Diabetes Outreach Network
QUICK REFERENCE GUIDE TO DIABETES FOR HEALTH CARE PROVIDERS

Chapter 1
Screening and Diagnosis of Diabetes

Criteria for screening adults for type 2 diabetes or pre-diabetes:

• All adults over 45 years of age, especially those with a BMI > 25
  • If blood glucose normal and no risk factors present, retest in 3 years
    
• Testing should be considered in younger adults or be carried out more frequently in individuals who are overweight (BMI > 25) and who have additional risk factors such as:
  • Physically inactive most of the time
  • Parent or sibling with diabetes
  • Member of a high risk ethnic group (African American, Latino, Asian American, Native American, or Pacific Islanders)
  • Hypertensive (>140/90 mmHg)
  • HDL-cholesterol < 35 mg/dl
  • Fasting triglycerides > 250 mg/dl
  • History of vascular disease
  • Woman with history of gestational diabetes or delivery of baby weighing more than 9 lbs
  • Diagnosis of polycystic ovary syndrome
  • Previously diagnosed with impaired glucose tolerance (IGT) or impaired fasting glucose (IFG)
  • Presence of other clinical conditions associated with insulin resistance (i.e. acanthosis nigricans).

    Screening should be carried out within a health care setting versus a community setting where there is absence of follow-up care.

Criteria for screening type 2 diabetes in children:

• Overweight (classified by any of the following)
  • BMI > 85th percentile for age and sex
  • Weight for height > 85th percentile
  • Weight > 120% ideal for height

• Plus any two of the following risk factors:
  • Parent or sibling with type 2 diabetes
  • Member of a high risk ethnic group (African American, Latino, Asian American, Native American, or Pacific Islanders)
  • Signs of insulin resistance or conditions associated with insulin resistance (acanthosis nigricans, hypertension, dyslipidemia or polycystic ovary syndrome)

    Screening (fasting plasma glucose preferred) should be done at age 10 or at the onset of puberty and repeated every 2 years.

Diabetes and Pre-diabetes diagnosis:

There are three methods of diagnosing diabetes and each must be confirmed on a subsequent day by any of the following methods:

1. Symptoms of diabetes (polyuria, polydipsia and unexplained weight loss) plus a casual plasma glucose > 200 mg/dl.
   (Casual: any time of the day without regard to time of last meal).
   This is the most common method for diagnosing type 1 diabetes
2. Fasting plasma glucose (Fasting: no caloric intake for at least 8 hours).
   Preferred method for type 2 diabetes and pre-diabetes
3. 2 hour postprandial plasma glucose during an oral glucose tolerance test using 75 gram glucose load.

Diagnostic Criteria

Gestational Diabetes Mellitus (GDM) Screening and Diagnosis:  

• At first prenatal visit, assess risk. If woman is at high risk for GDM (i.e. marked obesity, a personal history of GDM, glucosuria or a strong family history of diabetes), she should be tested as soon as possible.
• High-risk women found not to have GDM on initial screen and average risk women should be tested between 24 and 28 weeks of gestation.
• Either of the following approaches should be used:
  • One-step approach: A 100 gm oral glucose tolerance test (OGTT). Two or more abnormal plasma glucose values during this test is diagnostic of GDM (see below)

Diagnostic Criteria for the 100 g OGTT

References: American Diabetes Association (2003). Clinical Practice Recommendations, 2003. Diabetes Care, Vol 26 (1).