anik widijanti clinical pathology department saiful anwar hospital / medical faculty brawijaya...
TRANSCRIPT
ANIK WIDIJANTI
Clinical Pathology Department Saiful Anwar Hospital / Medical Faculty Brawijaya University MALANG
DM : Hyperglycemia because of deficient
insulin secretion and / or abnormal insulin
action
USA : in 2002, 18,2 million DM.
Indonesia : prevalence DM increasing
parallel with obesity. In 1981/1982 :1.5 - 1,6
%. In 2001/2005 : 12.5 - 14.7 %
Type 1 DM
Destruction
-cells
Deficiency
Insulin abs
Gx acute
G.D.M
DM in
pregnancy
Type 2 DM
Secretory
defect insulin
Insulin
resistance
Mixed
Others
Type DM
-cells defectAction defect ExocrineEndocrinopathyDrug inducedInfectionsOthers
Clinical symptoms DM
classic symptoms (+) classic symptoms (-)
FPGor
CPG
126------- 200
< 126--------< 200
FPGor
CPG
126------- 200
100 - 126 < 100
Repeat FPG or CPG
FPGor
CPG
100 - 199
126------- 200
< 126--------< 200
OGTT2-h PG
200 140-199 < 140
DIABETES MELLITUS IGT IFG NORMAL
Evaluation for gizi status, DM complications, dietary planning
Dietary planning, physical activity, Ideal body weight, No medication
Diagnostic
FPG
> 126 mg/dl
Casual PG
> 200 mg/dl
2-h PG
75-g OGTT
> 200 mg/dl
Others
GAD-65
IAA
ICA-512
Insulin
C-peptide
Genetics
Monitoring
A1C
SMBG
CBGM
Fructosamine
1,5-AG
Complication
CVD
Coma
Ketoacidosis
Nephropathy
Diabetic foot
Infections
Others
classic symptoms (+)
FPG
100-125 : IFG>126 : DM < 100 : N
75 g OGTT
> 200 :DM 140-199 : IGT < 140 : N
CPG
> 200 : DM
Type 1 DM : C-peptide (-)Acute symptoms : hyperglycemia
Auto-Ab screening : non recommended
Type 2 DM : C-peptide (+)
Insulin deficiency (+) /Insulin resistance
75 g OGTT more sensitive & specific than FPG
Poorly reproducible & difficult to perform in practice.
People who do not meet diagnostic criteria for DM
by FPG, but would by the OGTT : A1C < 7.0 %
OGTT not recommended for routine
Useful for further evaluation in whom DM is strongly
suspected but normal FPG or IFG
Fasting PG : 8-h
Enzymatic not SMBG
2-h Plasma G
Enzymatic, not SMBG
75-g glucose load + water( maximum < 15 minute )
Normal
I.F.G
I.G.T
D.M
Adults are BMI 25 kg/mm2 + 1 ore more risk
factors for DM
Risk factors (-) : test begin no later than age 45
If normal, repeat testing at least at 3-years
Test either FPG or 2-h 75-g OGTT
In pre-DM, treated other CVD risk factors
Dx consistent with recommendations for adults
BMI 25 kg/mm2
Family history of type 2 DM in 1st or 2nd degree
relative
Race / ethnicity
Insulin resistance or conditions associated
hypertension, dyslipidemia or PCOS
Maternal history of DM or GDM
Screen GDM using risk factor analysis, use OGTT
Carry out GDM risk assessment at the 1st prenatal visit
Screening / diagnosis at this stage of pregnancy use
standard diagnostic testing of DM
Two approach may be followed for GDM screening at
24-28 weeks
GDM should be screened for DM 6 -12 weeks post
partum, & followed with screening for DM / pre-DM
Screen GDM using risk factor analysis, use OGTT
Carry out GDM risk assessment at the 1st prenatal visit
Screening / diagnosis at this stage of pregnancy use
standard diagnostic testing of DM
Two approach may be followed for GDM screening at
24-28 weeks
GDM should be screened for DM 6 -12 weeks post
partum, & followed with screening for DM / pre-DM
Severe obese
Prior history of GDM < or delivery of large
for gestational-age infant
Presence of glucosuria
Diagnosis of PCOS
Strongly family history of type 2 diabetes
50-g OGTT
1-h PG 140 mg/dlIdentifies ~ 80 % GDM
1-h PG 130 mg/dlIdentifies ~ 90 % GDM
100-g OGTT
100-g OGTT
Initial screening
One step approach :
high prevalence
GDM
All woman at 24-28 weeks
gestation
Two step approach
1
2
Fasting : 95 mg/dl ( 5.3 mmol/L )
1 hour : 180 mg/dl ( 10.0
mmol/L )
2 hour : 155 mg/dl ( 8.6
mmol/L )
3 hour : 140 mg/dl ( 7.8
mmol/L )
Performed in the morning
Overnight fast for at least 8 h
GDM : 2 criteria
A1c ( NGSP-DCCT)
≥ 6.5 % 5.7-6.4 %
Diabetes Mellitus Pre diabetes
Diagnostic Criteria HbA1c (A1c) (A.D.A 2010)
PARAMETER Hb A1C Fructosamine 1,5-AGTime required for significance change
1-3 months 1-2 weeks 1-3 days
Reflection of mean glucose
++ ++ +
Reflection of glucose excursions/postprandial glucose
+ + ++
Association with complications
++ NA NA
Variance Small Small LargeGreatest degree of change is found during
Moderate to severe hyperglycemia
Moderate to severe hyperglycemia
Mild to moderate hyperglycemia
HPLC (reference)
Ion-Exchanges C : satisfactorily correlate with HPLC
Affinity binding C : little effect Hb variant . higher value than
HPLC ( because measure total glycated Hb)
Electrophoresis and isoelectric focusing
Immunoassay : using monoclonal Ab exhibit excellent
precision, Hb variant and carbamylated Hb are not
detected. Correlate well with HPLC, but exhibit low value
Cassette based Immunoassay
Enzyme methods /Chemical analysis : total glycated Hb
Hemoglobinopathy & Hb Variant → affect reliability test :
altering glycation, abnormal peak on chromatography, RBC
more prone to hemolysis
Transfusion, splenectomy, turnover RBC
Alcoholic chronic, opiate, iron deficiency, lead poisoning
Vitamin C and E can falsely lower level by inhibiting glyco-
sylation, but vitamine C also increase levels for some assays
Carbamylated Hb in Uremia, Hyper-triglyceridemia, hyper-
bilirubinemia
Measure of glycosilation of serum protein : interference by
albumin levels→ reflecting glycemia over 1-2 weeks
Whether fructosamine should be corrected for serum protein &
albumin : controversial ???
Not affected by Hb variants, moderate to strong correlation
With A1C → recommended for use in Hb pathy. Cheaper than
A1C, a lack of consensus exists as to it clinical value
Alternative to A1C for estimating glycemic control, particularly
where there are discrepancies SMBG and A1C and where
short-term glycemic monitoring is desired
Using serum sample & automatic equipment, has excellent
batch analytical precision.
In carbonate buffer, fructosamine rearranges to the eneaminol
form, which reduces NBT to a formasan. Absorbance at 530
nm is measured at two time points, and the absorbance
change is proportional to concentrations of fructosamine
Hb > 100 mg/dl and bilirubine > 4 mg/dl interfere : → grossly
hemolyzed and icteric samples should not be used
Vitamine C > 5 mg/dl : negative interfference
Is validated marker of short-term glycemic control
Metabolically inert polyol that competes with glucose in the
kidneys, otherwise stable levels of 1,5-AG are rapidly
depleted as blood glucose levels exceed the renal threshold
for glucosuria.
More accurately predicts rapid changes in glycemia than A1C
& fructosamine. Can not use as an index for glycemic control
in uremic patients.
More tightly associated with glucose fluctuations and
postprandial glucose
1,5-AG may offer complementary information to A1C
1.Measure fasting lipid profile at least annually.
2. In adults with low risk lipid value : LDL
cholesterol < 100 mg/dl, HDL cholesterol > 50
mg/dl, Triglycerides < 150 mg/dl) →
assessments may be repeated every 2 years
Total Cholesterol : enzymatic colorimetric, accurate and
easily automated
HDL Cholesterol : ultracentrifugation, precipitation, ion
exchange chromatography, electrophoresis.
LDL-Cholesterol : Formula Fridewald (not valid in TG > 400
mg/dl) → direct immunoassay, electrophoresis
Triglyceride : enzymatic colorimetric, free glycerol enzymatic
colorimetric, automated, good sensitivity, specifity, precision
UAE annually in Type 1 DM (> 5 years), type 2 DM
starting at diagnosis.
Microalbuminuria by measurement of albumin to
creatinine ratio in a random urine
Serum creatinine at least annually in adults with
DM regardless of the degree of UAE, should use to
estimate GFR and stage CKD if present
Another's test : CBC, Urinalysis, cystatine-C
Plasma Glucose (hypo or hyperglycemia)
Ketone bodies (blood or urine) particularly in
type 1 DM : beta-hydroxyl butyric acid, aceto
acetic acid, acetone. → colorimetric automated
or dipstick
Blood gas analysis
Blood electrolyte analysis
Bacteria : direct smear, culture (Bactec or
conventional)
Mycobacterium tuberculosis : direct smear,
culture
CRP (acute phase reactant), CBC, urinalysis
Sepsis / SIRS : Blood cultures, etc
Urinary keton
Blood keton, Beta hydroxybutarate & others
keton bodies
Plasma Glukosa
Type 1 diabetes Type 2 diabetesC-peptide
levels
Very low or undetectable Detectable
Pre-
diabetes
Auto antibodies (GAD65,
ICA512, IAA) maybe
present
Auto antibodies absent
(testing not indicated)
Medication
Therapy
Insulin absolutely
necessary : multiple daily
injection or insulin pump
Oral agents
Insulin Commonly
needed
Therapy to
prevent or
delay onset
of diabetes
None known
Clinical trial in progress
Lifestyle (weight loss and
physical activity )
Oral medications
Clinical trial in progress
Type 1 diabetes Type 2 diabetes
Frequency 5-10 % 90-95 %
Age of
onset
Any, but most common in
children and young adults
More common with
advancing age, but can
occur in children and
adolescents
Risk
Factor
Genetic, autoimmune,
environmental
Genetic, obesity, race/
ethnicity sedentary
lifestyle,
Pathogene
sis
Destruction of pancreatic
cells, usually autoimmune
No autoimmunity,
insulin resistance and
progressive insulin
deficiency
Pro-insulin → insulin + C-peptide (equivocal)
Ratio C-peptide : insulin serum = 5 : 1 to 15 : 1, due
primarily to hepatic clearance of insulin.
Half life C-peptide & pro-insulin 30 minute, but insulin
4-9 minute. → C-peptide more stabile
C-peptide levels : basal & pos glucagons stimulation
Assay : immunoassay → minor cross reactivity with
pro-insulin, in patients who have circulating Ab to
insulin
Two pairs of basic amino acid used for proteolytic processing
Insulin levels : fasting & 2-h postprandial
Wide variation in assay bias → standardization
Performed for Insulin resistance
1. RIA : cross reaction with pro-insulin & insulin
exogenous, circulating anti insulin antibodies
2. Immuno enzymometric assay specific for insulin :
interference from endogenous insulin & anti insulin Ab
3. Micro particle enzyme immunoassay (MEIA) :
interference from endogenous insulin & anti insulin Ab
Assay
GAD-65, IAA, ICA-512
Antibodies (+) may help in DD type 1 DM from the others
Antibodies (-) does not exclude this diagnosis.
GAD-65 has the highest sensitivity (91 %) as a single
screening marker for detecting multiple Antibodies
IAA : more common in young children who develop type 1
DM
GAD-65 more common in adults
Cut off value for immune marker : not completely
establish / standardized for clinical setting
No consensus as to what follow up testing should
be undertaken when a positive autoantibody test
Incidence DM type 1 is low, testing of healthy
individuals will identify only very small number
(< 0.5 %) who at that moment maybe pre-DM
At diagnosis Type 1 DM : performed Anti TPO & Anti TG
Autoimmune thyroid : 17-30 % in type 1 DM.
Thyroid Ab (+) : predictive of thyroid dysfunction
Check TSH : If normal, rechecked every 1-
2 years, or if patients develop thyroid
dysfunction, thyromegaly, or abnormal
growth rate.
SMBG Insulin therapy : 3 or more times daily
inconvenience, physical discomfort &
disability, along with expense
The procedure is complex for some
patients, advances in technology, errors in
technique
For accuracy & reproducibility : it is
important to routine evaluate maintenance
& standardization for each instrument by
committee POCT especially in hospital
Variation of methods, accuracy, presision
Interferen : temperature, humidity
Used good Calibrator
Strip Storage
Small Volume sample : Whole blood, serum
or plasma
Simple & rapid
For Monitoring, not diagnostic
Diagnostic test : FPG, 2-h PG, OGTT
Monitoring : SMBG, A1C, Fructosamine, 1,5-AG
Complication : as indicated to clinical conditions
GAD-65, IAA, ICA-512 : Auto antibodies may help
to DD Type 1 DM from others, it does not exclude
diagnosis, not recommended for screening.
Each method had false positive and negative
depend on sensitivity & specifity of the test