Ten-Year Incidence of Sarcopenia in a Population-Based Cohort: Results from the Research on Osteoarthritis/Osteoporosis Against Disability Study

OBJECTIVES

To investigate the prevalence and incidence rates of sarcopenia in Japanese community-dwelling people according to the criteria of the Asian Working Group for Sarcopenia 2019 recommendations, using a large-scale population-based cohort over a 10-year follow-up period.

DESIGN

Prospective cohort study.

SETTING AND PARTICIPANTS

This study was conducted using data from the Research on Osteoarthritis/Osteoporosis Against Disability (ROAD) study. In total, 1551 participants (521 men and 1030 women; mean age, 65.8 years) from the second ROAD survey (2008-2-10) were included in this study.

METHODS

The participants from the second survey were followed-up at 4, 7, and 10 years. Skeletal muscle mass, handgrip strength, and walking speed were assessed. Sarcopenia was defined according to the Asian Working Group for Sarcopenia 2019 criteria. The incidence of sarcopenia was calculated using the person-year method. Cox proportional hazard model was used to assess risk factors for incident sarcopenia.

RESULTS

The prevalence of sarcopenia was 8.1% (8.8% in men and 7.7% in women), and the prevalence of severe sarcopenia was 2.9% (2.7% in men and 3.1% in women). The incidence rates of sarcopenia were 17.8 per 1000 and 14.5 per 1000 person-years in men and women, respectively. Additionally, the incidence rates of severe sarcopenia were 6.4 per 1000 and 4.2 per 1000 person-years in men and women, respectively. The significant risk factors for the incidence of sarcopenia were age [+1 year; hazard ratio (HR), 1.10; 95% CI, 1.08-1.12] and body mass index (-1 kg/m2; HR, 1.27; 95% CI, 1.20-1.35). The significant risk factors for the incidence of severe sarcopenia were age (+1 year; HR, 1.18; 95% CI, 1.14-1.22) and body mass index (-1 kg/m2; HR, 1.21; 95% CI, 1.10-1.33).

CONCLUSIONS AND IMPLICATIONS

The prevalence and incidence rates of sarcopenia in Japan were clarified in this study.

A longitudinal population-based study identifies THBS2 as a susceptibility gene for intervertebral disc degeneration

PURPOSE

Intervertebral disc degeneration (IDD) is a common degenerative disease associated with ageing. Additionally, IDD is recognized as one of the leading causes of low back pain and disability in the working-age population and is the first step in the process leading to degenerative spinal changes. However, the genetic factors and regulatory mechanisms of IDD remain unknown. Therefore, we selected eight single nucleotide polymorphisms of genes to reveal the progression of IDD in a 7-year longitudinal study of the general population in Japan.

METHODS

IDD was evaluated in the Wakayama Spine Study (WSS), which is a population-based cohort study. Overall, 574 participants from the general population cohort who underwent whole spine magnetic resonance imaging and provided clinical information were included in this longitudinal survey.

RESULTS

The progression of IDD was affected only by THBS2 at the lumbar region, T12-L1 (p = 0.0044) and L3-4 (p = 0.0045). The significant interaction between THBS2 and age with IDD negatively affected the thoracic spines and passively influenced both the thoracolumbar junction and thoracic spines. The higher progression per year of Pfirrmann's score was rapid in young people with age; however, this decelerated the IDD progression per year in different ages.

CONCLUSION

Our longitudinal study found the genes associated with IDD progression and that genetic factors' impact on IDD differs depending on disc level and age.

Real-world effects, safety, and predictors of the effectiveness of romosozumab in primary and secondary osteoporosis: An observational study

Romosozumab is an anti-sclerostin antibody that increases bone formation and decreases bone resorption. It became available for patients at high risk of osteoporotic fractures in Japan in 2019. The aim of this study was to clarify the clinical effects, safety, and predictors of the effectiveness of 12 months of romosozumab therapy. The study had an observational pre-post design and included 460 patients. Romosozumab was administered at a dose of 210 mg subcutaneously every 4 weeks for 12 months. The incidence of new fractures, safety, and changes in bone mineral density (BMD) and bone turnover markers were recorded. New fractures occurred in 11 cases (3.0 %). Nine patients (2.0 %) experienced cardiovascular events, which were fatal in 3 (0.65 %). Percent changes in BMD at the spine and total hip at 12 months from baseline were +7.7 % and +1.8 %, respectively. Romosozumab had better effects in patients with good renal function, low spine BMD, and high TRACP-5b at baseline and low TRACP-5b or high P1NP after 1 month of treatment. The percent change in spine BMD at 12 months was significantly lower in patients transitioning from denosumab than in those not previously treated with other anti-osteoporosis agents. Romosozumab is considered to be relatively safe in patients with primary osteoporosis compared to those with secondary osteoporosis. Romosozumab resulted in larger increases in spine BMD in patients with primary osteoporosis who were not previously treated with other anti-osteoporosis therapies and those with low spine BMD at the start of treatment.

Impact of lumbar spine pathology on asymmetrical hallux valgus in a population-based cohort study

This study aims to investigate the influence of lumbar spine disorders on the development of asymmetric hallux valgus (HV). Data from the fifth survey of the Osteoarthritis/Osteoporosis Against Disability (ROAD) study, a nationwide prospective study in Japan, were analyzed. HV severity was categorized into 4 grades based on the radiographic HV angle, and asymmetric HV was defined as having at least one HV on either side, with a difference of two or more severity grades between the left and right. Controls were matched from both the Normal group (without HV on both sides) and the Symmetric group (HV on at least one side with a difference of one or less severity grades). Univariate analysis assessed lumbar conditions, and multinomial logistic regression analysis explored the association between lumbar spine disorders and asymmetric HV. Among 1997 participants, 27 had asymmetric HV. Univariate analysis revealed a higher incidence of L5 spondylolisthesis and scoliosis in the Asymmetric group. Multinomial logistic regression analysis revealed that scoliosis independently increased the likelihood of asymmetrical HV (Odds ratio [OR] = 3.586, 95%Confidence interval [CI] 1.111-11.582), but showed no significant impact on symmetrical HV (OR 0.910, 95% CI 0.355-2.334). Asymmetric HV is rare but may be associated with lumbar spine disorders, particularly scoliosis.

Identifying factors associated with locomotive syndrome using machine learning methods: The third survey of the research on osteoarthritis/osteoporosis against disability study

AIM

To identify factors associated with locomotive syndrome (LS) using medical questionnaire data and machine learning.

METHODS

A total of 1575 participants underwent the LS risk tests from the third survey of the research on osteoarthritis/osteoporosis against disability study (ROAD) study. LS was defined as stage 1 or higher based on clinical decision limits of the Japanese Orthopaedic Association. A total of 1335 items of medical questionnaire data came from this study. The number of medical questionnaire items was reduced from 1335 to 331 in data cleaning. From the 331 items, identify factors associated with LS use by light gradient boosting machine-based recursive feature elimination with cross-validation. The performance of each set was evaluated using an average of seven performance metrics, including 95% confidence intervals, using a bootstrapping method. The smallest set of items is determined with the highest average of receiver operating characteristic area under the curve (ROC-AUC) under 20 items as association factors of LS. Additionally, the performance of the selected items was compared with the LS risk tests and Loco-check.

RESULTS

The nine items have the best average ROC-AUC under 20 items. The nine items show an average ROC-AUC of 0.858 (95% confidence interval 0.816-0.898). Age and back pain during walking were strongly associated with the prevalence of LS. The ROC-AUC of nine items is higher than that of existing questionnaire-based LS assessments, including the 25-question Geriatric Locomotor Scale and Loco-check.

CONCLUSIONS

The identified nine items could aid early LS detection, enhancing understanding and prevention. Geriatr Gerontol Int 2024; 24: 806-813.

Osteoporosis, spinal degenerative disorders, and their association with low back pain, activities of daily living, and physical performance in a general population

Osteoporosis, vertebral fractures, and spinal degenerative diseases are common conditions that often coexist in older adults. This study aimed to determine the factors influencing low back pain and its impact on activities of daily living (ADL) and physical performance in older individuals with multiple comorbidities. This cross-sectional study was part of a large-scale population-based cohort study in Japan, involving 1009 participants who underwent spinal magnetic resonance imaging (MRI) to assess cervical cord compression, radiographic lumbar spinal stenosis, and lumbar disc degeneration. Vertebral fractures in the thoracolumbar spine were evaluated using sagittal MRI with a semi-quantitative method. Bone mineral density was measured using dual-energy X-ray absorptiometry. Low back pain, Oswestry Disability Index (ODI), and physical performance tests, such as one-leg standing time, five times chair-stand time, maximum walking speed, and maximum step length, were assessed. Using clinical conditions as objective variables and image evaluation parameters as explanatory variables, multiple regression analysis showed that vertebral fractures were significantly associated with low back pain and ODI. Vertebral fractures and osteoporosis significantly impacted physical performance, whereas osteoporosis alone did not affect low back pain or ODI. Our findings contribute to new insights into low back pain and its impact on ADL and physical performance.

Ten-year trends in values of joint space width and osteophyte area of knee joints: Comparison of the baseline and fourth ROAD study surveys

Objective

Considering the joint space width and osteophyte area (OPA) of the knee joints of Japanese adults, this study elucidated the ten-year trends in medial minimum joint space width (mJSW) and OPA using data of two independent cohorts from a population-based cohort study.

Methods

The baseline survey of the Research on Osteoarthritis/Osteoporosis Against Disability study was conducted from 2005 to 2007; 2975 participants (1041 men, 1934 women) completed all knee osteoarthritis (OA) examinations. The fourth survey was performed from 2015 to 2016; distinct 2445 participants (764 men, 1681 women) completed identical examinations. The medial mJSW and medial tibial OPA were measured bilaterally using an automated system.

Results

The mean medial mJSW (standard deviation) was 3.22 (0.96) mm and 2.65 (0.95) mm at baseline and 3.81 (1.20) mm and 3.13 (1.15) mm in the fourth survey for men and women, respectively. The mean medial mJSW in the fourth survey was significantly greater in both men and women in all age groups than at baseline (p ​< ​0.01). The mean OPAs in men aged 40-49 and 60-69 years and women aged 40-49, 50-59, 60-69, and 70-79 years were significantly smaller in the fourth survey (p ​< ​0.05). The trend in mJSW remained the same even after adjusting for confounding factors in the multivariate analysis, but the trend in OPA was weakened.

Conclusions

A significant improvement in the medial mJSW within 10 years could decrease the incidence and progression of knee OA and prevent the risk of walking disability.

Unicompartmental Knee Arthroplasty for Osteoarthritis Eliminates Lateral Thrust: Associations between Lateral Thrust Detected by Inertial Measurement Units and Clinical Outcomes

The purpose of this study was to investigate the relationship between clinical outcomes and lateral thrust before and after unicompartmental knee arthroplasty (UKA) using inertial measurement sensor units. Eleven knees were evaluated with gait analysis. The varus angular velocity was used to evaluate lateral thrust. The femorotibial angle (FTA) and hip-knee-ankle angle (HKA) were used to evaluate lower-limb alignment, and the Oxford Knee Score (OKS) and Japanese Orthopaedic Association Score (JOA) were used to evaluate clinical outcomes. The mean pre-UKA peak varus velocity was 37.1 ± 9.8°/s, and that for post-UKA was 28.8 ± 9.1°/s (p = 0.00003), such that instabilities clearly improved. Assuming the definition of lateral thrust is when the varus angular velocity is more than 28.1°/s, 81.8% of patients had lateral thrust preoperatively, but this decreased to 55.6% postoperatively, such that the symptoms and objective findings improved. Both OKS and JOA improved after surgery. In addition, HKA was -7.9° preoperatively and -5.8° postoperatively (p = 0.024), and FTA was 181.4° preoperatively and 178.4° postoperatively (p = 0.012). There was a positive correlation between postoperative JOA and FTA, indicating that changes in postoperative alignment affected clinical outcomes. This study quantitatively evaluated the disappearance of lateral thrust by UKA, and it found that the stability can be achieved by UKA for unstable knees with lateral thrust.

Factors associated with cam deformity in Japanese local residents

Femoroacetabular impingement has increasingly been recognized as a cause of primary hip osteoarthritis; however, its epidemiological indications remain unclear. We aimed to clarify the epidemiological indications and factors associated with cam deformity in a large-scale population-based cohort in Japan. Overall, 1480 participants (2960 hips) (491 men, 989 women; mean age, 65.3 years) analyzed in the third survey of the Research on Osteoarthritis/Osteoporosis Against Disability study were included. The α angle and spinopelvic parameters (lumbar lordosis, sacral slope, pelvic tilt, and pelvic incidence) were radiographically measured. Cam deformity was defined as α angle ≥ 60°. Overall, the cam deformity prevalence was 147/2960 (5.0%). Cam deformity prevalence tended to increase with age; in the univariate analysis, a higher percentage of men was observed in the group with cam deformity than in the group without it. No relationship was observed between cam deformity and hip pain. Factors associated with α angle were examined via multiple regression analysis for each gender; α angle was significantly associated with age and BMI in each gender. The α angle and PT were correlated in women. Thus, α angle and cam deformity prevalence increase with age in Japanese individuals. Accordingly, cam deformity can be considered a developmental disease.

Plasma pentosidine concentration is associated with ligament ossification and high-grade osteoarthritis: The ROAD study

AIM

No studies have examined the association between plasma pentosidine levels and ossification diseases in large cohorts of Japanese residents. This study aimed to investigate the association between cervical ossification of the posterior longitudinal ligament (OPLL) and other ossification diseases, including diffuse idiopathic skeletal hyperostosis, lumbar spondylosis and knee osteoarthritis (OA), by examining plain radiographs of the knee, and cervical, thoracic and lumbar spine from 1690 participants, and the association between these diseases and plasma pentosidine.

DESIGN

We enrolled 1690 participants (596 men and 1094 women) from mountainous and coastal areas from the study population of the previous Research on Osteoarthritis/Osteoporosis Against Disability study. X-ray examination of the cervical/thoracic/lumbar spine and knee was carried out only in these individuals, and not those from urban areas. Plasma pentosidine concentrations were determined using enzyme-linked immunoassays.

RESULTS

Radiographic OPLL was detected in 30 (17 men, 13 women) of 1562 individuals who underwent X-ray examination of the cervical spine. OPLL, diffuse idiopathic skeletal hyperostosis, lumbar spondylosis Kellgren-Lawrence (KL) grade, and knee OA KL grade were associated with high plasma pentosidine concentrations (all P < 0.05). Furthermore, significant intragroup differences (KL grade 4 vs 3) of plasma pentosidine concentration were observed between the lumbar spondylosis and knee OA groups. The plasma pentosidine concentration was significantly associated with age, OPLL, lumbar spondylosis (KL grade 4) and knee OA (KL grade 4).

CONCLUSIONS

OPLL is significantly associated with other ossification diseases. The development of more severe OA might lead to the accumulation of plasma pentosidine. Plasma pentosidine levels were associated with OPLL and severe OA. Geriatr Gerontol Int 2024; 24: 154-160.

Prevalence and distribution of Schmorl node and endplate signal change, and correlation with disc degeneration in a population-based cohort: the Wakayama Spine Study

PURPOSE

Degenerative spinal conditions, including disc degeneration (DD), Schmorl nodes (SN), and endplate signal changes (ESC), are pervasive age-associated phenomena that critically affect spinal health. Despite their prevalence, a comprehensive exploration of their distribution and correlations is lacking. This study examined the prevalence, distribution, and correlation of DD, SN, and ESC across the entire spine in a population-based cohort.

METHODS

The Wakayama Spine Study included 975 participants (324 men, mean age 67.2 years; 651 women, mean age 66.0 years). Magnetic resonance imaging (MRI) was used to evaluate the intervertebral space from C2/3 to L5/S1. DD was classified using Pfirrmann's system, ESC was identified by diffuse high-intensity signal changes on the endplates, and SN was defined as a herniation pit with a hypointense signal. We assessed the prevalence and distribution of SN, ESC, and DD across the entire spine. The correlations among these factors were examined.

RESULTS

Prevalence of ≥ 1 SN over the entire spine was 71% in men and 77% in women, while prevalence of ≥ 1 ESC was 57.9% in men and 56.3% in women. The prevalence of ESC and SN in the thoracic region was the highest among the three regions in both sexes. Positive linear correlations were observed between the number of SN and DD (r = 0.41, p < 0.001) and the number of ESC and DD (r = 0.40, p < 0.001), but weak correlations were found between the number of SN and ESC (r = 0.29, p < 0.001).

CONCLUSION

The prevalence and distribution of SN and ESC over the entire spine were observed, and correlations between SN, ESC, and DD were established. This population-based cohort study provides a comprehensive analysis of these factors.

Relationship between medial partite hallux sesamoid and hallux valgus in the general population

BACKGROUND

An association between the medial partite hallux sesamoid (MPHS) and hallux valgus (HV) has been suggested; however, a causal relationship has not been confirmed. This study aimed to determine their causal relationship using a cross-sectional radiographic survey of a large-scale population cohort covering a wide age group.

PATIENTS AND METHODS

The fifth survey of the Research on Osteoarthritis/Osteoporosis against Disability study involved 1997 participants aged 21-95 years who had undergone anteroposterior radiography of bilateral feet. The presence of MPHS, its morphology, and radiographic parameters related to the HV were assessed using radiographs. Changes in the prevalence of MPHS with age were assessed using trend tests. The relationship between the MPHS and HV was assessed based on sex and age.

RESULTS

MPHS was found in 508 out of 3994 feet (12.7 %), with a significant difference in prevalence between men and women (10.0 % vs. 13.7 %, p < 0.001). Trend analysis demonstrated a significant decrease in MPHS occurrence with age in both sexes. HV angle was significantly higher in feet with MPHS than in those without (Men: 17.8 ± 7.0° vs. 14.0 ± 5.9°, p < 0.0001; Women: 19.6 ± 7.7° vs. 17.7 ± 7.9°, p < 0.0001). The prevalence of HV angle ≥ 20° was also significantly higher in feet with MPHS than in those without (Men: 33.3 % vs. 14.6 %, p < 0.0001; Women: 46.5 % vs. 34.6 %, p < 0.0001). This association between MPHS and HV was noticeable in younger adults and became less prominent with age.

CONCLUSIONS

MPHS is associated with HV. The weakening of this relationship and the decreased prevalence of MPHS with age suggest that MPHS is not caused by HV, but is one of the causes of HV, especially in younger adults.

Do lifestyle, anthropometric and demographic factors associated with muscle strength differ in a UK and Japanese cohort? An exploratory analysis

BACKGROUND

Muscle weakness is associated with adverse clinical outcomes including disability and mortality. We report demographic, anthropometric and lifestyle correlates of grip strength in UK and Japanese population-based cohorts.

AIM

To report prevalence of low grip strength according to 2019 European Working Group on Sarcopenia in Older People (EWGSOP2) and 2019 Asian Working Group for Sarcopenia (AWGS 2019) thresholds and to consider correlates of grip strength in Eastern and Western populations.

METHODS

UK (1572 men; 1415 women) and Japanese (519 men; 1027 women) participants were recruited from two cohorts harmonised by consensus. Muscle strength was measured by grip strength dynamometry. Potential correlates of grip strength were examined using sex-stratified linear regression; univariate correlates (p < 0.05) were included in mutually adjusted models.

RESULTS

Mean (SD) age was 66.2 (2.8) and 65.8 (12.3) in UK and Japanese cohorts, respectively. Prevalence of low grip strength was higher in Japanese participants (EWGSOP2 5.4% versus 2.4%, AWGS 2019 9.0% versus 3.7%). In both cohorts and sexes, univariate correlates of lower grip strength were older age, shorter height, not consuming alcohol, leaving education earlier and greater comorbidity. Apart from older age and shorter height, the only factors related to lower grip strength in mutually adjusted analyses were greater comorbidity among UK participants (kg difference in grip strength (95%CI) per additional comorbidity - 0.60(- 0.98, - 0.21) among men and - 0.50(- 0.86, - 0.13) among women) and not consuming alcohol among Japanese men (- 1.33(- 2.51, - 0.15)).

DISCUSSION

Correlates of muscle strength were similar in both cohorts.

CONCLUSIONS

A global approach to age-related muscle weakness prevention may be appropriate.

Excessive salt intake reduces bone density in the general female population

BACKGROUND

Osteoporosis is a multifactorial disorder in which nutrition is associated with its onset and progression. Excessive salt intake is closely associated with the onset and progression of various diseases, such as osteoporosis and hypertension. We investigated the effects of dietary salt intake on bone density in the general female population.

METHODS

In 884 female participants (60.1 ± 10.1 years old) who visited our hospital for an annual physical checkup, salt intake (g/day) was assessed using a spot urine sample, and bone density was evaluated as a speed of sound (m/s) of ultrasonic pulses in a calcaneus by quantitative ultrasound. We investigated the relationship between bone density and salt intake and the differences in bone density or salt intake between the presence and absence of lifestyle-related diseases such as hypertension, diabetes mellitus and dyslipidaemia.

RESULTS

The average bone density and salt intake were 1497 ± 26 m/s and 8.5 ± 1.8 g/day, respectively. Univariate and multivariate regression analyses revealed that bone density was significantly negatively associated with salt intake. Bone density was lower, and salt intake was higher in participants with hypertension, diabetes mellitus and dyslipidaemia than in those without. After adjusting for age, hypertension, diabetes mellitus and dyslipidaemia, bone density was negatively correlated with salt intake.

CONCLUSIONS

We confirmed that excessive salt intake reduces bone density independently of age and lifestyle-related diseases in the general female population. Since dietary salt intake is a modifiable factor, osteoporosis can be prevented by dietary intervention, including salt reduction.

Pelvic compensation accompanying spinal malalignment and back pain-related factors in a general population: the Wakayama spine study

Some older adults with spinal deformity maintain standing posture via pelvic compensation when their center of gravity moves forward. Therefore, evaluations of global alignment should include both pelvic tilt (PT) and seventh cervical vertebra-sagittal vertical axis (C7-SVA). Here, we evaluate standing postures of older adults using C7-SVA with PT and investigate factors related to postural abnormality. This cross-sectional study used an established population-based cohort in Japan wherein 1121 participants underwent sagittal whole-spine radiography in a standing position and bioelectrical impedance analysis for muscle mass measurements. Presence of low back pain (LBP), visual analog scale (VAS) of LBP, and LBP-related disability (Oswestry Disability Index [ODI]) were evaluated. Based on the PT and C7-SVA, the participants were divided into four groups: normal, compensated, non-compensated, and decompensated. We defined the latter three categories as "malalignment" and examined group characteristics and factors. There were significant differences in ODI%, VAS and prevalence of LBP, and sarcopenia among the four groups, although these were non-significant between non-compensated and decompensated groups on stratified analysis. Moreover, the decompensated group was significantly associated with sarcopenia. Individuals with pelvic compensation are at increased risk for LBP and related disorders even with the C7-SVA maintained within normal range.

Trends in the prevalence of atrophic gastritis and Helicobacter pylori infection over a 10‑year period in Japan: The ROAD study 2005‑2015

Few large population-based studies have examined the prevalence of atrophic gastritis (AG) and Helicobacter pylori infection in Japan. The purpose of the present study was to estimate the prevalence of AG and H. pylori infection by age, in addition to investigating their change rates from 2005 to 2016 in Japan using data from a large population-based cohort. A total of 3,596 participants [1,690 in the baseline survey (2005-2006) and 1,906 at the fourth survey (2015-2016)] aged 18 to 97 years were included in the cohort. The prevalence of AG and H. pylori infection were examined at baseline and in the fourth survey based on serological tests for the H. pylori antibody titer and pepsinogen levels. The prevalence of AG and H. pylori infection were 40.1% (men, 44.1%; women, 38.0%) and 52.2% (men, 54.8%; women, 50.8%), respectively, at baseline. AG seropositivity rates showed a significant decrease from 40.1 to 25.8% in 10 years. H. pylori seropositivity rates decreased significantly from 52.2 to 35.5% in 10 years. Stratified for age, the prevalence of AG showed an increasing trend with age, whereas the prevalence of H. pylori infection increased with aging, except for in the elderly group, showing an inverted U-shaped association. In this population-based, cross-sectional study with a 10-year interval survey, the prevalence of AG and H. pylori infection decreased significantly. This change may influence the prevalence of H. pylori-related diseases, including extra-gastric disorders associated with H. pylori-induced systemic subclinical inflammation and hypochlorhydria, such as colorectal neoplasia and arteriosclerosis.

Association between modic changes, disc degeneration, and pelvic incidence-lumbar lordosis mismatch in a large population based cohort: the Wakayama spine study

PURPOSE

Sagittal plane alignment is crucial for treating spinal malalignment and low back pain. Pelvic incidence-lumbar lordosis (PI-LL) mismatch is commonly used to evaluate clinical outcomes in patients with sagittal malalignment. The association between PI-LL mismatch and changes surrounding the intervertebral disc is very important to understand the compensatory mechanisms involved. This study aimed to examine the association between PI-LL mismatch and magnetic resonance imaging (MRI) changes surrounding the intervertebral disc in a large population-based cohort.

METHODS

We evaluated participants from the second Wakayama Spine Study, recruiting the general population aged 20 years or older, irrespective of sex, who were registered residents in one region in 2014. In total, 857 individuals underwent an MRI of the whole spine; however, 43 MRI results were not included due to incomplete or inadequate quality images. PI-LL mismatch was defined as > 11°. We compared the MRI changes, such as Modic change (MC), disc degeneration (DD), and high-intensity zones (HIZ), between PI-LL mismatch and non-PI-LL mismatch groups. Multivariate logistic regression analysis was conducted to determine the association between the MRI changes and PI-LL mismatch with adjustment for age, sex, and body mass index in the lumbar region and at each level.

RESULTS

A total of 795 participants (243 men, 552 women, mean age 63.5 ± 13.1 years old) were evaluated; 181 were included in the PI-LL mismatch group. MC and DD in the lumbar region were significantly higher in the PI-LL mismatch group. MC in the lumbar region was significantly associated with PI-LL mismatch (odds ratio (OR); 1.81, 95% confidence interval (CI) 1.2-2.7). MC at each level was significantly associated with PI-LL mismatch (OR; 1.7-1.9, 95%CI 1.1-3.2), and DD at L1/2, L3/4, and L4/5 was associated with PI-LL mismatch (OR; 2.0- 2.4. 95%CI 1.2-3.9).

CONCLUSION

MC and DD were significantly associated with PI-LL mismatch. Therefore, profiling MC may be helpful in improving the targeted treatment of LBP associated with the adult spinal deformity.

A common variant rs2054564 in ADAMST17 is associated with susceptibility to lumbar spondylosis

The molecular pathophysiology underlying lumbar spondylosis development remains unclear. To identify genetic factors associated with lumbar spondylosis, we conducted a genome-wide association study using 83 severe lumbar spondylosis cases and 182 healthy controls and identified 65 candidate disease-associated single nucleotide polymorphisms (SNPs). Replication analysis in 510 case and 911 control subjects from five independent Japanese cohorts identified rs2054564, located in intron 7 of ADAMTS17, as a disease-associated SNP with a genome-wide significance threshold (P = 1.17 × 10-11, odds ratio = 1.92). This association was significant even after adjustment of age, sex, and body mass index (P = 7.52 × 10-11). A replication study in a Korean cohort, including 123 case and 319 control subjects, also verified the significant association of this SNP with severe lumbar spondylosis. Immunohistochemistry revealed that fibrillin-1 (FBN1) and ADAMTS17 were co-expressed in the annulus fibrosus of intervertebral discs (IVDs). ADAMTS17 overexpression in MG63 cells promoted extracellular microfibrils biogenesis, suggesting the potential role of ADAMTS17 in IVD function through interaction with fibrillin fibers. Finally, we provided evidence of FBN1 involvement in IVD function by showing that lumbar IVDs in patients with Marfan syndrome, caused by heterozygous FBN1 gene mutation, were significantly more degenerated. We identified a common SNP variant, located in ADAMTS17, associated with susceptibility to lumbar spondylosis and demonstrated the potential role of the ADAMTS17-fibrillin network in IVDs in lumbar spondylosis development.

Efficacy and Safety of Dietary Undenatured Type II Collagen on Joint and Motor Function in Healthy Volunteers: A Randomized, Double-Blind, Placebo-Controlled, Parallel-Group Study

Prevalence of osteoarthritis (OA) is increasing alarmingly worldwide. Slowing down the progression of OA and diverse locomotive organ disorders is gaining interest in improving the quality of life (QOL) and extending healthy life-span. In a pilot study, intake of a small amount of undenatured type II collagen exhibited suppression of damage to the articular cartilage via oral immune tolerance. It also demonstrated improvement of knee and joint flexibility and mobility with continued intake of undenatured type II collagen (NEXT-II®) derived from chicken sternum cartilage. This randomized, double-blind, placebo-controlled, parallel-group clinical investigation (RCT) evaluated the efficacy and safety of 12 weeks of regular intake of NEXT-II^® on joint and motor function in healthy Japanese male and female participants (aged 20 to <75 years).

Sixty-four participants were randomized to receive either NEXT-II^® (undenatured type II collagen 3.2 mg/d) or placebo over a period of 12 consecutive weeks. Efficacy on joint and motor functions were evaluated measuring knee passive range of motion as the primary outcome; the Japan Knee Osteoarthritis Measure (JKOM), Visual Analog Scale (VAS) for knee discomfort, and motor functions (10-meter walking and stair-climbing test) as the secondary outcomes; and Japan Low back pain Evaluation Questionnaire (JLEQ) and VAS for lower back discomfort as the exploratory outcomes.

Fifty-eight participants (placebo = 28; NEXT-II^® group = 30) completed the study. In the assessment of knee passive range of motion, significant improvements in "flexion" and "flexible angle (range)" were observed in the NEXT-II^® group at 4, 8, and 12 weeks of treatment. NEXT-II^® induced significant improvements in JKOM, VAS for knee and lower back discomfort, 10-meter walking test, stair-climbing test, and JLEQ.

Results demonstrate that undenatured type II collagen is safe and efficacious in improving knee flexibility and mobility, reducing knee and lower back pain, and enhancing motor function.

The effect of postmenopausal osteoporosis on subchondral bone pathology in a rat model of knee osteoarthritis

This study aimed to investigate the additional effect of ovariectomy-induced osteoporosis (OP) on the pathology of knee osteoarthritis (OA) in a rat meniscectomized model, particularly focusing on subchondral bone changes and pain behaviour. Rats were divided into four groups, sham, OP, OA, OP plus OA, and assessed for histology, osteoclast activity, subchondral bone microstructure, and pain-related behaviour. Rats with OP plus OA had significantly increased calcified cartilage and subchondral bone damage scores, increased densities of subchondral osteoclasts in the weight-bearing area, and more porous subchondral trabecular bone compared with rats with OA. Loss of tidemark integrity was observed most frequently in rats with OP plus OA. The density of subchondral osteoclasts correlated with the calcified cartilage and subchondral bone damage score in rats with OA (OA and OP plus OA). No significant differences in the receptor activator of nuclear factor-kappa B ligand (RANKL)/osteoprotegerin (OPG) expression ratio in subchondral bone and pain-related behavioural tests were observed between rats with OA and rats with OP plus OA. In rats with OA, coexisting OP potentially aggravated OA pathology mainly in calcified cartilage and subchondral trabecular bone by increasing subchondral osteoclast activity.

Protocol for a randomised, placebo-controlled, double-blinded clinical trial on the effect of oestrogen replacement on physical performance to muscle resistance exercise for older women with osteoarthritis of knee joint: the EPOK trial

BACKGROUND

Knee osteoarthritis (KOA) is highly prevalent in older women, and previous studies suggest the involvement of hormonal factors play a role in the pathogenesis of osteoarthritis. KOA causes musculoskeletal impairment, resulting in decreased physical activity, muscle mass, and strength, which leads to sarcopenia and further increases the burden on healthcare systems. Oestrogen replacement therapy (ERT) improves joint pain and muscle performance in early menopausal women. Muscle resistance exercise (MRE) is a non-pharmacological method that preserves the physical functions of patients with KOA. However, data on short-term oestrogen administration combined with MRE in postmenopausal women, especially in those aged > 65 years, are limited. Therefore, this study presents a protocol of a trial aimed to examine the synergistic effect of ERT and MRE on lower-limb physical performance in older women with KOA.

METHODS

We will conduct a double-blinded, randomised placebo-controlled trial in 80 Japanese women aged > 65 years living independently with knee pain. The participants will be randomly categorised into two groups: (1) 12-week MRE programme with transdermal oestrogen gel containing 0.54 mg oestradiol per push and (2) 12-week MRE programme with placebo gel. The primary outcome measured using the 30-s chair stand test, and secondary outcomes (body composition, lower-limb muscle strength, physical performance, self-reported measure of knee pain, and quality of life) will be measured at baseline, 3 months, and 12 months, and these outcomes will be analysed based on the intention-to-treat.

DISCUSSION

The EPOK trial is the first study to focus on the efficacy of ERT on MRE among women aged > 65 years with KOA. This trial will provide an effective MRE to prevent KOA-induced lower-limb muscle weakness, confirming the benefit of short-term oestrogen administration.

TRIAL REGISTRATION

Japan Registry of Clinical Trials: jRCTs061210062. Registered 17th December 2021, https://jrct.niph.go.jp/en-latest-detail/jRCTs061210062 .

Prevalence of osteoporosis and incidence of related fractures in developed economies in the Asia Pacific region: a systematic review

Robust data on osteoporosis in the Asia Pacific region could improve healthcare decision-making. Osteoporosis affects 10-30% of women aged 40 + , and up to 10% of men in 7 developed economies in Asia Pacific. Fractures affect 500-1000 adults aged 50 + per 100,000 person-years. Policymakers and clinicians must address this problem.

PURPOSE

Osteoporosis and associated fractures result in considerable morbidity, loss of productivity, early mortality, and increased healthcare expenses. Many countries in the Asia Pacific (AP) region, especially middle- and higher-income economies, are faced with aging and increasingly sedentary populations. It is critical to consolidate and analyze the available information on the prevalence and incidence of the disease in these countries.

METHODS

We systematically reviewed articles and gray literature for Australia, China, Hong Kong, Japan, Singapore, South Korea, and Taiwan. We searched PubMed, ScienceDirect, JSTOR, Cochrane, Google Scholar, and other databases for data published 2009-2018. We included articles with prevalence or incidence estimates for adults with osteoporosis or related fractures.

RESULTS

All locations had data available, but of widely varying quantity and quality. Most estimates for osteoporosis prevalence ranged from 10 to 30% for women ages 40 and older, and up to 10% for men. Osteoporotic fracture incidence typically ranged between 500 and 1000 per 100,000 person-years among adults aged 50 and older. Both outcomes typically increased with age and were more common among women.

CONCLUSION

Osteoporosis and associated fractures affect significant portions of the adult population in developed economies in the AP region. Governments and healthcare systems must consider how best to prevent and diagnose osteoporosis, and manage affected individuals, to reduce healthcare costs and mortality associated with fractures.

Risk factors for future osteoporosis in perimenopausal Japanese women

OBJECTIVE

The aims of this study were to investigate trends in bone mineral density (BMD) loss and related factors in early postmenopausal women in Japan, identify risk factors for future osteoporosis, and predict osteoporosis before it occurs.

METHODS

The study population consisted of women who were 50 to 54 years old at the time of the survey in 2002 or 2006. The study included a questionnaire and physical measurement findings (BMD, height, body weight [WT], body mass index [BMI], and handgrip strength). One hundred sixty-seven women continued to participate in the study and had BMD measurements at the 9- or 10-year follow-up of the Japanese Population-based Osteoporosis study. Statistical analyses were performed using Pearson correlation to examine each factor of physical measurement and BMD for lumbar spine (LS) and femoral neck (FN). The receiver operating characteristic curve of this data was also predictive of osteoporosis in 2011 for 2002 data; BMD at the age of 50 to 54 years was then used to predict the likelihood of being diagnosed with osteoporosis 9 and 10 years later.

RESULTS

At the baseline in 2002 and 2006, WT, BMI, height, and handgrip strength were positively correlated with BMD. The optimal cutoff values for BMD in 2006 to predict osteoporosis in 2016 were LS less than 0.834 g/cm 2 and FN less than 0.702 g/cm 2 . These data were also predictive of osteoporosis in 2011 for 2002 data; applying this to the 2002 data, LS/FN had a sensitivity of 92%/100%, a specificity of 87%/81%, a positive predictive value of 55%/48%, and a negative predictive value of 98%/100%. The larger WT and BMI also resulted in a greater decrease in BMD of FN after 9 or 10 years.

CONCLUSIONS

We have identified a cutoff value for BMD to predict future osteoporosis in menopausal women and found a negative correlation between WT and BMI in menopausal women and changes in BMD of the FN over the next 10 years.

Trends in osteoporosis prevalence over a 10-year period in Japan: the ROAD study 2005-2015

INTRODUCTION

This study aimed to clarify the trends in the prevalence of osteoporosis among general inhabitants using population-based cohort data of the baseline and the survey 10 years later.

MATERIALS AND METHODS

The baseline survey of the Research on Osteoarthritis/Osteoporosis Against Disability (ROAD) study was conducted in 2005-2007; 1690 participants (596 men, 1094 women, mean age 65.2 years) completed all examinations of osteoporosis, including a questionnaire of medical information in the present/past and bone mineral density measurement using dual-energy absorptiometry. The fourth survey was performed in 2015-2016; 1906 individuals (637 men, 1269 women, 65.0 years) completed assessments identical to those at the baseline survey. Osteoporosis was defined using the World Health Organization criteria.

RESULTS

The prevalence of lumbar spine (L2-L4) osteoporosis at the baseline survey was 13.6% (men, 3.4%; women, 19.2%) and that at the fourth survey was 9.7% (men, 1.4%; women, 13.9%), which decreased significantly (p < 0.01), while that of the femoral neck was not significantly different between the baseline and fourth surveys. Regarding the prevalence of osteoporosis of L2-L4 or the femoral neck, the prevalence of osteoporosis in women aged ≥ 70 was 38.8% at the fourth survey and 48.9% at the baseline study; thus, the prevalence at the fourth survey was significantly lower than that at the baseline survey (p < 0.01).

CONCLUSIONS

In the population-based survey with a 10-year interval, the prevalence of osteoporosis at lumbar spine tended to decrease significantly. This preferable change in osteoporosis could contribute to the decrease in the occurrence of osteoporotic fracture in the future.

Associations between physical physique/fitness in children and bone development during puberty: a 4-year longitudinal study

Bone growth is most remarkable during puberty. This study aimed to clarify the effects of physique and physical strength on bone mineral density and bone metabolism markers during puberty to help improve bone growth during puberty and prevent future osteoporosis. There were 277 pubertal participants (125 boys and 152 girls) in this survey from 2009 to 2015, all aged 10/11 and 14/15 years. The measures included physical fitness/physique indices (such as muscle ratio etc.), grip strength, bone density (osteo sono-assessment index, OSI), and bone metabolism markers (bone-type alkaline phosphatase and type I collagen cross-linked N-telopeptide). At 10/11-years-old for girls, a positive correlation was found between body size/grip strength and OSI. At 14/15-year-old for boys, all body size factors/grip strength were positively correlated with OSI. The change in body muscle ratio was positively correlated with change in OSI for both sexes. The height, body muscle ratio and grip strength at 10/11-year-old were significantly associated with OSI (positively) and bone metabolism markers (negatively) at 14/15-year-old for both sexes. Adequate physique building after 10/11 years for boys and before 10/11 years for girls may be effective in increasing peak bone mass.

Association between acetabular dysplasia and sagittal spino-pelvic alignment in a population-based cohort in Japan

The relationship between acetabular dysplasia and spino-pelvic alignment remains unclear. The aim of this study was to clarify the association between acetabular dysplasia and spino-pelvic alignment, based on a large-scale population-based cohort in Japan. From the third survey of the Research on Osteoarthritis/Osteoporosis Against Disability (ROAD) study, 1,481 participants (491 men and 990 women; mean age, 65.3 years) were analyzed. Center-edge (CE) angle and spino-pelvic parameters (lumbar lordosis, LL; sacral slope, SS; pelvic tilt, PT; pelvic incidence, PI) were measured radiographically. Acetabular dysplasia was defined as a CE angle < 20°, and associations between acetabular dysplasia and spino-pelvic parameters were assessed. The group with acetabular dysplasia had significantly higher age, higher percentage of female, higher SS and higher PI than the group without acetabular dysplasia in a univariate analysis. On the other hand, acetabular dysplasia was not significantly associated with spino-pelvic parameters in a multiple logistic regression analysis that include age, sex, SS and PI as explanatory variables; however, PI demonstrated a positive odds ratio (odds ratio, 1.02; 95% CI 1.00–1.04). In conclusion, acetabular dysplasia was not significantly associated with spino-pelvic parameters, but higher PI may be an associated factor for acetabular dysplasia.

Epidemiology of locomotive syndrome using updated clinical decision limits: 6-year follow-ups of the ROAD study

INTRODUCTION

Locomotive syndrome (LOCOMO) is defined by the Japanese Orthopaedic Association (JOA) as a condition requiring nursing care due to a decline in mobility resulting from musculoskeletal disorders. In 2020, the JOA announced the new definition of LOCOMO stage 3 and revision of clinical decision limits in stages of LOCOMO. However, there are few reports on the epidemiological indices of LOCOMO. This prospective cohort study aimed to investigate the prevalence, incidence, and association of poor prognosis with LOCOMO stages.

MATERIALS AND METHODS

The third survey of the Research on Osteoarthritis/Osteoporosis Against Disability (ROAD) study was conducted during 2012-2013, examining a population-based cohort of 1575 participants (513 men and 1062 women, mean age 65.6 years). Three LOCOMO risk tests were performed, and patients were classified into LOCOMO stages 0, 1, 2, and 3. They were followed up for 6 years, and identical examination of LOCOMO was performed in 3- and 6-year follow-ups. Data on patients' prognoses, including disability and death, were collected.

RESULTS

The prevalence of LOCOMO stages 1, 2, and 3 was 41.3, 14.9, and 11.6%, respectively. The incidence of LOCOMO stages 1, 2, and 3 were 83.7, 23.0, and 18.6 per 1000 person-years, respectively. Compared with LOCOMO stage 0, logistic regression analysis showed that LOCOMO stage 3 significantly increased the risk of disability and mortality. In addition, each value of LOCOMO risk tests for LOCOMO stage 3 increased the risk of poor prognosis.

CONCLUSION

LOCOMO stage 3 is a sensitive indicator of future disability and mortality.

Bone regeneration: A message from clinical medicine and basic science

Population aging is a global phenomenon and with it, the number of bone fractures increases due to higher incidences of osteoporosis. Bone fractures in the elderly increase the risk of bedridden status and mortality. Therefore, the control of osteoporosis and bone fracture is important for healthy life expectancy, and the fundamental understanding of its pathogenesis and its application in treatment is of great social significance. To solve these clinical problems, it is necessary to integrate clinical medicine and basic research. Bone regeneration after a fracture is an essential function of the living body. The prevailing view is that a small number of resident skeletal stem cells are solely responsible for regenerative capacity. Although these cells have long been considered to be in the bone marrow, it has been shown that they are also present in the growth plate and periosteum. More recently, distinct types of cells in the bone marrow, including bone marrow stromal cells, osteoblast progenitor cells, and osteoblasts, have been shown to participate in bone regeneration. Interestingly, the cellular plasticity of differentiated cells, rather than active recruitment of resident stem cell populations, may largely account for regeneration of bone tissues; terminally differentiated cells de-differentiate into a stem cell-like state, and then re-differentiate into regenerating bone. In this review, we discuss the clinical risk and preventive therapy of bone fractures and the current concept of bone regeneration in basic mechanical insights, which may prove useful to both clinicians and researchers.

Osteoporosis in nontuberculous mycobacterial pulmonary disease: a cross-sectional study

Background

Since nontuberculous mycobacterial pulmonary disease (NTM-PD) is common in middle-aged/elderly slender women at risk of osteoporosis, we hypothesized that NTM-PD could be associated with osteoporosis. The study aimed to evaluate the prevalence of osteoporosis in patients with NTM-PD compared with that in the general population and determine the factors associated with osteoporosis in the subjects, including the serum estradiol (E₂) and 25-hydroxyvitamin D (25OHD) levels.

Methods

We have recruited 228 consecutive adult patients with NTM-PD from a prospective cohort study at the Keio University Hospital, who had no history of osteoporosis or osteoporosis-associated bone fracture but underwent dual-energy X-ray absorptiometry-based bone mineral density (BMD) evaluation from August 2017–September 2019. The E₂ and 25OHD levels were measured in 165 patients with available stored serum samples. We performed multivariable logistic regression analyses for osteopenia and osteoporosis.

Results

Osteoporosis (T-score ≤  − 2.5) and osteopenia (T-score − 1 to − 2.5) were diagnosed in 35.1% and 36.8% of patients with NTM-PD, respectively. Compared with the general population, the proportion of osteoporosis was significantly higher in 50–59-, 60–69-, and 70–79-year-old women with NTM-PD. Multivariable analysis revealed that older age (adjusted odds ratio [aOR] for 1-year increase = 1.12; 95% confidence interval [CI] = 1.07–1.18), female sex (aOR = 36.3; 95% CI = 7.57–174), lower BMI (aOR for 1 kg/m² decrease = 1.37; 95% CI = 1.14–1.65), and chronic Pseudomonas aeruginosa (PA) infection (aOR = 6.70; 95% CI = 1.07–41.8) were independently associated with osteoporosis. Additionally, multivariable analysis in 165 patients whose serum E₂ and 25OHD levels were measured showed that both low E₂ levels (< 10 pg/mL) and lower 25OHD levels were independently associated with osteoporosis.

Conclusions

Middle-aged/elderly women with NTM-PD have a higher prevalence of osteoporosis than the general population. BMD screening should be considered in NTM-PD, especially in older females with severe diseases such as chronic PA infection and lower BMI, and low serum E₂ and 25OHD levels.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-01991-3.

Artificial Neural Networks Can Predict Early Failure of Cementless Total Hip Arthroplasty in Patients With Osteoporosis

BACKGROUND

Total hip arthroplasty (THA) done in the aging population is associated with osteoporosis-related complications. The altered bone density in osteoporotic patients is a risk factor for revision surgery. This study aimed to develop and validate machine learning (ML) models to predict revision surgery in patients with osteoporosis after primary noncemented THA.

METHODS

We retrospectively reviewed a consecutive series of 350 patients with osteoporosis (T-score less than or equal to -2.5) who underwent primary noncemented THA at a tertiary referral center. All patients had a minimum 2-year follow-up (range: 2.1 to 5.6). Four ML algorithms were developed to predict the probability of revision surgery, and these were assessed by discrimination, calibration, and decision curve analysis.

RESULTS

The overall incidence of revision surgery was 5.2% at a mean follow-up of 3.7 years after primary noncemented THA in osteoporotic patients. Revision THA was done because of periprosthetic fracture in nine patients (50%), aseptic loosening/subsidence in five patients (28%), periprosthetic joint infection in two patients (11%) and dislocation in two patients (11%). The strongest predictors for revision surgery in patients after primary noncemented THA were female sex, BMI (>35 kg/m2), age (>70 years), American Society of Anesthesiology score (≥3), and T-score. All four ML models demonstrated good model performance across discrimination (AUC range: 0.78 to 0.81), calibration, and decision curve analysis.

CONCLUSION

The ML models presented in this study demonstrated high accuracy for the prediction of revision surgery in osteoporotic patients after primary noncemented THA. The presented ML models have the potential to be used by orthopaedic surgeons for preoperative patient counseling and optimization to improve the outcomes of primary noncemented THA in osteoporotic patients.

Hospital-wide surveillance of fracture risk assessment by both FRAX and medication patterns in acute care hospital

To identify patients at a high risk for primary and secondary osteoporotic fractures using fracture risk assessments performed using the current method and the proposed method, in an acute care hospital and to identify departments where high-risk patients are admitted. This retrospective study included patients aged 40-90 years who were hospitalized at Fujita Health University Hospital. We collated the clinical data and prescriptions of all study participants. We also gathered data pertaining to risk factors according to Fracture Risk Assessment Tool (FRAX). Of the 1,595 patients, the mean number of major osteoporotic fracture risk predicted using FRAX was 11.73%. The department of rheumatology showed the highest fracture risk (18.55 ± 16.81) and had the highest number of patients on medications that resulted in reduced bone mineral density (1.07 ± 0.98 medication). Based on the FRAX, the proportion of patients in the high-risk group in this department was significantly higher compared with those in the remaining departments with respect to glucocorticoid administration, rheumatoid arthritis, and secondary osteoporosis. However, the departments included in the high-risk group were not necessarily the same as the departments included in the top group, based on the administered medications. FRAX score is calculated based on various risk factors; however, only glucocorticoid corresponds to medications. We should focus on medication prescription patterns in addition to FRAX to improve fracture risk assessment in hospital-wide surveillance. Therefore, we recommend the use of FRAX along with the prescribed medications to identify departments that admit high-risk patients.

The cumulative incidence of and risk factors for morphometric severe vertebral fractures in Japanese men and women: the ROAD study third and fourth surveys

This population-based cohort study with a 3-year follow-up revealed that the annual incidence rates of vertebral fracture (VF) and severe VF (sVF) were 5.9%/year and 1.7%/year, respectively. The presence of mild VF at the baseline was a significant risk factor for incident sVF in participants without prevalent sVF.

INTRODUCTION

This study aimed to estimate the incidence of morphometric vertebral fracture (VF) and severe VF (sVF) in men and women and clarify whether the presence of a mild VF (mVF) increases the risk of incident sVF.

METHODS

Data from the population-based cohort study, entitled the Research on Osteoarthritis/Osteoporosis Against Disability (ROAD) study, were analyzed. In total, 1190 participants aged ≥ 40 years (mean age, 65.0 ± 11.2) years completed whole-spine lateral radiography both at the third (2012-2013, baseline) and fourth surveys performed 3 years later (2015-2016, follow-up). VF was defined using Genant's semi-quantitative (SQ) method: VF as SQ ≥ 1, mVF as SQ = 1, and sVF as SQ ≥ 2. Cumulative incidence of VF and sVF was estimated. Multivariate logistic regression analyses were performed to evaluate risk factors for incident sVF.

RESULTS

The baseline prevalence of mVF and sVF were 16.8% and 6.0%, respectively. The annual incidence rates of VF and sVF were 5.9%/year and 1.7%/year, respectively. The annual incidence rates of sVF in participants without prevalent VF, with prevalent mVF, and with prevalent sVF were 0.6%/year, 3.8%/year, and 11.7%/year (p < 0.001), respectively. Multivariate logistic regression analyses in participants without prevalent sVF showed that the adjusted odds ratios for incident sVF were 4.12 [95% confident interval 1.85-9.16] and 4.53 [1.49-13.77] if the number of prevalent mVF at the baseline was 1 and ≥ 2, respectively.

CONCLUSIONS

The annual incidence rates of VF and sVF were 5.9%/year and 1.7%/year, respectively. The presence of prevalent mVF was an independent risk factor for incident sVF.

A Prospective, 3-year Longitudinal Study of Modic Changes of the Lumbar Spine in a Population-based Cohort: The Wakayama Spine Study

STUDY DESIGN

Large-scale, prospective, population-based, longitudinal observational study.

OBJECTIVE

The aim of this study was to investigate the rate of incidence, transformation, and reverse transformation of Modic changes (MCs) using T1-weighted (T1W) and T2-weighted (T2W) lumbar magnetic resonance images (MRI) over a 3-year period.

SUMMARY OF BACKGROUND DATA

Although MCs in populational study are considered significant, existing epidemiological evidence is based on cross-sectional studies only.

METHODS

Overall, 678 subjects (208 men, 470 women, mean age 62.1 ± 12.8 years in 2013) in both 2013 and 2016 surveys were included. The rate of change in Modic Type I (T1W: low-intensity, T2W: high-intensity), Type II (T1W: high, T2W: high), and Type III (T1W: low, T2W: low) at five endplates was analyzed over a 3-year period. An incidence of MC at each level and in the lumbar region was defined as no MC at baseline with signal changes at follow-up. Transformation was defined as Type I or II MC at baseline with conversion at follow-up Type II from Type I or Type III MC from Type I and II. Furthermore, reverse transformation was defined as Type I, II, or III MC at baseline, with at least one endplate showing a reversion in Modic type (no MC for baseline Type I; no MC and Type I for baseline Type II; no MC, Type I or Type II for baseline Type III) at follow-up.

RESULTS

Overall, 3390 endplates were included. For 3 years, the incidence, transformation, and reverse transformation of MCs were seen in 395 (11.7%), 84 (2.5%), and 11 (0.3%) endplates, respectively. The highest levels of incidence, transformation, and reverse transformation were at L2/3 (96 [14.2%] endplates), L5/S1 (32 [4.7%] endplates), and L2/3 (5 [0.7%] endplates), respectively.

CONCLUSION

This study revealed a high incidence of MCs at the upper lumbar levels and transformation at the lower lumbar levels. Reverse transformation of MCs occurs but are rare.Level of Evidence: 2.

Relationship Between Age-Related Spinopelvic Sagittal Alignment and Low Back Pain in Adults of Population-Based Cohorts: The ROAD Study

Purpose

The demand for surgical correction in elderly patients with adult spinal deformity (ASD) has recently increased with the growth of the aging population. Age-related changes in spinopelvic sagittal alignment have been recently reported; thus, sagittal realignment should consider age-related changes. This study aimed to investigate the relationship between age-specific sagittal spinopelvic radiographic parameters and low back pain (LBP) to support the establishment of age-specific realignment targets for patients with ASD.

Materials and Methods

A population-based cohort consisting of 1461 subjects (466 men and 995 women) was used. The participants were divided into five groups based on their age: (1) younger than 50 years, (2) 50–59 years, (3) 60–69 years, (4) 70–79 years, and (5) 80 years and older. Standing lateral whole-spine radiographs were assessed to measure lumbar lordosis (LL), pelvic tilt (PT), pelvic incidence (PI), and sagittal vertical axis (SVA). In addition, all participants were asked if they had LBP or not, using the following question: “Have you experienced LBP on most days during the past month and/or now?”.

Results

The crucial parameter associated with LBP was the mismatch between PI and LL (PI-LL). The mean values of all the radiographic parameters increased with age. PI-LL and PT reached 11.5° and 25.6°, respectively, for women without LBP in the super-aged group (age >80 years), which did not lie in the range of optimal values reported in the previous literature.

Conclusion

A new optimal age-related target may be needed for the management of patients with ASD.

Differences in the prevalence of locomotive syndrome and osteoporosis in Japanese urban and rural regions: The Kashiwara and Yakumo studies

OBJECTIVES

To clarify whether the prevalence of locomotive syndrome (LS) and osteoporosis differed according to region, gender, and physical functions in Japan.

METHODS

Data were collected in Kashiwara City (urban region) and Yakumo Town (rural region). Totally, 208 participants from the urban region and 782 participants from the rural region were included in this study. LS was assessed using the 25-item Geriatric Locomotive Function Scale and osteoporosis was assessed using a quantitative ultrasound. Physical functions were measured using grip strength and the 3-m timed up-and-go test. Differences between urban and rural regions were investigated using standardized incidence ratio and multivariate analysis.

RESULTS

The prevalence of LS and osteoporosis was 24.5% and 42.8% in the urban region and 10.9% and 28.8% in the rural region, respectively. The standardized incidence ratio of the urban region versus the rural region was 1.80 (95% confidence intervals [CI] = 1.35-2.39) for LS and 1.21 (95% CI = 1.32-2.43) for osteoporosis, showing that the prevalence of LS was significantly higher in the urban region. Multivariate analysis indicated that LS was significantly associated with the urban sample and timed up-and-go was significantly longer in the urban sample.

CONCLUSION

Regional differences may be considered when evaluating LS in health checkups. Understanding the results of this study may help reduce LS prevalence.

The discrepancy between radiographically-assessed and self-recognized hallux valgus in a large population-based cohort

Background

There has been a paucity of literature revealing the discrepancy between self-recognition about hallux valgus (HV) and radiographically-evaluated foot configuration. Knowing this discrepancy will help to make a comparative review of the findings of previous literatures about epidemiological studies about the prevalence of HV.

Questions/purposes

(1) Is there a discrepancy between radiographically-assessed and self-recognized HV in the general population? (2) What factors affect the self-recognition of HV in the general population?

Methods

The fifth survey of the Research on Osteoarthritis/Osteoporosis against Disability study involved 1996 participants who had undergone anterior-posterior radiography of bilateral feet and answered a simple dichotomous questionnaire on self-recognition of HV. Measurements of the HV angle (HVA), interphalangeal angle of the hallux (IPA), and intermetatarsal angle between 1st and 2nd metatarsals (IMA) were performed using radiographs. Radiographic diagnosis of HV was done using the definition of hallux valgus angle of 20° or more. After univariate comparison of the participant backgrounds and radiographic measurements between participants with or without self-recognition of HV, multivariable logistic regression analysis was conducted in order to reveal independent factors affecting self-recognition.

Results

Significant difference was found between the prevalence of radiographically-assessed and self-recognized HV (29.8% vs. 16.5%, p <  0.0001). The prevalence of self-recognized HV increased with the progression of HV severity from a single-digit percentage (normal grade, HVA < 20°) up to 100% (severe grade, HVA ≥ 40°). A multivariable logistic regression analysis demonstrated that HVA, IMA, and female sex were independent positive factors for self-recognition of HV (HVA [per 1° increase]: OR, 1.18; 95% CI, 1.15–1.20; p <  0.0001; IMA [per 1° increase]: OR, 1.15; 95% CI, 1.09–1.20; p <  0.0001; and female sex [vs. male sex]: OR, 3.47; 95% CI, 2.35–5.18; p <  0.0001).

Conclusions

There was a significant discrepancy between radiographically-assessed and self-recognized HV which narrowed with the progressing severity of HV. HVA, IMA, and female sex were independent positive factors for self-recognition of HV. Attention needs to be paid to potentially lowered prevalence of HV in epidemiological studies using self-reporting based on self-recognition.

Prevalence and associated factors of primary elbow osteoarthritis in the Japanese general elderly population: a Japanese cohort survey randomly sampled from a basic resident registry

BACKGROUND

The epidemiology of primary elbow osteoarthritis (PEOA) remains unknown. We aimed to evaluate the prevalence and associated factors of PEOA in a cross-sectional resident cohort from a municipal registry of a Japanese town.

METHODS

A total of 415 residents over 50 years of age were randomly sampled from a Japanese town and were adjusted for age and gender. Those with diseases that could potentially cause a secondary osteoarthritis of the elbow were excluded. The remaining 318 subjects (150 men and 168 women) underwent bidirectional radiography of the elbow. Subjects were diagnosed with PEOA if one of their elbows was Kellgren-Lawrence (KL) grade 2 or greater. In addition, motion pain and tenderness at the elbow were examined by orthopedic surgeons. Associated factors for the PEOA were statistically analyzed.

RESULTS

The prevalence of PEOA was 25.2% (male, 27.3%; female, 23.2%), and the prevalence of symptomatic PEOA was 0.9%. The age-stratified prevalence of PEOA was as follows: 50-59, 6.2% (male, 5.0%; female, 7.3%); 60-69, 15.4% (male, 17.5%; female, 13.7%); 70-79, 29.5% (male, 35.3%; female, 25.0%); and 80-89, 55.9% (male, 55.6%; female, 56.3%). Age and body mass index were revealed as associated factors that increased the prevalence of PEOA with KL grade 2 or greater. The use of vibrating tools was demonstrated as an independent associated factor that increased the prevalence of PEOA with KL grade 4 in addition to the 2 aforementioned factors.

CONCLUSIONS

The prevalence of PEOA in Japanese subjects was 25.2% for those aged 50-89 years with a mean age of 69.2 years, most of which was asymptomatic OA without motion pain or tenderness at the elbow. Age and body mass index increased the prevalence of PEOA with KL grade 2 or greater. The prevalence of PEOA increased with age, but the disease was self-accommodated by most people.

Does intra-articular injection of adipose-derived stem cells improve cartilage mass? A case report using three-dimensional image analysis software in knee osteoarthritis

BACKGROUND

Mesenchymal stem cells are currently a research focus because of the possibility of cartilage regeneration through several mechanisms, including mesenchymal stem cell sheets. However, there are no published reports visualizing cartilage in three dimensions. Here, we report a case of improved cartilage volume. We purified and cultured adipose-derived mesenchymal stem cells and then performed adipose-derived mesenchymal stem cell therapy by directly injecting these cells into the articular cartilage. Cartilage was quantitatively evaluated before and after injection using three-dimensional image analysis software based on the magnetic resonance imaging.

CASE PRESENTATION

The patient, a 55-year-old Japanese woman, experienced pain in both knees and was diagnosed with osteoarthritis of the knee. We performed adipose-derived mesenchymal stem cell therapy in both knees at our hospital and quantitatively evaluated cartilage before and after the treatment using the three-dimensional image analysis software "SYNAPSE VINCENT".

CONCLUSIONS

Preoperatively, the cartilage defect area was 33.59 mm² in the femur and 122.31 mm² in the tibia; however, 12 months postoperatively, it improved to 13.59 mm² and 51.43 mm², respectively. Furthermore, the preoperative femur and tibia volumes were 9.58 mL and 3.82 mL, respectively; however, 12 months postoperatively, these values improved to 10.00 mL and 4.17 mL, respectively. For the quantitative analysis of cartilage, SYNAPSE VINCENT visualizes the state of cartilage in a high-definition three-dimensional image, which is excellent for understanding the state of the disease and explaining it to the patient. Although SYNAPSE VINCENT can only analyze the thickness of cartilage, and the reproducibility of the error is debatable, SYNAPSE VINCENT would be useful as a clinical tool for regenerative medicine. We have shown in this case report the promising effects of adipose-derived stem cell intraarticular injections in treating osteoarthritis and the use of new diagnostic instruments.

Detailed Subphenotyping of Lumbar Modic Changes and Their Association with Low Back Pain in a Large Population-Based Study: The Wakayama Spine Study

INTRODUCTION

To examine the association between the five types of Modic changes and low back pain (LBP) in a large population-based cohort.

METHODS

Of the 952 participants in the second Wakayama Spine Study, 814 (men, 246; women, 568; mean age, 63.6 years) were included in this study. Endplate changes on magnetic resonance imaging were classified according to the Modic classification system. Low back pain (LBP) was defined as continuous back pain for at least 48 h in the past month that is currently present. The prevalence of Modic changes in the lumbar region was assessed. Multivariate logistic regression analysis was conducted to determine the association between detailed subphenotype of Modic change and LBP comparing no Modic change in the lumbar spine and each level, respectively.

RESULTS

Modic changes throughout the lumbar spine were noted in 63.5% (n = 516) of all participants, with types I, I/II, II, II/III, and III observed in 7.8% (n = 63), 10.8% (n = 88), 40.0% (n = 326), 2.1% (n = 17), and 2.7% (n = 22), respectively. Modic types I/II were associated with LBP [odds ratio (OR): 3.26; 95% confidence interval (CI) 1.9, 5.5]. Furthermore, Modic type I/II changes at L2/3 and L4/5 were significantly associated with LBP (odds ratio: 2.77; 95% CI 1.04, 7.39 at L2/3; odds ratio: 2.86; 95% CI 1.39, 5.90 at L4/5).

CONCLUSIONS

Type I/II Modic changes in the lumbar region are significantly associated with LBP. To the best of our knowledge, this is the first large population-based study on the association between various Modic changes and LBP.

The Relationship Between Disorders of Bone Metabolism and Benign Paroxysmal Positional Vertigo: A Systematic Review

OBJECTIVES

Several studies have reported an association between benign paroxysmal positional vertigo (BPPV) and bone mineral density or serum vitamin D levels. The aim of this review is to provide further clarification regarding the relationship between BPPV and calcium metabolism.

DESIGN

PubMed and MEDLINE databases were systematically reviewed to identify all English language papers regarding the relationship between BPPV and the following terms: osteoporosis, osteopenia, bone mineral density, serum vitamin D levels, and bone metabolism.

RESULTS

Of the 456 identified records, 28 studies were eligible for this review. Most were retrospective studies with inherent limitations and often conflicting results. While the literature is not conclusive, osteoporosis in patients of at least 50 years old appears to have an association with BPPV. Similarly, an association was observed between recurrent BPPV and vitamin D deficiency.

CONCLUSION

There is only weak evidence to support the relationship between BPPV and osteoporosis or low serum 25-hydroxyvitamin D levels. Further prospective studies with more robust methodologies are needed to clarify the association between BPPV and disorders of bone metabolism.

Relationship of sagittal spinal alignment with low back pain and physical performance in the general population

Studies have suggested a relationship between sagittal spinal malalignment and low back pain (LBP). The current study investigated the relationship of spinal alignment with LBP and physical performance in 1491 individuals who attended the second follow-up visit of the Wakayama Spine Study. The sagittal vertical axis at C7 (C7 SVA) was measured by a spine surgeon. The occurrence of LBP within one month, pain intensity, Oswestry Disability Index (ODI), and physical performance (grip strength, 6-m walking time, chair stand test, one-leg standing test) were also evaluated. LBP in the previous month was determined using ODI, and indicators of physical performance were measured. The mean C7 SVA was 11.0 ± 42.7 mm and was significantly greater in older participants (p < 0.001). LBP was more prevalent in participants with a greater C7 SVA (< 40 mm, 35.7%; 40–95 mm, 47.3%; ≥ 95 mm, 59.4%; p < 0.001) and those with a higher ODI score (10.0%, 17.5%, and 29.4%, respectively; p < 0.001). Physical performance significantly decreased in participants with a greater C7 SVA (p < 0.001). Multiple linear regression analysis revealed that LBP and physical performance were significantly associated with C7 SVA (p < 0.001). Thus, sagittal spinal malalignment may lead to LBP and decreased physical performance.

Early clinical effects, safety, and predictors of the effects of romosozumab treatment in osteoporosis patients: one-year study

Romosozumab is an effective treatment for spine osteoporosis because it reduces the incidence of new fractures and significantly increases the percent change in the spine BMD at 12 months. The percent change in the spine BMD is higher in patients not previously treated with other anti-osteoporosis medications.

INTRODUCTION

Romosozumab appeared as a new osteoporosis medication in Japan in 2019. It is an anti-sclerostin antibody, which increases bone formation and suppresses bone resorption. The aim of our study was to elucidate the clinical effects, safety, and predictors of the effects of one-year romosozumab treatment.

METHODS

This study was an observational study designed as a pre-post study in 262 patients. Romosozumab (210 mg) was administered subcutaneously once every 4 weeks during 12 months. We focused on incidence of new fractures, safety, bone mineral density (BMD) at the spine and total hip, and bone metabolism markers.

RESULTS

There were five cases of new fractures during one-year romosozumab treatment. There were no fatal adverse events. Percent changes from baseline in the spine and total hip BMD after 12 months of romosozumab treatment were 10.67% and 2.04%, respectively. Romosozumab had better effects in cases of severe osteoporosis with low spine BMD, high TRACP-5b, and high iP1NP at the start of romosozumab treatment. The percent change in the spine BMD at 12 months was significantly lower in the group transitioning from bisphosphonates than in the group not previously treated with other anti-osteoporosis medications.

CONCLUSION

Romosozumab is an effective treatment for spine osteoporosis because it significantly increases the percent change in the spine BMD at 12 months. The percent change in the spine BMD is higher in patients not previously treated with other anti-osteoporosis medications.

Effects of anthropometric parameters on bone mineral density in women: from perimenopause to old age

AIM

To analyze the influence of body components on bone mineral density (BMD) in women from perimenopause to old age.

MATERIAL AND METHODS

A total of 117 women were allocated into three groups according to the reproductive stage (STRAW): perimenopausal (PEM, N = 28, mean age 44.8 ± 3.6), early postmenopausal (EPM, N = 36, mean age 51.4 ± 2.8) and late postmenopausal (LPM, N = 53; mean age 64.0 ± 1.7). Total body mass, body mass index (BMI), lean mass (LM), fat mass (FM), fat percentage (FP) and BMD at the lumbar spine (lBMD) and femoral neck (fBMD) were assessed.

RESULTS

BMI, FM, LM and BMD values decreased from PEM to LPM. The total effect of FM on fBMD and lBMD was of 42% and 8% for PEM, 28% and 33% for EMP and 9% and 1% for LPM respectively. Additionally, the total effect of LM on fBMD and lBMD was 48% and 3% for PEM, 54% and 53% for EMP and 9% and 11% for LPM women respectively.

CONCLUSION

BMI, LM, and FM decreased with aging. All these components had great influence on both fBMD and lBMD in EMP women. Conversely, in PEM these parameters only had influence on femoral BMD, but not on lumbar spine. These data suggests that LM is the most important component in BMD for women older than 50 years old, particularly in the hip.

Family caregiver burden of patients with osteoporotic fracture in Japan

INTRODUCTION

Osteoporotic fractures are the most common serious consequence of osteoporosis. Patients who suffer such fractures often require caregiver assistance afterwards. This study characterized the humanistic burden experienced by family caregivers of patients with osteoporotic fractures in Japan.

MATERIALS AND METHODS

Family caregivers were defined as individuals who provided non-professional care to an osteoporotic fracture patient (> 50 years old). Caregivers were asked through an online survey panel about their caregiving situation, health-related quality of life (HRQoL), work impairment, and the health status of their patient. The Zarit Caregiver Burden Interview (ZBI-22), 8-item Short Form Health Survey (SF-8), and Work Productivity and Activity Impairment Caregiver version (WPAI-CG) were used to better understand the impact of osteoporotic fracture caregiving.

RESULTS

Respondents (n = 309) were family caregivers who were employed (81.6%) and cared for a parent (71.5%). Over 75% of caregivers had HRQoL physical and mental component scores below 50 on SF-8. Although most patients received welfare services (78.3%), the mean ZBI-22 score was 42.2 and 57.0% of caregivers perceived their burden to be moderate or severe (ZBI-22 score ≥ 41). Over half of caregivers changed their employment status due to their caregiving responsibilities and experienced 61.4% overall work impairment. The mean productivity loss for caregivers was estimated to be over 43,000 JPY per week.

CONCLUSION

The substantial humanistic and financial burden of caregiving by family members to osteoporotic fracture patients should be considered when evaluating the impact of fragility fractures, disease management and support systems for osteoporosis.

Artificial intelligence improves the accuracy of residents in the diagnosis of hip fractures: a multicenter study

BACKGROUND

Less experienced clinicians sometimes make misdiagnosis of hip fractures. We developed computer-aided diagnosis (CAD) system for hip fractures on plain X-rays using a deep learning model trained on a large dataset. In this study, we examined whether the accuracy of the diagnosis of hip fracture of the residents could be improved by using this system.

METHODS

A deep convolutional neural network approach was used for machine learning. Pytorch 1.3 and Fast.ai 1.0 were applied as frameworks, and an EfficientNet-B4 model (a pre-trained ImageNet model) was used. We handled the 5295 X-rays from the patients with femoral neck fracture or femoral trochanteric fracture from 2009 to 2019. We excluded cases in which the bilateral hips were not included within an image range, and cases of femoral shaft fracture and periprosthetic fracture. Finally, we included 5242 AP pelvic X-rays from 4851 cases. We divided these 5242 images into two images per image, and prepared 5242 images including fracture site and 5242 images without fracture site. Thus, a total of 10,484 images were used for machine learning. The accuracy, sensitivity, specificity, F-value, and area under the curve (AUC) were assessed. Gradient-weighted class activation mapping (Grad-CAM) was used to conceptualize the basis for the diagnosis of the fracture by the deep learning algorithm. Secondly, we conducted a controlled experiment with clinicians. Thirty-one residents;young doctors within 2 years of graduation from medical school who rotate through various specialties, were tested using 300 hip fracture images that were randomly extracted from the dataset. We evaluated the diagnostic accuracy with and without the use of the CAD system for each of the 300 images.

RESULTS

The accuracy, sensitivity, specificity, F-value, and AUC were 96.1, 95.2, 96.9%, 0.961, and 0.99, respectively, with the correct diagnostic basis generated by Grad-CAM. In the controlled experiment, the diagnostic accuracy of the residents significantly improved when they used the CAD system.

CONCLUSIONS

We developed a newly CAD system with a deep learning algorithm from a relatively large dataset from multiple institutions. Our system achieved high diagnostic performance. Our system improved the diagnostic accuracy of residents for hip fractures.

LEVEL OF EVIDENCE

Level III, Foundational evidence, before-after study.

CLINICAL RELEVANCE

high.

A Metabolomic Profile Predictive of New Osteoporosis or Sarcopenia Development

The increasing number of patients with osteoporosis and sarcopenia is a global concern among countries with progressively aging societies. The high medical costs of treating those patients suggest that prevention rather than treatment is preferable. We enrolled 729 subjects who attended both the second and third surveys of the Research on Osteoarthritis/Osteoporosis Against Disability (ROAD) study. Blood samples were collected from subjects at the second survey, and then a comprehensive metabolomic analysis was performed. It was found that 35 had newly developed osteoporosis at the third survey performed four years later, and 39 were newly diagnosed with sarcopenia at the third survey. In the second survey, we found that serum Gly levels were significantly higher even after adjustment for age, sex, and BMI in subjects with newly developed osteoporosis relative to those who remained osteoporosis-negative during the four-year follow-up. We also show that serum taurine levels were significantly lower at the second survey, even after adjustment for age, sex, and BMI in subjects with newly developed sarcopenia during the four-year follow-up compared with those not diagnosed with sarcopenia at the second or third surveys. Though our sample size and odds ratios were small, increased Gly and decreased taurine levels were found to be predictive of new development of osteoporosis and sarcopenia, respectively, within four years.

The role of oxidation of low-density lipids in pathogenesis of osteoarthritis: A narrative review

Osteoarthritis (OA) is a chronic joint disorder that causes degeneration of cartilage, synovial inflammation, and formation of osteophytes. Aging, obesity, and sex are considered the main risk factors of OA. Recent studies have suggested that metabolic syndrome (MetS) disorders, such as hypertension, hyperlipidemia, diabetes mellitus, and obesity, may be involved in the pathogenesis and progression of OA. MetS disorders are common diseases that also result in atherosclerosis. Researchers believe that OA and atherosclerosis have underlying similar molecular mechanisms because the prevalence of both diseases increases with age. Oxidation of low-density lipoprotein (ox-LDL) is believed to play a role in the pathogenesis of atherosclerosis. Recent reports have shown that ox-LDL and low-density lipoprotein receptor 1 (LOX-1) are involved in the pathogenesis of OA. The purpose of this narrative review is to summarize the current understanding of the role of the LOX-1/ox-LDL system in the pathogenesis of OA and to reveal common underlying molecular pathways that are shared by MetS in OA and the LOX-1/ox-LDL system.