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.

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.

Association between types of Modic changes in the lumbar region and low back pain in a large cohort: the Wakayama spine study.

PURPOSE: The clinical significance of Modic changes in low back pain (LBP) is yet to be clarified. Thus, this study aimed to examine the association between Modic changes and LBP after adjustment for confounding factors. METHODS: We evaluated participants in the second Wakayama Spine Study. The degree of endplate changes as measured using magnetic resonance imaging was classified based on the Modic classification system. The prevalence of the types of Modic change in the lumbar region and at each level was assessed. Multivariate logistic regression analysis was conducted to determine the association between the types of Modic changes and LBP with adjustment for age, sex, body mass index, disc degeneration score, and disc displacement score. The LBP intensity was also compared according to the Visual Analogue Scale (VAS) score among the three types of Modic change. RESULTS: Overall, 814 subjects were evaluated. Type II Modic changes were the most prevalent (41.9%). Only type I Modic changes were significantly associated with LBP (odds ratio): 1.84, 95% confidence interval [CI]: 1.1-2.9). The LBP VAS score was significantly higher in subjects with type I Modic change than that in those with no Modic change (23.9 ± 26.3 vs. 9.9 ± 19.4, p < 0.05). CONCLUSION: Type I Modic changes in the lumbar region are significantly associated with LBP. Profiling Modic changes may be helpful to improve targeted treatment of LBP.

Prevalence and co-existence of locomotive syndrome, sarcopenia, and frailty: the third survey of Research on Osteoarthritis/Osteoporosis Against Disability (ROAD) study.

This study aimed to estimate the prevalence of locomotive syndrome, sarcopenia, and frailty and clarify their co-existence in a population-based cohort. The third survey of Research on Osteoarthritis/Osteoporosis Against Disability (ROAD) study was conducted between 2012 and 2013, examining 963 subjects (aged ≥ 60 years; 321 men, 642 women). Locomotive syndrome, sarcopenia, and frailty were defined using three tests proposed by Japanese Orthopaedic Association, Asian Working Group for Sarcopenia criteria, and Fried's definition, respectively. Prevalence of locomotive syndrome stages 1 and 2 were 81.0% (men, 80.4%; women, 81.3%) and 34.1% (men, 30.5%; women, 35.8%), respectively, and those of sarcopenia and frailty were 8.7% (men, 9.7%; women, 8.3%) and 4.5% (men, 2.8%; women, 5.3%), respectively. Locomotive syndrome stage 1, sarcopenia, and frailty co-existed in 2.1%; 6.5% had locomotive syndrome stage 1 and sarcopenia, 2.4% had locomotive syndrome stage 1 and frailty, while none had sarcopenia and frailty. Locomotive syndrome stage 1 presented alone in 70.0%, sarcopenia in 0.1%, and no frailty. The remaining 18.9% had none of these conditions. Co-existence of locomotive syndrome stage 2, sarcopenia, and frailty was observed in 2.0%; 5.0% had locomotive syndrome stage 2 and sarcopenia, 2.2% had locomotive syndrome stage 2 and frailty, and 0.1% had sarcopenia and frailty. Locomotive syndrome stage 2, sarcopenia, and frailty alone, presented in 24.9%, 1.7%, and 0.2%, respectively. The remaining 64.0% had none of these conditions. Most subjects with sarcopenia and/or frailty also had locomotive syndrome. Preventing locomotive syndrome may help prevent frailty and sarcopenia and subsequent disability.

Differences in prevalence and associated factors between mild and severe vertebral fractures in Japanese men and women: the third survey of the ROAD study.

Vertebral fracture (VF) is a common osteoporotic fracture, while its epidemiology varies according to regions and ethnicities, little is known about it in Japan. Using whole-spine radiographs from a population-based cohort study, the Research on Osteoarthritis/Osteoporosis Against Disability study 3rd survey performed in 2012-2013, we estimated the sex- and age-specific prevalence of VF in the Japanese. Genant's semiquantitative method (SQ) was used to define VF; SQ ≥ 1 as VF, SQ = 1 as mild VF, SQ≥ 2 as severe VF. We also revealed accurate site-specific prevalence, and associated factors with mild and severe VF. The participants were 506 men [mean age 66.3 years, standard deviation (SD):13.0] and 1038 women (mean age 65.3 years, SD: 12.6). The prevalence of VF in participants aged under 40, in their 40s, 50s, 60s, 70s, and ≥ 80 years was 17.4, 7.9, 18.5, 25.6, 26.3, and 41.5%, respectively, in men, and 2.9%, 2.4%, 7,3, 10.3, 27.1, and 53.0%, respectively, in women. Men had a significantly higher prevalence of mild VF (21.2%) than women (10.0%, p < 0.001); whereas, severe VF was significantly more prevalent in women (9.1%) than in men (4.7%, p = 0.003). VF was distributed with 2 peaks regarding site; one large peak at the thoracolumbar region, and another at the middle thoracic lesion. Low back pain and decreased walking ability were independently associated with severe VF, but not with mild VF, after adjustment for participant characteristics. Decreased walking ability was associated with multiple VFs in women, but not in men.

Serum levels of matrix metalloproteinase-3 and autoantibodies related to rheumatoid arthritis in the general Japanese population and their association with osteoporosis and osteoarthritis: the ROAD study.

To purpose of this study was to reveal the mean levels and positive proportion of serological markers related to rheumatoid arthritis, and clarify their relationship with osteoporosis and hand osteoarthritis (OA). A total of 1546 participants from the third survey of the research on osteoarthritis/osteoporosis against disability study were enrolled in the current study. Using participant blood samples, the levels of anti-cyclic citrullinated protein (CCP) antibody, rheumatoid factor (RF), matrix metalloproteinase-3 (MMP-3), C-reactive protein (CRP), and high-sensitivity CRP (hsCRP) were measured. Subjects with higher than normal levels were defined as being positive. Osteoporosis was defined according to the recommendations set by World Health Organization criteria in 1994. Radiographic hand OA was evaluated using the modified Kellgren-Lawrence (KL) scale. The positive proportion of anti-CCP antibody, RF, MMP-3, CRP, and hsCRP was 1.8, 7.1, 15.0, 6.7, and 6.4%, respectively. MMP-3 was associated with age, and was significantly higher in men than in women. Positive MMP-3 was not significantly related to osteoporosis or severe hand OA (KL grade ≥3) after adjustment for other factors including age, sex, and body mass index. The results from this study clarified the values and positive proportion of RA-related markers and revealed their relationship with osteoporosis and hand OA.

The prevalence of tandem spinal stenosis and its characteristics in a population-based MRI study: The Wakayama Spine Study.

PURPOSE: Tandem spinal stenosis (TSS) is a condition of combined spinal stenosis in the cervical and lumbar regions. The purpose of this study was to determine the prevalence of radiographic TSS and its association with developmental canal stenosis (DCS). The second purpose was to investigate the extent to which radiographic TSS is associated with cervical myelopathy and symptomatic LSS. METHODS: We recruited 1011 (336 men and 675 women) participants in this population-based study. After excluding those with a pacemaker, a history of cervical or lumbar surgery, disqualification, the MRI data of whole spine was analysed in 931 (mean, 67.3 years) participants. Cervical cord compression (CCC) and radiographic lumbar spinal stenosis (LSS) were evaluated by MRI. The canal-to-body ratio was also measured by plain X-ray. DCS was diagnosed as canal-to-body ratio <0.75. The diagnosis of cervical myelopathy and symptomatic LSS was made by presentation of both symptoms and radiographic compression using MRI. RESULTS: The prevalence of CCC was 24.7%, that of radiographic LSS was 30.2%, and that of radiographic TSS was 11.0% (men, 14.1%; women, 9.4%). The prevalence of TSS was significantly higher in the DCS group than in the non-DCS group (p < 0.001). Among the participants with radiographic TSS, the prevalence of cervical myelopathy and symptomatic LSS was 9.8 and 18.6%, respectively. The coexisting cervical myelopathy and symptomatic LSS was 6.1% in the participants with LSS. CONCLUSIONS: The present study is the first population-based study to clarify TSS characteristic using whole-spine MRI.

[Two Cases of Tension Pneumothorax during Posterior Spinal Fusion -Diagnosis and Decision on Emergency Drainage-].

We experienced two cases of tension pneumothorax during posterior spinal fusion. Case 1 : A 67-year-old female underwent posterior thoracic-lumbar spinal fusion. One hour after the operation had started, a sudden elevation of airway pressure and decreased Pa02 were observed. Then occasional decrease in blood pressure, tachycardia, and premature ventricular contractions followed. SpO2 re- mained stable throughout the surgery. Case 2 : A 57-year-old female underwent posterior thoracic-lumbar spinal fusion. During the surgical pro- cedure, a sudden decrease in SpO2 accompanied by an air leak from pleura occurred. No remarkable change was observed in hemodynamics. Immediately after the operation had finished, chest X-ray on supine position revealed tension pneumotho- rax in both cases. Patients were extubated after effec- tive lung expansion by insertion of thoracic drainage tube. Tension pneumothorax is a potentially lethal compli- cation during anesthesia, resulting in cardiac arrest Though rapid diagnosis is crucial, physical examination and assessment are limited in patients on prone posi- tion. The possibility must be considered that several conditions as increased airway pressure, impaired oxy- genation and hemodynamics suggest tension pneumo- thorax. Image diagnosis using radiography or ultra- sound can be of value. If once patient on prone position develops cardiac arrest, resuscitation is extremely difficult Emergency drainage should be considered in case of highly im- paired hemodynamics.

Prevalence of hand osteoarthritis and its relationship to hand pain and grip strength in Japan: The third survey of the ROAD study.

OBJECTIVES: To examine the prevalence and pattern of hand osteoarthritis (HOA), and determine its relationship with grip strength and hand pain. METHODS: Among the participants of the third survey of the Research on Osteoarthritis/Osteoporosis Against Disability (ROAD) study, 507 Japanese men and 1028 Japanese women were included. Radiographs of both hands were graded for osteoarthritis (OA) using the modified Kellgren-Lawrence (KL) scale. HOA was defined as the presence of at least one affected joint. The absence or presence of subchondral erosion was also scored. RESULTS: The prevalence of HOA (KL grade ≥2) was 89.9% in men and 92.3% in women (p = 0.11), and it was significantly associated with age. OA in the distal interphalangeal (DIP) joint was the highest overall. After adjusting for age, sex, body mass index, and the residing area, both severity (KL grade ≥3) and erosion were significantly related to low grip strength and hand pain. With regard to the joint groups, severe OA in the DIP and first carpometacarpal joints were related to hand pain. CONCLUSION: This study showed a high prevalence of radiographic HOA and a significant relationship between hand pain and the severity of HOA, in addition to erosion.

Prevalence of diffuse idiopathic skeletal hyperostosis (DISH) of the whole spine and its association with lumbar spondylosis and knee osteoarthritis: the ROAD study.

We aimed to assess the prevalence of diffuse idiopathic skeletal hyperostosis (DISH) and its association with lumbar spondylosis (LS) and knee osteoarthritis (KOA) using a population-based cohort study entitled Research on Osteoarthritis/osteoporosis Against Disability (ROAD). In the baseline ROAD study, which was performed between 2005 and 2007, 1,690 participants in mountainous and coastal areas underwent anthropometric measurements and radiographic examinations of the whole spine (cervical, thoracic, and lumbar) and both knees. They also completed an interviewer-administered questionnaire. Presence of DISH was diagnosed according to Resnick criteria, and LS and KOA were defined as Kellgren-Lawrence (KL) grade ≥3. Among the 1,690 participants, whole-spine radiographs of 1,647 individuals (97.5%; 573 men, 1,074 women; mean age, 65.3 years) were evaluated. Prevalence of DISH was 10.8% (men 22.0%, women 4.8%), and was significantly higher in older participants (presence of DISH 72.3 years, absence of DISH 64.4 years) and mainly distributed at the thoracic spine (88.7%). Logistic regression analysis revealed that presence of DISH was significantly associated with older age [+1 year, odds ratio (OR): 1.06, 95% confidence interval (CI): 1.03-1.14], male sex (OR: 5.55, 95% CI: 3.57-8.63), higher body mass index (+1 kg/m(2), OR: 1.08, 95% CI: 1.02-1.14), presence of LS (KL2 vs KL0: 1, OR: 5.50, 95% CI: 2.81-10.8) (KL ≥3 vs KL0: 1, OR: 4.09, 95% CI: 2.08-8.03), and presence of KOA (KL ≥3 vs KL0: 1, OR: 1.89, 95% CI: 1.14-3.10) after adjusting for smoking, alcohol consumption, and residential area (mountainous vs coastal). This cross-sectional population-based study clarified the prevalence of DISH in general inhabitants and its significant association with LS and severe KOA.

Incidence of disability and its associated factors in Japanese men and women: the Longitudinal Cohorts of Motor System Organ (LOCOMO) study.

We investigated the incidence of disability and its risk factors in older Japanese adults to establish an evidence-based disability prevention strategy for this population. For this purpose, we used data from the Longitudinal Cohorts of Motor System Organ (LOCOMO) study, initiated in 2008 to integrate information from cohorts in nine communities across Japan: Tokyo (two regions), Wakayama (two regions), Hiroshima, Niigata, Mie, Akita, and Gunma prefectures. We examined the annual occurrence of disability from 8,454 individuals (2,705 men and 5,749 women) aged ≥65 years. The estimated incidence of disability was 3.58/100 person-years (p-y) (men: 3.17/100 p-y; women: 3.78/100 p-y). To determine factors associated with disability, Cox's proportional hazard model was used, with the occurrence of disability as an objective variable and age (+1 year), gender (vs. women), body build (0: normal/overweight range, BMI 18.5-27.5 kg/m(2); 1: emaciation, BMI <18.5 kg/m(2); 2: obesity, BMI >27.5 kg/m(2)), and regional differences (0: rural areas including Wakayama, Niigata, Mie, Akita, and Gunma vs. 1: urban areas including Tokyo and Hiroshima) as explanatory variables. Age, body build, and regional difference significantly influenced the occurrence of disability (age, +1 year: hazard ratio 1.13, 95% confidence interval 1.12-1.15, p < 0.001; body build, vs. emaciation: 1.24, 1.01-1.53, p = 0.041; body build, vs. obesity: 1.36, 1.08-1.71, p = 0.009; residence, vs. living in rural areas: 1.59, 1.37-1.85, p < 0.001). We concluded that higher age, both emaciation and obesity, and living in rural areas would be risk factors for the occurrence of disability.

Quadriceps muscle strength, radiographic knee osteoarthritis and knee pain: the ROAD study.

BACKGROUND: The objective of this study was to clarify the association of quadriceps muscle strength with knee pain using a large-scale, population-based cohort of the Research on Osteoarthritis/osteoporosis Against Disability (ROAD) study. METHODS: From the 2566 subjects at the third visit of the ROAD study, the present study analyzed 2152 subjects who completed radiographic examinations and measurements of muscle strength and mass (690 men and 1462 women; mean age, 71.6 ± 12.2 years). Knee pain was assessed by an experienced orthopedist. Knee osteoarthritis (OA) was defined according to Kellgren-Lawrence (KL) grade. Quadriceps muscle strength and muscle mass at the lower limbs were measured by the Quadriceps Training Machine (QTM-05F, Alcare Co., Ltd. Tokyo, Japan) and the Body Composition Analyzer MC-190 (Tanita Corp., Tokyo, Japan), respectively. RESULTS: Quadriceps muscle strength and weight bearing index (WBI: quadriceps muscle strength by weight) were significantly associated with knee pain after adjustment for age and body mass index, whereas grip strength and muscle mass at the lower limbs were not. The significant association of quadriceps muscle strength with knee pain was independent of radiographic knee OA. CONCLUSION: The present cross-sectional study showed an independent association of quadriceps muscle strength with knee pain.

Association between new indices in the locomotive syndrome risk test and decline in mobility: third survey of the ROAD study.

BACKGROUND: We aimed to clarify the association between new indices in a locomotive syndrome risk test and decline in mobility. METHODS: In the third survey of the Research on Osteoarthritis/osteoporosis Against Disability (ROAD) study, data on the indices were obtained from 1575 subjects (513 men, 1062 women) of the 1721 participants in mountainous and coastal areas. As outcome measures for decline in mobility, we used the five-times-sit-to-stand test (FTSST) and walking speed with cutoff values of 12 s and 0.8 m/s, respectively. RESULTS: We first estimated the prevalence of the indices in locomotive syndrome risk test stage 1, including two-step test score <1.3, difficulty with one-leg standing from a 40-cm-high seat in the stand-up test, and 25-question GLFS score ≥7, which were found to be 57.4, 40.6, and 22.6 %, respectively. Next, we investigated the prevalence of the indices in locomotive syndrome risk test stage 2, including two-step test score <1.1, difficulty with standing from a 20-cm-high seat using both legs in the stand-up test, and 25-question GLFS score ≥16, which were found to be 21.1, 7.9, and 10.6 %, respectively. Logistic regression analysis using slow FTSST time or slow walking speed as the objective factor, and presence or absence of indices as the independent factor, after adjusting for confounders, showed all three indices in both stages 1 and 2 were significantly and independently associated with immobility. Finally, we clarified the risk of immobility according to an increasing number of indices in both stages 1 and 2 and found that the odds ratio for both slow FTSST time and slow walking speed increased exponentially. CONCLUSION: We found that the three indices independently predicted immobility and that accumulation of indices increased the risk of immobility exponentially.

Mutual associations among musculoskeletal diseases and metabolic syndrome components: A 3-year follow-up of the ROAD study.

OBJECTIVE: This study aimed to assess the mutual associations between musculoskeletal diseases (knee osteoarthritis [KOA], lumbar spondylosis [LS], osteoporosis [OP]) and metabolic syndrome components (obesity [OB], hypertension [HT], dyslipidemia [DL], impaired glucose tolerance [IGT]). METHODS: Of the 1,690 participants (596 men, 1,094 women) at baseline, 1,384 individuals (81.9%; 466 men, 918 women) had complete data at the first follow-up in 2008. Logistic regression analysis included the occurrence or nonoccurrence of the musculoskeletal diseases or metabolic components as the outcome variable and the remaining musculoskeletal diseases and metabolic components at baseline as explanatory variables, adjusted for age, sex, residential region, smoking, and alcohol consumption. RESULTS: The risk of KOA occurring increased significantly with HT (odds ratio [OR], 2.57; 95% confidence interval [CI], 1.22-5.42; p = 0.013) and IGT (OR, 1.99; 95%CI, 1.07-3.70; p = 0.029). The risk of OP occurring at the lumbar spine increased with OP at the femoral neck (OR, 4.21; 95%CI 1.46-12.1; p = 0.008), and vice versa (OR, 2.19; 95%CI, 1.01-479; p = 0.047). KOA increased the risk of HT (Kellgren-Lawrence [KL] grade = 0, 1 vs. KL = 2: OR, 1.84; 95%CI, 1.09-3.12; p = 0.024) and DL (KL = 0, 1 vs. KL ≥ 3: OR, 1.66; 95%CI, 1.05-2.61; p = 0.029) occurring. Reciprocal relationships existed between the presence of metabolic components and the occurrence of the other metabolic components. CONCLUSION: Mutual relationships existed between the occurrence and presence of musculoskeletal diseases, particularly KOA, and metabolic syndrome components.

[The concept of locomotive syndrome and its relationship with frailty and sarcopenia].

Frailty and sarcopenia both contribute to a functional decline among the elderly, and are reportedly reversible with physical exercise. Locomotive syndrome represents the decline in locomotor function as a result of impairments of the locomotor organs. A healthy locomotor organ is essential for locomotor function, as well as daily living and social activities. Hence, elucidating the mechanism underlying locomotive syndrome may help provide physical fitness professionals with insight into the locomotor function in the elderly. Importantly, locomotor organs primarily undergo degenerative changes after middle age. Moreover, overloading may be a risk factor for degenerated cartilages and intervertebral disks, whereas underloading may also predispose bones and muscles to certain risks.

C/EBPß and RUNX2 cooperate to degrade cartilage with MMP-13 as the target and HIF-2α as the inducer in chondrocytes.

To elucidate the molecular mechanism underlying the endochondral ossification process during the skeletal growth and osteoarthritis (OA) development, we examined the signal network around CCAAT/enhancer-binding protein-ß (C/EBPß, encoded by CEBPB), a potent regulator of this process. Computational predictions and a C/EBP motif-reporter assay identified RUNX2 as the most potent transcriptional partner of C/EBPß in chondrocytes. C/EBPß and RUNX2 were induced and co-localized in highly differentiated chondrocytes during the skeletal growth and OA development of mice and humans. The compound knockout of Cebpb and Runx2 in mice caused growth retardation and resistance to OA with decreases in cartilage degradation and matrix metalloproteinase-13 (Mmp-13) expression. C/EBPß and RUNX2 cooperatively enhanced promoter activity of MMP13 through specific binding to a C/EBP-binding motif and an osteoblast-specific cis-acting element 2 motif as a protein complex. Human genetic studies failed to show the association of human CEBPB gene polymorphisms with knee OA, nor was there a genetic variation around the identified responsive region in the human MMP13 promoter. However, hypoxia-inducible factor-2α (HIF-2α), a functional and genetic regulator of knee OA through promoting endochondral ossification, was identified as a potent and functional inducer of C/EBPß expression in chondrocytes by the CEBPB promoter assay. Hence, C/EBPß and RUNX2, with MMP-13 as the target and HIF-2α as the inducer, control cartilage degradation. This molecular network in chondrocytes may represent a therapeutic target for OA.

Prevalence of knee pain, lumbar pain and its coexistence in Japanese men and women: The Longitudinal Cohorts of Motor System Organ (LOCOMO) study.

The Longitudinal Cohorts of Motor System Organ (LOCOMO) study was initiated in 2008 through a grant from the Ministry of Health, Labour, and Welfare of Japan to integrate information from several cohorts established for the prevention of musculoskeletal diseases. We integrated the information of 12,019 participants (3,959 men and 8,060 women) in the cohorts comprising nine communities located in Tokyo (two regions: Tokyo-1 and Tokyo-2), Wakayama [two regions: Wakayama-1 (mountainous region) and Wakayama-2 (seaside region)], Hiroshima, Niigata, Mie, Akita, and Gunma prefectures. The baseline examination of the LOCOMO study consisted of an interviewer-administered questionnaire, anthropometric measurements, medical information recording, X-ray radiography, and bone mineral density measurement. The prevalence of knee pain was 32.7 % (men 27.9 %; women 35.1 %) and that of lumbar pain was 37.7 % (men 34.2 %; women 39.4 %). Among the 9,046 individuals who were surveyed on both knee pain and lumbar pain at the baseline examination in each cohort, we noted that the prevalence of both knee pain and lumbar pain was 12.2 % (men 10.9 %; women 12.8 %). Logistic regression analysis showed that higher age, female sex, higher body mass index (BMI), living in a rural area, and the presence of lumbar pain significantly influenced the presence of knee pain. Similarly, higher age, female sex, higher BMI, living in a rural area, and the presence of knee pain significantly influenced the presence of lumbar pain. Thus, by using the data of the LOCOMO study, we clarified the prevalence of knee pain and lumbar pain, their coexistence, and their associated factors.

Association of physical activities of daily living with the incidence of certified need of care in the long-term care insurance system of Japan: the ROAD study.

BACKGROUND: The present study aimed to investigate association of physical activities of daily living with the incidence of certified need of care in the national long-term care insurance (LTCI) system in elderly Japanese population-based cohorts. METHODS: Of the 3,040 participants in the baseline examination, we enrolled 1,773 (699 men, 1,074 women) aged 65 years or older who were not certified as in need of care-level elderly at baseline. Participants were followed during an average of 4.0 years for incident certification of need of care in the LTCI system. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) was used assess function. Associated factors in the baseline examination with the occurrence were determined by multivariate Cox proportional hazards regression analysis. Receiver operating characteristic curve analysis was performed to evaluate cut-off values for discriminating between the occurrence and the non-occurrence group. RESULTS: All 17 items in the WOMAC function domain were significantly associated with the occurrence of certified need of care in the overall population. Cut-off values of the WOMAC function score that maximized the sum of sensitivity and specificity were around 4-6 in the overall population, in men, and in women. Multivariate Cox hazards regression analysis revealed that a WOMAC function score ≥4 was significantly associated with occurrence with the highest hazard ratio (HR) for occurrence after adjusting for confounders in the overall population (HR [95 % confidence interval (CI)] 2.54 [1.76-3.67]) and in women [HR (95 % CI) 3.13 (1.95-5.02)]. A WOMAC function score ≥5 was significantly associated with the highest HR for occurrence in men [HR (95 % CI) 1.88 (1.03-3.43)]. CONCLUSIONS: Physical dysfunction in daily living is a predictor of the occurrence of certified need of care. Elderly men with a WOMAC function score ≥5 and women with a score ≥4 should undergo early intervention programs to prevent subsequent deterioration.

Prevalence, incidence and progression of lumbar spondylosis by gender and age strata.

OBJECTIVES: To identify the prevalence, incidence and progression of radiographic lumbar spondylosis (LS). METHODS: From the Adult Health Study conducted by the Radiation Effects Research Foundation, 1,204 participants aged 44-85 years who had lumbar spine radiographs in 1990-1992 were reexamined in 1998-2000 (mean 7.9-year interval). The radiographic severity of LS was determined by Kellgren/Lawrence (KL) grading. RESULTS: In the overall population, the prevalence of radiographic KL ≥ 2 and ≥ 3 LS was 52.9% and 23.6%, respectively. KL ≥ 2 LS was more prevalent in men, whereas KL ≥ 3 LS was more prevalent in women. During the 8-year follow-up, the incidence of KL ≥ 2 LS in men and women was 65.5% and 46.6%, that of KL ≥ 3 LS was 27.3% and 29.5%, that of progressive LS was 31.3% and 34.0%, and multilevel LS was 44.9% and 33.4%, respectively. Body-mass index was a risk factor for both KL ≥ 2 and KL ≥ 3 LS, after adjusting for age and sex. CONCLUSIONS: The present longitudinal study revealed the prevalence, incidence and progression of radiographic LS. Prevalence and incidence of KL ≥ 2 LS was higher in men than women, while, those of KL ≥ 3 were similar between men and women.