Al Borg Laboratory

Al Borg Technical Newsletters

DIABETES MELLITUS 12/06/2003

The new guidelines issued by the American Diabetes Association changed the definition

of diabetes into Anyone with fasting glucose > 125 mg/dL on 2 seperate occasions now

ualifies as diabetic (the old threshold was 140) - and any reading over 110 is considered impaired glucose tolerance.

MONITORING & FOLLOW UP OF DIABETIC PATIENTS :

Monthly Blood glucose + Fructosamine .

3 Monthly Glycosylated Hemoglobin + Microalbuminuria .

Yearly Liver & Kidney functions + Lipid profile .

GLYCOSYLATED HEMOGLOBIN (HBA1c) :

HBA1c is formed by addition of a glucose molecule to the beta chain of hemoglobin .

This process is formed progressively and irreversibly inside the red cells and is directly

dependant on the blood glucose concentration.

HBA1c is probably the best single measure for monitoring diabetes over a three month

period especially if the physician plans to alter or stop therapy.

However, this test does not give information about same day variations in blood glucose.

It can also be falsely low in anaemic patients and falsely high in patients with hemoglobinopathies.

FRUCTOSAMINE :

Fructosamine is formed by glucose linkage to albumin or other proteins.

It has the advantage over (HBA1C) of having a shorter half life hence is more

useful in monitoring diabetes over a one month period.

This test may give false results in patients showing plasma protein fluctuations

as in hemodialysis.

MICROALBUMINURIA

Microalbuminuria is the elevated excretion of urine albumin above the normal

amount and below that detected by conventional urinary protein tests.

REF. RANGES: Normal < 20mg albumin / gm creatinine.

Microalbuminuria 20-200 mg albumin /gm creatinine.

Persistent proteinuria > 200 mg albumin /gm creatinine.

APPLICATIONS :

Nephropathy whether due to diabetes or hypertension.
To monitor the efficacy of therapy in controlling diabetes or hypertension.
Microvasculature complications leading to nephropathy, retinopathy and neuropathy.
Complications affecting the macrovasculature and leading to coronory heart disease (CHD)
, cerebrovascular disease and peripheral arterial disease.

INSULIN & C-PEPTIDE :

Proinsulin is cleaved into Insulin and the biologically inactive C-peptide which are useful

parameters in the following conditions :

· True hypoglycemia & Insulinoma : both Insulin & C-peptide are elevated.

· Factitious hypoglycemia : Insulin is elevated & C-peptide is decreased .

· Residual B cell function in Insulin dependant diabetics: many of those patients have antibodies
that interfere with the Insulin assay; hence C-peptide is the parameter of choice .

INSULIN ANTIBODIES :

They develop from impurities in animal Insulin .

Presence of Insulin antibodies suggests one or more of the following ;

· Exogenous intake of animal Insulin .

· Insulin Autoimmune Hypoglycemia .

· Insulin resistance especially if associated with high titres >1:64 .

LIPID PROFILE:

Hyperlipidemia is suggested if

Total Cholesterol >200mg%