Beyond Carbohydrate Counting: What Else Matters? Lorraine Anderson RD, CDE Senior Clinical Manager, Animas Canada 2015 CWD Friends for Life Canada Conference – Niagara Falls
Jan 18, 2016
Beyond Carbohydrate Counting:What Else Matters?
Lorraine Anderson RD, CDESenior Clinical Manager, Animas Canada2015 CWD Friends for Life Canada Conference – Niagara Falls
Disclosures
Employee, Animas Canada. No other conflicts to disclose.
Objectives
Discuss the importance of post-meal blood glucose management and strategies for children with type 1 diabetes.
Review the latest literature regarding the roles of carbohydrate, fat and protein in diabetes management.
Review strategies for practical application in day to day practice.
Optimizing Post-meal Blood Glucose
Why?
How?
Optimizing Post-meal Blood Glucose
Insulin:Carb (I:C) ratio Is it correct?
Insulin Sensitivity Factor (ISF)/Correction Factor Does it work?
Target BG/Duration of Insulin Action (pumps)
Matching Insulin to Food (quantity and quality) Carb Counting Glycemic Index Fat and Protein Content
Others? Timing, Exercise, Stress, Alcohol, More
Recommended Glycemic Targets for Children and Adolescents with Type 1 Diabetes
Wherrett D et al. Can J Diabetes 37 (2013) S153-S162.
* Postprandial monitoring is rarely done in young children except for those on pump therapy for whom targets are not available.
“It’s not just about the carbs”
Carbohydrate
Greatest glycemic impact (time and magnitude) Carbohydrates don’t affect blood glucose equally Some of the potential variables effecting glycemic impact:
Type and amount of CHO (starch, i.e. Basmati rice vs. short grain) Fiber (soluble vs. insoluble) Sugar alcohols Physical form of the food Acidity Temperature Processing Cooking method – degree of gelatinization i.e. al dente pasta
Franz M. Carbohydrate and Diabetes: Is the Source or the Amount of More Importance? Current Diabetes Reports 2001. 1:177-186.
Carbohydrate Counting
Beyond the Basics - 15g carbohydrate exchanges
Carbohydrate Counting Tools
How accurate are we?
Smart CE et al. 102 children, 8-18 years and 110 caregivers estimated CHO content of 17 standardized meals (8-90g)
Most of the time (73%), we estimate to within 10-15 g. The larger the carb content of the meal, the greater the
inaccuracy in carb counting. Large meals are commonly underestimated whereas snacks
are commonly overestimated. Foods in non-standard servings sizes such as rice, pasta, cereal
and fruit most often inaccurately estimated. The longer the children had been carb counting, the greater
the percentage error – need ONGOING education.
Smart, CE et al. Diabet. Med 2009; 26: 279-285.
Carbohydrate Counting
Two “inputs” when determining meal insulin dose, both have risk of error Carb counting Meter accuracy
And don’t forget adjustment for activity (↑↓), alcohol, stress, high fat, high protein meals…
Smart, CE et al. Diabet. Med 2009; 26: 279-285.
Carbohydrate Counting
Inaccurate carbohydrate counting is associated with higher daily blood glucose variability. Though accuracy within 10-20g is NOT correlated
to higher A1C or significant postprandial glucose excursion.
Of all the “inputs” when determining meal insulin dose, which has the greatest risk of error?
Smart, CE et al. Diabet. Med 2009; 26: 279-285.
Checking the I:C Ratio
Fix the basal first
Test the ratio when the pre-meal blood glucose is in target
Try to do this when it has been at least 4 hours since the last bolus
No recent lows or exercise
Eat a low-fat meal when you know the exact carb count(i.e. Lean Cuisine, or use Salter scale)
Test with ~ 1 g carbohydrate/kg body weight
Test pre-meal, at 2 hr and 4 hr after meals
Checking Insulin:Carb Ratios
What is an acceptable increase in BG at 2 hrs?
Insulin:Carbohydrate Ratio
If set right, the I:C ratio should keep the BG rise between 2.2 and 4.4 mmol/L, 2 hours later
Should bring the BG back close to target at 4-5 hrs.
If adjusting, do so by 1 or 2 g at a time
Walsh J. Pumping Insulin, 5th Ed. San Diego: Torrey Pines Press; 2012.
meal 2 hours 4 hours
14
11
8
5.5
Evaluating Carb Bolus
too much
dose just right
too little
Test before meal,every 1-2hr after and
before next meal.
1 hour 3 hoursAdapted - John Walsh
Checking the Insulin Sensitivity Factor (ISF)
When a correction bolus is injected/programmed, how quickly should the BG return to target?
Checking the Insulin Sensitivity Factor (ISF)
BG should return to target 4-5 hours LATER
Should not cause hypoglycemia afterwards
Walsh J. Pumping Insulin, 5th Ed. San Diego: Torrey Pines Press; 2012.
Matching Insulin to Food
The carbohydrate quantity causes the rise in blood glucose after a meal and determines the bolus size.
The carbohydrate quality affects the rate at which blood glucose rises and determines the type of bolus to be used.
Evelyne Pytka 2008
normal/standard bolus
extended or square wave bolus
combination or dual-wave bolus
Types of Boluses
Advanced Bolus Features
Normal bolus Entire bolus delivered immediately
Extended bolus Bolus delivered over an extended period of time
Combination bolus Portion of bolus is delivered immediately and portion is
extended over time Bolus mimics physiological insulin delivery – “first phase
and second phase delivery”
Why Use a Combination Bolus?
Prevents early post meal hypoglycemia (from insulin peaking before blood glucose rises)
Prevents late post-meal high blood sugars (from not having insulin to “cover” the late rise in glucose from carbohydrate)
The more rapidly-absorbed carbohydrate is “covered” now, and the more slowly absorbed carbohydrates are “covered” later
Why Combo Bolus?
Unpredictable eaters, such as young children
Gastroparesis (also pre-meal hyperglycemia slows gastric emptying)
Nutrient composition of meal
Ryan-Turek T. Variable Bolus Features on Insulin Pumps and Practical Applications for Use. On The Cutting Edge. 2005 26:4:16-18.Wolpert H. Smart Pumping: A Practical Approach to Mastering the Insulin Pump. Virginia: ADA; 2002: 128.Walsh J. Pumping Insulin, 5th Ed. San Diego: Torrey Pines Press; 2012.
Nutrient Composition of Meal
“Slow carbs” – low GI, high fat
“Fast carbs” – high GI, little or no fat
High protein/High fat effect Independent and additive
Smart CE et al. Diabetes Care December 2013 vol. 36.12: 3897-3902.
How to Determine a Combination Bolus
Starting point:
Split the bolus: 50% now, 50% over 3-5 hours (maybe longer?)
Check blood glucose at 2, 4, and 6 hours after eating
If “on the low side” at 2 hours, but “on the high side” 4-6 hours later, take less of the bolus up front, and spread more of the bolus over time
Adjust based on individual response
What about injectors?
Adapted from Wolpert H, Smart Pumping, Alexandria VA: American Diabetes Association, 2003,p. 134.
Challenge your knowledge – Missed Boluses
Question 1: True or False
Missing the occasional meal bolus does not impact A1C.
Missed meal boluses
TAKING the bolus is important!!!
“Forgetting” is very common – average of 2 missed meal boluses per week among 7-20 year olds
Burdick, J. et al. Pediatrics Vol. 113, No. 3, March 2004, e221-224.
Forgot to Bolus?
2 missed boluses per week A1C increased 0.5% 4 missed boluses per week A1C increased 1.0% Most common reason: “forgetting”
Burdick, J. et al. Pediatrics Vol. 113, No. 3, March 2004, e221-224.
Missed meal boluses
TAKING the bolus is important!!!
“Forgetting” is very common – average of 2 missed meal boluses per week among 7-20 year olds
Reasons? Privacy/discretion Low pre-meal, decided to wait to bolus “Just forgot”
Burdick, J. et al. Pediatrics Vol. 113, No. 3, March 2004, e221-224.
Bottom Line
MISSED MEAL DOSES ARE A MAJOR REASON FOR SUBOPTIMAL GLYCEMIC CONTROL
Challenge your knowledge – Bolus Timing
Question 2: True or False
Optimal glycemic control can be achieved when meal-time insulin is given during or after the meal.
Studies examining bolus timing
Jovanovic et al. 2004 Clin Ther. Sep; 26(9):1492-7. Cobry et al. 2010 Diab Tech Ther:12:173-7. Scaramuzza et al. 2010 Diab Tech Ther;12:149-52. De Palma et al. 2011 Diab Tech Ther;13(4):483-7 Danne et al. 2003 Diabetes Care;26:2359-64. Ratner et al. 2011 Diabetes Obes Metab. 13(12): 1142-8. Luijf et al. 2010 Diabetes Care; 33(10): 2152-5. Ryan et al. 2008 Diabetes Care;31(8): 1485-90. Liberty, I. et al. Practical Diabetes 2012; 29(3): 98–102.
When to bolus
Cobry et al. 2010 23 subjects aged 12-30, crossover study with three
treatment arms: Delivering a bolus 20 min prior to meal (PRE) Immediately before the meal 20 minutes after the meal
Cobry E, et al. Diab Technol & Therapeutics, 2010
Pre-meal vs start of meal vs post-meal bolusing
20 minutes pre-meal significantly better than start of meal or 20 minutes after
TiBoDi Study – Scaramuzza et al. 2010
30 pts, T1 DM X 8.07 +/- 4.1 years, 6-20 years of age, on pump therapy
Compared glucose response to a standard meal when bolus was given 15 min before, immediately before or immediately after the meal.
Results: No difference if the bolus is given 15 min or immediately before meal HOWEVER, there is a significant rise when the bolus is administered after the meal, even if the BG was in the hypo range pre-meal.
TiBoDi Study – Scaramuzza et al. 2010
If low pre-meal, correct the hypoglycemia, inject the bolus, then eat.
When bolus was given 15 min pre-meal, average post meal levels never exceeded 7.8 mmol/L. 15 min pre-meal bolus best option because it is
associated with smallest standard deviation (SD).
Bottom Line
NO STUDIES FAVOUR POST-MEAL BOLUSING*
If uncertain of the quantity to be eaten: give correction + grams carb likely to eat i.e. 20 g for child, 40 g for adolescent or adult
The higher the pre-meal BG, the earlier the bolus should be given.
Timing is important.
Challenge your knowledge
Question 3: True or False
Although carbohydrate is the primary stimulus for insulin secretion, it is not the only one.
Protein
Many people eat double the recommended amounts for protein
How protein impacts blood glucose is controversial
BG effect difficult to predict Up to 50-60% can be converted to glucose (TAG theory)
Common to see rise in BG 3-5 hours later, after significantly larger than normal portions are consumed.
Franz, M., ed. Diabetes Management Therapies: A Core Curriculum for Diabetes Education, 5h edition. Chicago: American Association of Diabetes Educators, 2001.
*Bao et at. Am J Clin Nutr 2009;90:986-92.
In people without diabetes: Protein ingestion stimulates the endogenous
production of both insulin and glucagon In people with type 1 diabetes:
No endogenous insulin production Production of endogenous glucagon Protein causes a slow rise in BG; 3-5 hours after
eating Occurs after the peak of rapid-acting insulin analogs Cannot be included in meal bolus
Protein
Nutall FQ et al. 1984
Fat
Effects on BG Delayed stomach emptying Decreased insulin sensitivity May last for several hours after eating
Minimal fat actually converted to glucose (<10%) Individual’s response needs to be evaluated
Wolpert H. Smart Pumping: A Practical Approach to Mastering the Insulin Pump. Virginia: ADA; 2002: 128.Funnell M., et al. Life with Diabetes: A Series of Teaching Outlines by the Michigan Diabetes Research and Training Center. Alexandria: American Diabetes Association; 2004.
Bolusing for Fat and Protein 100 kcal of fat/protein = 1 FPU = “10 g carb equivalent” Delivered as extended bolus
1 FPU is extended over 3 hours 2 FPU extended over 4 hours 3 FPU extended over 5 hours > 3 FPU extended over 8 hours
For example, a Hot Dog meal 30 g of CHO, 16 g of PRO, 28 g of FAT How many FPU? I:C ratio is 1 unit per 10 g of CHO
The ‘Warsaw School Program’ for dosing mealtime insulin
Answer:
30 g of CHO/10 g per unit = 3.0 units
Hot Dog Example
Answer:
30 g of CHO/10 g per unit = 3.0 units
3 FPU ≈ “30 g carb equivalents” = 3.0 units
Hot Dog Example
Answer:
30 g of CHO/10 g per unit = 3.0 units
3 FPU ≈ “30 g carb equivalents” = 3.0 units
Therefore, 3 units as a normal bolus and 3 units extended over 5 hours
Hot Dog Example
Pts with A1C < 7.5% (n=295) used this method more often than those with A1C >7.5% 19.5 +/- 18.4 times in 2 weeks vs 12.4 +/- 14.3 times in 2 weeks
For patients using less than 14 S-W boluses during a 2-wk period, basal insulin requirement was 34.3+/- 15.8%, and respectively, in patients using more than 1 S-W bolus/d, the % basal insulin was 27.7+/- 10.2%.
Also minimum of 6 boluses per day found to meet A1C goal.
RESULTS
Wolpert et al (2013):
7 adult patients with type 1 diabetes Compared 2x 18-h periods of closed-loop
glucose control after high fat (HF) and low fat (LF) dinners Identical carbohydrate and protein in each
dinner 10g fat in LF dinner and 60g fat in HF
dinner 15 minute ‘meal priming bolus’ given before
each meal
Wolpert et al. Diabetes Care. April 2013; 36: 810-816.
Wolpert et al (2013):
High fat dinner required more insulin than low fat dinner (12.6 vs. 9.0 units) (ICR 1:9 vs 1:13) Still more hyperglycemia vs. low fat dinner
No hypoglycemia These findings highlight limitations of carb
counting method.
Wolpert et al. Diabetes Care. April 2013; 36: 810-816.
Wolpert et al (2013):
HF dinner increased mean insulin requirement 42%
Marked inter-individual responses (-17% to 108%) ?differences in FFA concentrations, gastric emptying rates, glucagon, incretins Therefore need food records and must evaluate
based on a case by case basis. Dietary fat intake is an IMPORTANT consideration
for type 1’s striving for tight control.
Wolpert et al. Diabetes Care. April 2013; 36: 810-816.
Wolpert et al (2013) Conclusions:
Adults with type 1 diabetes require more insulin coverage for higher fat meals than for lower fat meals with identical carbohydrate content
Wolpert et al. Diabetes Care. April 2013; 36: 810-816.
Fat and Protein ↑ Blood Glucose
33 kids age 8-17 years 4 test breakfasts – same amount of carb
1. Low fat, low protein2. Low fat, high protein3. High fat, low protein4. High fat, high protein
Fat and Protein ↑ Blood Glucose
What did they find?
Smart CE et al. Results Fat and Protein
HP and HF significantly higher 180-300 min than LP/LF meal. This late effect was increased and sustained with
HP/HF meal. HF meal alone reduced glycemic excursion first 90
minutes (likely due to delayed gastric emptying) However addition of protein prevented this
(suggesting that protein may have a protective effect in early pp hypoglycemia)
Smart CE et al. Conclusions
Cause of late, sustained hyperglycemia with HP/HF has been postulated but is currently unknown. Protein may lead to delayed hyperglycemia by gluconeogenesis and ↑
glucagon secretion. Fat FFA impair insulin sensitivity and enhancement of hepatic
glucose production, also delayed gastric emptying
HP/HF (40 g pro, 35g fat) are commonly consumed. Hyperglycemia 3-5 hours after the meal dual/combo Most important with evening meal as potential for prolonged
hyperglycemia vs daytime when awake to correct.
Smart CE et al. Conclusions
Other studies suggest normal bolus for CHO and square wave bolus of supplemental insulin for fat and protein Reduced postprandial hyperglycemia however the
rate of hypoglycemia using this method is unacceptably high (33-35%).
So need further research for appropriate algorithm.
But what about “real life”?
The day-to-day realities….
Received on Tuesday March 18th, 2014
“Hi Lorraine, Are you still coming to the Tues. April 29 meeting as our guest speaker on Pump Tips and Tricks? I was in Mississauga yesterday and saw ________ from the Trillium Centre. Our group is going to the JDRF dinner at Boston Pizza in May. I never eat there...too many carbs, fats and calories!!!! _______ said to go and enjoy. It's a treat dinner.”
Example 1: Boston Pizza Lasagna
Example 1: Boston Pizza Lasagna
Patient has an I:C Ratio of 1:10g and is having 1 order of the lasagna.
CHO: 62g Fat: 49g x 9 kcal/g = 441 kcal Protein: 57g x 4 kcal/g = 228 kcal TOTAL: 669 kcal 6 FPUs equivalent to 60g additional ‘carbs’
Insulin Dose: Normal Bolus: 62/10 6.2 units Extended Bolus: 60 /10 6.0 units x 8h
Final thoughts…
Thank you! Questions?Lorraine Anderson RD, CDESenior Clinical Manager, Animas [email protected]
Animas® is a trademark of Animas Corporation.All other trademarks are property of their respective owners.© 2015 LifeScan Canada Ltd. AW105-076A 10/2015
Super Bolus
Adapted from John Walsh, 2004
http://www.diabetesnet.com/diabetes_technology/super_bolus.php
11.1 11.1
5.6 5.6
16.7
22.2
16.7
22.2
BG (m
mol
/L)
BG (m
mol
/L)
What are we aiming for?
“In all the work with diabetes technology I’ve done, I’ve worn CGM for long periods of time. I don’t have diabetes, but I’ll eat a dessert and go up to 200 mg/dl (11.1 mmol/L). I’ll also drop down to 50 (2.8 mmol/L) or 60 mg/dl (3.3 mmol/L). People with diabetes are comparing themselves to a false standard. The pancreas, for all of the advantages it has, still allows big excursions. It’s crazy to think it’s ideal.”
-Dr. Steven Russell (Massachusetts General Hospital, Boston, MA) urging people with diabetes not to be too hard on themselves at the 14th
North American Conference on Diabetes and Exercise in San Diego, CA, August 17-18.