An overview of diabetes mellitus

Question 1

What is diabetes

Answer 1

A metabolic disorder of multiple aetiologies
Chronic hyperglycaemia
Disturbances of carbohydrate, fat and protein
metabolism
Resulting from defects in:
insulin secretion
insulin action
or both.

Question 2

What are the 2 main types of diabetes

Answer 2

Type 1 Diabetes
ß-cell destruction
Absolute lack of insulin

Type 2 Diabetes
Defective insulin secretion (ß-cell dysfunction)
Insulin resistance
Relative lack of insulin
NIDDM, IDDM etc. outdated

Question 3

Describe some other types of diabetes

Answer 3

Monogenic diabetes
Gestational diabetes
Other types of diabetes
Pancreatic
Endocrine
Drugs
Other genetic syndromes

Question 4

What are some signs and symptoms of diabetes

Answer 4

Weight loss
* Polydipsia
* Polyuria
* Lethargy & general malaise
* Recurrent infections
* In type 2 often NO symptoms

Question 5

How is diabetes diagnosed

Answer 5

If symptoms present

Fasting plasma glucose ≥7 mmol/L
Random plasma glucose ≥11.1 mmol/L
2 hour OGTT ≥11.1 mmol/L

If no symptoms
Two of the above
DM may now be diagnosed on basis of HbA1c
≥6.5% (48 mmol/mol)

Question 6

What is HbA1c

Answer 6

Non-enzymatic glycosylation of
Hb
↑glucose → ↑glycosylation
Normally <42 mmol/mol
Reflects average blood glucose
over ~90 days

Question 7

Describe IGT and IFG

Answer 7

Impaired Glucose Tolerance (IGT)
stage of impaired glucose regulation
fasting plasma glucose < 7.0 mmol/L
75g OGTT 2-hour value > 7.8 but < 11.1

Impaired Fasting Glycaemia (IFG)
fasting plasma glucose > 6.1 mmol/L but < 7.0
OGTT needed to exclude diabetes.

Risk ↑ for CV disease ± diabetes
IGT: 2-5% per year progress to diabetes
Early treatment may reduce progression to diabetes
Healthy eating advice / weight management / exercise
effective in slowing progression
Metformin useful but less effective
Annual OGTT or HbA1c to diagnose diabetes

Question 8

What are some chronic complications of diabetes

Answer 8

Nephropathy
16% of all new patients
needing renal replacement
therapy have diabetes

Erectile Dysfunction
May affect up to 50% of men
with long-standing diabetes
R

Retinopathy
Most common cause of
blindness in people of working
age

Macrovascular and
Cerebrovascular
Disease
2–3 fold increased risk
of coronary heart disease
and stroke

Foot Problems
15% of people with
diabetes develop
foot ulcers; 5–15% of
people with diabetic
foot ulcers need
amputations

Question 9

What are the treatments for type 2 DM

Answer 9

Lifestyle management
Weight loss
Bariatric surgery
Very low calorie diets
Oral hypoglycaemic agents
Sulphonylureas, metformin
Gliptins, thiazolidinediones, gliflozins
GLP-1 analogues
Insulin therapy

Question 10

How to monitor glycaemic control

Answer 10

Home BG monitors
Spot readings
Rapid (3 secs)
Capillary blood
HbA1C measurement
Long-term
Fructosamine
Medium-term

Question 11

Describe type 1 DM

Answer 11

Generally < 30 yrs
Beta cell destruction
↓insulin
Need insulin to survive
Absence of insulin
causes ketogenesis
Ketoacidosis kills

Question 12

Treatment of type 1 DM

Answer 12

1-3 insulin injections/day
of the same insulin
Multiple daily injections
(4-5) with different
insulins
Continuous
subcutaneous insulin
infusion (‘
pump
’)

Question 13

Describe insulin analogues

Answer 13

Created to alter pharmacokinetics
inhibit hexamerisation → more rapid acting
bind albumin → slow acting, longer lasting
form insoluble depots under skin → ultra slow acting

Question 14

What is gestational DM

Answer 14

During pregnancy
Macrosomia, resp
distress, early delivery
Resolves after delivery
but may recur
Risk factors:
Obesity, family history
T2DM, prev GDM
↑future risk of T2DM,
hypertension
Insulin, metformin Rx

Question 15

What is monogenic diabetes

Answer 15

Strong family history of diabetes
Autosomal dominant
Diabetes develops at an early age (<25 years)
Multiple genes and counting being discovered
Diet or tablet treatment