Titrating Insulin to Glycemic Target

1
Titrating Insulin to Glycemic Target

• Judy Bowen, MD
• CIM Rotation
• September, 2006

2
Case 1

• Mrs. G, 46 y.o. was diagnosed with Type 2 DM
  diagnosed 5 years ago (initially treated with
  diet and exercise, then glipizide XL 5 mg BID and
  metformin 1,000 mg BID) has these Hgb A1c values
  q 3 months over the past year
• 5.8
• 6.3
• 7.4
• 7.8

3
Case 1, continued

• Her BMI is 33, BP is 126/72, micro-albumin is 9
  on lisinopril 10 mg, LDL is 89 on Lipitor 10 mg.
  She takes 81 mg ASA daily. Her eye exam is
  up-to-date and normal. Monofilament exam is
  normal. Your exam is normal except for her
  obesity.
• Her fasting a.m. CBGs are 140-180
• What do you recommend?

4
Schematic of 24-hour glucose profile
Riddle M. AJM, 2004 1163S-9S
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Initiating basal insulin therapy

• Add basal insulin therapy
• Start with 10 units insulin in most patients
• Use either NPH or glargine (both work)
• NPH q HS, glargine either q HS or q AM
• Glargine was associated with less nocturnal
  hypoglycemia (Riddle et al, Diabetes Care, 2003
  263080-3086)
• Continue with oral agents
• Consider adverse effects

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Treat-To-Target

• Goal near normal fasting CBGs (100 mg/dl)
• Adjust dose weekly
• based on average of two previous fasting CGBs
• Titration
• If CBG gt/ 180, increase insulin by 8 units
• If CBG 140-180, increase insulin by 6 units
• If CBG 120-140, increase insulin by 4 units
• If CBG 100-120, increase insulin by 2 units
• No increase if any hypoglycemia (CBG lt 72) with
  or without symptoms

7
Relationship of A1c to CBG
4
65
5
100
6
135
7
170
8
205
9
240
10
275
8
Relationship of A1c to CBG
4
65
5
100
6
135
7
170
8
205
9
240
10
275
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Case 1, continued

• Mrs. G agrees to start bedtime glargine 10 units,
  and feels confident she can titrate using the
  Treat to Target instructions with RN follow up.
  Over the next 3 weeks, she achieves fasting CBGs
  in the 100-120 range with 20 units glargine at
  bedtime, and no symptoms of hypoglycemia. Her
  follow up Hgb A1c 3 months after starting insulin
  is 6.5

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Case 2

• Mr. M, a 65 year-old patient with Type 2 DM for
  10 years is on metformin 1,000 mg BID and
  insulin
• NPH q a.m. 30 units Regular 10 units
• NPH q p.m. (supper) 25 units Regular 15 units
• His fasting CBGs are in the 120s but his Hgb A1c
  is now 8.0. He wants better control.
• What do you recommend?

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Switching to Basal/Prandial Insulin

• To switch to glargine
• Add up his current total insulin dose (80 units)
• Reduce by 20 (64 units)
• Give half as glargine (32 units)
• Titrate using fasting CBGs and treat-to-target
• To add lispro/aspart
• (Onset is 5-15 min, peak is 30-90 min, duration
  is 3.5 5 hours)
• Send to Diabetes Education to learn carb counting
• Give remaining half of total dose based on
  meals
• 10 10 12 depending on carb load

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Pearls

• Insulin therapy is associated with weight gain
• Glargine doesnt last 24 hours in every patient
  (nor is NPH predictable)
• We usually wait too long to start insulin in Type
  2 patients
• Early insulin therapy may be associated with
  better daytime prandial secretion from native
  pancreas
• Finger sticks are more painful than insulin shots