In addition to bone density, this monitoring indicator of osteoporosis treatment cannot be ignored!

*Read only for medical professionals Keeping low levels of bone turnover markers helps delay bone loss in elderly patients with osteoporosis
.

Like other diseases, the treatment of senile osteoporosis also has a process of gradual improvement and continuous improvement
.

In the 20th century, people knew little about osteoporosis, and treatment was often done after fractures.
After entering the 21st century, people gradually realized that osteoporosis should be treated as early as possible to reduce the occurrence of fractures
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In recent years, the medical community has paid increasing attention to the use of changes in bone turnover markers to guide the treatment of osteoporosis, and satisfactory results have been achieved
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A Bone Turnover Marker "Past and Present" Bone turnover markers are the products of bone tissue in the process of its metabolism, and can be divided into bone formation markers and bone resorption markers according to their different sources
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Type I procollagen amino-terminal propeptide (P1NP) and type I collagen carboxy-terminal peptide cross-linking (CTX) are two commonly used clinical markers of bone turnover.
They are both related to the metabolism of type I collagen.
The product of the synthesis of type I collagen by osteocytes is a marker of bone formation, while the latter is the product of the breakdown of type I collagen by osteoclasts and is a marker of bone resorption
.

In clinical practice, some physicians often believe that in patients with osteoporosis, the changing trends of bone formation markers (such as P1NP) and bone resorption markers (such as CTX) should be opposite, that is, bone resorption markers should be elevated, while bone resorption markers should be elevated.
The idea that the formation markers should go down is wrong
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This is because the resorption and formation of bone is a dynamic coupling process, and the acceleration of bone resorption must be accompanied by the acceleration of bone formation
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Therefore, the changes of different bone turnover markers in elderly patients with osteoporosis are often consistent, either increased or normal
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The study found that older adults with higher markers of bone turnover had lower bone density in the hip and lumbar spine, and the faster the increase in bone turnover markers, the faster the decline in bone density in the hip and lumbar spine
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Maintaining low levels of bone turnover markers can help delay bone loss in elderly patients with osteoporosis
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However, it should be pointed out that the level of bone turnover markers can only reflect the speed of bone loss and cannot be used as the basis for the diagnosis of osteoporosis
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The diagnosis of osteoporosis still relies on a history of fragility fractures and bone mineral density measured by dual-energy X-ray absorptiometry (DXA)
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Discussion on the cut-off point of high and low turnover In the clinical application of bone turnover markers, the concepts of "high turnover" and "low turnover" are often encountered.
What is the reference value range of bone turnover markers for elderly women? , where is the demarcation point of high and low conversion? At present, it is generally recommended to refer to the bone turnover marker levels of premenopausal healthy women aged 30 to 44 years to formulate the reference value range for elderly women in this region, so the reference value range may vary slightly in different regions
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Foreign data show that the reference values ​​of serum CTX and P1NP range from 0.
10 to 0.
65 μg/L and 17.
1 to 64.
7 μg/L, respectively
.

In view of the changing trend and clinical value of serum CTX and P1NP, serum CTX levels are generally preferred for preliminary judgment
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With reference to domestic and foreign literatures, it is advisable to take half of the upper limit of the reference range of serum CTX as the cut-off point for high and low conversion
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If the serum CTX is lower than half of the upper limit of the reference value range, it is low conversion, otherwise it is high conversion
.

The serum CTX level of elderly patients with osteoporosis generally does not exceed 1.
5 times the upper limit of the reference value.
If it exceeds 1.
5 times, it is necessary to exclude diseases such as hyperparathyroidism, multiple myeloma, and osteomalacia
.

We investigated 100 elderly women with osteoporosis (mean age 81 years) who had not received anti-osteoporosis drugs such as bisphosphonates, and found that serum CTX was less than the reference range ( In our hospital, there are 24 cases with half the upper limit (0.
34μg/L) of 0.
07～0.
68μg/L (low conversion), 53 cases with 0.
34≤CTX<0.
68μg/L, 0.
68≤CTX<1.
02 (the upper limit of the reference value) 1.
5 times) μg/L in 20 cases, and CTX≥1.
02 μg/L in only 3 cases
.

3.
Treatment plans based on bone turnover markers Generally speaking, elderly women with osteoporosis with low turnover (about 1/4) do not need to accept anti-bone resorption drugs such as bisphosphonates for the time being, and only need to take sun exposure , drinking milk, calcium supplements and non-drug treatment measures such as preventing falls
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Because anti-bone resorption drugs can further reduce the level of bone turnover markers, long-term use of drugs to inhibit the level of bone turnover does not help the metabolism of bones, but it is not good for bone health
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Elderly osteoporosis patients with high conversion should receive anti-bone resorption drugs such as bisphosphonates as soon as possible, and patients with higher serum CTX levels (indicating faster bone loss) need to be treated as soon as possible
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Early use of anti-resorptive drugs can rapidly reduce the level of bone turnover in patients and delay bone loss
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Bisphosphonates, such as alendronate sodium administered orally once a week and zoledronic acid administered intravenously once a year, are currently the two most commonly used anti-bone resorption drugs in China.
no more than 3 to 5 years
.

After receiving bisphosphonates, attention should be paid to regular monitoring of bone turnover markers
.

If the bone turnover markers are still at high turnover levels, it often indicates that the patient is not in compliance with treatment (ie, does not adhere to treatment).
At this time, the patient should be urged to continue treatment or adjust the treatment plan
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For patients with poor compliance with oral alendronate sodium, zoledronic acid needles that only need to be infused once a year can be switched to
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If the patient's bone turnover marker level is at a low turnover level, it indicates that the patient's treatment compliance is high, and a drug holiday should be considered
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During the drug holiday, bone turnover markers are generally reviewed every 3 to 6 months, and bone mineral density is reviewed every 12 months, and the next treatment plan is determined according to the changes in bone turnover markers and bone mineral density
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