Making the Mostof Continuous Glucose Monitoring1. What Information Is Available?2. How to Use Immediate Data?3. How to Use Intermediate Data?4. What Can Be Learned fromRetrospective Analysis?5. Optimizing CGM System Performance
MiniMed Paradigm ® &Guardian ® REAL-Time CGM SystemsOn-Screen Reports• 3-hr and 24-hr graphs (pump);3 / 6 / 12 / 24-hr graphs(Guardian)• Can scroll back for specificdata points• ‣ “direction” indicators• Updates every 5 minutes• Hi/Low Alerts• Predictive Alerts (Guardian)
CareLink Personal:Online Reports• Sensordailyoverlay• Sensoroverlayby mealMiniMed Paradigm ® &Guardian ® REAL-Time CGM Systems
Daily summaries &layered reports,including…• Sensor tracing• Basal & bolusdelivery• Carbohydrate &logbook entriesMiniMed Paradigm ® &Guardian ® REAL-Time CGM SystemsCareLink PersonalOnline Reports
DexCom Seven Plus ®On-Screen Reports• 1, 3, 6, 12, 24-hrgraphs• Updates every 5minutes• Hi/Low alerts• Rate of Changealerts
DexCom 7 STS ®Dexcom DM2Download ReportsHourly StatsGlucose Trend
Dexcom DM2Download ReportsDexCom 7 STS ®Trend AnalysisBGDistribution
Freestyle Navigator On-Screen Reports• 2/4/6/12/24-hr line graphs• Predictive alerts• ‣ “direction” indicators• Can scroll back to data points• Customizable time range:• Highest, Lowest, Avg, SD• % Time High, Low, In-Range• # Hypo, Hyper events• Updates every minute
Freestyle Navigator Download to CoPilot SoftwareModal Day ReportGlucose Line ReportStatistics Report
Practical Benefits of Real-Time CGM• Rumble strips (avoid serious extremes)• Peace of mind• Basal & bolus fine tuning• Postprandial analysis• Insulin action curve determination• Short-term Forecasting• Learning tool & immediate feedback• Eliminates some blood glucose checks???Partially derived from: Hirsch, et al. Clinical Application of Emerging Sensor Technologies in DiabetesManagement: Consensus Guidelines for Continuous Glucose Monitoring (CGM). Diabetes Technology& Therapeutics, 10:4, 2008, 232-244.
How to Look at the Information• Immediate• Intermediate• Retrospective
Immediate Info: Alerts• Customizable settings• Vibrate and/or beep• Alert the user of glucose levels thathave crossed specified high or lowthresholds• (predictive) Alert of anticipated crossingof high or low thresholds
Setting Alerts• Hi/Low alarm thresholds are not BGtarget ranges• Balance need for alerts against “nuisancefactor”
LOW:HIGH:Initial Alert SettingsRecommendation80 mg/dl (4.5 mmol)90 (5) + if hypo unaware300 mg/dl (16 mmol)lower progressively toward 180 (10)NOT RECOMMENDED: Low 70 (3.9)NOT RECOMMENDED: High 140 (7.8)Derived from: Hirsch, et al. Clinical Application of Emerging Sensor Technologies in DiabetesManagement: Consensus Guidelines for Continuous Glucose Monitoring (CGM). Diabetes Technology& Therapeutics, 10:4, 2008, 232-244.
Special Alert Settings• Young children (higher, wider range)• Hypoglycemia unawareness, highriskprofessions (higher hypo setting)• Pregnancy (lower, narrower range)• HbA1c of 11.0% (higher initially)
Immediate Info:Glucose and Trend• Prediction/Forecasting• Safety/Performance• Driving• Sports• Tests
Immediate Glucose Info:Can it ReplaceFingersticks?• Not during first 1-2 cycles ofusing the system• Wait at least 12 hrs aftersensor replacement• If BG Stable• If Recent calibrations in-line• If No recent alarms
Immediate Info:Potential Bolus AdjustmentBased on BG Direction• BG Stable:Usual Bolus Dose• BG Rising Gradually: bolus 10%• BG Rising Sharply: bolus 20%• BG Dropping Gradually: bolus 10%• BG Dropping Sharply: bolus 20%
Immediate Info:Hypoglycemia Alerts• Predictive Hypo Alert orHypo 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
Intermediate Info:Use of 2/3/4 Hr Trend Graphs• Effects of different food types• Effectiveness of bolus amt.• Reveals postprandial spikes• Pramlintide/Exenatide Influence• Exercise effects• Impact of Stress
Intermediate Info:Use of 9 / 12 / 24 Hr Trend Graphs• Facilitates decision-making for basalinsulin doses• Shows delayed effects of exercise,stress, high-fat foods• Reveals overnight patterns• Lets user know when bolus action iscomplete
Specific Insights to Derive(a purely retrospective journey)
Before You Analyze, Qualify.• Were sufficient calibrations performed?• Did the calibrations match the CGM datareasonably well?• Was the data mostly continuous?• Was the time/date set correctly?
These Are a Fewof My FavoriteStats… Mean (avg) glucose % Of Time Above, Below, Within TargetRange Standard Deviation # Of High & Low Excursions Per Week
Glucose (mg/dL)Case Study 1:Effectiveness of Current Program• Type 1 diabetes; using insulin glargine & MDI• Overnight readings are OK; HbA1c levels are elevated40030020010003 AM 6 AM9 AM 12 PM 3 PM 6 PM 9 PMMeal doses insufficient; not covering snacks?
Glucose (mg/dL)Case Study 2a:Basal Insulin Regulation400400300200100030020010003 AM 9 AM 3 PM 9 PM 3 AM 9 AM 3 PM 9 PM• Stable 12 AM – 4 AM, thendropping pre-dawn• Dropping late afternoon• Rising 2 AM – 8 AM
Glucose (mg/dL)Case Study 2b:Basal Insulin Regulation• Type 1 diabetes; using insulin glargine & MDI• History of morning lows• Now not “covering” highs at night40030020010003 AM 6 AM 9 AM 12 PM 3 PM 6 PM 9 PMBG dropping overnight; insulin dose too high
Glucose (mg/dL)Case Study 3:Detection of Silent Hypoglycemia• Type1 diabetes; on pump• Frequent fasting highs (9 AM)40030020010003 AM 6 AM 9 AM 12 PM 3 PM 6 PM 9 PMSomogyi effect during the night
Case Study 4:Determination of Insulin Action Curve3-HourDuration4-HourDuration5-HourDuration
Glucose (mg/dL)Case Study 5:Fine-Tuning Meal Boluses40030020010003 AM 6 AM 9 AM 12 PM 3 PM 6 PM 9 PMBreakfast andlunch dosesmay be too lowDinner doseappears OKNight-snackdose clearlyinsufficient
Glucose (mg/dL)Case Study 6:Fine-Tuning Correction Boluses• Dropping low after correcting for highs at bedtimeand wake-up time40030020010003 AM 6 AM 9 AM 12 PM 3 PM 6 PM 9 PMNeed to change correction factor & insulinsensitivity during AM hours
Glucose (mg/dL)Case Study 7:Postprandial Analysis• Pre-meal BG levels are usually in target range• HbA1c are higher than expected based on SMBG• Tired and lethargic after meals400300200Meal100MealMealMealSignificant postprandial spikes (300s)
Glucose (mg/dL)Case Study 8:Impact of Physical Activity• Type 1 diabetes; pump user• Basal rates confirmed overnight• Exercises in the evening (9 PM)400300Exercise20010003 PM 6 PM 9 PM 12 AM 3 AM 6 AM 9 AM 12 PMExperiencing delayed-onset hypoglycemia
Glucose (mg/dL)Case Study 9:Impact of Stress• Type 1 diabetes;pump user• 40 years old;athletic• Handsome,excellent speaker400300200• Late for meeting• Gets flat tire; eats15g carbs to preparefor tire change• Spare is flat too!!10009 AM 12 PM 3 PM 6 PM 9 PMSTRESS CAN RAISE BLOOD GLUCOSE… A LOT!!!
Case Study 10:Impact of Various Food TypesPasta MealStir-Fry Over RiceCerealOatmealYogurtBG peaks later withpasta than ricePostprandial peak:cereal > oatmeal > yogurt
Case Study 11:Impact of Hi-Fat MealsSaturday Nights,Dinner OutTemp basal increase following hi-fat meals
CGM “Homework”Assignments Verify basal doses See effect of dietary fat Study effects of specific exercises Evaluate impact of different food types Measure insulin sensitivity Determine insulin action curveDownload (if poss.) prior to appointments!
Optimizing CGMSystem Performance• Calibration• Site selection/care• Signal reception• Ingredients for success
Optimal Calibration• Calibrate at times when blood glucose(BG) is stable (fasting, pre-meals)*• Avoid calibrations during times of rapidglucose change*– Post meal– UP or DOWN arrows are displayed– In the period following a correction with food orinsulin– During exercise* Not required w/Dexcom system
Optimal Calibration• Calibrate before bedtime to avoid alarmsduring the night• Use good technique when performingBG checks for calibration– Proper coding– Clean hands• USE FINGERSTICKS• Enter the calibration immediately afterthe fingerstick (Dexcom, Medtronic systems)
• Site SelectionSensor Sites– “Fleshy” areas– At least 3” Away from insulin infusion– Avoid tight clothing areas, scars, bruises, lipoatrophy– Rotate sites• Bleeding/Irritation– Slight bleeding OK– Profuse bleeding: remove– Remove introducer needle at proper angle
• AdhesiveSensor Sites– Completely cover the Transmitter & Sensor(Navigator & Medtronic systems)– Check sensor daily for loose tape– Apply extra tape over sensor & transmitter if tapepatch 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 intoaccount• Adjust your therapy based on trends/patterns• Calibrate appropriately• Minimize “nuisance” alarms
Think Like A Pancreas!