What is the diagnostic criteria for diabetes mellitus?
- FBS > 140 mg/dl the most critical
- Random glucose > 200 mg/dl with symptoms
- GTT ? rarely indicated
What is the pathogenesis of diabetic symptoms?
- Urinary loss of glucose, when blood glucose exceeds renal
threshold of 180 mg/dl
- 4.1 calories loss for each gram of glucose loss in urine
- Loss of electrolytes and water with glucose
- Dehydration, hyperosmolarity of serum, hypovolemia
- Polyuria, thirst, polydypsia, polyphagia, loss of weight,
lack of energy
What is the pathogenesis of thirst in diabetes mellitus?
- Elevated blood sugar contributing to serum osmolality (5
mOsm per 100 mg/dl)
- Contribution of glucose to serum osmolality is small
- Thirst center in the hypothalamus are insulin dependant for
- Contraction of extra cellular fluid also a factor
Explain the genesis of dyspnea in diabetic ketoacidosis.
- Respiratory centers are extremely sensitive to acidic pH
Ventilation increases and CO2 gets blown out
- This is also a respiratory
compensation for metabolic acidosis
- Breathing is deep and rapid : Kussmal's respiration
What are the conditions where you can loose weight, in spite
of a voracious appetite?
- Diabetes mellitus
List the historical, clinical and lab evidence for
- Dry mucous membrane
- Elevated BUN
- Increased sodium
Explain the genesis of diabetes ketoacidosis. What is the lab evidence for acidosis?
- There is overproduction of ketones by liver
- Excessive amounts of free fatty acid is mobilized from
adipose tissue to liver
- In the liver the free fatty acid enters mitochondria and gets oxidized to ketones
- The acidosis results from the accumulation of beta-hydroxybutyrate
and acetoacetate, and is associated with low serum bicarbonate and an anion
What are the major derangements of diabetic ketoacidosis requiring treatment strategies?
- Hyperosmolality, dehydration, hypovolemia
- Potassium shifts
- Avoid complications of therapy
- Correct precipitating factor
How will you correct hyperglycemia in diabetic
What are the actions and types of insulin?
- Mechanism of action
- glucose transport into cells
- protein synthesis
- free fatty acid storage in adipose tissue
- Sources: Pork, Human
- Types based on duration of action
- short acting
- intermediate acting
- long acting
How will you correct hyperosmolality, dehydration and hypovolemia
associated with diabetic ketoacidosis?
- Usually they are about 6 liters in deficit
- Start with saline till hypotension is corrected and
to half normal saline
- This should be corrected over a 24 hour period
- Switch to fluids with sugar once blood sugar levels
fall around 240 mg/dl to prevent hypoglycemic episode
How will you correct ketosis?
- Insulin and hydration should correct acidosis
- No need to give bicarbonate unless the acidosis is very
severe pH < 6.9
How will you handle potassium shifts in diabetic ketoacidosis?
- Initially potassium is high
- Insulin facilitates entry of
potassium into cells
- Hypokalemia will result if not anticipated and replaced
- Once the patient starts to urinate potassium replacement should
What are the precipitating factors in diabetic ketoacidosis?
- Skipping insulin
- Dietetic indiscretion
- Idiopathic in some
How do you classify diabetes mellitus?
- Type I
- Type II
- insulin resistance
- decreased insulin
- chronic pancreatitis
- Cushing's Syndrome
- Impaired glucose tolerance
What are the characteristics of type I diabetes?
- Young age
- Sudden onset of symptoms
What is the pathogenesis of type I diabetes mellitus?
- Autoimmune destruction of beta cells
What is the pathogenesis of type II diabetes mellitus?
- Insulin deficiency
- Insulin resistance
There is relative insulin deficiency. It is not completely
absent, as in type I diabetes.
What is the treatment strategy for type I diabetes mellitus?
- Control of hyperglycemia
- insulin / diet and exercise
- Long term complication
- 'tight' control
- low fat < 30 percent
What role does diet play in type I diabetes mellitus?
- The main concern is to coordinate one's insulin dose and caloric intake for each meal
to optimize glucose levels and
- Fat intake should be approximately 30%
- Strict carbohydrate, protein and fat allotment is no longer
What is the treatment strategy for type II diabetes mellitus?
- Oral hypoglycemic agents
What role does diet play in type II diabetes mellitus?
Estimate caloric requirements to optimize body weight, as
nearly 90% of patients are obese
In most, weight loss alone can
How do you determine daily caloric requirements?
- 10 calories per pound body weight for basal requirements
- 3 calories per pound for sedentary activity
- 6 calories per pound for
- 9 calories for intense activity
How do you estimate an ideal body weight for a person?
- Males: 110 lbs for 5 feet of height, and 5 lbs for each
- Females: The same, but at 100 lbs for 5 feet height
To loose one pound, how many calories less should one consume?
- 3500 calories
- Ideally you should consume 500
calories less each day to loose one pound per week
What role does exercise play in type I diabetes mellitus?
- Important consideration in dose and timing of insulin
- To anticipate post exercise hypoglycemia
What is the role of exercise in type II diabetes mellitus?
- For weight reduction
- Increased glucose utilization by cells by increasing
sensitivity to insulin
What are the complications of insulin therapy?
- Allergic reactions
What are the oral antidiabetic agents and their mechanism of action?
- Metformin (Glucophage)
- Decrease insulin resistance and
facilitate glucose utilization by cells
- Sulfonyl urea (Glyburide)
- Post-prandial stimulation of
- Delay carbohydrate absorption and improves post
prandial glucose levels
How do you monitor diabetic control?
- Urinary glucose
- Urine glucose spillage occurs only when the blood glucose
levels exceeds the renal threshold (180 mg/dl)
- 24 hour urine collection can
give a quantitative measurement to assess diabetic control
- Blood glucose
- You need to monitor blood glucose levels, for dose
adjustment to control diabetes mellitus
- HbA1c is useful in giving overall picture of metabolic control,
are not helpful in making specific adjustments in insulin therapy
How do you determine if the current management is controlling
- HbA1c is useful in giving overall picture of metabolic
- For tight control you would like to see HbA1c < 7
What are the acute complications of diabetes mellitus?
- Diabetic ketoacidosis
- Non-ketotic hyperosmolar syndrome
Do the chronic complications of diabetes differ between type I and type II
- Chronic complications are the same for both type I and type
What are the macro vascular complications of diabetes mellitus?
Accelerated atherosclerosis. Worsened by hypertension.
- Coronary artery
- Cerebrovascular disease
- Peripheral vascular disease
What are the micro vascular complications of diabetes mellitus?
What are the neurological complications of diabetes mellitus?
- Symmetrical peripheral neuropathy
- Autonomic dysfunction
- postural hypotension
- gastric paresis
- loss of hair over extremities
- hypoglycemia unawareness
Explain feet care in diabetics to prevent foot ulcers.
- Careful trimming of nails
- Avoid injuries, callus
- Early attention to injuries
What are the ocular complications of diabetes mellitus?
- Refraction changes (changing serum osmolality and resultant change in size of lens)
- Non-proliferative (exudates, micro aneurysms,
- Proliferative: Neovascularization, vitreous hemorrhage,
retinal hemorrhage, retinal detachment, blindness
- Macular edema
- Cranial nerve 3, 4, 6 palsies
What is the recommended follow-up option for monitoring ocular
complications in a diabetic?
- Annual follow-up
- Should include dilated fundus examination
What infections are common in diabetes mellitus?
- Monilial vaginitis
- Susceptible to infections in general
What is the best agent for controlling hypertension in diabetics?
- Calcium channel blockers and angiotensin converting enzyme
inhibitors are preferred agents
- Diuretics and beta blockers may cause metabolic deregulation
- Beta blockers may cause hypoglycemia unawareness and
impairment of glycogen break down, which may interfere with correction of
What is the significance of glycosylated hemoglobin?
- Useful to monitor long-term effectiveness of diabetic
- Reflects average blood glucose levels during the preceding
- Normal levels 4 - 6.5
- Not useful in adjusting day to day insulin dose