Diabetes Mellitus Flashcards
Functions of Insulin
- hormone and control of carbohydrate, lipid and protein metabolism
- allows glucose to enter cells and converted into energy
- allows glucose uptake, metabolism and storage of glucose as glycogen
- facilitates transport of potassium, phosphate and magnesium into cells
Type 1 Diabetes
5-10% of all cases
characterized by destruction of beta cells of the pancreas by body’s own T-cells, causing inability to produce insulin
How does T1DM cause hyperglycemia?
without insulin, glucose is present in the blood but unable to enter cells for utilization
Clinical manifestations of T1DM
Polyphagia
(excessive hunger)
Polydipsia
(excessive thirst)
Polyuria
(frequent urination)
Glucosuria
(excretion of glucose in urine)
Fatigue
Weight loss
Blurred vision
Ketonuria
What are the two major metabolic abnormalities associated with T2DM?
Insulin Resistance
- inability of muscle and fat tissues to increase glucose uptake
- metabolic syndrome
- reduced glycogen synthesis and storage in liver
- failure to suppress glucose production
- hyperinsulinemia
Insulin Deficiency
- beta cells become fatigued and less efficient
- produced insulin is insufficient or poorly utilized
Four methods of diagnosis using plasma glucose testing
- A1C > 6.5%
- Fasting plasma glucose level >= 7 mmol/L
- Two hour OGTT level >= 11.1 mmol/L when glucose load of 75g is used
- Random or casual plasma glucose measurement >= 11.1 mmol/L
Goals of diabetes management
a. Normalize blood sugars
b. Prevent/resolve symptoms
c. Prevent acute and chronic complications
d. Avoid negative sequelae of therapy (i.e. hypoglycemia - too much insulin!)
Nutritional therapy for T1DM
- Meal plan is based on individual’s usual food intake and is balanced with insulin and exercise patterns
- Insulin regimen is managed day to day
Nutritional therapy for T2DM
- Emphasis is based on achieving glucose, lipid and blood pressure goals
- Calorie reduction
Diabetic Ketoacidosis
caused by profound deficiency of insulin
Insufficient insulin shifts carbohydrate metabolism to fat and protein metabolism to produce energy
Body breaks down fat stores causes:
- Ketones are byproducts of fat metabolism
- Alter pH balance, causing metabolic acidosis
- Ketone bodies excreted in urine
- Electrolytes become depleted
Precipitating factors of DKA
- Acute illness
- Infection
- Inadequate insulin dosage
- Undiagnosed Type 1
- Poor self-management
Clinical manifestations of DKA
a. Glucose level of 16-42 mmol/L
b. Polyuria, polydipsia
c. Fruity/acetone odour of ketones on breath
d. Lethargy/weakness (early symptoms)
e. Dehydration
f. Abdominal pain
g. Kussmaul’s Respirations
Kussmaul’s Respirations
- Initially breathing is deep and rapid - hyperventilation
- As acidosis worsens, breathing gradually becomes deep, slow, laboured and gasping
Associated with severe metabolic acidosis or diabetic ketoacidosis
Managment of DKA
a. treat promptly
b. airway management
c. rehydration and correction of acid-base and fluid imbalances
d. restore state of carbohydrate catabolism
e. identify and correct precipitating factors
Hyperosmolar Hyperglycemic Syndrome (HHS)
- life threatening, medical emergency
- results from any illness or condition that leads to dehydration or inadequate food intake
- ketoacidosis does NOT occur
- hyperglycemia leads to osmotic diuresis
- High glucose plus high sodium and urea lead to high serum osmolarity and subsequent intracellular dehydration
Clinical manifestations of HHS
a. Decreased LOC
b. Polyuria, polydipsia
c. Hypovolemia, profound dehydration
d. blood glucose >34 mmol/L
e. increase in serum osmolality
f. absent/minimal ketone bodies
Hypoglycemia
low blood glucose of <4 mmol/L
occurs when too much insulin in proportion to glucose in blood
Manifestations of Hypoglycemia
Anxiety, nervousness Diaphoresis Tremors Hunger Pallor Palpitations
Somogyi Effect
Hypoglycemia induced by insulin causes body to break down glycogen causing hyperglycemia
BG level is low at 2-4am
Requires reduction of insulin dosage
Dawn phenomenon
rise in blood sugar between 4-8am caused by overnight release of counter-regulatory hormones
BG level is normal or high at 2-4am
Requires insulin timing adjustment or increase in insulin
Macrovascular Complications of Diabetes
a. coronary artery disease
b. hypertension
c. cerebrovascular disease
d. peripheral vascular disease
Microvascular Complications of Diabetes
specific to diabetes
a. diabetic retinopathy
b. diabetic nephropathy
c. diabetic neuropathy
What are the conditions used to screen for metabolic syndrome?
- high fasting BG (>5.6 mmol/L)
- high bp (>130/85)
- high levels of triglycerides (>1.7 mmol/L)
- low levels of HDL (<1.0-1.3 mmol/L)
- abdominal obesity
Hormone that increases glucose in blood
Glucagon
Counter-regulatory hormones (CRH) (4)
- glucagon
- epinephrine
- growth hormone
- cortisol
2 mechanism of hepatic glucose production
- Glycogenolysis: breakdown of glycogen into glucose
2. Gluconeogenesis: synthesis of glucose from breakdown of proteins or TG
What are the ABCDES of DM?
A1C Bp Cholesterol Drugs to protect heart Exercise/eating Smoking cessation
Therapeutics of glycemic control
a. diet
b. exercise
c. oral hypoglycemic agents
d. insulin
Glycemic Targets
A1C <= 7.0%
Preprandial (fasting) PG = 4.0-7.0mmol/L
2hr postprandial PG = 5.0-10.0mmol/L
(5.0-8.0mmol/L if A1C not at target)
Drugs that cause hyperglycemia
Corticosteroids Diuretics (i.e. thiazides) Protease inhibitors Sympathomimetics Cyclosporine, tacrolimus phenytoin
Drugs that complicate hypoglycemia management
Alcohol
Beta-blockers by masking symptoms (blunt rapid heart rate)
Symptoms of hypoglycemia
Tremor, weakness, palpitations, tachycardia, sweating, tingling lips, hunger, blurred vision, agitation
Nightmares, restless sleep, morning HA or hangover
What complication can arise when diabetic patient has an infection?
stress can cause the release of CRH, which predisposes one to hyperglycemia
Which regimen has best prandial and fasting control?
Basal-bolus insulin (intensive)
- rapid/regular controls prandial BG
- long acting controls overnight and between meal fasting
Which type of diabetes is basal-bolus most recommended for?
T1DM
What is the effect of exercise and insulin?
Exercise increases insulin sensitivity during and after
- risk of hypoglycemia
especially with T1DM
Management strategies for patients with DM exercising
- extra carbohydrate consumption
- reduce pre-meal bolus insulin dose and basal insulin infusion rate
Which non-insulin agents reduce glucose production in the liver?
a. metformin
b. glitazones
c. DPP-4 inhibitors
d. GLP-1 agonists
Patient Education regarding SMBG
- How and when to perform SMBG
- How to record the results
- Meaning of various BG levels
- How behaviour and actions affect SMBG results
