Best Dx/Best Rx: Type I Diabetes Mellitus

From: Subject: Best Dx/Best Rx: Type I Diabetes Mellitus Date: Wed, 3 Jun 2009 21:13:39 -0700 MIME-Version: 1.0 Content-Type: multipart/related; type="text/html"; boundary="----=_NextPart_000_0142_01C9E490.2A8E9260" X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 This is a multi-part message in MIME format. ------=_NextPart_000_0142_01C9E490.2A8E9260 Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable Content-Location: http://www.acpmedicine.com/acp/newrxdx/rxdx/dxrx0901.htm Best Dx/Best Rx: Type I Diabetes Mellitus

Type 1 = Diabetes=20 Mellitus

Saul Genuth, M.D.
Case Western = Reserve=20 University School of Medicine

Defin= ition/Key=20 Clinical Features
Diffe= rential=20 Diagnosis
Best = Tests
Best = Therapy
Best = References

Definition/Key Clinical=20 Features

Absolute deficiency of insulin from = destruction of=20 pancreatic beta cells
Polyuria, polydipsia, weight loss despite = normal food=20 intake, fatigue, and blurred vision
- Typically occur 4=9612 wk before diagnosis=20
Family history increases susceptibility =

Complications

Acute Life-Threatening Complication =

Ketoacidosis

Chronic=20 Complications=20

Retinopathy=20
Nephropathy=20
Neuropathy=20
Increased risk of cardiovascular disease, = including=20 myocardial infarction and stroke=20
Chronic complications delayed or reduced by = intensive=20 treatment

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Differential = Diagnosis

Insulin deficiency secondary to chronic = pancreatitis,=20 pancreatectomy, or carcinoma of the pancreas=20
Gestational diabetes mellitus
- In first trimester, likely to be = presentation of type=20 1 or 2 diabetes precipitated by pregnancy
- In second or third trimester, often remits = after=20 delivery, but increases risk of future diabetes
Drug-induced hyperglycemia=20
- Primarily from glucocorticoids in high doses =

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Best=20 Tests

Diagnosis usually evident from history
Blood glucose level > 200 mg/dl
Urine for glucose and ketone

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Best=20 Therapy

Daily self-management by the patient, many = lifestyle=20 adaptations
Frequent contact with physician=20
- Illness, unusual stress, ketosis require = consultation=20

Insulin = Replacement

Schedules and doses individualized according = to blood=20 glucose levels and carbohydrate content of meals
- Blood glucose self-testing
  - Before each meal=20
  - Periodically 1=962 hr after meals=20
  - Before or after intensive exercise
  - Occasionally at 3 A.M.
  - Frequently during illness =
- Hemoglobin A_1c (HbA_1c = )=20 measurement twice a year (four times a year if glycemic goals not = met;=20 monthly during pregnancy)=20
- Test for ketoacids in urine or blood during=20 illness=20
- Anticipated meal carbohydrate intake
- American Diabetes Association goals
  - Preprandial capillary whole blood glucose = levels:=20 90=96130 mg/dl
  - Postprandial peak capillary whole blood = glucose=20 levels: < 180 mg/dl=20
  - HbA1c values < 7.0% (nondiabetic range, = ~4.0%=966.0%)=20
  - Goals difficult to achieve with current = therapeutic=20 tools
- Long-acting insulin to provide 24-hour basal = supply,=20 plus short-acting insulin before meals (each =3D ~50% of average = total daily=20 dose)=20
- Average total daily dose =3D 0.6=960.7 units = per kg body=20 weight
- Insulin requirements increased by weight = gain and=20 increased caloric intake and during adolescence, late pregnancy,=20 illness
Insulin delivery=20
- Subcutaneous injection in the abdomen =
  - Produces most consistent absorption = rates=20
- Continuous subcutaneous insulin infusion = (CSII) via=20 external pump=20
  - Use rapid-action or regular insulin =
  - Provides smooth basal delivery and more = predictable=20 coverage for meals
- Inhaled insulin=20
  - Can be used for meals together with = injected basal=20 insulin=20
  - Contraindicated for smokers and those with = lung=20 disease=20
  - Test pulmonary function before initiating = and=20 annually thereafter

Insulin Preparations=20

Rapid acting
- Regular, crystalline zinc insulin (CZI) =
  - Onset of action: 0.5=961.0 hr
  - Duration of action: 6=968 hr
  - Peak action: 2=964 hr
- Inhaled insulin=20
  - Onset of action: 15=9630 min
  - Peak action: 1.5=962 hr =
Very rapid acting
- Lispro, aspart, glulisine=20
  - Onset of action: 5=9615 min
  - Duration of action: 4=966 hr
  - Peak action: 1=962 hr =
Intermediate acting
- NPH
  - Onset of action: 1=962 hr
  - Duration of action: 10=9614 hr
  - Peak action: 4=968 hr =
Long acting
- Detemir=20
  - Onset of action: 2=963 hr
  - Duration of action: 9=9624 hr
  - Peak action: variable modest peak: 6=9610 = hr=20
- Glargine
  - Onset of action: 1.5=963 hr
  - Duration of action: 20=9624 hr
  - Peak action: no peak=20

Pramlintide=20 (Amylin)=20

Adjunct to insulin for patients who fail to = achieve=20 glycemic control with insulin alone=20
Inject subcutaneously before meals=20
Dose: 15 =B5g initially, titrate upward as = necessary to=20 30=9660 =B5g
Reduce preprandial insulin by 50% = initially=20

Lifestyle Measures

Diet controlled for carbohydrate intake and = tailored to=20 activity levels
Exercise regimen to maintain lean muscle mass=20

Diabetic Emergencies =

Ketoacidosis=20
- Caused by insulin deficiency resulting in = extremely=20 high plasma glucose and ketoacid levels=20
- Symptoms: nausea; vomiting; dehydration;=20 hyperventilation; depressed mentation or decreased = consciousness=20
- Treatment: 0.9% saline I.V. immediately for = volume=20 repletion; potassium repletion; rapid-acting insulin, 0.1=960.15 = U/kg S.C. q.=20 1=962 hr, after serum potassium rises to 4.0 mEq/L, if below normal=20 initially
Hypoglycemia=20
- Caused by missed meals, insulin dosage = errors,=20 exercise, alcohol, drugs=20
- Symptoms: palpitations, tremulousness, = anxiety,=20 sweating, blurred vision, dizziness; can cause confusion, seizures,=20 coma=20
- Treatment: simple carbohydrates p.o.; = glucagon, 1 mg=20 S.C. or I.M.

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Best References

American Diabetes Association: Diabetes Care = 29(suppl=20 1):S4, 2006 [PMID 16373931]

Diabetes Control and Complications Trial Research = Group: N=20 Engl J Med 329:977, 1993 [PMID 8366922]

Expert Committee on the Diagnosis and = Classification of=20 Diabetes Mellitus: Diabetes Care 26(suppl 1):S5, 2003 [PMID 12502614]=20

Hirsch IB: Am Fam Physician 60:2343, 1999 [PMID = 10593324]=20

Umpierrez GE, et al: Diabetes Care 27:1873, 200? = [PMID=20 15277410]

The author has no commercial relationships = with=20 manufacturers of products or providers of services discussed in this = module.=20

February=20 2007