Physical activity and insulin calculation Flashcards
what is a dawn phenomenon? Which diabetes types experiences it more frequently? WHy does it happen?
An abnormal early morning increase in blood sugar (between 4 AM – 8 AM). More common in type I DM than type 2.
Fasting glucose levels rise because of an increase in hepatic glucose production, which may be secondary to the midnight surge of growth hormone.
what is Somogyi Phenomenon/Nocturnal Hypoglycemia? What are the precautions and symptoms?
- Also known as rebound hyperglycemia or post hypoglycemia hyperglycemia.
- It is a pattern of hypoglycemia’s followed by hyperglycemia. (Counterregulatory hormones stimulate gluconeogensis)
- When it is suspected, the patient should wake between 2 and 4 am to monitor blood glucose levels.
- Symptoms: nightmares, sweating, difficulty waking up, morning headaches….but may be asymptomatic
Diabetes in the Elderly Checklist
2018
- ASSESS for level of functional dependency (frailty)
- INDIVIDUALIZE glycemic targets based on the above (A1C ≤8.5% for frail elderly) but if otherwise healthy, use the same targets as younger people
- AVOID hypoglycemia in cognitive impairment
- SELECT or ADJUST antihyperglycemic therapy carefully
- Caution with sulfonylureas or thiazolidinediones
- DPP-4 inhibitors should be used over sulfonylureas
- Basal analogues instead of NPH or human 30/70 insulin
- GIVE regular diets instead of “diabetic diets” or nutritional formulas in nursing homes
What are the components of Ramadan focussed educational program
- Went to break the fast
- risk stratification
- blood glucose monitoring
- fluids and dietary advice
- exercise advise
- medication adjustments
Which types of people are at very high risk and should not fast
- Poorly controlled T1DM (defined as a pre-Ramadan A1C >9%)
- Severe hypoglycemia within 3 months, recurrent hypoglycemia, and/or unawareness of hypoglycemia
- Ketoacidosis within 3 months
- Hyperosmolar hyperglycemic coma within 3 months
- Acute illness
- Advanced macrovascular complications, renal disease (on dialysis, stage IV or V CKD), cognitive dysfunction, or uncontrolled epilepsy
- Pregnancy in diabetes or GDM - treated with insulin
Which types of people are at high risk and should not fast (medical advise if fasting)
- T2DM with sustained poor glycemic control
- Well-controlled T2DM on MDI or mixed insulin
- Pregnant T2DM or GDM controlled by diet only
- CKD stage 3 or stable macrovascular complications
- Performing intense physical labour
- Well-controlled T1DM
Which types of people are at moderate/low risk and can fast with medical advise
• Well-controlled diabetes
• Treated with lifestyle alone, or with: metformin, acarbose, incretin-therapies
(DPP-4 inhibitors or GLP-1 RA), second generation SU, SGLT2 inhibitors, TZD or basal insulin in otherwise healthy individuals
Exercise recommendations for adults and young people with DM
- Adults: 150 minutes/week of moderate- to-vigorous physical activity (brisk walking or greater), with no more than 2 days off in a row + strength training 2-3 X/ week
- Youth: 60 minutes/day of moderate-to-vigorous physical activity (420 min/week), including vigorous-intensity activities 3+ days/week and strength building activities (for muscle and bone) 3+ days/week
why no more than 2 days off exercise?
exercise has an impact on insulin sensitivity which lasts over many hours and days. If you spread out your exercise days throughout the week - you benefit from this impact for the whole week but if it’s concentrated across several days you don’t benefit from it
Benefits of exercise in diabetes
- Decrease in CVD risk due to decreased blood pressure
- Lower LDL, increased HDL
- Psychological benefits
- Self-esteem
- Weight management and increased lean body mass
- increased insulin sensitivity
- decreased appetite
- decrease in A1C in type 2, the impact is unclear in type 1
challenges of exercise in diabetes
increased risk of hypoGL
BG Effects of Different Types of Exercise
Aerobic:
- decreases BG
Main variables: Intensity and duration of exercise, insulin to glucagon ratio, fitness, nutrition, initial glucose concentration
Mixed:
- keeps BG at relatively the same level
Main variables: Intensity and duration of exercise, insulin to glucagon ratio, fitness, nutrition, initial glucose concentration, counter-regulatory hormones, lactate concentration
Anaerobic
- increased BG
Main variables: intensity and number of intervals, insulin concentration, counter-regulatory hormones, fitness, nutrition, lactate concentration
when is the a risk of hypoGL during excercise?
early risk- in the beginning of exercise
late risk- at night, several hours after exercise
During sleep and after exercise, patients with type 1 diabetes have:
- Increased glucose requirements: Increased insulin sensitivity and Glycogen restoration
- Impaired counter regulation
- Relative excessive circulating insulin
- Absence of carbohydrate intake
exercise management
Understand factors affecting response to exercise
• Duration and intensity: Moderate intensity may lower BGs more than maximum intensity
• Type of activity-anaerobic vs aerobic
• Metabolic control
• BG level at time of exercise
• Timing and type of insulin
• Timing and type of food
• Absorption of insulin, site of injection (If they injected insulin into their legs and started running insulin absorption will be faster due to increased blood flow in the legs)
• Training status
• Stress / competition
• Timing of activity
tips to avoid hypoGL after exercise
- eat her snack before exercise
- do exercise closer to lunchtime when there is less active insulin which will act to decrease blood glucose levels
- discuss risks of late hypoglycaemia so she doesn’t take the insulin dose at night time to decrease the risk of nocturnal hypoglycaemia
- do exercise before breakfast
questions to ask yourself to determine the cause of exercise-related hypoglycemia?
Too much insulin
Not enough carbohydrate
Type of exercise
Duration of exercise
what can help to lower BG released during high intensity exercise
have a cool down doing a lower intensity exercise which will use up the BG released during high intensity exercise
How does GLUT-4 mediated glucose uptake differ in resting state and exercise
- At rest insulin will bind to the receptors on the cell which will lead to the release of GLUT-4 to the cell membrane resulting in glucose uptake into the cell
- During muscle contraction there is no need for insulin to trigger there they release of GLUT-4. It is released purely due to muscle contraction
- less insulin is needed to uptake glucose during exercise (in normal people less insulin is released)
- combination of GLUT-4 released due to injected insulin and muscle contraction leads to hypoGL
- when someone is injecting insulin we can reduce the amount of basal insulin given about 1h before exercise
why is there elevated glucose uptake post- exercise and how long does it last?
Post-Exercise Glucose Uptake Remains Elevated for Hours to Replenish Muscle Glycogen Stores
what are the danger of aerobic exercise w/o adjusting insulin
Aerobic Exercise Without Adjusting Insulin Promotes a Variable Drop in Glucose and
May Cause Hypoglycemia
what are the effects of exercise in insulin sensitivity and insulin requirement?
Training Increases Insulin Sensitivity and Lowers Daily Insulin Requirements
What are the risks of an anaerobic exercise and how does it affect insulin needs
Anaerobic Exercise Can Cause Hyperglycemia and May Increase Insulin Needs During Recovery due to inhibition of muscle glucose uptake by Epinephrin and norepinephrine
Without insulin administration, glucose rise is unchecked in type 1 diabetes
what is the benefit of sprints?
Sprints can be used to increase blood glucose level by provoking a release of BG-> may be used as a tactic to avoid HypoGL
Which exercise type results in a more stable glucose profile in T1DM
Resistance Exercise Results in a More Stable Glucose Profile
Aerobic exercise leads to a drop in blood glucose
Warm-Up and Cool Down Recommendations
Before Exercise:
• If hyperglycemic (≥14 mmol/L or ≥252 mg/dL) and ketotic (≥1.5 mmol/L plasma ketones) because of insulin deficiency, don’t exercise until hyperglycemia and ketones restored with insulin
• If mildly hyperglycemic (8-14 mmol/L or 144-252 mg/dL) do a 10-15 min mild aerobic warm-up
After Exercise:
• Always cool down for ~20 mins - aerobic, easy intensity
• Consider conservative insulin correction if remain hyperglycemic (≥ 12.2 mmol/L or ≥220 mg/dL)
Suggested reduction in bolus insulin dose before exercise based on duration and intensity of exercise
The longer the exercise the more you need to decrease the insulin dose
Mild aerobic exercise
30 min: ~25%
60 min: ~50%
Moderate aerobic exercise (~50% VO2max)
30 min: ~50%
60 min: ~75%
Heavy aerobic exercise (70–75% VO2max)
30 min: ~75%
60 min: NA
Intense aerobic or anaerobic exercise
30 min: No reduction recommended
60 min: NA
When should basal insulin be stopped in terms of excercise
When someone uses a pump he/she needs to disconnected or suspended the pump at least 30 minutes before exercise; preferably an hour before
Avoidance of Nocturnal Hypoglycemia: Recommendations for Patients
• Set alarms to check blood glucose levels during the night
• Advise household members on signs of severe hypoglycemia, and on appropriate use of glucose gels or glucagon
• Avoid alcohol following exercise
• We suggest that continuous glucose monitoring (CGM) should be used, with the benefits of:
- Alerts in case of hypoglycemia
- No alerts if no hypoglycemia is detected
Is CGM accurate during exercise?
CGM is slightly less precise at the moment of exercise then when someone is at rest
When someone is exercising there’s a rapid change in glucose so CGM does not pick up the level of glucose that the person is really at
arrows of tendency are very useful at this moment
Exercise After Hypoglycemia advise
Self-treated hypoglycemia within 1 hour of planned activity
- In case of exercise, treat hypoglycemia to stabilise blood glucose before activity
- If glucose level increases, it is okay to exercise; monitoring is necessary
- May need to retreat as hypoglycemia is more likely to occur
Severe hypoglycemia within 24 hours of planned activity
- Ideally, exercise should not be undertaken
- Patients should not exercise, and alert others of the potential for hypoglycemia
Hypoglycemia during exercise
- Discontinue the activity and treat hypoglycemia
Starting Blood Glucose Before Exercise : Summary
<5 mmol/L
- Ingest 10-20 g of glucose before exercise
- Delay exercise until blood glucose >5 mmol/L
5 – 6.9 mmol/L
- Ingest 10 g of glucose
- Anaerobic and Interval high intensity exercise can be started
7 –15 mmol/L
- Aerobic, anaerobic, and interval high intensity exercise can be started
> 15 mmol/L
- Check blood ketones and perform low intensity exercise, or give small corrective dose of insulin
- Low intensity exercise may be okay if blood ketones are <1.4 mmol/L. consider small corrective dose of insulin. No exercise if >1.5 mmol/L
exercise is not recommended as there is a high risk of DKA as their insulin levels is likely v low
Factors Influencing Carbohydrate Needs and Distribution During Exercise
Increased CHO needs:
- Blood glucose below 5 mmol/L
- Aerobic exercise
- New sport/ unfamiliar activity
Decreased CHO needs:
- Anaerobic exercise
- Short duration
- Insulin adjusted with meal prior to exercise
Can both decreases and increase:
- Fasting exercise
- Training Phase of athlete
- Competition
Strategies to reduce the risk of hypoGL:
Before, During and After
Before:
- reduce insulin bolus
- reduce basal insulin
- CHO snack right before the exercise
During
- reduce basal insulin
- have a snack at the end (especially in athletes to increase glycogen reserves)
- supra-maximal exercise at the end (Physical activity that alternates short bursts of energy with periods of rest)
After:
- resume basal insulin before bed
- reduce insulin bolus
- CHO snack before bed
- Reduce basal insulin before bed
Insulin initiation in type 2 diabetes
Basal insulin added to non-insulin antihyperglycemic agents:
1- Start with 10 un/day (= 1 injection at bedtime)
2- Add 1 un per day until target is reached (except Degludec: 2 units every 3-4 days or 4 units per week)
If you are starting multiple daily injections on someone who weight 80 kg:
• How much total daily insulin (TDD) will you suggest:
• How much will be given with a long-acting insulin (e.g., Glargine 300)?
• How much will be given via rapid-acting insulin (e.g., Glulisine)? • Breakfast
• Lunch • Diner
- How much total daily insulin (TDD) will you suggest: TDD = 0.5 X 80 = 40 un per day
- How much will be given with a long-acting insulin (e.g., Glargine 300)? Long acting: 16 un.
- How much will be given via rapid-acting insulin (e.g., Glulisine)?
- Breakfast: 8 un
- Lunch: 8 un
- Diner: 8 un
Estimate the insulin to carb ratio:
• Insulin (Glulisine and Glargine 300) : 8-10-7-19
- Insulin (Glulisine and Glargine 300) : 8-10-7-19
- What is the TDD?
- 500/TDDà500/44=1un:11.4gCHO
- (5.7 X (weightkg) )/TDD=5.7X80/44=10.4gCHO
Estimate ISF when TDD is 44
ISF = 100/TDD
In our case: ISF = 100/44 = 2.3
How much insulin should our patient give himself if his BG is at 13 mmol/L and he want to go down to 6 mmol/L:
àDifference in BG / ISFà7 / 2.3 = 3 units
Switching our patient to pump (TDD on MDI= 44un)
- TDD on MDI= 44un
- What is the estimated TDD on Pump= 0.75 of TDD on MDI=33un
- 80kg X 0.53= 42.4un
- Average both: (33 +40 )/2= 37.7 un = 37.5
