Evaluation Of Glycemic Control

Mrs. Mahem is a 68-year-old patient with a 25-year history of type 2 diabetes mellitus. In the past year, her A1c remains at around 8.5% with the use of the following medications: metformin, sitagliptin, and canagliflozin, at optimized doses and with adherence.  She states, “ I haven’t changed the way I eat and I walk about ½ h a day, just like I have for years”. Additional health issues include HTN and dyslipidemia, treated with medications and at therapeutic goal, and obesity with a BMI= 33. Her eGFR is 65. 

Which of the following is the most appropriate next step in the pharmacologic management of her diabetes?  

A. Add glyburide to enhance glycemic control.

B. Consider discontinuing metformin due to age and renal function.

C. Advise that her glycemic control is adequate for an older adult. 

D. Prescribe semaglutide to help her achieve A1c goal.  

---

YouTube: https://www.youtube.com/watch?v=CBH6MbYUIBQ&list=PLf0PFEPBXfq592b5zCthlxSNIEM-H-EtD&index=107

Visit fhea.com to learn more!

Transcript

Voiceover: Welcome to NP certification Q&A presented by Fitzgerald Health Education Associates. This podcast is for NP students studying to pass their NP certification exam. Getting to the correct test answers means breaking down the exam questions themselves. Leading NP expert Dr. Margaret Fitzgerald shares her knowledge and experience to help you dissect the anatomy of a test question, so you can better understand how to arrive at the correct test answer. 

So, if you're ready, let's jump right in. 

Margaret Fitzgerald: Mrs. Mahem is a 68-year-old patient with a 25-year history of type 2 diabetes. In the past year, her A1C has remained around 8.5% with the use of the following medications: metformin, sitagliptin, and canagliflozin at optimized doses and with adherence. She states, “I haven't really changed anything in the way I eat, and I walk about a half an hour a day, just like I have for years.” 

Additional health issues include hypertension and dyslipidemia, treated with medications and at therapeutic goal, and obesity with a BMI of 33. Her GFR is 65. Which of the following is the most appropriate next step in the pharmacologic management of her type 2 diabetes?  

A: Add glyburide to enhance glycemic control.  

B: Consider discontinuing metformin due to age and renal function. 

C: Advise that her glycemic control is adequate for an older adult.  

D: Prescribe semaglutide to help her reach A1C goal.  

The correct answer is D: Prescribe semaglutide to help her reach her A1C goal. Where should you start with a question like this? First, determine what kind of question it is. Given that we're provided with a diagnosis and lab results, treatment plan-and now we're asking for next steps, this is an evaluation question where we're considering whether response to care has been adequate or not. Some background information: treating type 2 diabetes in an older adult requires some special considerations. Usually, these patients have multiple comorbidities as this woman has with hypertension, dyslipidemia, and obesity. While avoiding hypoglycemia should be part of the therapeutic goal with anyone at any age with diabetes, it's a particular consideration with older adults.  

Older adults often have what's called hypoglycemia unawareness, where they don't get the typical shakes, sweat, tachycardia, hunger, and the like that a younger person would get as warning signs and symptoms for hypoglycemia. What older adults often do is when they're hypoglycemic, they get dizzy and they fall, and that's about it. And you know, we do not want older people to fall. 

But in addition, we don't want anyone to fall. But in addition, with older adults with hypoglycemia, the risk of cardiovascular, cerebrovascular, or renal vascular event is much higher with hypoglycemia as risk for cardiovascular and renal vascular disease increases in everyone as they age. The risks are significantly higher for the person with diabetes. And A1C goals can vary across the lifespan according to age. 

For example, an A1C goal of 6.5% or less is quite appropriate for a younger adult with type 1 diabetes. Let's say a 25-year-old on insulin replacement therapy-because of course, a person with type 1 diabetes has to be on insulin because their pancreas doesn't produce insulin due to the disease-but that 25-year-old, if that person becomes hypoglycemic, will likely feel shaky, sweaty, really hungry, tachycardic and jump into action and manage the hypoglycemia so that there's no great threat to their health by the hypoglycemic episode. 

However, in the older adults, sometimes what we do is often allow glycemic goal of as high as A1C of 8% or less, in part to avoid hypoglycemia. We should also consider it's perfectly appropriate for an older adult to have a more standard A1C goal of like less than 7%, particularly in the older adult who is not frail and without significant comorbidity. 

One last point, and this applies to anybody with diabetes and obesity. The use of medications associated with weight loss should be considered, particularly if losing weight is a patient goal. In this scenario, we've been given information about a woman whose glycemic control seems to have become worse over the past year. But without significant change in her lifestyle, as she's telling us, I’m eating the way I have, exercising the I have. And we're now challenged to take the next step. 

One question to ask is why is her glycemic control worse now? Please keep in mind she has had type 2 diabetes for 25 years. And let's consider the mechanism of action of the medication she's currently taking. Metformin provides insulin sensitization and as a result, reduces insulin resistance. Canagliflozin, an SGLT-2 inhibitor helps with glycemic control by causing an offloading of glucose via the kidneys when the blood sugar is elevated. 

Sitagliptin is a DPP-4 inhibitor and enhances insulin release in response to rising blood sugar. So, in other words, smart insulin release. So that's how the meds for her diabetes all work. With this information, let's take a look at the question and the potential answers. Mrs. Mahem is a 68-year-old patient with a 25-year history of type 2 diabetes. 

In the past year, her A1C remains at about 8.5% with the following medications: metformin, sitagliptin, and canagliflozin at optimized doses and with adherence. She states, “I haven't changed the way I eat, and I walk about a half an hour a day, just like I have for years.” Additional health issues include hypertension and dyslipidemia treated with medications and at therapeutic goal; as well as obesity with a BMI of 33. Her estimated GFR is 65.  

Which of the following is most appropriate next step in the pharmacologic management of her diabetes? A: Add glyburide to enhance glycemic control. This is incorrect. Well, glyburide is a sulfonylurea and albeit perhaps a bit more potent in causing insulin release than a DPP-4 inhibitor, but it provides insulin release in a constant manner, what I call casually dumb insulin release. 

Whether the blood sugar is 60 or whether it's 260. It's just telling the pancreas, release. We release insulin. The use sulfonylureas, particularly in older adults, is associated with the risk of hypoglycemia and is not considered to be part of optimize type 2 diabetes therapy. In particular, Beers criteria and a number of other resources for prescribing in the older adult encourage us to avoid prescribing glyburide if a sulfonylurea is going to be utilized because of its extraordinarily long duration of action and being associated with higher risk of hypoglycemia. 

When compared to other sulfonylureas, such as glipizide. B: Consider discontinuing metformin due to age and renal function. That's also not correct. According to the ADA, metformin therapy should be considered throughout the treatment of type 2 diabetes as long as it’s well tolerated and safe. Remember, metformin helps reduce insulin resistance. Insulin resistance usually does not go away during the course of type 2 diabetes. 

Now it can be improved by lifestyle modification, increased physical activity, weight loss, and the like. But the core issue with type 2 diabetes is that insulin resistance. Her estimated GFR is in the 60s. And there's nothing here that makes me think that she's frail. She's at extraordinarily low risk for having an adverse effect, such as lactic acidosis from metformin use. 

What's often forgotten about metformin, because it's been around for, I think, 40 years, available in the United States for a long time. And the fact that it's really inexpensive, it is $4 a month. This is a drug that also provides significant cardiovascular benefit to people with type 2 diabetes. So, metformin is good stuff. Leave people on it as long as safe and well-tolerated, even if insulin therapy needs to be added to the patient regimen in type 2 diabetes. 

C: Advise that her glycemic control is adequate for an older adult. This is incorrect. As I mentioned earlier, older adults can have different A1C goals higher than what we would consider acceptable in the younger adult. And this is, of course, to avoid hypoglycemia. 

But an A1C of 8.5% is not within an acceptable range. The scenario we're given is a woman who is physically active. I certainly would want more information about her ADLs, but I believe that an A1C of less than 7% would be acceptable for her. And maybe let it drift up between 7 and 8%. But not hanging around in the mid-eight. 

Clearly, she needs improved glycemic control. D: Prescribe semaglutide to help her achieve A1C. This is the best answer. Semaglutide is a GLP-1 agonist and is a more potent insulin releaser than a DPP-4 inhibitor. Typical A1C reduction with the use of a DPP-4inhibitor, such as sitagliptin, is in the range of about 0.7% well with a GLP-1 agonist. 

A1C reduction is usually more in the range of like 1.5%, which would then likely bring her into therapeutic goal range if she doesn't achieve glycemic control with a GLP-1 agonist, particularly if she's placed on a GLP-1 agonist and the A1C just immediately doesn't budge, just does not come down at all. Or it comes down by like maybe from 8.5 to like 8.3. 

So, we're hardly budging at all. What that might be telling you is her pancreatic beta cells are incapable of insulin release, and that is something that is noted after years of type 2 diabetes. In that case insulin replacement therapy would be warranted. As an aside, once a GLP-1 agonist is started, the DPP-4 inhibitor should be discontinued. 

They're not harmful when given together, but there appears to be no added therapeutic benefit to both products on board as there is not a cumulative improvement in glycemic control. And so just one last one last point to throw in there. Leaving the DPP-4 inhibitor, chances are insurance will not pay for the GLP-1 agonist as well as a DPP-4 inhibitor. 

Key takeaway: becoming a prescriber is one of the most important parts of NP practice. It is also one of the most daunting. Keep in mind most questions on the NP boards that have to do with medications are, at their core, safety and efficacy questions. This will require you to know how pathophysiology and mechanism of drug action. 

Voiceover: Thank you for listening to NP certification Q&A presented by Fitzgerald Health Education Associates. Please rate, review, and subscribe to this podcast and for more NP resources, visit FHEA.com.