PANCE Blueprint Endocrinology (6%)

Diabetes mellitus type 1

Patient will present as → a young patient with weight loss, increased thirst and urination. The patient has felt tired and nauseous. On examination her weight is below the 5th percentile, she looks thin, and her skin is pale. her blood pressure is 100/70 and her pulse is 104 bpm. Her respirations are deep at a rate of 28 breaths/minute. Her breath smells fruity

90% of Type I DM is autoimmune in origin with antibodies to insulin and islet cells. Pancreatic β cells fail to respond to stimuli and undergo autoimmune destruction

  • Some patients experience a long but transient phase of near-normal glucose levels after acute onset of the disease (honeymoon phase) due to partial recovery of insulin secretion
  • Type 1 occurs most often in young people (before school age or near puberty) for normal or low weight

Key terms to know for your exam:

  • Dawn Phenomenon: Normal glucose until 2-8 am when it rises. Results from decreased insulin sensitivity and nightly surge of counter regulatory hormones during nighttime fasting
    • Treat with bedtime injection of NPH to blunt morning hyperglycemia, avoiding carbohydrate snack late at night
  • Somogyi effect: Nocturnal hypoglycemia followed by rebound hyperglycemia due to surge in growth hormone
    • Treat with decreased nighttime NPH dose or give bedtime snack
  • Insulin waning: progressive rise in glucose from bed to morning
    • Treat with change of insulin dose to bedtime

DKA: Fruity breath, weight loss, rapid respirations, hypotension

  • Diabetic ketoacidosis (DKA) should always be handled in a hospitalized setting, usually an intensive care unit, and often with an endocrinologist’s consultation, if appropriate.
  • TREAT WITH FLUIDS! Patients with DKA are always dehydrated and need large-volume IV fluid resuscitation, usually isotonic fluids such as normal saline. If corrected serum sodium level is high, this can be reduced to half-normal saline. Insulin should always be administered by an IV pump to guard against accidental overdose.

Labs (secondary to little or no endogenous insulin secretion)

  • Random plasma glucose of more than 200 mg/dl with classic symptoms or fasting levels of 126 mg/dl or greter on more than one occasion is diagnostic. 
  • Glucosuria; they also may have ketonemia and/or ketonuria.
  • HGB A1c represents glucose control over previous 8-12 weeks.  6.5% or higher is diagnostic of DM.

Treatment guidelines

  1. Dietary control  + Insulin (all type 1 will need insulin) - *know the differences between insulin types (see "media" section for a chart)

Daily aspirin is used in primary prevention.

  • This includes men older than 50 years of age and women older than 60 years of age, with at least one CVD risk factor such as HTN, dyslipidemia, smoking or albuminuria.
  • Annual foot examination
  • Annual ophthalmologic monitoring
  • Vaccinations - annual flu exam, Tdap, PCV13, Pneumococcal vaccines etc.

Often ACE inhibitors and statins to prevent complications

  • In patients 18 to 59 years of age without major comorbidities, and in patients 60 years or older who have diabetes, chronic kidney disease (CKD), or both conditions, the new goal blood pressure level is <140/90 mm Hg.
  • ACE inhibitors or angiotensin II receptor blockers are indicated for patients with evidence of early nephropathy (microalbuminuria or proteinuria), even in the absence of hypertension, and are a good choice for treating hypertension in patients who have DM and who have not yet shown renal impairment.
  • Statins are currently recommended by the American Heart Association/American College of Cardiology guidelines for all diabetic patients 40 to 75 yr of age. Moderate to high intensity treatment is used, and there are no target lipid levels.
Know the onset, peak and duration of various insulins

Know the onset, peak and duration of various insulins

Question 1
Susie is a 17 year with no past medical history, how presents to your clinic complaining of "feeling horrible". She has a 13 pound weight loss in the last 1.5 months and has increased thirst and urination. She has felt tired and nauseous. On examination her weight is below the 5th percentile, she looks thin, and her skin is pale. her blood pressure is 100/70 and her pulse is 104 bpm. Her respirations are deep at a rate of 28 breaths/minute. Her breath smells fruity. What is the most likely diagnosis?
A
diabetes insipidus
B
early diabetic ketoacidosis
C
type 2 diabetes mellitus
D
alcohol intoxication
Question 1 Explanation: 
Her fruity breath is from ketosis, which can very rarely occur in poorly controlled type 2 DM but is much more likely to be type 1 DM in this age-group and clinical presentation.
Question 2
What is the best course of action?
A
treat her in the office with 1 L of intravenous (IV) normal saline to correct her dehydration and then send her home with a prescription for an antinausea agent. Tell her to continue to push fluids; order a CBC, chemistry screen, and urinalysis; and see her back in 3 days for follow-up and to discuss the results. She is to call if she is feeling worse.
B
start the patient on desmopressin (DDAVP), order some basic laboratory tests, have the patient push fluids, and refer her to an endocrinologist
C
check an office finger-stick glucose level and a urine dipstick, and if your suspicions are confirmed, admit Jackie to the hospital for stabilization and management with possible consultation with an endocrinologist
Question 2 Explanation: 
Diabetic ketoacidosis (DKA) should always be handled in a hospitalized setting, usually an intensive care unit, and often with an endocrinologist’s consultation, if appropriate.
Question 3
She follows your advice and is subsequently seen in the emergency department. Laboratory data include serum glucose concentration of more than 600 mg/dL, ketones in the urine at 4+, and a serum sodium concentration of 128 mEq/L (mmol/L). Initial treatment should include which of the following?
A
high-volume IV isotonic or half-normal saline fluids and regular insulin by IV pump
B
IV bicarbonate should be routinely used to correct the likely acidosis
C
give D5NS IV fluid until Jackie can reestablish adequate oral intake
D
subcutaneous insulin every 4 to 6 hours in a sliding scale, with laboratory tests every 12 hours until the situation is stabilized
Question 3 Explanation: 
Patients with DKA are always dehydrated and need large-volume IV fluid resuscitation, usually isotonic fluids such as normal saline. If corrected serum sodium level is high, this can be reduced to half-normal saline. Insulin should always be administered by an IV pump to guard against accidental overdose. Bicarbonate should not be used routinely to correct acidosis—the acidosis will correct itself with fluid and insulin. Bicarbonate is used only in extreme acidosis. Subcutaneous insulin is inappropriate in the setting of DKA. Virtually all DKA patients are total body potassium depleted, even if their serum potassium level is normal (acidosis raises serum potassium concentration).
Question 4
To minimize risk of cerebral edema, lowering of the blood glucose level should be done no faster than what rate per hour in a patient with severe hyperglycemia?
A
10 mg/dl
B
20 mg/dl
C
30 mg/dl
D
80 mg/dl
E
200 mg/dl
Question 4 Explanation: 
Lowering of the blood glucose level too fast is thought to predispose to cerebral edema, although this has not been proved.
Question 5
All except which of the following are true regarding type 1 DM?
A
age at onset is usually before 30 years
B
it is associated with other autoimmune disorders
C
there is approximately a 90% concordance in monozygotic twins for this type of DM
D
islet cell antibodies are found in approximately 90% of cases
E
suboptimal vitamin D nutrition is associated with increased incidence
Question 5 Explanation: 
Type 1 DM has a less strong genetic component than type 2 DM. Identical twins have a 30% to 70% concordance rate for type 1 DM, not 90%. Type 1 DM is associated with other autoimmune disorders such as Hashimoto hypothyroidism, and onset is usually in late childhood or adolescence. Islet cell antibodies are found in the majority of newly diagnosed type 1 DM but disappear once the beta cells are “burnt out.” A cohort study in Finland found an 80% decreased incidence of type 1 DM in children supplemented with high-dose vitamin D, strongly suggesting that suboptimal vitamin D levels are a risk factor in the genetically susceptible.
Question 6
True statements regarding macrovascular complications in type 1 or type 2 DM include all except which of the following?
A
treatment with insulin or sulfonylureas has clearly been shown to worsen macrovascular disease by worsening of hyperinsulinemia
B
low-density lipoprotein (LDL) level should be kept at least < 2.6 mmol/L (100 mg/dL), and probably < 70 mg/dL, if the patient has confirmed vascular disease
C
blood pressure goal is < 130/80 mm Hg
D
strict blood pressure control is more beneficial than tight glycemic control in reducing macrovascular complications
E
virtually all type 2 diabetics older than 40 years who do not have a contraindication to statins should be receiving them
Question 6 Explanation: 
Goals to reduce macrovascular complications include improving the lipid profile in the following order of priority: LDL < 100 mg/dL (< 70 mg/dL if confirmed atherosclerotic vascular disease), HDL > 40 mg/dL in men and > 50 mg/dL in women, and triglycerides < 150 mg/dL. The blood pressure goal is < 130/80 mm Hg (note: this is lower than the general hypertensive population goal of < 140/90 mm Hg). The effects of various medications used for tight glycemic control on macrovascular disease are unclear, but a major study did not show increased risk from sulfonylureas or insulin. Unlike glycemic control, strict blood pressure control has been clearly demonstrated to lower both microvascular and macrovascular complications. Statins have been shown to lower cardiovascular risk even in diabetics with “normal” lipid profile; therefore, they should probably be used in virtually all DM patients older than 40 years whenever there is no contraindication.
Question 7
Regarding fluid and electrolyte management in DKA, all except which of the following are true?
A
the initial fluid replacement should generally be normal (0.9%) saline unless there is severe hypernatremia
B
fluid deficits are often on the order of 6 to 8 L
C
potassium level should be monitored frequently (every hour at first and then every 2 to 4 hours) during the initial treatment phase of DKA
D
in the otherwise healthy adult with DKA, a reasonable rate of infusion generally needed for the first 3 hours of treating full DKA is 150 mL/hour
Question 7 Explanation: 
DKA requires large volumes of fluid resuscitation, generally normal saline at 5 to 10 mL/kg per hour or 2 or 3 L during the first few hours. Electrolytes need to be monitored closely and corrected as needed.
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