BACKGROUND:Osteoarthritis is pathologically characterized by progressive degeneration of the articular cartilage and abnormal deformation of the subchondral bone.In recent years,with the deepening of medical research,it has been found that the mitogen-activated protein kinases(MAPK)signaling pathway has a regulatory role in inflammatory cell infiltration,inflammatory factor release,and chondrocyte proliferation,which is particularly important for the treatment of osteoarthritis.OBJECTIVE:To briefly review the main research progress in the mechanism of MAPK signaling pathway regulating osteoarthritis in recent years,aiming to provide new ideas for the treatment of osteoarthritis.METHODS:CNKI,WanFang and PubMed databases were searched for relevant literature using the search terms of"mitogen-activated protein kinases,osteoarthritis,extracellular signal-regulated MAP kinases,p38 mitogen-activated protein kinases,JNK mitogen-activated protein kinase"in Chinese and English.Relevant literature published from January 2019 to November 2024 was searched,and 108 articles were finally included for summary analysis.RESULTS AND CONCLUSION:(1)Various stimuli inside and outside the cells activate the MAPK signaling pathway,regulate gene transcription and protein synthesis,and promote the release of inflammatory factors,such as tumor necrosis factor-α,interleukin-1β,and interleukin-6.The release of these inflammatory factors aggravates the progression of osteoarthritis.(2)The active ingredients of traditional Chinese medicine,mainly saponins and flavonoids,as well as Chinese herbal formulas and preparations with the main effects of activating blood circulation and removing blood stasis,tonifying the liver and kidney,can play a therapeutic role in osteoarthritis by inhibiting the MAPK signaling pathway,regulating the release of matrix metalloproteinases,balancing the homeostatic state of osteogenesis and osteoblastogenesis,attenuating the synovial inflammation,decreasing the release of inflammatory factors and inflammatory vesicles,decreasing cellular pyroptosis,promoting autophagy,and ameliorating oxidative stress.(3)Although traditional Chinese medicine has become popular in the treatment of osteoarthritis by virtue of its own advantages of multi-components,multi-targets,multi-pathways,and low side effects,the use of MAPK signaling pathway to guide the treatment of individual osteoarthritis is the difficulty of the technology,which needs to be continuously researched and explored.(4)Therefore,further development of relevant herbal inhibitors that can modulate the MAPK signaling pathway may be a potential drug strategy for the treatment of osteoarthritis in the future.

BACKGROUND:Myocardial hypertrophy often leads to severe cardiovascular diseases and is difficult to diagnose due to its early stages being hard to detect.Circulating inflammatory proteins have been found to be significantly associated with cardiovascular diseases,yet the specific mechanisms linking them to myocardial hypertrophy remain unclear.OBJECTIVE:To investigate the relationship between circulating proteins and myocardial hypertrophy using multiple Mendelian randomization approaches.METHODS:Utilizing data from 91 circulating inflammatory proteins in the GWAS Catalog database and the latest myocardial hypertrophy data from the R11 FinnGen database,we employed bidirectional two-sample Mendelian randomization,multivariate Mendelian randomization,and Genome-Wide Association Studies co-localization to investigate the causal relationship between circulating inflammatory proteins and myocardial hypertrophy.The accuracy of the results was verified through sensitivity tests including MR-PRESSO,Cochran's Q test,MR-Egger intercept assessment,leave-one-out analysis,and funnel plot analysis.RESULTS AND CONCLUSION:In the results of two-sample Mendelian randomization,the primary method used for evaluation was the Inverse Variance Weighting(IVW)approach.It was found that the level of T-cell surface glycoprotein CD6 isoform(IVW:P=0.046,OR=0.74,95％Cl:0.66-1.00),level of slit chemokine(IVW:P=2.1×10-2,OR=0.74,95％CI:0.556-0.95),level of Delta and Notch-like epidermal growth factor-related receptor(IVW:P=3.7×10-4,OR=0.66,95％CI:0.49-0.87),level of interleukin-2(IVW:P=3.8×103,OR=0.667,95％CI:0.50-0.88),and sulfotransferase 1A1(IVW:P=1.42×102,OR=0.80,95％CI:0.67-0.96)had a unidirectional causal effect on cardiac hypertrophy.(2)Among the findings in multivariate Mendelian randomization,the levels of the CD6 isoform of T-cell surface glycoprotein(IVW:P=1.39×102,OR=0.81,95％CI:0.69-0.96)and the levels of Delta and Notch-like epidermal growth factor-related receptor(IVW:P=3.7×10-2,OR=0.73,95％CI:0.55-0.98)were positive,indicating that the results remained significant after excluding the effects of other circulating inflammatory proteins that had an impact on myocardial hypertrophy.(3)In colocalization,T-cell surface glycoprotein CD6 isoform levels had H3+H4=0.96,with the most significant single nucleotide polymorphism being rs59570070,suggesting an intrinsic link between T-cell surface glycoprotein CD6 isoform levels and myocardial hypertrophy.(4)Sensitivity results showed no abnormalities,indicating no heterogeneity or pleiotropic effects influencing the results.(5)These results verified that T cell surface glycoprotein CD6 isoforms,Slit chemokine,Delta and Notch-like epidermal growth factor-related receptors,interleukin-2,and sulfotransferase 1A1 had a unidirectional causal effect on myocardial hypertrophy.T cell surface glycoprotein CD6 isoforms and Delta and Notch-like epidermal growth factor-related receptors had the deepest impact,suggesting that there may be related pathways between T cell surface glycoprotein CD6 isoforms and myocardial hypertrophy.Mendelian randomization studies require large amounts of clinical data and therefore often use European samples from international databases for analysis.Since this analytical method has significant advantages in causal inference,precision medicine,and cross-population validation,its research results still hold great significance for the medical development in China.As Mendelian randomization research deepens,it also promotes the collection and analysis of clinical data in China to some extent.In the future,we can further analyze key protein mechanisms,combine multiomics and clinical validation,develop an inflammatory marker monitoring system and novel anti-inflammatory therapies,thereby promoting the prevention and control of cardiovascular diseases and the development of personalized medicine.

BACKGROUND:Sarcopenia is an age-related systemic skeletal muscle disease,which is associated with a variety of adverse outcomes such as falls,functional decline,frailty,and death.Postmenopausal women are one of the high-risk groups for sarcopenia.OBJECTIVE:To develop a predictive model for assessing the risk of sarcopenia in Chinese postmenopausal women based on high-quality database.METHODS:Data for this study were derived from 2 370 postmenopausal women from the China Health and Retirement Longitudinal Study(CHARLS),and sarcopenia was assessed using the Asian Working Group on Sarcopenia 2019(AWGS2019)recommended metrics.The study cohort was randomized into a training set(70％)and a validation set(30％).Risk factors for sarcopenia in postmenopausal women were screened using the least absolute shrinkage and selection operator,ten-fold cross-validation,and logistic regression.Nomogram predicting the risk of sarcopenia in postmenopausal women was constructed based on the risk factors,and the model efficacy was evaluated by the receiver operating characteristic curve and area under the curve(AUC),calibration curve,and decision curve analysis.RESULTS AND CONCLUSION:The prevalence of sarcopenia in this study was 23.50％and age,place of residence,sleep quality,cognitive function,depression,and the number of chronic diseases were selected as predictors of sarcopenia in postmenopausal women.The nomogram model showed good discrimination between the training and validation sets,with an AUC value of 0.751(95％confidence interval=0.724-0.778,P＜0.001),a specificity of 72.2％,and a sensitivity of 63.2％in the training set,and an AUC value of 0.763(95％confidence interval=0.721-0.805,P＜0.001),with a specificity of 69.6％and a sensitivity of 70.8％.The calibration curve showed a relatively significant agreement between the nomogram model and the actual observations,and the decision curve analysis demonstrated broad and good clinical utility.To conclude,the nomogram to assess the risk of sarcopenia constructed based on age,place of residence,sleep quality,cognitive function,depression,and number of chronic diseases,provides an effective tool for identifying and eliminating risk factors for sarcopenia in Chinese postmenopausal women,and helps to reduce the incidence of sarcopenia.

BACKGROUND:Hippocampal injury caused by aortic coarctation has been poorly studied,and combined detection of tumor necrosis factor α,nuclear factor κB and ionized calcium binding adaptor molecule-1 expression in aortic dissection has not been reported.OBJECTIVE:To observe histomorphologic changes in the hippocampus of a mouse model of aortic dissection and investigate the expression and significance of tumor necrosis factor alpha,nuclear factor kappaB and ionized calcium binding adaptor molecule-1 in the hippocampus of aortic dissection mice.METHODS:Sixteen healthy 3-week-old male C57BL/6 mice were randomly divided into two groups:control group and aortic dissection group,with eight mice in each group.In the aortic dissection group,mice were given β-aminopropionitrile monofumarate as drinking water for 4 weeks,and the angiotensin Ⅱ microinfiltration pump was then implanted to establish an animal model of aortic dissection.Mice in the control group were given normal diet and water.After the model was established,the maximum diameter of the ascending aorta was measured,hematoxylin-eosin staining and EVG staining were performed to evaluate the model formation rate,and the levels of inflammatory factors tumor necrosis factor α and interleukin 6 in serum were detected by enzyme-linked immunosorbent assay.The hippocampus was dissected and stained with hematoxylin-eosin to observe the pathological changes of the hippocampus in brain sections.The protein expression of tumor necrosis factor α,nuclear factor κB and ionized calcium binding adaptor molecule-1 was detected by western blot analysis.RESULTS AND CONCLUSION:(1)Compared with the control group,the maximum diameter of the ascending aorta in the aortic dissection group was significantly enlarged.(2)Hematoxylin-eosin staining of the aorta showed obvious thickening of the middle aorta and destruction and disorder of the aortic wall structure in mice.Neurons in the CA1 and CA3 regions of mice were sparsely arranged,reduced in size,and showed pyknosis with deeply stained nuclei.(3)Serum levels of inflammatory factors tumor necrosis factor α and interleukin 6 were increased in the aortic dissection group compared with the control group(P＜0.01).(4)The expression levels of tumor necrosis factor α,nuclear factor κB,phosphorylated nuclear factor κB,and ionized calcium binding adaptor molecule-1 in the hippocampus were increased in the aortic dissection group compared with the control group(P＜0.05).To conclude,microglial activation and increased expression of tumor necrosis factor α and nuclear factor κB may be involved in hippocampal neuron injury in aortic dissection mice.

BACKGROUND:Mitochondrial dysfunction is a key mechanism underlying the pathogenesis and progression of diabetic cystopathy.Recent studies have suggested that drugs targeting mitochondrial metabolism,oxidative stress,and apoptosis pathways can inhibit bladder tissue degeneration,offering novel therapeutic directions for diabetic cystopathy.OBJECTIVE:To explore the association between mitochondrial abnormalities and diabetic cystopathy and to summarize the mechanisms of pharmacological interventions targeting mitochondrial function.METHODS:The key words are"mitochondria,diabetes,diabetic cystopathy,diabetic bladder dysfunction,detrusor,urothelium,neuron,peripheral nerves"in Chinese and English.Relevant literature was retrieved from CNKI,WanFang,PubMed,and Web of Science.Selected articles were systematically screened and analyzed.RESULTS AND CONCLUSION:During the progression of diabetic cystopathy,mitochondria in detrusor muscle,urothelium,and peripheral nerve cells exhibit alterations in characterization,activity,function,and behavior.Under diabetic conditions,mitochondrial damage leads to increased reactive oxygen species production,increased cytochrome C release,reduced Bcl-2/Bax ratio,enhanced nuclear translocation of apoptosis-inducing factors,and activation of the poly(ADP-ribose)polymerase/c-Jun N-terminal kinase/mitochondrial apoptosis pathway.Mitochondria also act as damage-associated molecular patterns to regulate NLRP3,triggering inflammatory responses.Disrupted mitochondrial energy metabolism involves AMP-activated protein kinase/peroxisome proliferator-activated receptor gamma coactivator-1α signaling axis-mediated phenotypic changes,decreased levels of respiratory chain complexes Ⅰ,Ⅱ,andⅣ,impaired oxidative phosphorylation,inhibited tricarboxylic acid cycle,and reduced mitochondrial spare respiratory capacity.Novel therapeutic agents or formulations can ameliorate diabetic cystopathy by alleviating oxidative stress,exerting anti-inflammatory effects,and modulating energy-sensing pathways to restore mitochondrial function.Although mitochondrial roles in other diabetic complications have been extensively studied,research on their involvement in diabetic cystopathy remains insufficient and warrants further exploration.

BACKGROUND:Abutment screw loosening is one of the most common mechanical complications in implant restoration.Mechanical wear,as a potential cause of thread loosening,warrants attention due to its impact on mechanical performance and long-term stability.However,studies on the mechanical effects of thread wear in abutment screws remain limited,and no definitive conclusions have been reached.OBJECTIVE:To investigate the effect of different degrees of mechanical wear on the spatial stress distribution of the Morse taper connection implant system,with a view to providing a theoretical basis for the clinical assessment of the long-term stability of dental implants.METHODS:Three-dimensional finite element models of Morse taper implants with central screw thread wear levels of 0,0.1,1,10,and 100 μm were established using SolidWorks software,and simulation analysis with Ansys Workbench software was performed.The implant models were inserted into artificial bone blocks(simulating type Ⅱ bone,with a cortical bone thickness of 2 mm on the outer layer and cancellous bone inside).An alternating load of 300 N in the buccolingual direction was applied at the centroid of the abutment(forming an angle of 30° with the long axis of the implant).The von Mises stress,principal stress,displacement,and fatigue life of the abutment,central screw,implant,and bone tissue in the five groups of models were analyzed.RESULTS AND CONCLUSION:(1)As the degree of mechanical wear on the central screw thread increased,the von Mises stress,principal stress,and strain in the implant and abutment also increased.The stress in the model was concentrated at the top of the implant,at the shoulder level of the implant,at the neck of the abutment,and at the bottom edge of the abutment.(2)Under moderate wear conditions(≥ 10 μm),the fatigue life of the implant system decreased by 30％,and the maximum von Mises stress of the central screw decreased by 37％,with the stress still primarily concentrated at the transition area between the head and the body of the central screw.(3)Under significant wear conditions(≥ 100 μm),the von Mises stress of the central screw decreased by 98％,with the stress concentrated at the screw head,and the fatigue life of the implant system decreased by 63％.Therefore,when the wear level of the central screw thread reaches ≥ 10 μm,the risk of screw loosening is significantly increased,and the fatigue life of the implant system is markedly reduced,warranting clinical attention.

BACKGROUND:Upper lumbar spinal stenosis is a multifactorial degenerative disorder of the spine.For narrowing of the spinal canal in the upper lumbar region(L1-L4),surgical decision-making is particularly complex.Existing minimally invasive surgeries each have their own advantages and limitations.Currently,there are few reports on biomechanical comparison and finite element analysis of different surgical methods for the treatment of high lumbar spinal stenosis.OBJECTIVE:To analyze the biomechanical impact of endoscopic unilateral laminotomy for bilateral decompression,transforaminal endoscopic lumbar decompression,and cross-overtop decompression in the treatment of upper lumbar spinal stenosis using endoscopy,and to verify the reliability and effectiveness of these three surgical techniques in treating upper lumbar spinal stenosis,providing a biomechanical basis for clinical decision-making.METHODS:The CT images of the lumbar spine of a healthy volunteer were selected,and the finite element model M0 of the normal lumbar L1-L5 segments was established using Mimics,Geomagic,Solid works,and Ansys software.The L2-L3 segment,representing upper lumbar characteristics,was chosen.Based on this model,the surgical models for endoscopic unilateral laminotomy for bilateral decompression(M1),transforaminal endoscopic lumbar decompression(M2),and cross-overtop decompression(M3)were established.Using software,the changes in the range of motion of the entire lumbar segment and the maximum Von Mises stress of the intervertebral discs were simulated and evaluated for each group of models under six loading conditions:flexion,extension,left lateral bending,right lateral bending,left rotation,and right rotation.RESULTS AND CONCLUSION:(1)Compared with model MO,the range of motion in M1,M2,and M3 increased under all six conditions,with M1 showing a greater increase.(2)M1 and M2 demonstrated significant increases in range of motion under forward bending,extension,and right rotation,while the increase under other conditions remained below 7％.(3)Compared with model M3,model M1 exhibited slightly increased overall joint range of motion during extension and left bending,while no significant changes were observed in other aspects,and the L1-L5 lumbar segments did not reach an unstable state.(4)In model M1,the maximum Von Mises stress of the intervertebral discs increased most significantly under flexion and extension loading conditions.However,under left lateral bending,right lateral bending,left rotation,and right rotation loading conditions,the increase did not exceed 5％.(5)These findings suggest that due to the sagittal anatomical characteristics of the facet joints,the unilateral laminotomy for bilateral decompression technique,while decompressing,involves resection of more facet joints,which impacts overall segmental stability.The transforaminal endoscopic lumbar decompression technique is suitable for patients with foraminal stenosis but cannot achieve complete decompression for those with severe ventral central stenosis.The Cross-Overtop technique effectively enlarges the volume of the central canal and lateral recess,optimizing decompression,and shows unique advantages in treating upper lumbar spinal stenosis.

BACKGROUND:The correlation between sacroiliac joint degeneration and lumbar degenerative disease has been analyzed in the literature in the past,but the clinical efficacy and imaging changes after interbody fusion with sacroiliac joint ankylosis in patients with lumbar degenerative disease have not been reported in the literature.OBJECTIVE:To investigate the effect of sacroiliac joint ankylosis on the clinical efficacy and lumbar sagittal regression after L5/S1 single-segment transforminal lumbar interbody fusion in patients with lumbar degenerative disease.METHODS:Thirty-seven patients who underwent L5/S1 segmental transforminal lumbar interbody fusion for lumbar degenerative disease with sacroiliac joint ankylosis between June 2020 and September 2023 in Affiliated Hospital of Xuzhou Medical University were retrospectively analyzed as group A.Thirty-seven patients with lumbar degenerative disease without sacroiliac joint ankylosis who were matched for general information during the same period were selected as controls in group B.Clinical efficacy was assessed using the Oswestry disability index and visual analog scale for lumbar and lower limb pain.The lumbar sagittal parameters included lumbar anterior convexity angle,lumbar partial anterior convexity angle,and lower lumbar anterior convexity angle.Pfirrmann grading was used to assess the degree of preoperative disc degeneration,postoperative endplate damage and screw loosening,and to record the fusion of the operated segments at the final postoperative follow-up visit.RESULTS AND CONCLUSION:(1)There was no statistically significant difference in age,body mass index,bone mineral density,operation time,intraoperative bleeding,preoperative primary diagnosis and postoperative follow-up time between the two groups(P＞0.05).(2)The preoperative Pfirrmann grading of lumbar disc degeneration in group A patients(3.4±0.9)was significantly higher than that of group B(3.1±0.6),and the difference was statistically significant(t=2.059,P=0.044).(3)All patients showed significant improvement in postoperative lumbar sagittal parameters compared with preoperative ones(all P＜0.05).During the follow-up period,there was a loss of correction in patients in group A.There was no statistical difference in the lumbar anterior convexity angle,lower lumbar anterior convexity angle,and local anterior convexity angle at the last follow-up compared with the preoperative period(P＞0.05).The lumbar anterior convexity angle,lower lumbar anterior convexity angle,and local anterior convexity angle in group A were significantly lower than those of group B patients at both preoperative and final follow-up,and the differences were statistically significant(all P＜0.05).(4)There was no statistically significant difference in postoperative endplate injury between the two groups(x2=0.181,P=0.670),and screw loosening was significantly higher in group A than in group B,with a statistically significant difference(x2=4.163,P=0.041).(5)At the last follow-up,the incidence of grade 3 fusion and grade 4 fusion was significantly higher in group A than in group B.The difference in the distribution of fusion grades between the two groups was statistically significant(x2=7.848,P=0.031).(6)The Oswestry disability index and lower limb visual analog scale scores at the last follow-up of both groups were significantly improved compared with the preoperative period(P＜0.05).The visual analog scale scores for low back pain at 3 months after surgery and at the last follow-up of group A were significantly higher than those of group B(t=2.010,P=0.048;t=2.133,P=0.036).(7)It is concluded that regardless of whether it is accompanied by sacroiliac joint ankylosis or not,lumbar degenerative disease patients who undergo interbody fusion with foramen magnum can achieve good therapeutic effects,but lumbar degenerative disease patients with sacroiliac joint ankylosis who undergo interbody fusion with foramen magnum at the L5/S1 segments have a poorer improvement of low back pain than patients without sacroiliac joint ankylosis after the operation.Furthermore,patients with preoperative sacroiliac ankylosis who underwent L5/S1 segmental transforminal lumbar interbody fusion had a low fusion rate and were prone to loss of correction of the lumbar sagittal position.

BACKGROUND:Due to the complex movement of the scapula,which is a six-degree-of-freedom activity in three-dimensional space,it is difficult to measure it accurately using traditional methods.The image and model matching technology based on dual-plane X-ray is a three-dimensional measurement method that has gradually developed and matured in recent years.Two high-speed cameras are used to project and shoot from orthogonal directions.Compared with a single perspective,this method has advantages in observation range and reduction of out-of-plane errors,and is suitable for the study of scapula kinematics.OBJECTIVE:X-ray biplane and image-model registration technology were used to explore the differences in scapular kinematics between normal individuals and patients with rotator cuff tears,providing a basis for the treatment and rehabilitation of rotator cuff tear patients.METHODS:From April 2023 to January 2024,10 patients with normal shoulders and 10 patients with rotator cuff tears who met the inclusion criteria were enrolled from Guanghua Hospital Affiliated to Shanghai University of Traditional Chinese Medicine.The subjects underwent a shoulder CT scan to create a 3D model and a local scapular coordinate system.X-ray biplane images were taken during shoulder abduction with two C-arm machines.The 2D and 3D images were registered to compare scapular kinematic differences between the two groups at 0°,15°,30°,45°,60°,75°,and 90° of abduction,including scapular rotation angle and displacement distance.RESULTS AND CONCLUSION:(1)During shoulder abduction,the scapula of both groups showed upward rotation,but the upward rotation of the rotator cuff tear group was greater than that of the control group,and the difference was significant when the abduction was 30°-90°(P＜0.01).At the same time,the scapula internal rotation of both groups gradually increased,but the rotator cuff tear group was significantly greater than the control group when the abduction was 45°-90°(P＜0.01).In addition,the anteroposterior tilt of the scapula of the two groups was significantly different when the abduction was 15°-90°(P＜0.01).The scapula posterior tilt of the control group gradually increased during abduction,while the scapula of the rotator cuff tear group tilted forward except for a slight posterior tilt at 15°-30° abduction.(2)In terms of displacement,the upward displacement of the rotator cuff tear group was less than that of the control group during abduction,and the difference was significant at 15°-90°(P＜0.05),but there was no significant difference in lateral and anterior-posterior displacement between the two groups(P＞0.05).(3)Rotator cuff tear can cause scapular dyskinesis,characterized by increased upward rotation,internal rotation,and abnormal forward tilt during shoulder abduction.Identifying and addressing scapular dyskinesis is crucial for treating rotator cuff tear.

BACKGROUND:Studies have shown that disorders of mineral metabolism may be responsible for premature aging and that the kl/FGF23 axis plays an important role in mineral metabolism.OBJECTIVE:To explore the effect of long-term endurance exercise on the kl/FGF23 axis in naturally aging mice,and to observe the impact of long-term endurance exercise on calcium and phosphorus metabolism,so as to provide a reference for the influence of long-term endurance exercise on natural aging.METHODS:Twenty-two 5-week-old SPF male balb/c mice were randomly divided into three groups:young and quiet control group,natural aging quiet group and natural aging exercise group.Mice in the young and quiet control group were then killed immediately.Mice in the natural aging quiet group were raised normally until 60 weeks of age.Mice in the natural aging exercise group were subjected to adaptive exercise for 1 week,followed by the maximum running speed test.The official exercise speed was set at 70％of the maximum running speed,and exercise was performed on Mondays,Wednesdays,and Fridays for 50 minutes each.Maximum running speed was retested at 8-week intervals to adjust the official exercise speed until the age of 60 weeks.(3)Enzyme-linked immunoassay was used to measure the levels of femoral fibroblast growth factor 23,renal fibroblast growth factor receptor 1,1α-hydroxylase,and serum 1,25(OH)2D3.RESULTS AND CONCLUSION:(1)Compared with the young and quiet control group,serum calcium and phosphorus levels in natural aging quiet group had no significant changes(P＞0.05),but bone calcium and phosphorus levels were significantly reduced(P＜0.01).Compared with the natural aging quiet group,the serum phosphorus level was significantly reduced(P＜0.05),the serum calcium level did not change(P＞0.05),and bone calcium and phosphorus levels were significantly increased in the natural aging exercise group(P＜0.05).(2)Compared with the young and quiet control group,the level of fibroblast growth factor 23 in the femur of the natural aging quiet group was significantly increased(P＜0.05).Compared with the natural aging quiet group,the level of fibroblast growth factor 23 in the femur of the natural aging exercise group was reduced,but it was not statistically significant(P＞0.05).(3)Compared with the young and quiet control group,the renal Klotho protein expression,the renal fibroblast growth factor receptor 1,1α-hydroxylase,and serum 1,25(OH)2 D3 levels in the natural aging quiet group were significantly decreased(P＜0.05,P＜0.01).Compared with the natural aging quiet group,the levels of the above-mentioned indicators were significantly increased in the natural aging exercise group(P＜0.05,P＜0.01).To conclude,long-term endurance exercise can regulate Klotho protein and fibroblast growth factor 23 through the kl/FGF23 axis,thereby affecting the expression of 1α-hydroxylase and the level of 1,25(OH)2D3,and further regulating the body's calcium and phosphorus metabolism,especially phosphate metabolism.This indicates that long-term endurance exercise can delay the natural aging of the body through the kl/FGF23 axis.