The document discusses the role of medical laboratories in managing diabetes mellitus. It outlines several routine laboratory indicators used to monitor diabetes, including glucose, HbA1c, lipids, and urinary albumin. Advanced tests like c-peptide and glucose clamps can also help assess diabetes. Laboratories play a key role in monitoring both acute issues like ketoacidosis and long-term control through markers like HbA1c. Self-monitoring of blood glucose is important for patients on insulin therapy. Reference ranges are provided for interpreting several diabetes-related laboratory tests.

1. • Role of Medical Laboratory In
Management Of
Diabetes Mellitus
• Dr Ghulam Murtaza
Resident Chemical Pathology R1
DUHS

2. Routine laboratory indicators for the
control of management of diabetes
Glucose (blood ,urine)
ketones (urine)
OGTT
HbA1c
fructosamine
Urinary albumin excretion
creatinine/urea
protein urea
plasma lipid profile

3. ADVACED LABORATORY MAY USE ADVANCED
TECHNIQUE ASSESSMENT & CONTROL OF DIABETES
ICA
GADA
IA-2A
C-PEPTIDE
INSULIN
CLAMP/IV
GLUCOSE
LOAD

4. Management based on Acute &
Chronic
 Acute management
 Diabetic ketoacidosis
 Hyper osmolar non ketotic coma
 Chronic management
HbA1c
fructosamine
glucose
Proteinuria ,albuminuria,
Evaluation of complication(creatinine, cholesterol,
triglycerides )

5. Self monitoring of blood glucose level
• Diabetic patient esp. Those who need insulin therapy, to achieve
normal glycemia
• The renal threshold ( blood glucose concentration above which
glucose appear in urine ) approx.: 160 to 180mg.dl (8.9 to 10
mmol)
• May be decrease in pregnancy or childhood
• A decrease threshold ±100mg/dl :5.6mmol/L is known as
renal glycosuria
(monitoring urine glucose concentration lacks sensitivity
& specifity )

6. Glucose Meters

7.  Most commonly used in routine by ,patient
,physicians ,hospitals ( in clinic & bed sides)
 Help in modification of insulin dose
 Use same methodology as used for glucose
analysis ( glucose oxidase ,glucose
dehydrogenase )

8. Advantages & Disadvantages of
glucose meter
ADVANTAGES DISADVANTAGES
Low Price of instrument
easy to use
Hematocrit (false increase ) &
polycythemia ( false depression )
Capillary blood
no need of pipettes
high precision ( CV3,0- 7.1 %)
Temperature ,humidity hypotension
,hypoxia ,high TG level causing false
result
Overcome color blindness & illumination
problems (WHO)
Higher cost of consumables ,inaccuracy
of measurement , lack of compatibility of
control samples

9. Minimally invasive monitoring of
blood glucose level
Implanted sensors
Minimally invasive glucose
monitoring
Non invasive glucose monitoring
( used infrared beam of light )

10. KETONE BODIES
• Ketone bodies acetoacetate ,acetone ,&β
hydroxybutyric acid are catabolic products of free fatty
acids
• Principal ketone bodies , βHBA,AcAc,are usually present
in equimolar amounts , Acetone usually present in only
small quantities, is derived from spontaneous
decarboxylation of AcAc
• In starvation or 3 days fast ketone provides 30 to 40 %
of energy requirements

11. Clinical significance
• Excessive formation is of ketone bodies results in increased
blood concentration ( ketonemia)
& increase excretion in urine ( ketonuria)
• Occurs in decrease availability of carbohydrates or ( such as
starvation or frequent vomiting) or decrease use of
carbohydrates (such as DM, glycogen storages disease
,alkalosis ,& alcohol )
• ADA states that urine ketone testing is an important part of
monitoring by patient with diabetes type one ,pregnancy
with pre existing diabetes ,& GDM

12. Detection of ketone bodies by
ketostix
• Modification of nitroprusside test in which
reagent strip is used instead of tablets
• Gives result in 15 se with specimen containing
at least 50mg of acetoacetate/L
• Accompanying color chart gives reading for
ketone concentration

15. Glycated protein
• Protein react spontaneously in blood with glucose to form
glycated derivatives , this reaction occurs under physiological
& without involvement of enzymes called glycation
o Hemoglobin ,HbA1,HbA1c have been used to refer to
hemoglobin that has been modified by nonenzymatic addition
of glucose residues
o Formation is irreversible ,depends on RBC life & blood
glucose concentration
Retrospective indicator of average blood glucose concentration
over the previous 8-10 weeks

16. • GHb values are free from day to day glucose
fluctuations, unaffected by recent exercise ,or
food ingestion
• Any condition that substantially changes
erythrocyte life span will alter HbA1c
like hemolytic anemia & IDA

18. Specimen :
Whole blood is used for
analysis :
Blood + EDTA – 100 µl
Heparinized blood 100l
Capillary blood – one drop
on special filter paper

19. Method for determination of glycated
Hemoglobin
• More than 150 method has been described for
GHb
• Most methods separate GHb from non-GHb using
technique based on Charge difference
(ion exchange ,chromatography,HPLC ,
electrophoresis & isoelectric focusing )
• Regardless of method are, results is expressed in
as percentage .

25. Albuminuria
• Microalbuminuria
• Microalbuminuria is detection of small
quantity of Albumin in the urine i.e. 30-300
mg/d (and NOT small-size albumin)
• Urinary Albumin: Creatinine ratio is more
useful (normal < 3.0 mg/mmol of creatinine)

26. • The normal rate of albumin excretion is less than
30 mg/day (20 µg/min)
• Persistent albumin excretion between 30 and
300 mg/day (20 to 200 µg/min) is called
microalbuminuria
• In patients with diabetes it may be indicative of early
diabetic nephropathy, unless there is some coexistent
renal disease.
• Protein excretion above 300 mg/day (200 µg/min) is
considered to represent macroalbuminuria (also called
overt proteinuria, clinical renal disease, or dipstick
positive proteinuria)

28. • Hemoglobin + Glucose ↔ Aldimine →
Glycated hemoglobin
• Glycated hemoglobin refers to hemoglobin
to which glucose is attached
nonenzymatically and irreversibly; its
amount depends upon blood glucose level
and lifespan of red cells

29. • REFERENCE RANGES
• Venous plasma glucose:
• Fasting: 60-100 mg/dl
• At 2 hours in OGTT (75 gm glucose): <140 mg/dl
• Glycated hemoglobin: 4-6% of total hemoglobin
• Lipid profile:
• – Serum cholesterol: Desirable level: <200 mg/dl
• – Serum triglycerides: Desirable level: <150 mg/dl
• – HDL cholesterol: ≥60 mg/dl
• – LDL cholesterol: <130 mg/dl
• – LDL/HDL ratio: 0.5-3.0
• C-peptide: 0.78-1.89 ng/ml
• Arterial pH: 7.35-7.45
• Serum or plasma osmolality: 275-295 mOsm/kg of water.
• Serum Osmolality can also be calculated by the following formula recommended by American Diabetes Association:
• Effective serum osmolality (mOsm/kg) = (2 × sodium mEq/L) + Plasma glucose (mg/dl) / 18
• Anion gap:
• – Na+ – (Cl– + HCO3–): 8-16 mmol/L (Average 12)
• – (Na+ + K+) – (Cl– + HCO3–): 10-20 mmol/L (Average 16)
• Serum sodium: 135-145 mEq/L
• Serum potassium: 3.5-5.0 mEq/L
• Serum chloride: 100-108 mEq/L
• Serum bicarbonate: 24-30 mEq/L
• CRITICAL VALUES
• Venous plasma glucose: > 450 mg/dl
• Strongly positive test for glucose and ketones in urine
• Arterial pH: < 7.2 or > 7.6
• Serum sodium: < 120 mEq/L or > 160 mEq/L
• Serum potassium: < 2.8 mEq/L or > 6.2 mEq/L
• Serum bicarbonate: < 10 mEq/L or > 40 mEq/L
• Serum chloride: < 80 mEq/L or > 115 mEq/L