Diabetes Flashcards
DIABETES MELLITUS
Diabetes mellitus is a chronic metabolic disorder of relative or absolute insulin deficiency characterized by disorders of carbohydrates, proteins and fat metabolism.
Diabetes is a heterogeneous group of disorders characterised by varying degrees of insulin hyposecretion and/or insulin insensitivity. It leads to hyperglycaemia.
Classification of diabetes mellitus
It is classified into type 1, type 2 and gestational diabetes.
Other related conditions:
Impaired glucose tolerance (IGT)
Gestational diabetes mellitus (GDM)
Malnutrition-related diabetes mellitus (MRDM).
Insulin-dependent diabetes mellitus (Type 1 diabetes):
Insulin-dependent diabetes mellitus (Type 1 diabetes): occurs as a result of insulin hyposecretion due to autoimmune destruction of beta cells in the pancreas.
onset of the disease is sudden Type I require exogenous insulin to maintain life Ketosis and ketoacidosis is common.
Non-insulin-dependent diabetes mellitus (Type 2 diabetes):
Non-insulin-dependent diabetes mellitus (Type 2 diabetes): It is further subdivided into two forms as non-obese and obese patients. It occurs as a result of decreased insulin secretion or due to insulin insensitivity.
Onset is gradual Tendency to develop later in life and Patients rarely develop ketoacidosis.
Gestational diabetes:
Gestational diabetes: this is glucose intolerance of variable degree with onset or first recognition during pregnancy. Occurs as a result of the antagonism effect of placental hormones such as human placental lactogen, estrogen and cortisol. After delivery, patient returns to normal.
Clinical manifestations
Polyuria and polydipsia as a consequence of osmotic diuresis secondary to sustained hyperglycaemia
Blurred vision due to change in refraction as a result of hyperosmolar state
Weight loss despite normal or increased appetite.
Investigations
Fasting blood glucose level greater than 6.7 mmol/L or a random value of more than 10 mmol/L
Glucose tolerance test: in clinical practice used only in patients who have borderline results
Urine testing not suitable due to the wide inter-individual variation in renal threshold
Risk factors
Family history
Obesity
Age: 45 years and older
Impaired fasting glucose
Hypertension
Hyperlipidaemia
Gestational diabetes.
Goals of treatment in diabetes mellitus
The primary goals of DM management are to:
Reduce the risk for microvascular and macrovascular disease complications,
To ameliorate immediate signs and symptoms,
To reduce mortality, &
To improve quality of life.
The risk of macrovascular complications include;
The risk of macrovascular complications include cardiovascular disease (coronary heart disease -MI, CVA and stroke) and peripheral vascular disease (PVD). PVD is also responsible for much of the morbidity associated with diabetic foot problems.
The risk of microvascular complications include:
Diabetic retinopathy is the leading cause of blindness.
Nephropathy: In diabetic renal disease, the kidneys become enlarged and the
glomerular filtration rate (GFR) initially increases. However, if the nephropathy progresses, the GFR starts to decline & is indicated by the detection of microalbuminuria (small amounts of albumin present in urine). If higher amounts of albumin are detected, this is termed proteinuria (or macroalbuminuria) and signifies more severe renal damage.
Peripheral neuropathy is the progressive loss of peripheral nerve fibres resulting in nerve dysfunction resulting in a complete loss of feeling.
Management
- Carbohydrate and total calorie restriction, increased fibre intake, decreased fat intake and increased physical activity to cause weight loss and produce normoglycaemia.
- In patients with type 2 diabetes oral hypoglycaemic agents may be required. Some
patients with type 2 diabetes will eventually require insulin therapy. - All patients with type 1 diabetes require a diet containing controlled amounts of
carbohydrate and insulin therapy.
Insulin Pharmacology:
Insulin Pharmacology: Insulin is an anabolic and anti-catabolic hormone. It plays major roles in protein, carbohydrate, and fat metabolism. Endogenously produced insulin is cleaved from the larger proinsulin peptide in the β cell to the active peptide of insulin and C-peptide, which can be used as a marker for endogenous insulin production. All commercially available insulin preparations contain only the active insulin peptide.
NOTE:
Insulin is a polypeptide hormone which can be destroyed if administered orally.
It is given by subcutaneous injection. Patient is advised to use a different site for each
injection to minimise fat hypertrophy at injection sites.
Product should be stored in a refrigerator.
Dose may need to be reviewed in relation to change in diet or increased exercise.
Side-effects: local reactions and fat hypertrophy at injection site, increase in body
weight, hypoglycaemia.
Short-acting insulin
Short-acting insulin (e.g. insulin aspart and insulin lispro) has a rapid onset of action.
Intermediate- and long-acting insulin
Intermediate- and long-acting insulin (e.g. isophane insulin, which is a suspension of insulin in protamine, or insulin zinc suspension, which includes addition of a suitable
zinc salt) has a slower onset of action but action is of longer duration.
Mixtures of short-acting and intermediate-acting insulin
Mixtures of short-acting and intermediate-acting insulin (e.g. in the proportion of 30% to 70%, which is administered twice daily) may be used. A short-acting insulin may be
required before meals to avoid excessive post-prandial hyperglycaemia.
Hypoglycaemia
Hypoglycaemia is defined as a blood glucose level of less than 4 mmol/l. Individuals with diabetes may experience hypoglycaemia due to the side effects of treatment with Insulin, Glitazones or Sulphonylureas
Signs and symptoms of hypoglycaemia
Autonomic: Activating sympathetic or para-sympathetic nervous system
Sweating
Tremor/Shaking
Anxiety/ Tingling
Palpitations
Hunger
Blurred vision
Neuroglycopenic: Caused by glucose deprivation to the brain
Confusion
Lack of Concentration
Drowsiness
Atypical behaviour
Speech Difficulty
Diplopia
Incoordination
Others Non Specific
Weakness
Dry Mouth
Headaches
Warning signs of hypoglycaemia may be minimised in patients who are taking ___________and those who are experiencing increased frequency of ____________ attacks.
Warning signs of hypoglycaemia may be minimised in patients who are taking beta blockers and those who are experiencing increased frequency of hypoglycaemic attacks.
Management of hypoglycaemia
Patient should be advised to consume a rapidly absorbed carbohydrate (e.g. dextrose tablets or non-sugar-free sweets or soft drinks) immediately until symptoms subside. If patient is unconscious then patient requires administration of glucagon and glucose.
Diabetic nephropathy / Management
Diabetic nephropathy
Incidence increases in type 2 diabetes
Presents with albuminuria, proteinuria and reduced glomerular filtration rate
Hypertension and oedema develop
Management:
ACE inhibitors +/- diuretic or calcium channel blockers
Target blood pressure in diabetics is 120/80 mmHg.
Retinopathy
Retinopathy
Most common microvascular complication.
Accumulation of sorbitol which cannot be metabolised by cells in the retina takes place
and this leads to oedema
Damage to existing vessels and formation of new unstable vessels
Precipitated with hypertension, hyperlipidaemia and pregnancy
Signs: haemorrhage, spots, venous changes on retina.
Peripheral neuropathy
Characterised by paresthesia and pain in the lower extremities, and decreased sensation which may contribute to foot injuries.
Management:
Pain – paracetamol or NSAIDs are first line of treatment.
Tricyclic antidepressants particularly amitriptyline and imipramine are used in patients where analgesics alone are not sufficient.
Carbamazepine and gabapentin may also be considered.
Other antiepileptic drugs, namely lamotrigine and topiramate, have been shown to be
effective.
SPECIFIC MANAGEMENT
OBESE
SPECIFIC MANAGEMENT
OBESE
- Metformin is first line
- After 2month scale up by adding sulfonylureas as second line
- Third line give insulin exenatide or Glitazones.
SPECIFIC MANAGEMENT
NON-OBESE
- Sulfonylureas or Meglitinide as first line
- Then metformin can be added as second line.
- Add insulin exenatide or Glitazones.
SPECIFIC MANAGEMENT
ELDERLY
SPECIFIC MANAGEMENT
ELDERLY
- Sulfonylureas or Meglitinide (lower doses)
- Then switch to simple insulin doses.
SPECIFIC MANAGEMENT
ELDERLY
ELDERLY
- Sulfonylureas or Meglitinide (lower doses)
- Then switch to simple insulin doses.
SPECIFIC MANAGEMENT
ASIANS
ASIANS
- Glitazones are first line
- Metformin is added as second line
- Sulfonylureas or insulin are third line
