POPULATION AT HIGH RISK FOR TYPE II DIABETES

POPULATION AT HIGH RISK FOR TYPE II DIABETES

            Evaluation of the general population should be considered by their health care providers at 3 years intervals beginning at age 45. The rationale for this interval is that false negative will be repeated before substantial time elapses, and there is little likelihood of an individual developing any of the complication of diabetes to a significant degree within 3 years of negative screening test result. Testing should be considered at a younger age or be carried out more frequently in individuals with one or more of the risk factors.

1. Family history of diabetes (i.e. parents, siblings with diabetes)
2. Over weight (BMI ³ 25kg/m²)
3. Habitual physical inactivity
4. Race/ethinicity
5. Previously identified IFG or IGT
6. Hypertension (³ 140 mm in adults)
7. HDL cholesterol ≤ 35mg/dl or TG level ³ 250mg/dl
8. History of GDM or delivery of a baby weighing >9 lbs
9. PCOD

      Patients presenting to health care providers with symptoms of marked hyperglycemia, including polyuria, polydipsia, weight loss (sometimes with polyphagia) and blurred vision, should receive diagnostic testing for diabetes as should those with potential complications of diabetes or with any other clinical presentation in which diabetes is included in differential diagnosis testing, however, does not constitute screening.

      The incidence of type II diabetes in children and adolescents is increasing. Consistent with screening recommendations for adults, only children and youth at substantial risk for presence or the development of type II diabetes should be tested in “type II diabetes in children and adolescents” recommends that over weight (defined as BMI>85 percent for age and sex). Weight for height >85 percent. Or weight >120% of ideal (50%) for height. Youths with any two of the risk factors listed below are screened.

      Testing should be done every 2 years starting at age 10years or at the on set of puberty if it occurs at a younger age. Testing may be considered in other high risk patients who display any of the following characteristics;

1. Have a family history of type II diabetes in I and II degree relatives
2. Belong to a certain race/ethinic group
3. Have signs of IR or conditions associated with IR (acanthosis nigricans, Hypertension, dyslipidemia, PCOD)

Test:

            The best screening test for diabetes the FPG, is also a components of diagnostic testing. The FPG test and the 75g OGTT are both suitable test for diabetes, however, the FPG test is preferred in clinical settings because it is easier and faster to perform, more convenient and acceptable to patients, and less expensive. An FPG ³ 126mg/dl is an indication for retesting, which should be repeated in a different day to confirm a diagnostic. If the FPG is <126mg/dl and there is high suspicion for diabetes, an OGTT should be performed.

            A 2 hrs postload value in the OGTT ³ 200mg/dl is a positive test for diabetes and should be confirmed on alternate day.

Criteria for the diagnosis of diabetes

Normoglycemia	IFG/IGT	Diabetes
FPG<110	FPG ³ 110 and <126mg/dl	FPG ³ 126
2hr PG<140	2hr PG ³ 140 and <200	2hr PG ³ 200 Symptoms of diabetes and casual plasma glucose concentration ³ 200mg/dl

            A diagnosis of diabetes must be confirmed on subsequent day, by measurement of FPG, 2 hrs PG or RBS (if symptoms are present), the FPG test is greatly preferred because of ease of administration, convenience and acceptability to patients and lower cost. Fasting is defined as no calorie intake for at least 8 hrs. This test requires the use of a glucose load containing the equivalent of 75g anhydrous glucose dissolved in water 2hr PG, 2 hr post load glucose.

            Fasting is defined as no consumption of food or beverage other than water for at least 8 hrs before testing. Nondiabetic individual with a fasting ³ 110mg/dl but <126mg/dl are considered to have IFG and those with 2 hr values in the OGTT ³ 140mg/dl but <200mg/dl are defined as having IGT. Both IFG and IGT are risk factors for future diabetes. Normoglycemia is defined as plasma glucose levels <110mg/dl in the FPG test a 2 hr post load value <140mg/dl in the OGTT.

            If necessary, plasma glucose testing may be performed in individuals who have taken food or drink shortly before testing. Such tests are referred to as causal plasma glucose measurements and are given without regard to time of last meal. A causal plasma glucose level ³ 200mg/dl with symptoms of diabetes is considered diagnostics of diabetes.

            A confirmation FPG test or OGTT should be completed on a different day if the clinical condition of the patient permits. Laboratory measurement of plasma glucose concentration is performed on venous samples with enzymatic assay techniques.

Note:

            Diabetes is frequently not diagnosed until complications appear, and ~ 1/3 of all people with diabetes may be undiagnosed. Also, clinician should be vigilant in evaluating clinical presentation suggestive of diabetes.

REFERENCE:

            Clinical Practice Recommendations, ADA