Diabetes Mellitus

List the problems in this case.

What is the diagnostic criteria for diabetes mellitus?

• FBS  >126 mg/dl Most critical
• Random glucose  >200 mg/dl with symptoms
• GTT ? indication

What is the pathogenesis of his 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?

• 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 extracellular fluid

Why was dyspnea his presenting symptom?

Respiratory centers are extremely sensitive to acidic pH. Ventilation increases and CO2 gets blown out. This is also a respiratory compensation for metabolic acidosis. If CO 2 levels are normal, in the presence of metabolic acidosis, one should suspect a co-existent obstructive lung disease.

What are the conditions, where you can loose weight in spite of voracious appetite. Explain the mechanism in this patient.

• Diabetes mellitus
• Hyperthyroidism

What historical, clinical and lab evidence you have for dehydration in this case? Calculate his serum osmolality.

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

Does he have kidney disease?

He certainly has dehydration to account for elevated BUN. Elevated Creatinine raises suspicion for Kidney disease

Explain the genesis of acidosis in this patient. What are the clinical and lab evidence for acidosis?

• There is overproduction of ketones by liver
• Excessive amounts of free fatty acid is mobilised from adipose tissue to liver
• In the liver  the free fatty acid enters mitochondia 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 is your diagnosis?

• Diabetic ketoacidosis.

What are the major treatment strategies for Diabetic ketoacedosis ?

• Hyperglycemia / insulin
• Hyperosmolality, dehydration, hypovolemia , 6 liters of negative balance
• Ketosis
• Potassium shifts
• Avoid complications of therapy
• Correct precipitating factor

How will you correct Hyperglycemia ?

• Insulin

What are the actions, 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, hypovolemia ?

• Start with saline till hypotension is corrected and 
• Switch to half normal saline. 
• Usually they are about 6 liters in deficit. 
• 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.

Explain the "episode of dehydration responding to fluids in a person in boot camp". Why did the patient improve after being given IV saline in his first admission?

Since one of the major defects is dehydration correction of it can temporarily make the patient better. Dehyration is not uncommon in boot camp, hence the physician failed to consider diabetes mellitus in this patient as the etiology for dehydration.

How will you correct Ketosis?

No need to give bicarbonate unless the acidosis is very severe  pH <6.9

How will you handle Potassium shifts?

Initially potassium is high. Insulin faciliates entry of potassium into cells. Hypokalemia will result if not anticipated and replaced. Once the patient starts to urinate potassium replacemnet should start.

What precipitated diabetic ketoacidosis?

• Infection
• Stress
• Skipping insulin
• Dietetic indiscretion
• In some idiopathc

Does he have type I or type II disease?

Type I diabetes mellitus.

• Young age
• Sudden onset of symptoms
• Ketoacidosis

How do you classify Diabetes mellitus?

• Type I
  • No endogenous insulin
• Type II
  • Insulin resistance
  • Decreased insulin
• Secondary
  • Gestational
  • Chronic Pancreatitis
  • Hemochromatosis
  • Cushing's syndrome
  • Pacreatectomy
• Impaired glucose tolerance

What is the pathogenesis of type I diabetes mellitus

• Autoimmune destruction of beta cells

• Genetics

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.

How will you manage him after he has recovered from this episode? 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 is the role of diet in type I diabetes mellitus

These patients are thin. The main concern is to co-ordinate insulin dose and caloric intake for each meal to optimize glucose levels and prevent hypoglycemia. Fat intake should be around 30%. No strict allotment of carbohydrate, protein and fat is considered necessary anymore.

What is the treatment strategy for type II diabetes mellitus?

• Diet
• Exercise
• Oral hypoglycemic agents
• Insulin

What is the role of diet in type II diabetes mellitus

Estimate caloric requirements to optimize body weight, as nearly 90% of patients are obese. Correction of excess weight by itself can control diabetes in most.

How do you estimate daily caloric needs for a person?

10 calories per pound body weight for basal requirements, plus 3 calories per pound for sedentary activity, 6 calories per pound for moderate activity and 9 calories for intense activity.

How do you estimate ideal body weight for a person?

For men 110 lbs for 5 feet of height, and 5 lbs for each additional inch. For females it is the same, but at 100 lbs for 5 feet height.

How many calorie deficit do you have to incur to loose a pound?

3500 calories. Ideally you  should plan on having a 500 calories deficit each day to loose one pound in one week.

What is the role of exercise 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 complication of insulin therapy

• Hypoglycemia
• Allergic reactions
• Lipoatrophy

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 endogenous insulin
• Acarbose: Delay carbohydrate absorption and improves post prandial glucose levels.

How do you monitor diabetic control?

• Urinary glucose
• Blood glucose
• HbA1c

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.

HbA1c is useful in giving overall picture of metabolic control, are not helpful in making specific adjustments in insulin therapy.

You need to monitor blood glucose levels, for dose adjustment to control diabetes mellitus. 

What are the acute complications of diabetes mellitus?

• Diabetic ketoacidosis
• Non-ketotic hyperosmolar syndrome

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

What are the macrovascular complications of diabetes mellitus

Accelerated atherosclerosis. Worsened by hypertension.

• Coronary artery
• Cerebrovascular disease
• Peripheral vascular disease

What are the microvascular complications of diabetes mellitus

• Kidney
• Retina
  • Non-proliferative
  • Proliferative / Annual follow up / Laser

What are the neurological complications of diabetes mellitus?

• Symmetrical peripheral neuropathy
• Mononeuropathy
• Autonomic dysfunction
  • Impotence
  • Postural hypotension
  • Gastric paresis
  • Loss of hair over extremities
  • Hypoglycemia unawareness

How will you care for feet 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 omolality and resultant change in size of lens)
• Retina
  • Non-proliferative (exudates, microaneurysms, hemorrhage)
  • Proliferative: Neovascularization. Vitreous hemorrhage, Retinal hemorrhage, Retinal detachment, blindness
  • Macular edema
• Glaucoma
• Cranial nerve 3, 4, 6 palsies
• Cataract

What infections are common in diabetes mellitus

• Monilial vaginitis

Best agent for control of hypertension in diabetics?

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. Calcium channel blockers and angotensin converting enzyme inhibitors are preferred agents.

What is the significance of glycosylated hemoglobin?

• 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