This document discusses diabetes mellitus and insulin. It defines the two major types of diabetes as Type 1 (caused by beta cell destruction) and Type 2 (caused by relative beta cell deficiency and decreased tissue sensitivity). The key signs and symptoms of diabetes are described. The discovery of insulin by Banting, Best, and others in the 1920s is summarized. The mechanisms of action, absorption, and types of insulin are outlined. Factors affecting glucose homeostasis and the treatment of diabetes with insulin are also summarized.

2. • Metabolic disorder - Hyperglycaemia,
- Glycosuria,
- Hyperlipidaemia,
- Negative nitrogen balance,
- Ketonaemia.
Pathological changes
Thickening of capillary basement
membrane,
 Increased vessel wall matrix,
 Cellular proliferation
Vascular complications
 Lumen narrowing,
 Early atherosclerosis,
 Sclerosis of glomerular capillaries,
 Retinopathy,
 Neuropathy,
 Peripheral vascular insufficiency

3. Type – I Type – II
Synonym
• IDDM
Insulin Dependent DM
• Juvenile Onset DM
• NIDDM
Non-Insulin Dependent DM
• Maturity Onset DM
Pathology Beta cell destruction No / moderate loss of beta cells
Etiology
• Type IA:
Autoantibodies in blood
• Type IB:
No antibodies
• No antibodies
• Genetic predisposition
Insulin level ↓ or ↓↓↓ ↓ or Normal or ↑
Two major types of DM

4.  Abnormality in glucoreceptors of β cells or Relative β cell deficiency:
• ↓ed Insulin secretion
 ↓ed Sensitivity of peripheral tissues to insulin:
• Down regulation of insulin receptors
 ↑ed Hyperglycaemic hormones or obesity:
• β cells lag behind

5. Type of diabetes
Normal
Glucose
Tolerance
Hyperglycemia
Pre-diabetes Diabetes mellitus
Impaired fasting
glucose or
Impaired glucose
tolerance
No
Insulin
Required
Insulin
Required
for
Control
Insulin
Required
for
Survival
• Type 1
• Type 2
• Other specific
types
• Gestational DM
• Time (years)
• FPG (mg/dl)
• 2-h PG (mg/dl)
< 100
< 140
100-125
140-199
≥ 126
≥ 200
Spectrum of Glucose homeostasis & DM

6. 1
2
3
Symptoms of Diabetes plus Random Blood Glucose ≥ 200 mg/dl
Fasting Plasma Glucose ≥ 126 mg/dl
Two-hour plasma glucose ≥ 200 mg/dl during OGTT
Or
Or

7. Glucose
< 100 mg/dl
Fatty Acids
400 μM
Liver
Brain
Pancreatic islet Adipose tissue
Fasting
State
Skeletal
muscle
Insulin

8. Prandial
State
Glucose
120-140 mg/dl
Fatty Acids
< 400 μM
GI tract

9. Neural factors

10. β cells
Insulin
Amylin
α Cells
Glucagon
δ cells
Somatostatin
Hormonal
factors

11. of
α2 Adrenergic
receptor
⇓
of β cell
Adenylyl cyclase
⇓
↓ed Insulin release
of
β2 Adrenergic
receptor
⇓
of β cell
Adenylyl cyclase
⇓
↑ed Insulin release
of
Muscarinic
cholinergic receptor
⇓
↑ed Ca++ in β cells
(IP3-DAG)
⇓
↑ed Insulin release
Neural factors

12. Glucose
G-6-P
Metabolism
↑ ATP
K+ ↓ K+
K+
Depolarization
Ca++
↑ Ca++
↑ cAMP
Incretins
(GPCR-Gs-AC)GLUT
Stored
Insulin
Chemical
Factors

13. • More insulin release if glucose is given orally than i.v.
• Chemical signals called ‘Incretins’ from gut act on beta cells of pancreas –
• Release of insulin occurs
Examples:
• GLP-1 (Glucagon-Like Peptide-1)
• GIP (Glucose dependent Intestinal Peptide)
• VIP (Vasoactive Intestinal Polypeptide)
• CCK-PZ (Cholecystokinin-Pancreozymine)
Incretins

14. The most powerful agent we
have to control glucose.
Miracle discovery that saved
many lives
Insulin
F. Banting
C. Best

15. 1869 - Paul Langerhans
- Pancreas contains 2 distinct types of cells
- Acinar cells – secrete digestive enzymes
- Islet cells - some other function
1889 - Minkowski &Von Mering
- Pancreatectomized dogs exhibit a syndrome similar to human Diabetes
1903 – 1909 - Nicolas Paulesco
- Injection of pancreatic extracts reduces urinary sugar & ketones in diabetic dogs
- Published the results indicating isolation of glucose-lowering substance
History of Insulin

16. 1921:
• Frederick Banting (Canadian surgeon), with permission of
• J.J.R. Macleod (Professor of Physiology,Toronto), together with
• Charles Best (Fourth year medical student)
- Assessed Antidiabetic principle of pancreas
- Assumed that the pancreatic extract was destroyed by the proteolytic enzymes
- Ligated the pancreatic duct – Acinar tissues degenerated – Islets undisturbed
• With help of J. B. Collip (Chemist with expertise in extraction & purification of Epinephrine)
• Extracted the active extracts

17. 1922:
• LeonardThompson – 1st patient to receive the active extract of pancreas
• Age of 14 years, presented with blood glucose level of 500 mg/dl
• Despite rigid diet control, he excreted large quantities of glucose in urine
• Without insulin, he would likely have died
• After administration of pancreatic extract,
- Marked decrease in blood glucose level & urinary excretion
- Marked clinical improvement
⇓
Eventually, stable extracts were obtained & patients were treated
From porcine & bovine sources

18. 1923: Nobel prize to Banting & Macleod
• Since conflicts about credits,
• Banting shared his prize with Best
• Macleod with Collip
1958: Nobel prize to Frederick Sanger
• Amino acid sequence of insulin
1964: Nobel prize to Dorothy Hodgkin and coworkers
• Three-dimentional structure of insulin
1977: Nobel prize toYalow & Berson
• Radioimmunoassay for the hormone insulin

19. 24 30 31 21
A
B
C
Preproinsulin
Proinsulin
Insulin
Synthesis & Processing of Insulin
SP B chain C peptide A chain
 SP cleavage
 Folding
 S-S bond formation
 PC1: cleavage of Arg31/Arg32
 PC2: cleavage of Lys64/Arg65

20. • Doses & concentrations of insulin are measured in InternationalUnits (I.U.)
• In past, hormone preparations were impure
• Bioassay was used to standardise the hormone
 1 Unit of insulin:
• “The amount required to reduce the blood glucose
concentration to 45 mg/dl (2.5 mM) in a fasting rabbit.”
 U-100 :
• Insulin suspension at a concentration of 100 U/ml
• ∼ 3.6 mg/ml
 U-40 andU-500
Insulin Bioassay

21. Mechanism of
Action

22. • Distribution: only extracellularly
• Peptide – if given orally, degraded in g.i.t.
• Metabolism: Liver > muscles, kidney
• Nearly half of it entering in portal vein is inactivated in the first passage through liver
• Liver – exposed to much higher (4-8 fold) concentration than other tissues
• Degradation – disulphide bonds are reduced,A & B chains separated.
• Plasma half life : 5 – 9 min
Fate of Insulin

23. (1) Hypoglycaemia:
• Most frequent, most serious
• Patients with ‘labile’ diabetes, in whom insulin requirements fluctuate unpredictably
Reasons:
• Injection of large dose of insulin
• Missing a meal after injection
• Vigorous exercise
Reactions to Insulin

24. • Symptoms:
Due to counter-regulatory sympathetic stimulation:
• sweating, anxiety, palpitation, tremor, etc.
Due to deprivation of brain of glucose (Neuroglucopenic):
• Dizziness, headache, behavioural changes, visual disturbances, fatigue, weakness, etc.
Finally, if blood glucose is < 40 mg/dl:
• Mental confusion, seizure, coma, irreversible neurological deficit

25.  Hypoglycaemic Unawareness:
• After long term treatment – 30% patients lose adrenergic symptoms
• Diabetic neuropathy can abolish the autonomic symptoms
• In patients who experience frequent episodes of hypoglycaemia
Treatment: (Hypoglycaemia):
• Glucose is a must, orally or i.v. – reverses the symptoms rapidly
• If glucose not available or patient not able to take glucose orally,
• Glucagon 0.5 – 1 mg i.v., or
• Adrenaline 0.2 mg s.c.

26. (2) Insulin resistance:
If insulin requirement > 100 U/day
Common with beef / pork insulin, less with human insulin
Mechanism:- Antibody to homologous contaminating protein
(3) Local reactions:
• Swelling, erythema, stinging
• Lipodystrophy of s.c. fat, if same site is used repeatedly.
(4) Allergy:
• Due to contaminating proteins
• Urticaria, angioedema, anaphylaxis
(5) Edema:
• Due to Na+ retention

27. Beta adrenergic blockers:
• Inhibit compensatory mechanism operating through beta-2 receptors
• Prolong hypoglycaemia
• Warning signs of hypoglycaemia are masked
Thiazides, furosemide, corticosteroids, OCP, salbutamol, nifedipine:
• Increase blood glucose & reduce effectiveness of insulin
Acute alcohol ingestion:
• Depletes hepatic glycogen – Precipitates hypoglycaemia
Lithium, aspirin (high dose), theophylline:
• Increase insulin secretion & peripheral glucose utilization – Accentuate hypoglycaemia
Drug interactions

29. • Facilitates glucose transport across cell membrane;
• Skeletal muscles & fat are highly sensitive
• Intracellular glucose is the limiting factor in these & some other tissues
• Other tissues, it is largely independent of insulin
• Ketoacidosis – interferes with glucose utilization by brain – diabetic coma
• Muscular activity - ↑ed glucose entry without insulin need – insulin sparing effect
• Upregulation of GLUT synthesis
• Regulates dynamic equilibrium between,
Intracellular pool of vesicles containing GLUT4 & GLUT1, and
GLUT vesicles inserted into the membrane
Actions on Glucose

30. • ↑ed Phosphorylation of glucose (first step in glucose utilization)
• Stimulates enzyme glycogen synthase – ↑ed glycogen synthesis
• Inhibits glycogen degrading phosphorylase – ↓ed glycogenolysis in liver
• Insulin inhibits gluconeogenesis (from protein, FFA, glycerol) by ↓ed synthesis of PEP
carboxykinase
Insulin deficiency:
• Proteins & AAs are funnelled into liver – converted into carbohydrate & urea –
underutilization & over production of glucose – hyperglycaemia – glycosuria

31. • Insulin Inhibits lipolysis & stimulatesTG synthesis
Diabetes mellitus
⇓
Unchecked action of lipolytic hormones (glucagon, Adr, thyroxine, etc.)
⇓
↑ed break down of fat
⇓
↑ed FFA & glycerol in blood
⇓
Taken up by liver to produce acetyl CoA
⇓
Actions on Lipid
Normally,
⇓
Resynthesized to FA &TG
Diabetes
⇓
Diverted to produce ketone bodies
⇓
Ketonaemia, ketonuria

32. • Insulin facilitates AA entry & synthesis into proteins
• Inhibits protein break down
Diabetes mellitus
⇓
Protein break down
⇓
AA released into blood & taken up by liver
⇓
Converted into pyruvate, urea, glucose
⇓
Excess urea is excreted into urine
⇓
Negative nitrogen balance
Actions on Protein

33.  Rapid actions:
• Within seconds or minutes
• Most of the above metabolic effects
 Intermediate actions:
• Few hours
• DNA mediated synthesis of glucose transporter
• Synthesis of AA metabolism
 Long-term actions:
• Multiplication & differentiation of many types of cells
Actions over period of time

34. • ↑Glucose uptake &
Glycogen synthesis
• glycogenolysis
& glucose output
• gluconeogenesis
from protein, FFA,
pyruvate, glycerol
Actions of Insulin Producing Hypoglycaemia
Liver Muscle Adipose tissue
• ↑Glucose uptake &
utilization
• Proteolysis &
release of AAs,
pyruvate, lactate
into blood which
form substrate for
gluconeogenesis
in liver
• ↑ Glucose uptake
& storage as fat &
glycogen
• Lipolysis &
release of FFA +
Glycerol which
form substrate for
gluconeogenesis
in liver

35.  Site of injection:
• Abdomen > Arm > Buttock >Thigh
Blood flow:
• Intramuscular > Subcutaneous
 Regional muscular activity at site of injection
 Type of insulin
 Volume & concentration of insulin
Depth of injection
Factors affecting absorption of insulin

36. Rapid acting
Preparations of Insulin
• Insulin lispro
• Insulin aspart
• Insulin glullisine
Short acting
• Regular (soluble)
insulin
Intermediate acting
• Insulin zinc suspension
(lente)
• NPH (isophane)
Long acting
• Insulin glargine
• Insulin detemir

37. • Older preparations – beef & pork pancreas
• 1% (10,000 ppm) other proteins (proinsulin, pancreatic proteins, insulin derivatives, etc.)
• Potentially antigenic
Highly purified insulin preparations:
• ‘single peak’ & ‘monocomponent’ (MC) insulins - < 10 ppm proinsulin
• MC insulins are more stable, less insulin resistance or injection site

38. Limitations:
• Peak action only after 2-3 hours
• When injected just before meal,
creates mismatch between
meal & insulin availability
• S.c. injection is not suitable for
low constant basal level of
action in interdigestive period
• Slow onset is not applicable to
i.v. injection, as hexamers
dissociate rapidly – prompt
action
Insulin + Zn
Neutral pH
S.C. tissue
Neutral pH
Hexamers
Surrounded by Zn
Hexamers Dimers
Dissolution
Monomers
Capillary membrane
Insulin released in blood
Regular (soluble) insulin

39. • To overcome the fore mentioned problems
• Rapidly acting
• Peak less, longer acting insulins
• Insulin is rendered insoluble by –
Precipitating it with excess of zinc & increasing particle size, or
 Complexing it with protamine
• Available preparations –
 Lente insulin ( insulin – zinc suspension )
 NPH / Neutral Protamine Hagedorn / Isophane insulin
‘Retard’ or ‘Modified’ Insulin Preparations

40.  NPH (Neutral Protamine Hagedorn) or Isophane insulin:
• Protamine is added to fix the insulin molecules
• S.c. injection – dissociates slowly
• Intermediate action
• Combined with regular insulin (70:30 or 50:30)
• Twice daily (before breakfast & dinner)
Ultralente Semilente Lente
Large particles Smaller 7:3 ratio of ultralente &
semilenteCrystalline Amorphous
Long acting Short acting Intermediate acting
 Lente insulin (Insulin-Zinc suspension)

41. • Recombinant DNA technology
• E.coli – ‘prb’ (Proinsulin Recombinant Bacterial)
• Yeast – ‘pyr’ (PrecursorYeast Recombinant)
• emp – Enzymatic Modification of Porcine insulin
• More water soluble & hydrophobic than porcine or bovine insulin
• Slightly more rapid s.c. absorption
• Earlier & more defined peak
• Slightly shorter duration of action

42. B chain
A chain
1 23 28 29 30
1 21
-s-s-
• The sequence matches with that of IGF-1
• Unlike regular insulin, after injection, it dissociates instantaneously into monomers
• Rapid absorption, Shorter duration of action
• Advantages:
 ↓ed prevalence of hypoglycaemia,
 Improved glucose control.

43. B chain
A chain
1 23 28 29 30
1 21
-s-s-
• ↓ ed self-association same as lispro
• Profile same as lispro
• Advantage:
 Lower rates of nocturnal hypoglycaemia

44. B chain
A chain
1 23 28 29 30
1 21
-s-s-
• Profile similar to both of the above
• Use:
 CSII (Continuous Subcutaneous Insulin Infusion)

45. B chain
A chain
1 23 28 29 30 31 32
1 21
-s-s-
• Clear solution with acidic pH (4.2)
• After injection subcutaneously (neutral pH), it aggregates
• Prolonged but predictable absorption from injection site.
 Note:
• It has acidic pH, so NOT to be combined with short acting preparations
(i.e. regular, lispro, aspart) as they have neutral pH

46. • Sustained peakless absorption profile
• Better once-daily 24-hour insulin coverage than NPH insulin
• Lower risk of nocturnal hypoglycaemia
• May be administered at any time of day
• Does not accumulate after several injections
• Site of administration or exercise does not affect its time-action profile

47. B chain
A chain
1 23 28 29 30
1 21
-s-s-
• After injection, it binds with albumin via fatty acid chain
• Smoother time-action profile on twice a day administration
• Profile same as glargine

48. Type of Insulin &
Brand Names
Onset Peak Duration
Role in Blood Sugar
Management
Rapid-Acting
Lispro 15-30 min. 30-90 min 3-5 hours
Covers insulin needs for meals
eaten at the same time as the
injection.
Aspart 10-20 min. 40-50 min. 3-5 hours
Glulisine 20-30 min. 30-90 min. 3-5 hours
Short-Acting
Regular 30-60 min 2-3 hours 6-8 hours
Covers insulin needs for meals
eaten within 30-60 minutes
Intermediate-Acting
NPH (N) 1-2 hours 8-10 hours 20-24 hours
Covers insulin needs for about
half the day or overnight.

49. Name of
Insulin
Onset Peak Duration
Role in Blood Sugar
Management
Long-Acting
Degludec 30-90 min
No peak:
insulin is
delivered at
a steady
level.
20-24
hrs
covers insulin needs for
about one full day.Glargine 30-90 min
Detemir 1-120 min

50. Type of Insulin Onset Peak Duration
Role in Blood Sugar
Management
Pre-Mixed* or Split-mixed regimens
30/70 30 min. 2-4 hours 14-24 hours
These products are
generally taken two or
three times a day before
mealtime.
50/50 30 min. 2-5 hours 18-24 hours
25/75 15 min.
30 min.-2½
hours
16-20 hours
Inhaler
Exubera Banned
Afrezza Within min 12 to 15 min 2-3 hours Post prandial effects.
*Premixed insulins are a combination of specific proportions of intermediate-acting and
short-acting insulin in one bottle or insulin pen (the numbers the brand name indicate the
percentage of each type of insulin).

51. Long acting analogue
Glargine
And
Pre-meal
Short acting analogue
Twice daily NPH insulin
And
Regular / other analogue
For meal-time coverage
Insulin pump injection
Short acting analogue;
Bolus is given at each meal
Basal bolus
Split-mixed

52.  Insulin syringes
 Pen devices
 Inhaled insulins
 Insulin pumps
 Implantable pumps
 Other route of delivery

53. • Prefilled disposable syringes
• Contain specific types or mixtures of regular & modified insulins

54. • Fountain pen like device
Use:
• Insulin cartridge for s.c. injection through a needle
• Preset amounts (in 2 U increments) are propelled by pushing a plunger
Advantage:
• Convenient in carrying
• Easy to inject

55. Fill up the syringe Attach the needle,
Remove the cap
Check if drug comes
Out of needle
Set the dose Identify the site Inject the drug Discard the needle,
Recap the syringe

56. • Inhaled human insulin preparation was marketed in USA & Europe
• Fine powder
• Delivered through a nebulizer
Action:
• Controls meal-time glycaemia
• Not suitable for round-the-clock basal effect
• Withdrawn from market due to risk of pulmonary fibrosis & other complications.

58. • Portable infusion devices connected to cannula placed subcutaneously
• Provides CSII (Continuous Subcutaneous Insulin Infusion)
• Only regular insulin or a fast acting analogue is used
Advantages:
• Can be programmed to deliver insulin –
- at a low basal rate (1 U/hr), and
- premeal bolus insulin (4 – 15 times the basal rate) to control post-prandial
hyperglycaemia

59. Limitations:
• No definite advantage over multidose s.c. insulin has been demonstrated
• Cost
• Strict adherence to diet, exercise
• Risk of pump failure
• Care of the device
• Infection at the site
• Suitable for selective type 2 DM patients only

61. • Electro-mechanical mechanism
• Regulates insulin delivery from a percutaneously refillable reservoir
Examples:
• Mechanical pumps,
• Propellant driven pumps,
• Osmotic pumps.

62. • Insulin injected s.c. without a needle
• Jet flow of insulin is injected directly into s.c. tissue

64. • Intraperitoneal
• Rectal
• Oral (by combining insulin with liposomes or coating with impermeable polymer)
• Advantage:
• Higher concentrations into portal circulation, i.e. more physiological

65. Concept:
• To compensate the spatial distance between patient and physician using
telecommunication devices
• Drug delivery via insulin pump is remotely controlled by GSM modem

67. • Alvin C. Powers and David D’Alessio. Endocrine pancreas and pharmacotherapy of diabetes
mellitus and hypoglycaemia.In : Bruton LL, editor. Goodman & Gilman’s –The
Pharmacological basis of therapeutics. 12th edition. NewYork : Mc Graw Hill Publication;
2011. p. 1237- 54.
• Tripathi KD. Essentials of Medical Pharmacology. 6th ed. New Delhi : Jaypee brothers
medical publishers; 2009. p. 258-70.
• Sharma HL & Sharma KK. Principles of Pharmacology. 2nd ed. New Delhi: Paras
publication; 2012. p. 626-36.
• R. Gr¨oning et al. / InternationalJournal of Pharmaceutics 339 (2007) 61–65
References