well experienced benefits from using it continuously or at least 90 percent of the time. Patients who have experience with insulin pump therapy seemed to benefit more than those who were new to pump therapy and therefore still learning how to optimize their insulin pump usage. Patients who looked at it frequently, almost times per day, but did not overreact to the data. Patients who had their CareLink data examined by the healthcare team, and with the help of the healthcare team, looked at trends and patterns and responses of glucose to insulin and made changes in carbohydrate to insulin ratios and basal rates. Patients who used the Bolus Wizard calculator did best and avoided hypoglycemia. It can also be said to the contrary that a lot has been learned from patients who do not benefit as much of the time: patients who did not wear the sensor at least 50 percent of the time; patients who did not trust the readings, and therefore did not look at the sensor; and patients who became extremely frustrated with nuisance alarms, causing them to stop using the sensor.
So patient behavior during wearing CGM is also a key factor to achieve a better outcome. 61

62. Questions?