What is the diagnostic criteria for diabetes mellitus?

Answer

• FBS  > 140 mg/dl the most critical
• Random glucose  > 200 mg/dl with symptoms
• GTT ? rarely indicated

What is the pathogenesis of diabetic symptoms?

Answer

• 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?

Answer

• 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 glucose utilization
• Contraction of extra cellular fluid also a factor

Explain the genesis of dyspnea in diabetic ketoacidosis.

Answer

• 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? 

Answer

• Diabetes mellitus
• Hyperthyroidism

List the historical, clinical and lab evidence for dehydration? 

Answer

• Hypotension
• Dry mucous membrane
• Thirst
• Elevated BUN
• Increased sodium

Explain the genesis of diabetes ketoacidosis. What is the lab evidence for acidosis?

Answer

• 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 gap

What are the major derangements of diabetic ketoacidosis requiring treatment strategies?

Answer

• Hyperglycemia 
• Hyperosmolality, dehydration, hypovolemia 
• Ketosis
• Potassium shifts
• Avoid complications of therapy
• Correct precipitating factor

How will you correct hyperglycemia  in diabetic ketoacidosis?

Answer

• Insulin

What are the actions and types of insulin?

Answer

• 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?

Answer

• Usually they are about 6 liters in deficit
• Start with saline till hypotension is corrected and 
• Switch 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?

Answer

• 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?

Answer

• 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 start

What are the precipitating factors in diabetic ketoacidosis?

Answer

• Infection
• Stress
• Skipping insulin
• Dietetic indiscretion
• Idiopathic in some 

How do you classify diabetes mellitus?

Answer

• Type I
  • no endogenous insulin
• Type II
  • insulin resistance
  • decreased insulin
• Secondary
  • gestational
  • chronic pancreatitis
  • hemochromatosis
  • Cushing's Syndrome
  • pacreatectomy
• Impaired glucose tolerance

What are the characteristics of  type I diabetes?

Answer

• Young age
• Sudden onset of symptoms
• Ketoacidosis

What is the pathogenesis of type I diabetes mellitus?

Answer

• Autoimmune destruction of beta cells
• Genetics

What is the pathogenesis of type II diabetes mellitus?

Answer

• 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?

Answer

• 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?

Answer

• The main concern is to coordinate one's insulin dose and caloric intake for each meal to optimize glucose levels and prevent hypoglycemia
• Fat intake should be approximately 30%
• Strict carbohydrate, protein and fat allotment is no longer considered necessary 

What is the treatment strategy for type II diabetes mellitus?

Answer

• Diet
• Exercise
• Oral hypoglycemic agents
• Insulin

What role does diet play in type II diabetes mellitus?

Answer

• Estimate caloric requirements to optimize body weight, as nearly 90% of patients are obese
• In most, weight loss alone can control diabetes 

How do you determine daily caloric requirements?

Answer

• 10 calories per pound body weight for basal requirements
• Plus 
  • 3 calories per pound for sedentary activity
  • 6 calories per pound for moderate activity 
  • 9 calories for intense activity

How do you estimate an ideal body weight for a person?

Answer

• Males:  110 lbs for 5 feet of height, and 5 lbs for each additional inch
• Females:  The same, but at 100 lbs for 5 feet height

To loose one pound, how many calories less should one consume?

Answer

• 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?

Answer

• Important consideration in dose and timing of insulin
• To anticipate post exercise hypoglycemia

What is the role of exercise in type II diabetes mellitus?

Answer

• For weight reduction
• Increased glucose utilization by cells by increasing sensitivity to insulin

What are the complications of insulin therapy?

Answer

• Hypoglycemia
• Allergic reactions
• Lipoatrophy

What are the oral antidiabetic agents and their mechanism of action?

Answer

• Metformin (Glucophage) 
  • Decrease insulin resistance and facilitate glucose utilization by cells
• Sulfonyl urea (Glyburide) 
  • Post-prandial stimulation of endogenous insulin
• Acarbose:
  • Delay carbohydrate absorption and improves post prandial glucose levels

How do you monitor diabetic control?

Answer

• 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
  • 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 one's diabetes.

Answer

• HbA1c is useful in giving overall picture of metabolic control
• For tight control you would like to see HbA1c < 7

What are the acute complications of diabetes mellitus?

Answer

• Diabetic ketoacidosis
• Non-ketotic hyperosmolar syndrome

Do the chronic complications of diabetes differ between type I and type II diabetes?

Answer

• Chronic complications are the same for both type I and type II diabetes

What are the macro vascular complications of diabetes mellitus?

Answer

Accelerated atherosclerosis. Worsened by hypertension.

• Coronary artery
• Cerebrovascular disease
• Peripheral vascular disease

What are the micro vascular complications of diabetes mellitus?

Answer

• Kidney
• Retina
  • non-proliferative
  • proliferative 

What are the neurological complications of diabetes mellitus?

Answer

• Symmetrical peripheral neuropathy
• Mononeuropathy
• Autonomic dysfunction
  • impotence
  • postural hypotension
  • gastric paresis
  • loss of hair over extremities
  • hypoglycemia unawareness

Explain feet care in diabetics to prevent foot ulcers.

Answer

• Careful trimming of nails
• Avoid injuries, callus
• Early attention to injuries

What are the ocular complications of diabetes mellitus? 

Answer

• Refraction changes (changing serum osmolality and resultant change in size of lens)
• Retina
  • Non-proliferative (exudates, micro aneurysms, hemorrhage)
  • Proliferative: Neovascularization, vitreous hemorrhage, retinal hemorrhage, retinal detachment, blindness
  • Macular edema
• Glaucoma
• Cranial nerve 3, 4, 6 palsies
• Cataract

What is the recommended follow-up option for monitoring ocular complications in a diabetic?

Answer

• Annual follow-up
• Should include dilated fundus examination

What infections are common in diabetes mellitus?

Answer

• Monilial vaginitis
• Susceptible to infections in general

What is the best agent for controlling hypertension in diabetics?

Answer

• Calcium channel blockers and angiotensin converting enzyme inhibitors are preferred agents
• Diuretics and beta blockers may cause metabolic deregulation and dyslipidemia
• Beta blockers may cause hypoglycemia unawareness and impairment of glycogen break down, which may interfere with correction of hypoglycemia

What is the significance of glycosylated hemoglobin?

Answer

• Useful to monitor long-term effectiveness of diabetic therapy
• Reflects average blood glucose levels during the preceding 2-3 months
• Normal levels 4 - 6.5
• Not useful in adjusting day to day insulin dose