Diabetes Mellitus - Insulin Therapy

Question 1

When is insulin indicated as an appropriate therapy in T2DM?

Answer 1

• glucose toxicity
• insufficient endogenous insulin production
• contraindication to oral therapy

Question 2

What are some barriers to the use of insulin?

Answer 2

• fear of injection
• permanence of having to take insulin
• feeling of personal failure in managing diabetes
• inconvenience of monitoring
• fear of the demands of therapy

Question 3

What is the point of having different time acting insulins and the goal of insulin therapy?

Answer 3

• goal is to mimic functions of normal pancreas as much as possible (this is best achieved by insulin pump)
• long acting insulins can provide a basal maintenance dose while short acting can provide bursts at meal times

Question 4

What are the three rapid acting insulins?

Answer 4

• lispro
• aspart
• gluisine
• Onset: 5-30 mins, Peak: 0.5-3 hrs, Duration: 3-5 hrs

Question 5

What are the intermediate acting insulin analogs?

Answer 5

• detemir (duration of action is dose dependent, can be long acting at higher doses)
• Onset: 3-4 hrs, Peak: 4-8 hrs, Duration: 6-24 hrs
• neutral protamine lispro (NPL) - in premixed solutions
• neutral protamine aspart (NPA) - in premixed solutions
• Onset: 1-4 hrs, Peak: 4-10 hrs, Duration: 14-24 hrs

Question 6

What is the long acting insulin analog?

Answer 6

• glargine insulin
• Onset: 2-3 hrs, Peak: none, Duration: 24-30 hrs
• cannot mix in same syringe as any other insulin due to low pH
• When all T1DM initially present, start on glargine + rapid acting insulin

Question 7

What are the advantages and disadvantages of premixed insulin solutions?

Answer 7

• Good: useful for older adults that have trouble with measurements, syringes, or dexterity; convenient; longer shelf life; fewer dosing errors
• Bad: hard to get good glucose control due to loss of flexibility in adjusting for carb intake or physical activity
• premixed insulins are very rarely used in T1DM

Question 8

Why is the abdomen the preferred site odf insulin injection?

Answer 8

• abdomen has the most constant blood flow that is not subjected to change with physical activity, so dose is most consistent
• abdomen > arm > buttocks > thigh

Question 9

What is the advantage of doing the “split-mixed” treatment program with an intermediate acting insulin at bedtime?

Answer 9

• in the classical model, the intermediate is given at dinner time and will peak in the middle of the night, putting the patient at risk of hypoglycemia
• in the bedtime model, the intermediate is given at bedtime which greatly reduces the chance of overnight hypoglycemia

Question 10

What percentage of daily requirement of insulin are the basal and bolus insulins, respectively?

Answer 10

• basal: 40-50%

- bolus: 10-20%

Question 11

What are some adverse reactions in insulin therapy?

Answer 11

• hypoglycemia
• weight gain: before insulin, patients have been wasting calories in urine. Now with insulin, these calories are able to be stored but patients often continue increased intake. Also risk of hypoglycemia can cause overeating.
• local or systemic allergic reactions
• lipoatrophy or lipohypertrophy: these cause erratic absorption of insulin. To avoid, rotate sites of injection.

Question 12

What are some pros and cons of continuous subcutaneous insulin infusion systems (only rapid acting insulin)?

Answer 12

• Pros: programmable basal profiles and greater flexibility based on individual and lifestyle
• Cons: risk of DKA if interrupted, more complex

Question 13

What are some pros and cons of continuous glucose monitoring?

Answer 13

• Pros: alarms built in to prevent highs and lows, can communicate with insulin pump, ***shows trends much more accurately than self testing!
• Cons: expensive, may be inaccurate and needs calibration