Diabetes Mellitus – Treatment with diet, drugs and insulin Flashcards
(43 cards)
Describe Type 1 Diabetes
- Autoimmune destruction of islet beta cells
- Insulin deficiency
- Ketosis-prone
- Seldom overweight
- Diagnosed young, median age 9
Describe Type 2 Diabetes
- Decreased beta cell mass and dysfunction of islets
- Insulin resistance
- Not ketosis-prone
- Often overweight
- Tends to be diagnosed in later life
What are the aims of diabetes treatment?
- To restore disturbed metabolism to near normal
- To prevent, or delay progression, of diabetic complications
- To educate people about diabetes and motivate them to achieve effective self-management
What are the aims of dietary management in diabetes?
- To achieve good glycaemic control
- To reduce hyperglycaemia and avoid hypoglycaemia
- To ensure adequate nutritional intake
- To assist with weight management
- To avoid aggravating diabetic complications
What are the calorific values of food constituents?
- Carbohydrate= 4 kcals
- Protein= 4 kcals
- Fat= 9 kcals
- Alcohol= 7 kcals
Describe a weight-reducing diet
-Reduce/ eliminate refined carbohydrates and saturated fat
-Restrict TOTAL caloric intake (portion size)
=Increase insulin sensitivity
=Lower blood glucose
=Lower triglycerides/ LDL-cholesterol
What is the Glycaemic Index?
-GLYCAEMIC INDEX (GI) is a measure of change in blood glucose following ingestion of a particular food
=Post-prandial rise in blood glucose is influenced by amount and source of carbohydrate
-Different carbohydrate-containing foods can be ranked by their effect on post-prandial glycaemia
=Low GI foods produce a slow, gradual rise in blood glucose after ingestion
=Low GI foods include starchy foods (rice, spaghetti, granary bread, porridge) and pulses like beans and lentils
What is the recommended composition of a healthy diet as % energy intake?
- Carbohydrate= 45-60% (unrefined, complex)
- Fat <35% (monosaturated 10-20%)
- Protein= 10-15% (do not exceed 1g/kg body wt)
- High intake of dietary fibre (fruit, vegetables), low intake of salt
Describe dietary treatment of Type 1 Diabetes
- At diagnosis insulin should be started immediately
- Dietary modification requires restriction of refined sugars and saturated fats
- Diet is weight-maintaining for most people
- Insulin dosage adjustment is based on carbohydrate content of meals
- Structured education programmes are available, e.g. DAFNE (Dose Adjustment For Normal Eating)
- Other lifestyle changes (regular exercise) are supplementary
What are the potential therapeutic targets in T2DM?
- Adipose deposition
- Liver (gluconeogenesis)
- B-cell (dysfunction)
- Kidneys= promote more release of glucose through urine
Describe the intensification of therapy in Type 2 Diabetes management
- Diet and exercise
- Oral monotherapy
- Oral combination
- Oral and insulin
- Insulin
What are the indications and contraindications for oral hypoglycaemic drugs?
-Indications= T2DM (if diet alone inadequate)
=Insulin sensitizers in combination with insulin Type 1
-Contraindications= ketoacidosis, severe intercurrent illness
Describe sulphonyreas (T2DM)
- stimulate secretion of endogenous insulin
- used in non-obese patients (may be insulin-deficient)
- used as monotherapy or in combination with metformin, glitazone or insulin
- Glipizide (intermediate duration of action), gliclazide (older patients as shorter duration)
- choice of sulfonylurea is based on duration of action and method of elimination
- promote weight gain
- main adverse effect is hypoglycaemia
Describe Biguanide/ Metformin (T2DM)
- decreases hepatic glucose production
- increases insulin sensitivity in muscle
- encourages weight loss
- effective as monotherapy or in combination with sulfonylurea, glitazone or insulin
- side-effects include nausea and diarrhoea
- contraindicated in renal impairment (risk of lactic acidosis)
Describe Glucose Prandial Regulators (Glinides)
- Repaglinide (MEGLITINIDE)
- Nateglinide (AMINO ACID DERIVATIVE)
- Insulin secretagogues – direct effect on beta cells
- Stimulate rapid endogenous insulin release when given with meals
- Side-effects include weight gain and hypoglycaemia
- Lower risk of hypoglycaemia than sulfonylureas
Describe a glucosidase inhibitors
-Acarbose, Miglitol
-Delay digestion of carbohydrate and slow down postprandial absorption of glucose
-Do not cause weight gain
Limited efficacy; can be used in combination
-Gastrointestinal side-effects are common, including bloating and flatulence
Describe how PPAR gamma works
-Work in fat (lipolysis reduced)
0-lower plasma free fatty acids, increases adiponectin
-increase insulin sensitivity/ reduces insulin resistance in liver and muscle
=reduces glucose output in liver
=Increases glucose uptake from muscle
Describe Thiazolidinedione
- Pioglitazone
- Slow onset of action - take 2-3 months to achieve maximal effect (works at level of nucleus)
- Promote weight gain - but redistribute body fat to reduce visceral depot
- Contraindicated in congestive cardiac failure; hepatic impairment (water retention) May cause vertebral fractures
What is the Incretin Effect?
-Plasma insulin response to oral and IV insulin
=Secretion of insulin is greater in response to oral than IV
=Promoted by release of GI hormones “incretins”
Describe Glucagon-like peptide (GLP-1)
- Potent insulinotropic hormone (incretin) is released in response to meals
- Rapidly degraded in plasma by enzyme Dipeptidyl Peptidase 4 (DPP- 4)
- Plasma GLP-1 is lower in people with impaired glucose tolerance (IGT) and type 2 diabetes compared to healthy non-diabetic subjects
What are the physiological effects of GLP-1?
-Upon ingestion of food, GLP-1 is secreted from the L-cells of the intestine
=Stimulates glucose-dependent insulin secretion
=Suppresses glucagon secretion
=Slows gastric emptying
=Reduces food intake
=Improves insulin sensitivity
What are the therapeutic forms of GLP-1?
- Incretin mimetic, synthetic exendin-4 (Exenatide)
- GLP-1 analogue (Liraglutide)
- DPP- 4 inhibitors (Gliptins)
- EXENATIDE: synthetic form of Exendin-4
Describe incretin mimetics
- Exenatide, Liraglutide
- Act like a GLP-1 peptide
- Have to be given by injection
- Promote weight loss
- Given in combination with either metformin or sulfonylurea
- Main side-effect is nausea
- Hypoglycaemia rare except when given with SU
Describe gliptins
- Sitagliptin, vildagliptin
- DPP-4 inhibitors – inhibit degradation of incretin hormones and enhance their actions
- Oral route of administration
- Taken in combination with metformin
- Produce modest reduction in HbA1c so less effective
- Weight neutral
- Few side-effects, with minimal hypoglycaemia