Zero to GP - GP Revision Podcast

Osteoporosis - Essential GP Revision

• Thomas Watchman • Season 1 • Episode 13

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SPEAKER_01

Hi, this is Tom, and welcome back to the Zero to GP podcast. In this episode, we're going to be going through osteoporosis. So that's all the key facts you need to know about prevention and management of osteoporosis. As always, the format of these episodes is I'll present a case, ask you questions, I want you to come up with your answer. Ideally, say it out loud or write it down. Commit that answer down to paper and see whether you actually know the answer. Then we'll go through an explanation. If you like these podcast episodes and you have your AKT exam coming up sometime in the future, consider the Zero to GP AKT revision resources. That includes the AKT Revision book, which is a book containing notes on all the key stuff you need for your AKT exam, the 02GP.com website, which contains practice questions, a fact trainer tool, flashcards, and all the notes. And there may be an upcoming AKT revision course with me where we go through on a whole face-to-face day all the stuff you need to know for your AKT exam. Links to all of those are in the description. So let's get straight into this episode. So let's introduce our case. It's a 65-year-old woman, and she comes in to see you as a GP because she's worried about her risk of fractures. She tells you that her mother, who was around the same age, had a hip fracture. So she's worried about having a fracture herself. So you want to assess her and kind of calculate her risk.

SPEAKER_00

The first question is: what's the preferred risk assessment tool in this scenario?

SPEAKER_01

So there's two risk assessment tools that the NISE Clinical Knowledge Summaries talk about. The first one, which is the preferred one, is the Q fracture tool. The second one, which is an alternative, is the fracks tool. The fracts used to be used more commonly, but now Q fracture is preferred. The next question is what's the outcome from the risk assessment? So you do, you calculate the Q fracture score.

SPEAKER_00

What is the outcome? What does that tell you?

SPEAKER_01

So the result of the Q fracture score or tool is that you get a percentage 10-year risk of an osteoporotic fracture. So let's say somebody comes in and you calculate the score and it comes out with 5%. That means they have a 5% risk of an osteoporotic fracture in the next 10 years. Or let's say it's 20%, they have a 20% risk or a 1 in 5 risk of having a fracture in the next 10 years. So let's say this patient, you calculate her Q fracture score, and it's 17%, 17.3% risk of a hip, wrist, shoulder, or spine fracture in the next 10 years.

SPEAKER_00

The next question is what would be the threshold where you would organize a DEXA scan? The threshold is above 10%.

SPEAKER_01

So if that Q factor score comes out above 10%, the next step is to organize a DEXA scan.

SPEAKER_00

So my next question for you is what's measured with a DEXA scan?

SPEAKER_01

A DEXA scan measures the bone mineral density or BMD, specifically at the hip and the spine. So it uses X-rays, and based on how much of the radiation is absorbed by the bones, the X-rays used in a DEXA scan can tell you, they can calculate how dense the bones are in these areas, particularly the hip and the uh the spine. So you've got the 65-year-old woman, and you get the results of her DEXA scan. And now she's sat in front of you and she says, What's the results? The T-score at the hip on her DEXA scan is minus 2.6. So the next question I have for you is what do what does the T score and the Z score on a DEXA scan result mean?

SPEAKER_00

What's the definition of a T score and a Z score?

SPEAKER_01

So the T score represents the number of standard deviations that the patient's bone mineral density is from a healthy young adult. So this means you take a healthy young adult and you take their bone density at, say, the hip, then you look at the patient that's in front of you or that's being scanned and you take their bone density and you calculate how far, how many standard deviations below or away from that healthy young adult that the patient's bone density is. So if their T score is minus 2.6, like our patient here, that means their bone density is 2.6 standard deviations below a healthy young adult. The Z score is again standard deviations, but it's standard deviations away from the average for their age, sex, and ethnicity. So they take similar demographic patients and compare the average compare their T-score, their sort of uh their bone mineral density to equivalent demographic patients. That's the Z score. In terms of uh osteoporosis, what's important is the T score. So my next question is, what's the interpretation of the T score?

SPEAKER_00

How like what how do you uh define their diagnosis based on the T score?

SPEAKER_01

A normal T score is above or equal to minus one. So if somebody's minor one standard deviation below the the bone mineral density for a healthy young adult, that's normal. Osteopenia is from minus two point five to minus one. So let's say they're minus two, they would be in the osteopenia category. And then osteoporosis is defined as less than or equal to minus two point five a T-score. My next question is what's the threshold for offering treatment to increase the bone mineral density? You would offer treatment if the T-score is less than or equal to minus 2.5, meaning they're in the osteoporosis category.

SPEAKER_00

Next question is what would be the thirst the first line treatment? So what would you offer them? The first line class of medications for osteoporosis is bisphosphonates.

SPEAKER_01

The next question is what nutritional factors um would contribute and you would need to address these alongside offering bisphosphonates?

SPEAKER_00

So the key things here are vitamin D.

SPEAKER_01

So anyone who's older and particularly people who don't get enough sunshine are at risk of deficiency of vitamin D. So you'd offer them at least 400 international units, which is the equivalent to 10 micrograms daily of vitamin D. You could increase that up to 800 international units if the patient is at increased risk of vitamin D deficiency. For example, they're over 70 or they don't get much sunlight. Plus, they need sufficient calcium. So you'd assess how much calcium they get in their diet, but they need at least a thousand milligrams daily of calcium. So often these patients are prescribed a combined vitamin and calcium, sorry, vitamin D and calcium uh tablet to take alongside their bisphosphonates. Okay, so you got the 65-year-old woman, the T-score at the hip is minus 2.6, and you're starting bisphosphonates.

SPEAKER_00

The next question I have for you is what are the first line choices of bisphosphonate? There are two first line choices of bisphosphonate, both of them are taken orally.

SPEAKER_01

The first is alindronic acid, which is 70 milligrams weekly, so you only take it once a week on the same day each week, or resedronate, which is uh 35 milligrams weekly. Interestingly, all the uh bisphosphonates are licensed for postmenopausal women, but resedrinate is the only one that's licensed for men, although the other ones are, so for example, allangronic acid, they're all commonly used in men, even though they're not technically licensed. The next question is let's say these allandronic acid or resedrinate are not tolerated. What other bisphosphonate options are available if they're not tolerated. One option is oral ibandronic acid, which is a hundred and fifty milligrams monthly, so it's only taken once a month. It's easier to tolerate something once a month than once weekly. Or intravenous zolidronic acid. So if you give an intravenous infusion of solidronic acid, this can be done once yearly. So that's very convenient.

SPEAKER_00

They go in once a year, have the infusion, and then they're they're covered for the whole year.

SPEAKER_01

The next question is what would you advise the patient before starting treatment with bisphosphonates, and why would you advise them to go and do that thing. So you'd advise everyone to go and have a dental checkup, and this is because there's with bisphosmonates, there's rarely a risk of osteonecrosis of the jaw with some death of the bone tissue in the jaw or bad healing in the jaw. And the reason to go and have a dental checkup is obviously to check the dental health, which can be a risk factor if they've got poor dental health, but also if they do need some dental work done, um it's better to get that dental work done before having the bisphosphonate, because if they're on bisphosphonates and they need major dental work, that can affect the healing of the dental work, and there's a higher risk of osteonecrosis of the jaw. Okay, on to the next question, which is what other rare adverse effect can happen with bisphosphonates, which you would warn people about. But this is a rare adverse effect. But the important thing to warn people about is make sure you report any new hip, groin, or thigh pain. And you'd ask people about this to to um determine whether they may have had or may be at risk of an atypical femoral fracture. Okay, so you've got the 65-year-old woman, she's starting bisphosphonates.

SPEAKER_00

What instructions are you gonna give her about how to take oral treatment. With bisphosphonates, there's some very specific instructions on how to take them.

SPEAKER_01

Firstly, take it on an empty stomach, ideally first thing in the morning, and take it while sitting upright or standing upright. So the patient needs to be upright when taking their bisphosphonates. Advise them to take it with at least 200 milliliters of water, so a big glass of water, and take it at least 30 minutes before any food, other medications, or drinks that are not just plain water, as these things can affect the absorption of the bisphosphonate, and then they need to remain upright for at least 30 minutes, so for at least 30 minutes after taking. So they shouldn't get up, take their bisphosphonate, and then go back to bed for 30 minutes. That'll cause some trouble. Next question is what's the reason for this? What's the common side effect with bisphosphonates that kind of prompt you to have all of these um all of this advice about how to take them.

SPEAKER_00

There's really upper gastrointestinal symptoms such as reflux and dyspepsia.

SPEAKER_01

The bisphosphonates are quite irritating to the lower esophagus. So if you're upright, the bisposphonate will stay in the stomach and you shouldn't have too much trouble. But if, for example, you're lying down, there'll be some reflux, and refluxing of the bisphosphonate will cause local irritation to the upper GI tract. Um, so that's a key side effect to warn people about. And this is probably the reason most uh if anybody doesn't tolerate bisphosphonates, this is most often the reason. This tends to be worse in the first month or so of treatment and does tend to improve with time. And it will be that the better you are at taking them, the less likely you are to have these symptoms. So the next question is this patient is now taking their bisphosphonate, they're getting on fine with it. When are you gonna reassess treatment and how are you gonna reassess it? So let's say the patient says, How long am I gonna be taking these bisphosphonates for? And you say, keep taking them, and then we'll reassess at this point.

SPEAKER_00

How are you gonna do that as well? So typically you reassess after five years.

SPEAKER_01

So they'd have five years of treatment and then you reassess them. Unless they're at high risk. For example, they were over age 70 when you started treatment, or let's say they had a fracture during treatment. If they're high risk and they fall into these categories, then you might reassess after 10 years instead. And the way you reassess is to arrange another DEXA scan to see what their bone mineral density is at this point. So let's say you reassess after five years and you do another DEXA scan, and this time the T-score is minus 1.9.

SPEAKER_00

So what's the next step now? What are you gonna do next?

SPEAKER_01

So they've had five years of treatment, now their T-score's minus 1.9. So you're gonna pause treatment uh for the next one and a half to three years and then reassess. So the reason um to pause is if they are now, if they're if their bone mineral density, their T-score is now above minus 2.5. So if they're no longer in the osteoporotic range, then you can stop treatment for a period, 1.5 to 3 years, and then reassess and look at restarting treatment if needed. So I got some random kind of rapid fire questions on specific scenarios around osteoporosis management, some kind of um things that don't that we haven't covered already. So the first one is when would you arrange a DEXA scan without calculating the Q fracture score? In patients who are older than 50 with fragility fractures. So let's say somebody had a hip fracture or they had a fall from just a standing height, not a major fall, and they fractured their wrist. In that case, you don't need to calculate the Q fracture score or do a risk assessment, just go straight to a DEXA scan to see what their bone mineral density is. The next question is when would you start treatment without even considering a DEXA scan? So somebody has this meets these criteria. Um, instead of doing a Q fracture score, instead of doing a DEXA score, you just immediately start bisphosphono treatment.

SPEAKER_00

In patients with vertebral fractures.

SPEAKER_01

So let's say someone just f falls from a standing height, they present with back pain, they have an X-ray, it shows a vertebral fracture. At that point, you would just start bisphosphonates, they don't need a risk assessment or a or a DEXA scan. Next question is what drug might you be prescribing where you would just start treatment with a bisphosphonate before you have the results of a DEXA scan. This applies in patients taking high dose glutic uh high dose glucocorticoids. So, for example, if someone's taking prednisolone, at least sort of 7.5 milligrams per day for more than three months, at that point you can just give them bisphosphonates. And the reason for this is they may not be osteoprotic currently, but if they're on long-term steroids for long enough, that will start to thin the bones and they will become osteoprotic. So you're giving a bisphosphonate to prevent the osteoporosis. And this applies in postmenopausal women and men over the age of 50. Next question is what drug? Uh sorry, next question is what option is there if somebody's uh has a woman has early menopause? So let's say she goes through the menopause at age 42, and because it's an early menopause, there's lower estrogen levels, so you're thinking she's at higher risk of osteoporosis. What option do you have available to prevent osteoporosis in these patients?

SPEAKER_00

The option here is hormone replacement therapy.

SPEAKER_01

So putting some estrogen back into their system will help prevent uh protect their bones and prevent osteoporosis. Using hormone replacement therapy for osteoporosis is recognized as a like a legitimate thing if they're early menopause, but using HRT, say after a normal age of menopause, around 51, is not recognized as using it to prevent osteoporosis, but that is kind of a benefit of it, even if you use it in older patients. So the next question is what if bisphosphonates are not suitable? So they've maybe tried bisphosphonates and not tolerated them, or they're contraindicated for some reason. You refer them to a specialist, what's the usual next option other than bisphosphonates for osteoporosis prevention? There's quite a few options in this scenario, but the main one is donozumab. And this is a monoclonal antibody that targets osteoclasts. So it helps to prevent the breakdown of bones, and so the bone mineral density increases. So thanks for listening to this episode on osteoporosis. Hopefully you found it helpful. And do remember if you can subscribe or subscribe to the podcast or subscribe to the YouTube channel, and I'll see you in the next episode.