What Your DEXA Scan Numbers Actually Mean | Dr Vonda Wright | #169

**Dr. Vonda Wright** (0:00)
How to understand your DEXA scan. Hey, everybody, I'm Dr. Vonda Wright. I'm your orthopedic surgeon and founder of Skeletal Longevity. I order DEXA scans on everybody. And why is that? It's because bone health is a life-long interest. It's not just something that we need to be concerned about when we get old. We need to be concerned about it today. Did you know that we peak out on our bone density at 30? And then when we're in our 40s and when estrogen walks out the door, you can lose up to 20% of your bone density in your perimenopause as you approach menopause. If we wait until we're 65, which is when insurance will pay for your DEXA scan, you've already lost your bone density. Let's not let that happen.
How to understand your DEXA scan. Hi, everybody. I'm Dr. Vonda Wright. I'm your orthopedic surgeon and founder of skeletal longevity. And I order DEXA scans on everybody. And why is that? It's because bone health is a life-long interest. It's not just something that we need to be concerned about when we get old. We need to be concerned about it today, because did you know that we peak out on our bone density at 30? And then when we're in our 40s, we have the cataclysmic changes that happen when estrogen walks out the door. And you can lose up to 20% of your bone density in your perimenopause as you approach menopause. And so, in my opinion, as an orthopedic surgeon, finding out after the fact that you have a low bone density is too late. Here's why. We know that it can take up to 10 years to truly impact your fracture risk, so we need to get on it early. So when do we do DEXA scans? Well, remember, at 30 we reach peak bone density.
At 40 to about 52, on average, we are impairing menopause and menopause, and that's when we're gonna lose 20% of our bone density. Let's not let that happen. If we wait until we're 65, which is when insurance will pay for your DEXA scan, you've already lost your bone density and it's harder to get in front of it. So what are we gonna do? Number one, we're getting a DEXA scan. And I wanna show you what your numbers mean. If you were coming to my office, I'm a teaching surgeon, meaning I will sit with you and I will likely draw out something that looks just like this that you can take home. So how do we read a DEXA scan? Well, a DEXA scan is read as if we were taking a test. Remember in school when we had this bell curve that we were graded against? And right up the middle is the average. Well, when it comes to DEXA scans, this average or zero is the bone density of a 30-year-old healthy woman, right? We're comparing most of our DEXA scan numbers to healthy 30-year-old women. When we read this, we have the following numbers. We have bone mineral density. You're given T scores. You're given Z scores. And you're given trabecular bone score. Now, most of us focus on T scores. The other numbers are important, but it's the T score, once you're over 30, that helps us predict your fracture risk. So just to go over these numbers, you may have your results in hand. Bone mineral density normal is around one gram per centimeter squared. Trabecular bone score is around one to 1.3, is considered healthy and normal. But what about T score and Z score? The Z score that you get compares your bone density to that of an age matched woman. So my Z scores, which I'm going to show you, compare me to other women who are my age and what their bone density is. So this is age matched.
A T score, which is the most important score we commonly use, compares your current bone density to that of a healthy 30-year-old. So this compares you to the 30-year-old. On this graph, that is zero. So when you get your T scores, any positive number is amazing. It means that you have a bone density in that body part better than a healthy 30-year-old who has reached peak bone density, right? So if your T scores are any positive number, amazing.
When we get our scores and we get a number that's around negative one, negative one is the number that diagnoses osteopenia.
Osteo meaning bone, penia meaning low.
Osteopenia is reversible.
The next score you might see is a bone density that is lower than minus 2.5.
Minus 2.5 is the definition of osteoporosis, which is osteoporosis, which means bones that are full of holes. Porous means holes, bones. And why do we get osteoporosis? I'm going to take two seconds to talk to you about the biology before I show you my scores. Remember, bone is constantly remodeling, meaning we're using bone because it is the storehouse of all the minerals in our body. We're using bone and we're replacing bone. The osteoclasts resorb bone by creating these little acidic pockets that release all the minerals your body needs. Coming behind the osteoclasts are the osteoblasts, which build the bone. They gotta fill those potholes. And prior to menopause, these two systems are about equal. But estrogen is critical for controlling the osteoclast, meaning keeping it in balance. Without estrogen, when estrogen starts walking out the door in perimenopause and menopause, this balance becomes unbalanced. And we're breaking down bone faster than we are building it. Now, that is not to say that we can't continue to build bone, which I talk about all the time. And in fact, I have a video called 10 Ways to Build Better Bone. And so I hope you go watch that. But the first step is knowing what your bones are doing now. And thus, we're doing this video. So to do it again, we're going to be talking about T-scores, which tells you your bone density compared to the bone density of a healthy 30-year-old. And we've chosen that, the researchers have chosen that because that is your time of peak bone density. Any positive T-score is great, because it tells you your bone density is better than an average 30-year-old. Any bone density down to minus one tells you, okay, you're still normal, minus one is the diagnosis of osteopenia, the beginning of low bone density. A number that's lower than minus 2.5, that's the definition of osteoporosis, which significantly increase fracture risk. One in two women in this country will have an osteoporotic fracture. So, I'm going to actually use my data as an example. And if you come into my office, and I do a DEXA scan on you, which I do on almost everybody, I will sit down and draw this out for you. You know what, the truth is, every single day, I give a lot of thought to my skin. And I want to talk about something today that I think a lot of you listening have thought about, but maybe haven't connected to the same science we talk about when it comes to bones, muscle and longevity.