Glucose Tolerance TestDiabetes Mellitus

Dr. David Gee

FCSN 442 - Nutrition Assessment Laboratory

Prevalence2006

20.8 million Americans– 7% population

9.6% adults over 20 years21% adults over 60 years

30% undiagnosed– 6.2 million undiagnosed

41 million with ‘pre-diabetes’

Implications of the Diabetes Control and Complications Trial

Diabetes Care 25:S25-S27, 2002

Conventional Treatment vs Intensive Treatment– IT had lower HA1C and FBG

Average 7 year follow up Measured outcomes:

– Retinopathy, nephropathy, neuropathy

Results:– 60% reduction in risk in intensive treatment group

Report of the Expert Committee on the Diagnosis

and Classification ofDiabetes Mellitus

Diabetes Care 28:S4-S36, 2005

See at

Diabetes.org

For health professionals

2005 clinical practice recommendations

Criteria for testing for DM in assymptomatic, undiagnosed patients

> 45 yrs, every 3 yrs (if normal)< 45 yrs, every 3 yrs if:

– BMI > 25 and any of the following 1st degree relative with DM Blacks, Hispanic, Native American, Asian

American Habitually inactive Hx Gestational Diabetes or baby > 9 lbs History of vascular disease

Criteria for testing for DM in assymptomatic, undiagnosed

patients< 45 yrs, every 3 yrs if: (cont.)

– Hypertension (>140/90)

– HDL < 35 mg/dl

– TG > 250 mg/dl

– previous Dx of impaired glucose tolerance or impaired fasting glucose

Testing of children for Type 2 Diabetes

Criteria– Overweight (BMI >85th percentile for age and sex,

weight for height >85th percentile, or weight >120% of ideal for height)

– Plus any two of the following risk factors Family history of Type 2 DM, 1o or 2o

Native American, black, asian, latino Signs of insulin resistance (acanthosis nigricans, hypertension,

dyslipidemia)

– Age of initiation: 10 yrs or onset of puberty– Frequency – every two years– Test: FBG test preferred

Acanthosis nigricans

Fasting Blood Glucose

> 8 hr fastDM if FBG > 126 mg/dl (7.0mM)

– on 2 occasionsPre-Diabetes

– Impaired fasting glucose (IFG) – if : 110 - 125 mg/dl

Casual Plasma Glucose

Casual is defined as any time of day without regard to time since last meal

> 200 mg/dl (11.1mM) plus– Symptoms of diabetes

Polyuria, polydipsea, unexplained weight loss

Confirm on subsequent visit with fasting blood glucose or oral glucose tolerance test

Glucose Tolerance Testing

for – adults with impaired FBG– during pregnancy if at risk

Procedure– Following 8 hour fast– Glucose dose = 1.75g/kg IBW

Maximum 75 g dose (BW<43kg, 94lbs) 25 g/dl glucose test solution Test at 2 hours

Diagnostic Criteria

DM if [glu] > 200 mg/dl at 2 hours IGT if [glu] >140 - 199 at 2 hoursnormal if [glu] < 140 mg/dl IGT and IFT recently termed “pre-

diabetic”

Hemoglobin A1cglycated hemoglobin

Average lifespan of red blood cells– ~ 120 days (4 months)

Glycosylation of blood proteins in proportion to blood glucose concentration– Normal: 5%– Goal for diabetics: < 7%