Associations between radiographic lumbar spinal stenosis and clinical symptoms in the general population: the Wakayama Spine Study

OBJECTIVE

Many asymptomatic individuals have radiographic lumbar spinal stenosis (LSS), but the prevalence of symptoms among individuals with radiographic LSS has not yet been established. The purpose of this study was to clarify the association between radiographic LSS and clinical symptoms in the general population.

METHODS

In this cross-sectional study, data from 938 participants (308 men, 630 women; mean age, 66.3 years; range, 40-93 years) were analyzed. The severity of radiographic LSS, including central stenosis, lateral stenosis, and foraminal stenosis, was assessed by mobile magnetic resonance imaging and rated qualitatively. Assessment of clinical symptoms was based on the definition of symptomatic LSS in the North American Spine Society guideline.

RESULTS

We found that 77.9% of participants had more than moderate central stenosis and 30.4% had severe central stenosis. Logistic regression analysis after adjustment for age, sex, body mass index, and severity of radiographic LSS showed that severe central stenosis was related to clinical symptoms. However, only 17.5% of the participants with severe central stenosis were symptomatic.

CONCLUSION

Although radiographic LSS was common in our cohort, which resembled the general Japanese population, symptomatic persons were relatively uncommon.

Osteoporosis as a risk factor for the recurrence of benign paroxysmal positional vertigo

OBJECTIVES/HYPOTHESIS

Benign paroxysmal positional vertigo (BPPV) frequently occurs in females over 50 years old, suggesting that a postmenopausal decrease in estrogen secretion might be involved in its onset. An estrogen deficiency is generally known to cause osteoporosis through a reduction in bone mass. This study was designed to investigate a clinical association between idiopathic BPPV and osteoporosis.

STUDY DESIGN

Case-control study.

METHODS

We measured the bone mineral density (BMD) at the lumbar vertebrae in 61 patients with idiopathic BPPV who were postmenopausal women over 50 years old using dual-energy x-ray absorptiometry. After being treated with the canalith repositioning maneuver, the patients were followed up for at least 1 year.

RESULTS

Our results showed that the incidence of osteoporosis in patients with BPPV was 26.2%, which was similar to those observed in epidemiological surveys conducted in Japan. However, we found that in BPPV patients with osteoporosis, the incidence of recurrence was 56.3%, which was significantly higher than that observed in patients with normal bone mineral density (16.1%). Furthermore, the frequency of BPPV recurrence increased as BMD decreased.

CONCLUSIONS

These results suggest that osteoporosis is a risk factor for BPPV recurrence. The prognosis of BPPV might be clinically predicted by BMD reduction.

Association of dietary intake with joint space narrowing and osteophytosis at the knee in Japanese men and women: the ROAD study

OBJECTIVE: The objective of the present study is to identify dietary nutrients associated with joint space narrowing (JSN) and osteophytosis at the knee in a population-based cohort of the Research on Osteoarthritis/osteoporosis Against Disability (ROAD) study. METHODS: From the baseline survey of the ROAD study, 827 participants (305 men and 522 women) in a rural cohort were analyzed. Dietary nutrient intakes for the last month were assessed by a self-administered brief diet history questionnaire. Minimum joint space width (mJSW) and osteophyte area (OPA) in the medial compartment of the knee were measured using a knee osteoarthritis (OA) computer-aided diagnostic system. RESULTS: In men, there were no associations of dietary nutrient intakes with mJSW or OPA. In women, vitamins K, B1, B2, B6, and C were associated with mJSW after adjustment for age, body mass index, and total energy (p < 0.05). Vitamins E, K, B1, B2, niacin, and B6 were significantly associated with OPA (p < 0.05) in women. Vitamins K, B and C may have a protective role against knee OA in women and might lead to disease-modifying treatments. CONCLUSIONS: The present study revealed that low dietary intake of vitamins K, B, and C are associated with JSN and osteophytosis in women.

Physical performance, bone and joint diseases, and incidence of falls in Japanese men and women: a longitudinal cohort study

SUMMARY

This study examined whether physical performance and bone and joint diseases were risk factors for falls in 745 men and 1,470 women from the Research on Osteoarthritis/osteoporosis Against Disability (ROAD) study (mean, 69.7 years). Slower walking speed was a risk factor for falls in men and women. Knee pain was a risk factor for falls in women.

INTRODUCTION

The objective of the present study was to clarify the incidence of falls by sex and age and to determine whether physical performance and bone and joint diseases are risk factors for falls in men and women using a large-scale population-based cohort of the ROAD.

METHODS

A total of 745 men and 1,470 women were analyzed in the present study (mean age, 68.5 years). A questionnaire assessed the number of falls during 3 years of follow-up. Grip strength and walking speed were measured at baseline. Knee and lumbar spine radiographs were read by Kellgren-Lawrence (KL) grade; radiographic knee osteoarthritis and lumbar spondylosis were defined as KL = 3 or 4. Knee and lower back pain were estimated by an interview.

RESULTS

During a mean follow-up of 3 years, 141 (18.9 %) men and 362 (24.6 %) women reported at least one fall. Slower walking speed was a risk factor for falls in men (0.1 m/s decrease; odds ratio [OR], 1.15; 95 % confidence interval [CI], 1.09-1.23) and women (0.1 m/s decrease; OR, 1.05; 95 % CI, 1.01-1.10). Knee pain was also a risk factor for falls (OR, 1.38; 95 % CI, 1.03-1.84) in women, but lower back pain was not.

CONCLUSION

We examined the incidence and risk factors for falls in men and women. Slower walking speed was a risk factor for falls in men and women. Knee pain was a risk factor for falls in women.

Risk factors for falls in a longitudinal population-based cohort study of Japanese men and women: the ROAD Study

The objective of this study was to clarify the associations of physical performance and bone and joint diseases with single and multiple falls in Japanese men and women using a population-based longitudinal cohort study known as Research on Osteoarthritis/osteoporosis Against Disability (ROAD). A total of 452 men and 896 women were analyzed in the present study (mean age, 63.9 years). A questionnaire was used to assess the number of falls during the 3-year follow-up. Grip strength, 6-m walking time, and chair stand time were measured at baseline. Knee osteoarthritis (OA) and lumbar spondylosis were defined as Kellgren Lawrence=2, 3 or 4. Vertebral fracture (VFx) was assessed with the Japanese Society of Bone and Mineral Research criteria. Osteoporosis was defined by bone mineral density using dual energy X-ray absorptiometry based on World Health Organization criteria. Knee and lower back pain were estimated by an interview. During a 3-year follow-up, 79 (17.4%) men and 216 (24.1%) women reported at least one fall, and 54 (11.9%) men and 111 (12.4%) women reported multiple falls. Knee pain was a risk factor for multiple falls in women, but not in men. VFx tended to be associated with multiple falls in women, but not in men. A longer 6-m walking time was a risk factor for multiple falls in women, whereas a longer chair stand time was a risk factor for multiple falls in men. We found gender differences in risk factors for falls.

Accumulation of metabolic risk factors such as overweight, hypertension, dyslipidaemia, and impaired glucose tolerance raises the risk of occurrence and progression of knee osteoarthritis: a 3-year follow-up of the ROAD study

OBJECTIVE

To clarify the association between the occurrence and progression of knee osteoarthritis (KOA) with components of metabolic syndrome (MS), including overweight (OW), hypertension (HT), dyslipidaemia (DL), and impaired glucose tolerance (IGT), in a general population.

DESIGN

From the large-scale population-based cohort study entitled Research on Osteoarthritis/Osteoporosis Against Disability (ROAD) initiated in 2005, 1,690 participants (596 men, 1,094 women) residing in mountainous and coastal areas were enrolled. Of these, 1,384 individuals (81.9%; 466 men, 918 women) completed the second survey, including knee radiography, 3 years later. KOA was defined as Kellgren-Lawrence (KL) grade ≥ 2 using paired X-ray films. Based on changes in KL grades between the baseline and second surveys, cumulative incidence and progression of KOA were determined. OW, HT, DL, and IGT at baseline were assessed using standard criteria.

RESULTS

The cumulative incidence of KOA among 1,384 completers over 3 years was 3.3%/year, and progression in KL grades for either knee, 8.0%/year. Logistic regression analyses after adjusting for potential risk factors revealed that the odds ratio (OR) for the occurrence of KOA significantly increased according to the number of MS components present (OR vs no component: one component, 2.33; two components, 2.82; ≥three components, 9.83). Similarly, progression of KOA significantly increased according to the number of MS components present (OR vs no component: one component, 1.38; two components, 2.29; ≥three components: 2.80).

CONCLUSION

Accumulation of MS components is significantly related to both occurrence and progression of KOA. MS prevention may be useful in reducing future KOA risk.

Prevalence of cervical cord compression and its association with physical performance in a population-based cohort in Japan: the Wakayama Spine Study

STUDY DESIGN

A population-based magnetic resonance imaging (MRI) study of the cervical spine.

OBJECTIVE

This study was undertaken in order to investigate the prevalence of cervical cord compression (CCC) and to examine the association between CCC and physical performance measures in a population-based cohort established in Japan.

SUMMARY OF BACKGROUND DATA

Population-based cohort studies of the prevalence of CCC, although essential for clarification of the prevalence of slowly progressive disease and specification of the time of incidence of CCC, are not available.

METHODS

This cross-sectional study was performed as a part of the Research on Osteoarthritis/osteoporosis Against Disability study, a large-scale population-based cohort study in Japan. From 1011 inhabitants who underwent MRI examinations, images of the cervical spine of 977 subjects (324 men and 653 women, mean age of 66.4 yr) were evaluated. CCC was assessed by sagittal T2-weighted MRI and was defined as spinal cord compression. The prevalence of CCC and its association with myelopathic signs (hyper-reflexia of the patellar tendon and Hoffmann and Babinski reflexes) were examined. In addition, physical performance measures (grip and release test, grip strength, 6-m walking time, step length, chair-stand time, and one-leg standing time) were tested.

RESULTS

The prevalence of CCC was 24.4% and was significantly higher in men (29.3% in men and 21.9% in women, P = 0.011). The prevalence of CCC was higher with increasing age in both sexes. CCC was not significantly associated with any myelopathic signs but was significantly associated with grip and release test, 6-m walking time, step length, and chair-stand time.

CONCLUSION

In this MRI study, the prevalence of CCC was examined. The present results indicate that CCC correlates with physical performance measures from an early stage of the disease before myelopathic signs appear.

Prevalence of symptomatic lumbar spinal stenosis and its association with physical performance in a population-based cohort in Japan: the Wakayama Spine Study

OBJECTIVE

The purpose of this study was to investigate the prevalence of symptomatic lumbar spinal stenosis (LSS) and to clarify the association between symptomatic LSS and physical performance using magnetic resonance imaging (MRI) in a population-based cohort.

DESIGN

This cross-sectional study was performed as a part of the research on osteoarthritis/osteoporosis against disability (ROAD) in Japan and 1,009 subjects (335 men, 674 women, mean age 66.3 years, age range 21-97 years) were analyzed. An experienced orthopedic surgeon obtained the medical history and performed the physical testing for all participants. Symptomatic LSS diagnostic criteria required the presence of both symptoms and radiographic LSS findings. A 6-m walking time, chair standing time, and one-leg standing time were obtained from all participants.

RESULTS

The prevalence of symptomatic LSS was 9.3% (95% confidence interval [CI]: 7.7-11.3) overall, 10.1% (CI: 7.4-13.8) in men and 8.9% (CI: 7.0-11.3) in women. There was a difference in the prevalence with increasing age by gender. The LSS prevalence showed little difference with age greater than 70 years for men, but the LSS prevalence for women was higher with increasing age. Among physical performance measures, 6-m walking time at a maximal pace was significantly associated with symptomatic LSS (P = 0.03).

CONCLUSION

The prevalence of symptomatic LSS was approximately 10% in a cohort resembling the general Japanese population. A 6-m walking time at a maximal pace was a more sensitive index than walking at a usual pace in assessing decreased physical performance associated with symptomatic LSS.

Radiographic features and risk of curve progression of de-novo degenerative lumbar scoliosis in the elderly: a 15-year follow-up study in a community-based cohort

BACKGROUND

Little information is available on the prevalence, incidence, and risk factors associated with curve progression in de-novo degenerative lumbar scoliosis (DNDLS) in the general population. Development of treatment guidelines requires further knowledge about the etiology and natural history of DNDLS in the elderly.

METHODS

To identify the cumulative incidence and radiographic features of DNDLS in the elderly, the authors reanalyzed the results of lumbar radiographic examinations from the Miyama study, which was originally conducted in a Japanese rural community to determine the prevalence of vertebral fractures in Japanese people. DNDLS was defined as a coronal curvature greater than 10° in the Cobb angle in the second survey and progression of greater than 5° compared with curve magnitude in the initial survey. The radiological features of the new curves were documented. The DNDLS group was recruited to compare the risk of curve progression with that in a control group of participants who had no scoliosis during a 15-year follow-up. Ten radiographic features were measured for statistical analysis to determine the prognostic factors of curve progression.

RESULTS

The cumulative incidence of DNDLS was 33/194 (17.0%) in this cohort. There was a tendency for female predominance and frequency increased with age. However, the severity of these curves was relatively low and no curves developed a Cobb angle of greater than 30°, with most in the range 10°-20°. The 2 groups differed significantly in lateral spondylolisthesis and vertebral rotation only at the L3 level.

CONCLUSIONS

The radiographic features of DNDLS revealed mild scoliosis with minimal rotatory deformity. Spinal decompensation by the upper lumbar segments of the asymmetric anatomical deformity in the lower lumbar segments may induce de-novo lumbar scoliosis. Rotatory deformity and lateral spondylolisthesis of the L3 vertebra may be a prognostic factor for DNDLS in the elderly.

The mid-term efficacy of intra-articular hyaluronic acid injections on joint structure: a nested case control study

OBJECTIVE

Intra-articular (IA) injection of hyaluronic acid (HA) has been shown to relieve osteoarthritis (OA)-related pain and improve joint structure within a 1-year period. We examined the mid-term (2-year) efficacy of IA-HA in Japanese subjects by using a large-scale population-based cohort of the Research on Osteoarthritis/Osteoporosis Against Disability study.

METHODS

We performed a nested case control study of 60 case control pairs matched for age (within 1 year), sex, Kellgren and Lawrence grade, and history of knee pain. The mean follow-up period after IA-HA series was 2.9 years in case patients. We examined the association of IA-HA with knee radiographic severity and knee pain. To estimate radiographic severity of OA, six distinct features--joint space area and the minimum joint space width at medial and lateral sides, osteophyte area, and tibiofemoral angle--were measured using a fully automatic computer-assisted program.

RESULTS

Comparison of the radiographic parameters between case patients and controls showed that the medial and lateral joint space areas were significantly bigger in case patients than in controls. After constructing a multivariate logistic regression model to examine the correlation of knee pain, IA-HA, and radiographic features, we found that unlike radiographic features, IA-HA was protectively associated with the presence of pain.

CONCLUSION

IA-HA might effectively improve joint structure and relieve pain in patients with knee OA.

Incidence and risk factors for radiographic lumbar spondylosis and lower back pain in Japanese men and women: the ROAD study

OBJECTIVE

To determine the incidence of radiographic lumbar spondylosis (LS)and lower back pain, and their risk factors in Japan using a large-scale population from the nationwide cohort Research on Osteoarthritis/osteoporosis Against Disability (ROAD) Study.

METHODS

Participants in the ROAD study who had been recruited between 2005 and 2007 were followed up with lumbar spine radiography for 3 years. A total of 2,282 paired radiographs (75% of the original sample) were scored using Kellgren and Lawrence (KL) grades, and the incidence and progression rate of radiographic LS was analyzed. The incidence of lower back pain was also examined. In addition, associations between risk factors and incident and progressive radiographic LS as well as incident lower back pain were tested.

RESULTS

Given a 3.3-year follow-up, the incidence of KL≥2 radiographic LS was 50.0% and 34.4% (15.3% and 10.5% per year), while that of KL≥3 LS was 15.3% and 23.7% (4.6% and 7.2% per year) in men and women, respectively. The progression rate of LS was 20.5% and 27.4% (6.2% and 8.3% per year) in men and in women, respectively. In addition, the incidence of lower back pain was 28.3% and 31.2% (8.6% and 9.5% per year) in men and women. Lower back pain was not significantly associated with incident radiographic LS, while a more severe KL grade at baseline was associated with incident lower back pain.

CONCLUSION

The present longitudinal study revealed a high incidence of radiographic LS in Japan.

Locomotor dysfunction and risk of cardiovascular disease, quality of life, and medical costs: design of the Locomotive Syndrome and Health Outcome in Aizu Cohort Study (LOHAS) and baseline characteristics of the study population

BACKGROUND

There is little evidence regarding long-term outcomes of locomotor dysfunction such as cardiovascular events, quality of life, and death. We are conducting a prospective cohort study to evaluate risk of cardiovascular disease, quality of life, medical costs, and mortality attributable to locomotor dysfunction. The present study determined baseline characteristics of participants in the Locomotive Syndrome and Health Outcome in Aizu Cohort Study (LOHAS).

METHODS

Cohort participants were recruited from residents between 40 and 80 years old who received regular health check-ups conducted by local government each year between 2008 and 2010 in Minami-Aizu Town and Tadami Town in Fukushima Prefecture, Japan. Musculoskeletal examination included assessment of physical examination of the cervical and lumbar spine, and upper and lower extremities and of physical function, such as grasping power, one-leg standing time, and time for the 3-m timed up-and-go test. Cardiovascular risk factors, including blood pressure and biological parameters, were measured at annual health check-ups. We also conducted a self-administered questionnaire survey.

RESULTS

LOHAS participants comprised 1,289 men (mean age 65.7 years) and 1,954 women (mean age 66.2 years) at the first year. The proportion of obese individuals (body mass index 25.0 kg/m(2)) was 31.9% in men and 34.3% in women, and 41.0% of participants reported being followed up for hypertension, 7.0% for diabetes, and 43.6% for hypercholesterolemia. Prevalence of lumbar spinal stenosis was 10.7% in men and 12.9% in women, while prevalence of low back pain was 15.8% in men and 17.6% in women.

CONCLUSION

The LOHAS is a novel population-based prospective cohort study that will provide an opportunity to estimate the risk of cardiovascular disease, quality of life, medical costs, and mortality attributable to locomotor dysfunction, and to provide the epidemiological information required to develop policies for detection of locomotor dysfunction.

Independent association of joint space narrowing and osteophyte formation at the knee with health-related quality of life in Japan: a cross-sectional study

OBJECTIVE

To clarify the individual associations of joint space narrowing (JSN) and osteophytosis at the knee with quality of life (QOL) in Japanese men and women using a large-scale population-based cohort from the Research on Osteoarthritis Against Disability (ROAD) study.

METHODS

The associations of minimum joint space width (JSW) and osteophyte area in the medial compartment of the knee with QOL parameters, such as the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), were examined. Minimum JSW and osteophyte area in the medial compartment of the knee were measured using a computer-aided system for the diagnosis of knee osteoarthritis.

RESULTS

Of the 3,040 participants in the ROAD study, the present study included 2,039 participants age 40 years or older who completed the questionnaires (741 men and 1,298 women with a mean ± SD age of 68.6 ± 10.9 years). Multiple regression analysis after adjustment for age and body mass index showed that minimum JSW was significantly associated with scores on the pain domains of the WOMAC in men and women, while osteophyte area was significantly associated with scores on the physical function domains of the WOMAC in men and women.

CONCLUSION

The findings of this cross-sectional study using a large-scale population from the ROAD study indicate that JSN and osteophytosis are independently associated with QOL.

Does mild cognitive impairment affect the occurrence of radiographic knee osteoarthritis? A 3-year follow-up in the ROAD study

OBJECTIVE

To determine whether mild cognitive impairment (MCI) increases the risk of occurrence or progression of radiographic knee osteoarthritis (KOA) in a general population.

DESIGN

Population-based cohort study.

SETTING

Residents in mountain and seaside areas of Wakayama Prefecture, Japan.

PARTICIPANTS

1690 participants (596 men, 1094 women; mean age 65.2 years old) were enrolled from the large-scale cohort for the Research on Osteoarthritis (OA)/osteoporosis Against Disability (ROAD) study initiated in 2005 to investigate epidemiological features of OA in Japan. Of these, 1384 individuals (81.9%; 466 men, 918 women) completed the second survey including knee radiography 3 years later.

PRIMARY OUTCOME MEASURES

Radiographic KOA was defined as Kellgren-Lawrence (KL) grade ≥ 2 using paired x-ray films. Incidence of KOA during follow-up defined on radiographs as KL grade ≥2, progression of KOA defined as a higher KL grade (either knee) at follow-up compared with baseline. MCI defined as a summary mini-mental state examination (MMSE) score ≤23. Associations between MCI and incidence or progression of KOA were analysed.

RESULTS

The annual cumulative incidence of KOA was 3.3%; for progression of OA it was 8.0%. On logistic regression analysis adjusted for age, gender, regional differences, body mass index, grip strength (worse side), smoking, alcohol consumption, regular exercise and history of knee injury, baseline MMSE summary score was significantly associated with the incidence of KOA (+1 MMSE score; OR 0.83, p=0.010). Baseline MCI was also significantly associated with the incidence of KOA (vs non-occurrence of KOA; OR 4.90, p=0.027). There was no significant association between MMSE scores, the presence of MCI and progression of KOA (+1 MMSE score; OR 0.96, p=0.232; vs non-progression of KOA; OR 1.38, p=0.416).

CONCLUSIONS

MCI significantly increases the risk of incident radiographic KOA, but not the progression of KOA.

C/EBPβ 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-β (C/EBPβ, 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/EBPβ in chondrocytes. C/EBPβ 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/EBPβ 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/EBPβ expression in chondrocytes by the CEBPB promoter assay. Hence, C/EBPβ 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.

Health-related quality of life in subjects with low back pain and knee pain in a population-based cohort study of Japanese men: the Research on Osteoarthritis Against Disability study

STUDY DESIGN

Cross-sectional surveys of health-related quality of life (QOL) in subjects with low back pain and knee pain using a population-based cohort.

OBJECTIVE

The purpose of the present study was to clarify the impact of low back pain and knee pain on QOL in men. In addition, we analyzed the impacts of vertebral fracture (VFx), lumbar spondylosis, and knee osteoarthritis (OA) on the magnitude of QOL loss in men with low back pain and knee pain.

SUMMARY OF BACKGROUND DATA

Low back pain and knee pain are major public health issues causing disability among the elderly men, but there were no population-based studies to compare the impact of low back pain on QOL with that of knee pain in Japanese men.

METHODS

From 3040 participants in the Research on Osteoarthritis Against Disability study, data from 767 men older than 40 years who completed questionnaires (mean age = 69.7 years) were examined. To carry out the QOL assessment, the Medical Outcomes Study Short Form 8 (SF-8) and EuroQol (EQ-5D) were used. We examined the association of low back pain and knee pain with QOL. Furthermore, we also examined the presence of VFx and the severity of lumbar spondylosis and knee OA with the magnitude of QOL loss in men with low back pain and knee pain, respectively.

RESULTS

The impact of low back pain on QOL was larger than that of knee pain. In men with low back pain, there were few associations between Kellgren-Lawrence grade and QOL, whereas VFx was associated with physical QOL. For men with knee pain, Kellgren-Lawrence grade equal to 4 knee OA was associated with QOL.

CONCLUSION

This study revealed that low back pain has a larger impact than knee pain on QOL. Furthermore, low back pain with VFx is strongly associated with physical QOL loss.

Association of occupational activity with joint space narrowing and osteophytosis in the medial compartment of the knee: the ROAD study (OAC5914R2)

OBJECTIVE

We investigated the association of occupational activity with joint space narrowing and osteophytosis at the knee separately in Japanese subjects using a large-scale population-based cohort of the Research on Osteoarthritis Against Disability (ROAD).

METHODS

From the baseline survey of the ROAD study, 1,402 participants (512 men and 890 women) living in mountainous and seacoast communities were analyzed. Information collected included a lifetime occupational history and details of specific workplace physical activities. To estimate the severity of joint space narrowing and osteophytosis at the knee, minimum joint space width (mJSW) and osteophyte area (OPA) in the medial compartment of the knee were measured using a knee osteoarthritis (OA) computer-aided diagnosis system.

RESULTS

For women, agricultural, forestry, and fishery workers had significantly lower mJSW values compared with clerical workers or technical experts, whereas OPA did not differ significantly among job titles in men or women. For occupational activities, kneeling and squatting were associated with lower mJSW as well as higher OPA. Walking and heavy lifting were associated with lower mJSW, but not with OPA.

CONCLUSION

This cross-sectional study using a population-based cohort suggests that an occupational activity that includes kneeling and squatting appears to have a greater effect on knee OA.

Biochemical markers of bone turnover as predictors of osteoporosis and osteoporotic fractures in men and women: 10-year follow-up of the Taiji cohort

We aimed to assess the capacity of biochemical markers of bone turnover (BTMs) to predict bone loss, osteoporosis (OP), and osteoporotic fractures. We randomly selected 400 individuals (age 40-79 years in 1993; 50 of each gender and age stratum) from a list of registered residents. In the years 1993, 1996, 2000, and 2003, bone mineral density (BMD) of the spine and hip were measured by dual-energy X-ray absorptiometry. The BTMs assessed at baseline were serum intact osteocalcin (OC), total OC, bone-specific alkaline phosphatase, C-terminal propeptide of type I procollagen, N-terminal propeptide of type I procollagen (PINP), C-terminal cross-linking telopeptide of type I collagen generated by matrix metalloproteinase, C-terminal cross-linking telopeptide of type I collagen (beta-CTX), N-terminal cross-linking telopeptide of type I collagen (NTX), urinary pyridinoline, and deoxypyridinoline (DPD). For 307 completers, multivariate analysis after adjusting for confounders revealed that serum PINP levels in men [hazard ratio (HR) 2.80, P < 0.05] and serum PINP (HR 1.65, P < 0.05), beta-CTX (HR 1.80, P < 0.001), NTX (HR 1.96, P < 0.01), and urinary DPD levels (HR 1.40, P < 0.05) in women were significantly related to the occurrence of spinal OP. In addition to adjustment for the baseline status of BMD, i.e., osteopenia or normal range, PINP, beta-CTX, and NTX in women could significantly predict the future occurrence of spinal OP. BTMs were not significant predictors of bone loss, femoral OP, or osteoporotic fractures. In conclusion, various BTMs in women can predict the occurrence of spinal OP.

Association of Knee Osteoarthritis with the Accumulation of Metabolic Risk Factors Such as Overweight, Hypertension, Dyslipidemia, and Impaired Glucose Tolerance in Japanese Men and Women: The ROAD Study

Objective.

To clarify the association of knee osteoarthritis (KOA) with overweight (OW), hypertension (HTN), dyslipidemia (DL), and impaired glucose tolerance (IGT), which are components of metabolic syndrome (MS), in a Japanese population.

Methods.

We enrolled 1690 participants (596 men, 1094 women) from the large-scale cohort study Research on Osteoarthritis Against Disability (ROAD), begun in 2005 to clarify epidemiologic features of OA in Japan. KOA was evaluated by the Kellgren-Lawrence grade, minimum joint space width (MJSW), minimum joint space area (JSA), and osteophyte area (OPA). OW, HTN, DL, and IGT were assessed using standard criteria.

Results.

The prevalence of KOA in the total population in the age groups ≤ 39, 40–49, 50–59, 60–69, 70–79, and ≥ 80 years was 2.2%, 10.7%, 28.2%, 50.8%, 69.0%, and 80.5%, respectively. Logistic regression analyses after adjustment for age, sex, regional difference, smoking habit, alcohol consumption, physical activities, regular exercise, and history of knee injuries revealed that the OR of KOA significantly increased according to the number of MS components present (1 component: OR 1.21, 95% CI 0.88–1.68, p = 0.237; 2 components: OR 1.89, 95% CI 1.33–2.70, p < 0.001; 3 or more components: OR 2.72, 95% CI 1.77–4.18; p < 0.001). The number of MS components was inversely related to medial MSJW (ß = −0.148, R2= 0.21, p < 0.001), medial JSA (women only; ß = −0.096, R2= 0.18, p = 0.001), and positively related to OPA (ß = 0.12, R2= 0.11, p < 0.001).

Conclusion.

The accumulation of MS components is significantly related to presence of KOA. MS prevention may be useful to reduce cardiovascular disease and KOA risk.

HIF-2α as a possible therapeutic target of osteoarthritis

OBJECTIVE

Endochondral ossification, a conversion process from nonvascularized and hypoxic cartilage to highly vascularized bone, plays a crucial role in osteoarthritis (OA) development as well as in physiological skeletal growth. We have shown that hypoxia-inducible factor-2α (HIF-2α, encoded by EPAS1) is an extensive regulator of the endochondal ossification process. Here we review the possible signaling network regulating OA development on the axis of HIF-2α.

METHODS

Peer reviewed publications published prior to August 2010 were searched in the Pubmed database. Articles that were relevant to HIF and molecular mechanisms of the endochondral ossification and OA were selected.

RESULTS

As a trigger of OA, mechanical stress may induce the upstream NF-κB signal and HIF-2α expression in joint cartilage of mice and humans, which causes transactivation of endochondral ossification-related molecules with the most potent β-subunit partner aryl hydrocarbon nuclear translocator-like (ARNTL). In contrast to HIF-2α, HIF-1α functions to maintain cartilage via a distinct mechanism, so that the shifting of the HIFs might possibly be involved in an OA pathogenesis.

CONCLUSION

Signals on the HIF-2α axis from NF-κB signaling to the endochondral ossification-related molecules, possibly in combination with HIF-2α and ARNTL, may represent a rational therapeutic target for OA with minimal effects on physiological skeletal homeostasis.

Normal and threshold values of radiographic parameters for knee osteoarthritis using a computer-assisted measuring system (KOACAD): the ROAD study

BACKGROUND

Although radiographic severity of the knee is commonly determined by the Kellgren-Lawrence (KL) grading scale, it does not separately assess joint space narrowing or osteophyte formation. The present study aimed to establish normal and threshold values of radiographic parameters for knee osteoarthritis (OA) using the knee osteoarthritis computer-aided diagnosis (KOACAD) measuring system on a large-scale population-based cohort of the Research on Osteoarthritis/Osteoporosis Against Disability (ROAD) population.

METHODS

From a total of 3040 participants in the ROAD study, standing anteroposterior radiographs of the knee were obtained from 2975 subjects (1041 men, 1934 women) in the ROAD cohort, and 5950 knees were evaluated using the KOACAD system to obtain the medial and lateral minimum joint space width (mJSW), medial and lateral joint space area (JSA), osteophyte area (OPA), and femorotibial angle (FTA). These indices were compared with the KL scores, and cutoff values for radiographic knee OA were determined by receiver operating characteristic (ROC) curve analysis.

RESULTS

The mean KOACAD parameters for KL = 0 were as follows: medial mJSW 3.70 mm; lateral mJSW 4.77 mm, medial JSA 125.0 mm(2), lateral JSA 140.0 mm(2), OPA 0, and FTA 176.1° in men; for women they were medial mJSW 3.26 mm, lateral mJSW 4.22 mm, medial JSA 100.9 mm(2), lateral JSA 111.0 mm(2), OPA 0, and FTA 174.9°. Threshold values for KL ≥ 2 provided by ROC curve analysis with area under the curve (AUC) > 0.7 were medial mJSW 2.8 mm and medial JSA 107.3 mm(2) in men and medial mJSW 2.7 mm in women. Those for KL ≥ 3 were medial mJSW 2.1 mm, medial JSA 81.1 mm(2), OPA 2.4 mm(2), and FTA 179.6° in men; and medial mJSW 2.1 mm, medial JSA 66.6 mm(2), OPA 2.5 mm(2), and FTA 178.1° in women. We then determined the cutoff values for medial knee OA and lateral knee OA.

CONCLUSIONS

The present study established normal and threshold values of parameters for knee OA using an automated computer-assisted program on plain radiographs.

Association of radiographic and symptomatic knee osteoarthritis with health-related quality of life in a population-based cohort study in Japan: the ROAD study

OBJECTIVE

Knee osteoarthritis (OA) is a major public health issue causing chronic pain and disability. However, there is little information on the impact of this disease on quality of life (QOL) in Japanese men and women. The objective of the present study was to clarify the impact of radiographic and symptomatic knee OA on QOL in Japan.

METHODS

This study examined the association of radiographic and symptomatic knee OA with QOL parameters such as the Medical Outcomes Study Short Form-8 (SF-8), EuroQOL (EQ-5D) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Radiographic knee OA was defined according to Kellgren/Lawrence (KL) grades, and symptomatic knee OA was defined as KL=3 or 4 with knee pain. We also examined the independent association of symptomatic knee OA and grip strength with QOL.

RESULTS

From the 3040 participants in the Research on Osteoarthritis Against Disability (ROAD) study, the present study analyzed 2126 subjects older than 40 years who completed the questionnaires (767 men and 1359 women; mean age, 68.9+/-10.9 years). Subjects with KL=3 or 4 had significantly lower physical QOL as measured by the physical component summary (PCS) score of the SF-8 and pain domains of the WOMAC, whereas mental QOL, as measured by the mental component summary (MCS) score of the SF-8, was higher in subjects with KL=3 or 4 than KL=0 or 1. Symptomatic knee OA was significantly more likely than radiographic knee OA without pain to be associated with physical QOL loss as measured by the PCS score and physical domains of the WOMAC. Symptomatic knee OA and grip strength were independently associated with physical QOL.

CONCLUSION

This cross-sectional study revealed that subjects with symptomatic knee OA had significantly lower physical QOL than subjects without it.

Impact of knee and low back pain on health-related quality of life in Japanese women: the Research on Osteoarthritis Against Disability (ROAD)

Although knee and low back pain are major public health issues, little information is available on their impact on the quality of life (QOL). We have investigated the impact of knee and low back pain on the QOL in Japanese women by assessing the associations between knee pain and low back pain and various QOL domains using measures such as the Medical Outcomes Study Short Form-8, EuroQOL, and the Western Ontario and McMaster Universities Osteoarthritis Index. From the 3,040 Japanese women participating in the Research on Osteoarthritis Against Disability (ROAD) study, we analyzed data on 1,369 women >40 years old (mean age 68.4 years). We further examined the associations of Kellgren-Lawrence (KL) grade at the knee and lumbar spine and the presence of vertebral fracture (VFx) with the magnitude of QOL loss in women with knee pain and low back pain, respectively. Knee pain and low back pain were found to be significantly associated with lower QOL scores among the women comprising the study cohort. In women with knee pain KL = 4, knee osteoarthritis was strongly associated with the magnitude of QOL loss. For women with low back pain, no significant associations were found between KL grade and magnitude of QOL loss, while there was a moderate association between the latter and VFx.