What is the role of insulin pumps in the modern day care of patients with Type 1 diabetes? Dr. Fiona Wotherspoon Consultant in Diabetes and Endocrinology Dorset County Hospital Fiona.Wotherspoon@dchft.nhs.uk
Aims of Managing Diabetes Reduce HbA1c Prevent complications Avoid Hypoglycaemia Maintain hypo awareness Blood glucose Blood glucose NORMOGLYCAMEIA
Basal Bolus Insulin (MDI)
Problems with MDI Erratic absorption Dawn phenomenon Adjusting for exercise Dosing errors Unpredictable hypoglycaemia Hypo unawareness Fear of hypos
Continuous Subcutaneous Insulin Infusion (CSII) Device to deliver continuous s.c. insulin Reservoir of short acting insulin within pump Fine bore cannula sited in abdominal wall Cannula replaced every 3 days Pre programmed basal (background) insulin Variable hourly rate Bolus insulin for meals or to correct hyperglycaemia Bolus calculator
Continuous Insulin Infusion Basal and Bolus: What s the Dernce? Basal Rate Attempts to mimic Pancreatic insulin production Max 48 rates Preprogrammed Continuous flow of fast acting insulin Matching variable metabolic needs Meal Bolus Matching insulin to carbohydrates Correcting high blood glucose levels Adapting the bolus to the type of meal 6 5 4 3 2 1 Pancreas Delivery Meal Bolus 12 am 12 pm 12 am
Insulin Pumps
Infusion Sets
NICE guidance (TA 151) July 2008 12 years and over Recommended as a treatment option for adults and children older than 12 years with type 1 diabetes provided that: 1. HbA 1c > 8.5% or 2. Disabling hypoglycaemia Under 12 years Recommended as a treatment option for children younger than 12 years with type 1 diabetes provided that: Multiple Daily Injection therapy is considered to be inappropriate Treatment initiated by specialist team of diabetes specialist physician, DSN and dietician with specialist education and advice on diet, exercise and lifestyle.
Evidence for CSII Improvement in HbA1c Reduced hypoglycaemia Improved quality of life
Improvement in HbA1c Mean reduction in HbA1c 0.3 0.6% vs. MDI 10 20% reduction in dose of insulin Greatest effect seen in those with worst control at baseline Mean expected reduction of 2% when baseline HbA1c 10% Pickup JC et al. Diabetes Metab. Res.Rev. 2006; 22: 232 237 Pickup JC et al. Diabetic Medicine 2008; 25:765 774
Reduced glycaemic variability Reduced within day and between day glycaemic variability Smaller sc depot of insulin Low coefficient of variation of absorption of basal infusion (±3% vs ±50% for isophane insulin) Bruttomesso D, et al. Diabetic Medicine 2008; 25: 326 332
Reduced Hypoglycaemia Meta analysis (n=1414) of studies 6 months with >10 episodes severe hypos per 100 patient years on MDI Frequency of severe hypos 4X greater with MDI vs. insulin pump therapy Greatest reduction in those with highest baseline rates of severe hypos and longest duration diabetes 30X greater with MDI vs. insulin pump Pickup JC et al. Diabetic Medicine 2008; 25:765 774
Improved Quality of Life Cochrane review 2010 Insulin pump therapy associated with greater Treatment satisfaction Quality of life Perception of general and mental health Misso ML et al. Cochrane Database Syst. Rev 2010;1:CD005103
Other Benefits Dawn phenomenon Insulin sensitive patients Special circumstances pregnancy Children, adolescence Insulin Absorption Flexibility Fewer injections Patient preference Variable basal rates programmed temporary e.g.. exercise Bolus calculator CHO, pre meal and target BG, insulin sensitivity, active insulin Downloading data Link with CGMS
Adverse Events Rapid development DKA interruption of insulin increased demand frequency of DKA similar to MDI Skin/site infection rarely serious Pump malfunction low battery alarm failure
Patient selection Test blood glucose levels 4X daily Able to carb count Physically able to use pump Willing to wear pump 24/7 Realistic expectations Willing to engage with health care team Motivated, committed and competent
Discontinuation Patient preference No benefit gained Safety DKA hypoglycaemia Non attendance at pump clinic Most centers <5%
UK Insulin Pump Audit 2013 6% adults using CSII 19% children using CSII Predicted: 15 20% adults with Type 1 diabetes 25 50% children with Type 1 diabetes
Pickup J. Insulin pump therapy: then and now. In: Pickup J. Insulin Pump Therapy and Continuous Glucose Monitoring (ed), pp 1 10. Oxford University Press, Oxford, 2009.
Summary For patients with type 1 diabetes CSII Improves HbA1c Reduces hypoglycaemia/severe hypos Improved hypo awareness Improves QoL Other lifestyle benefits
Continuous Glucose Monitoring Systems Continuous glucose sensor Measures interstitial s.c. glucose every 5 mins Provides real time glucose trends Needs calibration with CBG readings 7 day use Transmitter Wirelessly sends glucose readings to pump CGM enabled insulin pump Receives and displays glucose readings on screen
CGMS
CGMS vs. CBG
Using CGMS Diagnostic/troubleshooting Education Monitoring Sensor augmented pump therapy Automated insulin suspension for hypoglycaemia
STAR 3 Study Sensor augmented pump therapy vs. MDI 485 patients (329 adults, 156 children) Baseline HbA1c 8.3% At 1 year 7.5% in Pump therapy group vs. 8.1% in MDI group No difference in rates of severe hypos No significant weight gain Greatest reduction in HbA1c seen in those with most frequent sensor use
STAR 3 N Engl J Med 2010; 363:311 320
Low Glucose Suspend Automated insulin suspension for Hypoglycaemia Low glucose threshold set by user Alarm sounds If no response insulin delivery suspended for up to 2 hours Basal insulin resumed at programmed rate Basal insulin may be resumed by patient at any time
Duration of nocturnal hypoglycemia (sensor glucose < 2.2 mmol/l) with and without LGS. The bars show median duration of hypoglycemia at night with LGS-OFF (black bars) and LGS-ON (gray bars) by quartile (q) of nocturnal hypoglycemia exposure at baseline. Choudhary P et al. Dia Care 2011;34:2023-2025 Copyright 2014 American Diabetes Association, Inc.
Artificial Pancreas Project
Artificial Pancreas Project International project Funded by JDRF Research teams in 8 universities One team in Cambridge UK Avoidance of night time hypos in children Closed loop in pregnancy Joint funded by DUK
Featured Article: Overnight Closed-Loop Insulin Delivery in Young People With Type 1 Diabetes: A Free- Living, Randomized Clinical Trial Roman Hovorka, Daniela Elleri, Hood Thabit, Janet M. Allen, Lalantha Leelarathna, Ranna El-Khairi, Kavita Kumareswaran, Karen Caldwell, Peter Calhoun, Craig Kollman, Helen R. Murphy, Carlo L. Acerini, Malgorzata E. Wilinska, Marianna Nodale, and David B. Dunger Diabetes Care Volume 37: 1204-1211 May, 2014
Hovorka R. et al. Diabetes Care 2014;37:1204 1211
Hovorka R. et al. Diabetes Care 2014;37:1204 1211
Hovorka R. et al. Diabetes Care 2014;37:1204 1211
Questions?