This document discusses normal and abnormal blood glucose levels related to carbohydrate metabolism disorders. It provides details on factors that influence blood glucose levels such as the rates of glucose entry and removal from blood. These include absorption, hepatic glycogenolysis, gluconeogenesis, and glucose utilization by tissues. Hormones like insulin and glucagon that regulate blood glucose are also mentioned. The document further describes blood glucose levels in fasting and postprandial states and the body's response to low or high glucose. Oral glucose tolerance tests to diagnose diabetes and laboratory tests for monitoring diabetes are summarized.

1. Interpret the results of blood
glucose levels related to disorders
of carbohydrate metabolism.
DR.VIDHYALOGINI , BIOCHEMISTRY

2. Normal Blood glucose levels
Fasting levels: 70-110 mg/dL
Postprandial : up to 140 mg/dL
Maintained with in physiological limits by
1. Rate of Glucose entrance into blood
circulation
2. Rate of its removal from the blood stream.

3. Rate of glucose entrance in to the blood by:
1. Absorption from intestine
2. Hepatic glycogenolysis
3. Gluconeogenesis
4. Glucose obtained from other
carbohydrates, eg: fructose, galactose etc

4. Rate of Removal of Glucose from blood depends on:
1. Oxidation of glucose by tissue to supply energy
2. Hepatic glycogenesis
3. Glycogen formation in muscles
4. Conversion of glucose to fats in adipose tissues
5. Synthesis/formation of fructose in seminal fluid,
lactose in mammary gland, synthesis of
glycoproteins.
6. Formation of ribose sugars and nucleic acid
synthesis.

6. It is essential to maintain blood
glucose at optimum level
Hormones Involved in
Regulation of blood glucose
DECREASE Blood Glucose
• Insulin
• Somatostatin
INCREASE Blood Glucose
• Glucagon
• Epinephrine
• Cortisol
• ACTH
• Growth Hormone
• Thyroxine

7. Blood glucose levels in Fasting state
Also called as post absorptive state.
Aprox 12-14 hrs after the meal.
Only source of glucose – Liver glycogen-
Muscle glycogen

8. Blood glucose levels in postprandial state
Condition following ingestion of food.
Absorbed monosaccharides are utilised for
oxidation to provide energy.
Remaining in excess is stored as glycogen in the
Liver and Muscle.
40% of the glucose absorbed is used for
lipogenesis and remaining is used for synthesis
of glycoproteins and glycolipids.

9. Response to low Blood Glucose
In the fasting state there will be decreased blood
glucose levels.
This stimulates the secretion of Glucagon from
pancreas.
The Glucagon released into the blood will stimulate
hepatic glycogenolysis and
gluconeogenesis, there by increasing the blood
glucose levels.
Once the blood glucose levels raises to the normal
levels, the stimulus for the release of Glucagon
will diminish

10. Response to Elevated Blood Glucose
In the post prandial state (after a meal)
 Remember there are two separate signaling events
 First signal is from the ↑ Blood Glucose to pancreas
 To stimulates insulin secretion in to the blood
stream
 The second signal from insulin to the target cells
 Insulin signals to the muscle, adipose tissue and
liver to permit to glucose in and to utilize glucose
 This effectively lowers Blood Glucose

11. Oral Glucose Tolerance Test
It is the test to assess the ability of an individual
to metabolize a particular level of glucose
which reflected by changes in the blood
glucose level. It is useful to diagnose early
cases of diabetes mellitus and it is not
required for known cases of diabetes
mellitus,.

15. Procedure
• On high carbohydrate for3 days prior to
the test
• Fasting blood sample (10-12 hours of
fasting) is drawn
• 75 gms glucose in 300 ml water to be
taken orally in 5-10 mins
• Blood and urine samples are collected
every ½ hr for 2 hours
• Blood glucose is estimated
• Urine is tested for glucose

18. Diabetes
• OGTT
CURVE
•
•
250-
200-
180
-
•
•
•
•
150
-
100
-
50
-
½ 1 11/2 2 Time
(Hrs)
-ve +ve +ve +ve
•
•
•
•
•
• 0
• -ve
• urine
Sugar
•

22. ESTIMATION OF GLUCOSE

25. FLUORIDE COATED GRAY TUBE to prevent
glycolysis

36. Microalbuminuria is defined as the excretion of 30-
300mg of albumin in urine per day.
Microalbuminuria represents an intermediary stage
between normal albumin excretion (2.5-30mg/d) &
macroalbuminuria (>300 mg/d).
The small increase in albumin excretion predicts
impairment in renal function in diabetic patients.
It indicates reversible renal damage.

37. Reducing Substances in Urine detected by Benedict's
test.
• Copper Sulphate, Sodium Carbonate, Sodium Citrate
• 5 ml Benedict's reagent 0.5 ml of urine boiled for 2 minutes
• (or kept in a boiling water bath for 2 min).
• Semi-quantitative
• Colour of precipitate roughly parallels the concentration of reducing sugar.
• Blue colour = absence of sugar
• Green = 0.5%
• Yellow = 1%; (1%=1 g per 100 ml).
• Orange = 1.5%
• Red = 2% or more of sugar
• Any reducing sugar will give a positive Benedict's test

41. Laboratory Tests in Proven
Diabetics
Blood glucose monthly
Lipid profile once in a year
Cholesterol, LDL, HDL, Triglycerides
Micro albuminuria once in a year
Serum creatinine once in a year
Glycated Hb monthly