Insulin therapy

Question 1

Type 1 DM

Answer 1

• 5-10% of diabetics
• cellular-mediated autoimmune destruction of the pancreatic beta cells
• requires insulin for survival

Question 2

Type II DM

Answer 2

• 90-95% of diabetics
• begins as insulin resistance with relative insulin deficiency
• progresses with gradual loss of insulin production by pancreas
• becomes similar to Type I DM eventually
• also has unrestrained hepatic glucose production

Question 3

BG Treatment Goals

Answer 3

HgbA1C less than 7%

pre-prandial plasma glucose 70-130mg/dL

peak post-prandial glucose less than 180mg/dL (two hours after start of meal)

Question 4

Basal insulin

Answer 4

long acting insulin

eg glargine or detemir or NPH

helps patient in fasting state

Question 5

Bolus insulin

Answer 5

short acting insulin

eg aspart, lispro, glulisine or Regular

helps patient in a post prandial state

Question 6

Intensive insulin

Answer 6

both basal and bolus insulin

helps patient in both fasting and post prandial state

Question 7

ADA algorithm for treatment

Answer 7

A1C greater than 8.5% on diagnosis: consider combo therapy

A1C greater than 10% on diagnosis: intensive insulin therapy

A1C greater than 8.5% in a patient on metformin: consider use of basal insulin instead of sulfonylurea

Type I DM: intensive insulin therapy on diagnosis, lifelong tx

Type II DM:

• intensive insulin therapy on diagnosis if A1c is over 10% (try to change to orals once A1c is at goal)
• basal insulin therapy plus orals when A1c is not at goal despite metformin (and possibly secretogogue)
• stop secretagogue and use intensive insulin therapy as beta cell function declines over time

Question 8

Insulin main SE

Answer 8

weight gain (less so with newer agents/insulin analogs)
hypoglycemia

Question 9

General dosing guidelines

Answer 9

Type 1 DM:

• start at 0.4-0.6 units/kg/day
• may drop to 0.2 units/kg/day during honeymoon phase
• eventually require 0.8-1 unit/kg/day

Type 2 DM:

• highly variable
• basal insulin may start as low as 5-10 units
• intensive insulin therapy start at 0.4-0.6 units/kg/day if not obese, or 0.7-1 unit/kg/day if obese
• eventually may require over 3 units/kg/day or several hundred units
• obesity needs more mg/kg = marker of insulin resistance
• pregnant women and teens need more insulin, as much as 2 units/kg/day
• patients with renal and hepatic failure need less insulin, as little as 0.3 units/kg/day
• medications can increase or decrease the need for insulin, esp corticosteroids

Question 10

Initiating insulin therapy: basal insulin (glargine QDay or detemir qDay or BID)

Answer 10

• start with 10 units, or 0.2 units/kg
• increase by 1 unit/day until fasting BG less than 100
  OR
• increase by 2 units/q3days (or 4 units if FBG is greater than 180) until fasting BG less than 100
  OR
• increase every 5-7 days until FBG less than 100:
  2 units for FBG 100-120
  4 units for FBG 120-140
  6 units for FBG 140-180
  8 units for FBG greater than 180

Question 11

Initiating insulin therapy: Spot bolus plus basal insulin (assuming Type II DM already on basal insulin)

Answer 11

• Decrease basal by 10% and add that 10% in bolus dose at the largest meal
  OR
• Check BG before lunch, supper, and bedtime and add a bolus dose of 4 units before previous meal of highest BG, then increase by 2 units every 3 days until BG in in range

Question 12

Initiating insulin therapy: Intensive insulin (basal and pre-meal boluses)

Answer 12

• Use starting dose on a unit/kg based on Type I or Type II DM and other patient factors (obese?)
• Balance between bolus and basal insulin
  
  • Adults 50% basal/50% bolus
  • Kids/Athletic Adults 30-40% basal/60-70% bolus
• Bolus dose: balance between number of meals and CHO size of meals

Question 13

Adjusting insulin therapy

Answer 13

• adjust total daily dose by 10-20% (near 10% if lean and/or near glycemic target, near 20% if obese and/or BG still elevated)
• consider previous dose adjustments
• frequent f/u is key
• check BG before any insulin dosing, look at trends over 3-7 days and “fall back” to previous dose of insulin

Question 14

Correction dosing

Answer 14

Rule of 1800 or 1700

• use with rapid acting insulin analogs (aspart, lispro, glulisine)
• use 1500 with regular insulin
• Calculate total daily dose of insulin
• Divide TDD into 1800 or 1700 (1500 for regular)
• Result is the number of points you can expect a single unit of insulin to affect BG

Question 15

Ratio dosing

Answer 15

Rule of 500

• Use with rapid acting insulin analogs (aspart, lispro, glulisine)
• Use 450 with regular insulin

Calculate TDD of insulin
Divide TDD into 500, or 450 for regular insulin
Result is the number of CHO grams you can expect a single unit of insulin to cover

Question 16

Carb Counting basics

Answer 16

• carbs are the main thing that affect BG
• protein is free unless over 4oz, then 5gm/oz for ea. gram over the first 4oz

Look at food label:

• look at serving size
• subtract 1/2 of dietary fiber
• subtract 1/2 of sugar alcohols
• multiply/divide by the number of serving sizes eaten

snacks: general rule, up to 15gm without insulin
carb factors: percent of total weight of food that is CHO = weigh food and multiply by carb factor (many printout and online tools available)

Question 17

Treatment of hypoglycemia

Answer 17

Rule of 15

• Take 15gm of rapid acting CHO
• Recheck BG in 15min, if still not over 70, repeat
• If over 70 and over one hour to next meal, have a protein/starch snack
• All type I and type II DM patients on intensive insulin therapy should have an emergency glucagon kit (injectable)
• Family member or friend needs to be instructed on proper use, use if patient is unconscious