Pump and Sensor Data Interpretation Irl B. Hirsch, MD University of Washington School of Medicine
Dualities Research: Medtronic Diabetes Consulting: Abbott Diabetes Care, BD, Bigfoot, Roche
Raise Your Hand If In Your Practice Every patient gets their meter downloaded Every patient gets their pump downloaded Every patient gets their CGM downloaded No patient gets downloaded, but you encourage your patients to download at home If your downloads are uploaded into your EMR
What You Need (Minimal) A program which allows downloading of various meters/pumps/sensors Clinipro (Numedics.com), Glooko/Diasend, Carelink, Tidepool Ideally, many of the native softwares are also available A better solution: immediate upload to the cloud Livongo, Accucheck Aviva Connect, Dexcom Clarity Clarity Given all of the nuances we are appreciating with HbA1c, using TIRs from CGM is becoming a new standard
International Consensus Panel Recommendations Self-evident glucose metrics for patients, clinicians, and researchers 5 thresholds TIR: 70-180 mg/dl (3.9-10.0 mmol/l) TBR: < 70 mg/dl (< 3.9 mmol/l)*; < 54 mg/dl (< 3.0 mmol/l)** TAR: > 180 mg/dl (> 10.0 mmol/l); > 250 mg/dl (> 13.9 mmol/l In addition to (or as opposed to) A1C, we can now compare studies to each other by comparing buckets and patients can now also be compared-not like A1C * alert hypoglycemia; ** severe hypoglycemia; Danne T, et al: Diabetes Care 2017;40:1631-40
Transitioning is Always Difficult For glycemic variability, it is time to transition away from SD and to CV For > 25 years: SD X 3 < mean (for means 120-180 mg/dl) has been our target Consensus: CV (SD/mean) a better metric CV target: 36? 33?
But For a Busy Endocrine Practice, Why Treat the Glucose (and spend time with downloading) and Not Simply the HbA1c, Especially for T2D Not Receiving Insulin? ACP: Most patients with T2D should aim to achieve HbA1c a HbA1c level between 7-8% A1C (%) AG (mg/dl [95% CI]) 5 97 (76-120) 6 126 (100-152) 7 154 (123-185) 8 183 (147-217) 9 212 (170-249) 10 249 (192-282) 11 269 (217-314) 12 298 (240-347) Based on the new ACP Guidelines glucose targets can range from an average of 123 to 217 mg/dl (not including all of the discordant patients we ve discovered)
HbA1c levels for a Given Time in Range (70-180 mg/dl) for an Individual with T1D Measured TIR Estimated HbA1c 95% CI 40% 8.1% 7.1-9.1% 50% 7.7% 6.6-8.7% 60% 7.2% 6.2-8.3% 70% 6.8% 5.8-7.8% 80% 6.4% 5.2-7.4% Beck R: ATTD, Vienna, 2018 8
The Painful Reality: Few Endocrinologists Routinely Look at Downloads Due to The Time Commitment and Overwhelming Data Presentation
ONE Reason Why Downloading Is So Important: Understanding the Mean and Estimated A1C 24 year-old woman, MDI, using Dexcom, 14 years T1D This patient s HbA1c is 8.2%. She has a discordance with her A1C due to iron deficiency anemia
Hematologic conditions Anemia Accelerated erythrocyte turnover Thalassemia Sickle cell disease Reticulocytosis Hemolysis Physiologic States Aging Pregnancy Drugs/Medications Alcohol Opioids Vitamin C Vitamin E Aspirin Erythropoetin Dapsone Ribavirin What Alters A1C Disease States HIV infection Uremia Hyperbilirubinemia Dyslipidemia Cirrhosis Hypothyroidism* Medical Therapies Blood transfusion Hemodialysis In a typical diabetes practice, about 20% of A1C measurements are misleading Miscellaneous Glycation rate Protein turnover Race and ethnicity* Laboratory assay Glycemic Variability Smoking Mechanical heart valves Exogenous testosterone?
CASE 2: 20 y/o T1D, Down Syndrome T1D X 11 years, CSII and CGM. Last SH 5 years ago; HbA1c 7.6%
High basals in the evening do help to cushion dinner but usually result in hypoglycemia if not snacking. Timing of nocturnal basal change is important! Hypoglycemic seizure at 1:30am. Why?
What Happens When This Patient (now 21 years-old) Goes on a 670G? Raise your hand if you have at least 1 patient on a 670g? Raise your hand if you have more than 10 patients on a 670 g? My opinion: for the right patient personality, they clearly improve diabetes control and quality-of-life There are certain patient personalities they don t work well-like everything there are pros and cons and while this is an advancement in our technology, it is a first (but important) step
Case 2a: 15 months later
Case 2a: HCL No sensors! Need more aggressive ICR?
Case 2a: HCL
What I Did Shorter AITr More aggressive ICR
What Are The Goals with Hybrid Closed Loop Pumps? Pivotal trial (N=124, mean age 38 years, A1C 7.4%, 12 weeks no control group): TIR: 72% TBR: 3.3%* TAR: 9.2% A1C: 6.9% Mean glucose: 148 mg/dl* Basal insulin: 46%* * My observations: Difficult to obtain mean glucose less than 140 mg/dl with current HCL systems. Goal TBR is < 4%. Almost everyone who does well needs less basal than bolus insulin (often 40%)
Problems in 2018 With our Technology Daily details on Carelink which allows us to understand if the bolus calculator is working correctly taken away from manual mode in 670g Smart Pens only now becoming available for MDI patients (my prediction: this will be the biggest change to our practices in the next 3 years Solutions: use of other software
Case 3: Included With Infrastructure: Assessing The Data With Other Pump/CGM 38 y/o woman with T1D preparing for pregnancy Uses OmniPod and Libre (Libre started 12/17) BMI 30; on hypocaloric diet to lose weight A1C 11/17= 7.4% Details of boluses, over-rides, temp basals important but views from the sky can also be important
Tidepool Carbs, amount suggested, amount delivered with Libre 1. Increase basal 10p-4a 2. Less aggressive carb ratio with more use of extended boluses with dinner
Opinion: Bolus Calculators Are An Important and Under-Utilized Tool BUT, they are not smart! If the glucose is trending up or down, more or less insulin will be required Estimate Details: Bolus Calculator Est. total 4.5 U Food intake 36 g (meter) BG 210 Food 3 U Correction 2 U IOB 0.5 U
CASE 4: A Common Problem 59 y/o woman with hypoglycemia unawareness T1D since 11 years old No interest to use CSII; A1C rarely below 8% x 20 years 2014-2015: monthly severe hypoglycemia, insurance refused payment for CGM Dec 2015: after much discussion, CGM allowed 25
First CGM Download, January 2016 Mean/SD = 168/70; A1C 7.9% 26
Worked with Patient and Husband Use of share app Focused on frequent looking of data Adjusted both basal and bolus insulin accordingly Upgraded to G5 Most important: learned how to use trend arrows J Endo Soc 2017;1:1445-1460
2 Years Later
FreeStyle Libre All CGM systems have the same general accuracy in the 80-200 mg/dl range Libre has a higher MARD with blood glucose < 70 mg/dl (MARD 24%) (BMJ Open Diabetes Research and Care 2017;5:e000320. doi:10.1136/bmjdrc-2016-000320) Results can read low, meaning insulin-requiring patients may be tempted to treat perceived hypoglycemia when none is actually present The device gives an icon to measure blood glucose to mitigate this problem
Case 5: 64 y/o Lawyer with T2D History of RA and breast cancer, now not on steroids T2D X 10 years, recently moved to Seattle from SF area Receiving glipizide, metformin, and liraglultide When first seen placed Libre Pro on her. HbA1c at the time was 6.0%
March/April, 2017
March/April 2017 Glipizide stopped, blood sugars spiked into high 100s, started empagliflozin, later started Libre 12/17
March, 2018 Measured HbA1c = 6.5%
New Old CGM for MDI Patients Medtronic Guardian Connect: Guardian 3 CGM CASE 6: -55 y/o man trying to determine basal dose using degludec and aspart -He now takes 18 units of degludec with aspart at an ICR of 1/12 and an ISF of 40
DAY 1 2 units aspart I have no idea! Smart pens will make this much easier to understand Hypoglycemia: what s the problemthe degludec or the aspart?
Case 7: AGP from 60 y/o Woman Recently Dx ed with SPS Feb 2016, HbA1c 10.1%; Last A1C 7.3% h
CASE 7: The Answer to the Problem No bolus
Case 7: First week on HCL (2/18)
Case 7: First Week on HCL
What I Want To See In A Download Basic statistics Overall and time specific means/sd SMBG standard: SD X 3 < mean if mean 120-180 CGM: SD X 3 < mean or CV < 33 CSII: Basic insulin stats TDD, % basal, over-ride % for bolus calculator Daily summary to better understand ICR, ISF, basal rates, and if appropriate over-under-rides for trends or anticipated exercise CGM: basic BG stats Overall patterns and daily decision making to best understand how patient thinks through each challenge. TIRs are now the standard
Summary Downloading remains as important as ever-no excuses for clinicians not to look at the data with the patient We are doing better with standardization of glucometrics Always observe concordance of HbA1c Real-time and retrospective review of CGM is helpful for many and many if not most patients will require assistance from you Our first HCL is an amazing tool for many but like all technologies has pros and cons and is not for everyone.