Glucose Tolerance Test Diabetes Mellitus Dr. David Gee FCSN Nutrition Assessment Laboratory

Prevalence 2006 l 20.8 million Americans –7% population l 9.6% adults over 20 years l 21% adults over 60 years l 30% undiagnosed – 6.2 million undiagnosed l 41 million with ‘pre-diabetes’

Implications of the Diabetes Control and Complications Trial Diabetes Care 25:S25-S27, 2002 l Conventional Treatment vs Intensive Treatment –IT had lower HA1C and FBG l Average 7 year follow up l Measured outcomes: –Retinopathy, nephropathy, neuropathy l Results: –60% reduction in risk in intensive treatment group

Report of the Expert Committee on the Diagnosis and Classification of Diabetes 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 l > 45 yrs, every 3 yrs (if normal) l < 45 yrs, every 3 yrs if : –BMI > 25 and any of the following l 1st degree relative with DM l Blacks, Hispanic, Native American, Asian American l Habitually inactive l Hx Gestational Diabetes or baby > 9 lbs l History of vascular disease

Criteria for testing for DM in assymptomatic, undiagnosed patients l < 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 l 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 l Family history of Type 2 DM, 1 o or 2 o l Native American, black, asian, latino l 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 l > 8 hr fast l DM if FBG > 126 mg/dl (7.0mM) –on 2 occasions l Pre-Diabetes –Impaired fasting glucose (IFG) –if : mg/dl

Casual Plasma Glucose l Casual is defined as any time of day without regard to time since last meal l > 200 mg/dl (11.1mM) plus –Symptoms of diabetes l Polyuria, polydipsea, unexplained weight loss l Confirm on subsequent visit with fasting blood glucose or oral glucose tolerance test

Glucose Tolerance Testing l for –adults with impaired FBG –during pregnancy if at risk l Procedure –Following 8 hour fast –Glucose dose = 1.75g/kg IBW l Maximum 75 g dose (BW<43kg, 94lbs) l 25 g/dl glucose test solution l Test at 2 hours

Diagnostic Criteria l DM if [glu] > 200 mg/dl at 2 hours l IGT if [glu] > at 2 hours l normal if [glu] < 140 mg/dl l IGT and IFT recently termed “pre- diabetic”

Hemoglobin A1c glycated hemoglobin l Average lifespan of red blood cells –~ 120 days (4 months) l Glycosylation of blood proteins in proportion to blood glucose concentration –Normal: 5% –Goal for diabetics: < 7%