Blood Glucose Levels

[reder]

A 10 year old boy goes to a physician complaining of polyuria (increased urinary volume and frequency) and weight loss. A blood test reveals elevated blood glucose. What would further tests more likely reveal?
A) low insulin
B) Low ACTH
C) Low glucagon
D) Low cortisol

The answer is A. But I don't understand this answer, Here is my reasoning: When a person has elevated blood glucose levels, the body tries to achieve homeostasis by increasing insulin in the blood and decreasing glucagon levels. So this person would have high levels of insulin in the blood. Is the question badly worded or my reasoning is wrong? Any help would be appreciated.

Thank You.

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[rjosh33]

A 10 year old boy goes to a physician complaining of polyuria (increased urinary volume and frequency) and weight loss. A blood test reveals elevated blood glucose. What would further tests more likely reveal?
A) low insulin
B) Low ACTH
C) Low glucagon
D) Low cortisol

The answer is A. But I don't understand this answer, Here is my reasoning: When a person has elevated blood glucose levels, the body tries to achieve homeostasis by increasing insulin in the blood and decreasing glucagon levels. So this person would have high levels of insulin in the blood. Is the question badly worded or my reasoning is wrong? Any help would be appreciated.

Thank You.

Normally, yes, that's what would happen. However, a person with type I diabetes cannot produce insulin (thought to be a result of immnologic destruction of pancreatic beta cells), and as a result cannot take in much glucose from the blood. The polyuria also results from excess glucose in the urine.

 

[pm1]

A 10 year old boy goes to a physician complaining of polyuria (increased urinary volume and frequency) and weight loss. A blood test reveals elevated blood glucose. What would further tests more likely reveal?
A) low insulin
B) Low ACTH
C) Low glucagon
D) Low cortisol

The answer is A. But I don't understand this answer, Here is my reasoning: When a person has elevated blood glucose levels, the body tries to achieve homeostasis by increasing insulin in the blood and decreasing glucagon levels. So this person would have high levels of insulin in the blood. Is the question badly worded or my reasoning is wrong? Any help would be appreciated.

Thank You.

The question stem indicates that something is out of whack (otherwise the boy wouldn't have polyuria and increased levels of glucose in the blood).

low insulin --> high levels of glucose in blood

 

[Izak]

But otherwise, normally a person with high blood glucose would show high insulin levels too right?

I think this Kaplan question is poorly worded.

 

[Prncssbuttercup]

A normal person should NOT have high glucose levels. The question took me .2 seconds to answer, if you have high glucose it means there is not enough insulin in the bloodstream for the cells to absorb the excess glucose.

 

[loveoforganic]

This is a pretty classic DM I presentation. I don't know that that's fair for the MCAT though

 

[gentlebeast]

I would back up SBB 2016.
A normal person would be found high insulin to reduce high blood glucose level.
But the boy is sick(polyuria), and so his insulin level is messed up.

 

[LifeTake2]

This is a pretty classic DM I presentation. I don't know that that's fair for the MCAT though

Yes very classic (I live with a 4yr old with DM1), but nothing about the MCAT is fair...and I think this honestly is just a case of over-thinking what was intending to be a freebie.

 

[Prncssbuttercup]

I agree Tom, I really think it was a simple question... BUT I'm an EMT and my dad is diabetic, and I am hypoglycemic... sooooooo maybe I'm not the best person to answer, but I think the question is fair... To the OP and others, there should be some way to figure out if that is considered a 'hard-med-easy' question isn't there? In the AAMC stuff it tells you how many people get that question correct at least...

 

[loveoforganic]

I'm not sure how I feel about the question. I'm having a hard time remembering what my actual MCAT knowledge base was. I'm inclined to say most people would know it, but that doesn't necessarily make it a fair question. Oh well, I'll let other people who are closer to their MCAT debate it

 

[indianjatt]

You can also eliminate low ACTH and low cortisol levels because both are essentially the same because low ACTH doesn't stimulate the adrenal medulla as much as thus there is less cortisol released into the blood stream.. If one was right, the other should be correct too thus making them most likely both incorrect statesments.

 

[loveoforganic]

Unless you extend the pathology knowledge extensively and assume a cortisol-secreting tumor is possible. The presentation doesn't match that (well, it does, but it isn't how it would typically be phrased, wrong buzz words), but just being nitpicky with where should they draw the line with pathology knowledge (I think none should be required)

 

[MedPR]

A 10 year old boy goes to a physician complaining of polyuria (increased urinary volume and frequency) and weight loss. A blood test reveals elevated blood glucose. What would further tests more likely reveal?
A) low insulin
B) Low ACTH
C) Low glucagon
D) Low cortisol

The answer is A. But I don't understand this answer, Here is my reasoning: When a person has elevated blood glucose levels, the body tries to achieve homeostasis by increasing insulin in the blood and decreasing glucagon levels. So this person would have high levels of insulin in the blood. Is the question badly worded or my reasoning is wrong? Any help would be appreciated.

Thank You.

Your understanding of endocrine/feedback is lacking. For the MCAT, if something is abnormally high, that means there's a problem with a hormone; insulin in this case. High glucose results from low insulin. If insulin levels were high (again, for the MCAT), glucose levels would be low.

 

[MedPR]

You can also eliminate low ACTH and low cortisol levels because both are essentially the same because low ACTH doesn't stimulate the adrenal medulla as much as thus there is less cortisol released into the blood stream.. If one was right, the other should be correct too thus making them most likely both incorrect statesments.

Adrenal cortex, not medulla.

Adrenal medulla = catecholamines (epi, norepi)
Adrenal cortex = "Salt, sugar, and sex: The deeper you go, the sweeter it gets." = mineral corticoids (aldosterone), glucocorticoids (cortisol), androgens.