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.

Incidence rate and risk factors for radiographic hip osteoarthritis in Japanese men and women: a 10-year follow-up of the ROAD study

OBJECTIVE

To investigate the incidence and progression rate of radiographic hip osteoarthritis (OA) and its risk factors in Japanese men and women using a large-scale population of a nationwide cohort study, Research on Osteoarthritis/osteoporosis Against Disability (ROAD).

METHODS

From the baseline survey of the ROAD study, 2,975 participants (1,043 men and 1,932 women) aged 23-94 years (mean, 70.2 years) living in urban, mountainous, and coastal communities were followed up with hip radiography at 3, 7, and 10 years (mean follow-up, 7.1 years). Radiographs were scored using the Kellgren/Lawrence (K/L) grading system, and radiographic hip OA was defined as K/L ≥ 2. The incidence and progression rate of hip OA were examined. Acetabular dysplasia was defined as a central-edge angle <20°. Cox's proportional hazard model was used to assess risk factors for incident and progressive radiographic hip OA.

RESULTS

The incidence rate of radiographic hip OA was 5.6/1,000 person-years and 8.4/1,000 person-years in men and women, respectively. The progression rate of hip OA was 2.2/1,000 person-years and 6.0/1,000 person-years in men and women, respectively. The significant risk factors for incident hip OA were age, obesity, and acetabular dysplasia at baseline (hazard risk [HR] 1.05, 95% confidence interval [CI] 1.03-1.08; 1.78, 1.10-2.75; 2.06, 1.30-3.17, respectively). The significant risk factors for progressive hip OA were baseline hip pain and acetabular dysplasia (HR 5.68, 95%CI 1.07-22.61; 14.78, 3.66-56.06, respectively).

CONCLUSION

Continued longitudinal surveys of the ROAD study will contribute to knowledge about and potential prevention of incident and progressive hip OA.

Do sarcopenia and/or osteoporosis increase the risk of frailty? A 4-year observation of the second and third ROAD study surveys

In this 4-year follow-up study including 1083 subjects (≥ 60 years), the prevalence of frailty was estimated to be 5.6%; osteoporosis was found to be significantly associated with frailty. Moreover, the presence of both osteoporosis and sarcopenia increased the risk of frailty compared to the presence of osteoporosis or sarcopenia alone.

INTRODUCTION

This study aims to examine the contribution of sarcopenia and osteoporosis to the occurrence of frailty using 4-year follow-up information of a population-based cohort study.

METHODS

The second survey of the Research on Osteoarthritis/Osteoporosis Against Disability (ROAD) study was conducted between 2008 and 2010; 1083 subjects (aged ≥ 60 years, 372 men, 711 women) completed all examinations on frailty, sarcopenia, and osteoporosis, which were defined using Fried's definition, Asian Working Group for Sarcopenia criteria, and WHO criteria, respectively. The third survey was conducted between 2012 and 2013; 749 of 1083 individuals enrolled from the second survey (69.2%, 248 men, 501 women) completed assessments identical to those in the second survey.

RESULTS

The prevalence of frailty in the second survey was 5.6% (men, 3.8%; women, 6.6%). The cumulative incidence of frailty was 1.2%/year (men, 0.8%/year; women, 1.3%/year). After adjustment for confounding factors, logistic regression analysis indicated that osteoporosis was significantly associated with the occurrence of frailty (odds ratio, 3.07; 95% confidence interval, 1.26-7.36; p = 0.012). Moreover, the occurrence of frailty significantly increased according to the presence of osteoporosis and sarcopenia (odds ratio vs. neither osteoporosis nor sarcopenia: osteoporosis alone, 2.50; osteoporosis and sarcopenia, 5.80).

CONCLUSIONS

Preventing osteoporosis and coexistence of osteoporosis and sarcopenia may help reduce the risk of frailty.

Radiographic measurements of the hip joint and their associations with hip pain in Japanese men and women: the Research on Osteoarthritis/osteoporosis Against Disability (ROAD) study

OBJECTIVE

To investigate radiographic measurements of the hip joint and their associations with hip pain, and the prevalence of acetabular dysplasia defined by radiographic measurements of the hip joint in Japanese men and women using the large-scale population-based cohort of the Research on Osteoarthritis/osteoporosis Against Disability (ROAD) study.

METHODS

From the baseline survey of the ROAD study (cross-sectional study), 2963 participants (1040 men, 1923 women; mean age, 70.2 years) were analyzed. All participants underwent radiographic examinations of both hips using an anteroposterior view under weight-bearing. Minimum joint space width (mJSW), central-edge (CE) angle, acetabular depth-to-width ratio (ADR), and acetabular head index (AHI) were measured. Associations between these radiographic measurements and hip pain were assessed by calculating odds ratios (ORs) using multivariable logistic-regression analysis. Acetabular dysplasia was defined as a CE angle <20°.

RESULTS

Mean radiographic measurements of the hip joint for men were: mJSW, 3.8 mm; CE angle, 30.6°; ADR, 262.1 per 1000; and AHI, 81.4%. For women, these values were: mJSW, 3.4 mm; CE angle, 29.9°; ADR, 262.7 per 1000; and AHI, 81.2%. Associations were seen between hip pain and each of mJSW, CE angle, ADR, and AHI (OR 4.52, 95% confidence interval 3.45-5.97; 1.14, 1.11-1.18; 1.31, 1.24-1.40; and 1.15, 1.12-1.18, respectively). Acetabular dysplasia showed an overall prevalence of 13.9%, and was significantly more prevalent in women than in men (P = 0.012).

CONCLUSION

The present study of radiographic measurements of the hip joint showed that mJSW, CE angle, ADR, and AHI were associated with hip pain.

Is osteoporosis a predictor for future sarcopenia or vice versa? Four-year observations between the second and third ROAD study surveys

In a 4-year follow-up study that enrolled 1099 subjects aged ≥60 years, sarcopenia prevalence was estimated at 8.2%. Moreover, the presence of osteoporosis was significantly associated with short-term sarcopenia occurrence, but the reciprocal relationship was not observed, suggesting that osteoporosis would increase the risk of osteoporotic fracture and sarcopenia occurrence.

INTRODUCTION

The present 4-year follow-up study was performed to clarify the prevalence, incidence, and relationships between sarcopenia (SP) and osteoporosis (OP) in older Japanese men and women.

METHODS

We enrolled 1099 participants (aged, ≥60 years; 377 men) from the second survey of the Research on Osteoarthritis/Osteoporosis against Disability (ROAD) study (2008-2010) and followed them up for 4 years. Handgrip strength, gait speed, skeletal muscle mass, and bone mineral density were assessed. SP was defined according to the Asian Working Group for Sarcopenia. OP was defined based on the World Health Organization criteria.

RESULTS

SP prevalence was 8.2% (men, 8.5%; women, 8.0%) in the second survey. In those with SP, 57.8% (21.9%; 77.6%) had OP at the lumbar spine L2-4 and/or femoral neck. SP cumulative incidence was 2.0%/year (2.2%/year; 1.9%/year). Multivariate regression analysis revealed that OP was significantly associated with SP occurrence within 4 years (odds ratio, 2.99; 95% confidence interval, 1.46-6.12; p < 0.01), but the reciprocal relationship was not significantly observed (2.11; 0.59-7.59; p = 0.25).

CONCLUSIONS

OP might raise the short-term risk of SP incidence. Therefore, OP would not only increase the risk for osteoporotic fracture but may also increase the risk for SP occurrence.

Prevalence of radiographic hip osteoarthritis and its association with hip pain in Japanese men and women: the ROAD study

OBJECTIVE

Although hip osteoarthritis (OA) is a major cause of hip pain and disability in elderly people, few epidemiologic studies have been performed. We investigated the prevalence of radiographic hip OA and its association with hip pain in Japanese men and women using a large-scale population of a nationwide cohort study, Research on Osteoarthritis/osteoporosis Against Disability (ROAD).

METHODS

From the baseline survey of the ROAD study, 2975 participants (1043 men and 1932 women), aged 23-94 years (mean 70.2 years), living in urban, mountainous, and coastal communities were analyzed. The radiographic severity at both hips was determined by the Kellgren/Lawrence (K/L) grading system. Radiographic hip OA was defined as K/L ≥ 2, and severe radiographic hip OA as K/L ≥ 3.

RESULTS

The crude prevalence of radiographic hip OA was 18.2% and 14.3% in men and women, respectively, that of severe radiographic hip OA was 1.34% and 2.54%, and that of symptomatic K/L ≥ 2 OA was 0.29% and 0.99%, respectively. The crude prevalence of hip OA, including severe OA, was not age-dependent in men or women. Male sex was a risk factor for radiographic hip OA, whereas female sex was a risk factor for severe radiographic hip OA and hip pain. Compared with K/L = 0/1, hip pain was significantly associated with K/L ≥ 3, but not with K/L = 2.

CONCLUSION

The present cross-sectional study revealed the prevalence of radiographic hip OA and severe hip OA in Japanese men and women. Hip pain was strongly associated with K/L ≥ 3.

Factors affecting changes in the serum levels of 25-hydroxyvitamin D: a 3-year follow-up of the ROAD study

In this 3-year population-based cohort study, among 1346 subjects, the mean annual change in the serum 25-hydroxyvitamin D levels was 7.6 %/year, which tended to increase during the 3-year period. Multivariate regression analysis indicated that the L2-4 bone mineral density and total daily energy intake were significant independent associated factors.

INTRODUCTION

The aim of this study was to clarify the change rate of the serum levels of 25-hydroxyvitamin D (25D) and the associated factors in a general Japanese population during a 3-year period.

METHODS

The baseline survey of Research on Osteoarthritis/osteoporosis Against Disability study (ROAD), a large-scale population-based cohort study, was performed between 2005 and 2007, and a follow-up survey was repeated 3 years later. Among 1690 participants at baseline, the change rate of the serum 25D levels were assessed in 1346 individuals (79.6 %; 458 men and 888 women) who completed measurements of 25D at both the baseline and follow-up examinations. The change rate was calculated, and the factors associated with the changes in the 25D levels were determined using multivariate regression analysis after adjustment for age, gender, body mass index, participated month, and regional differences at baseline.

RESULTS

The mean (standard deviation) change rate of the 25D levels in all subjects was 7.6 (13.3) %/year (men, 8.2 [12.4] %/year; women, 7.3 [13.7] %/year). Multivariate regression analysis indicated that higher bone mineral density at lumbar spine L2-4 (p = 0.05) and total daily energy intake (p = 0.04) were significantly associated with the change rate of the 25D levels.

CONCLUSIONS

The serum levels of 25D tended to increase over the 3-year period, and higher lumbar bone mineral density and daily energy intake were found to be associated with increases in the 25D levels over time.

Serum levels of 25-hydroxyvitamin D and the occurrence of musculoskeletal diseases: a 3-year follow-up to the road study

Assessment of serum 25-hydroxyvitamin D levels in association with the occurrence of musculoskeletal diseases using a population-based cohort study design revealed that serum 25-hydroxyvitamin D levels could predict the occurrence of osteoporosis at the femoral neck within 3 years, but not the occurrence of knee osteoarthritis or lumbar spondylosis.

INTRODUCTION

The aim of this study is to clarify the association between serum 25-hydroxyvitamin D (25D) levels and occurrence of osteoporosis and osteoarthritis in the general population.

METHODS

The Research on Osteoarthritis/Osteoporosis Against Disability study, a large-scale population-based cohort study, was performed during 2005-2007. Serum 25D levels were measured in 1,683 participants. Of these, 1,384 individuals (81.9%) completed a second follow-up survey 3 years later. Osteoporosis was defined according to World Health Organization criteria, in which osteoporosis is diagnosed by T-scores of bone mineral density (BMD) that are 2.5 standard deviations (SD) less than normal BMD. Knee osteoarthritis and lumbar spondylosis were defined as Kellgren-Lawrence grade ≥2, using paired X-ray films. Cumulative incidences were determined according to changes in measurements using World Health Organization criteria for osteoporosis or Kellgren-Lawrence grades for osteoarthritis between the baseline and second survey.

RESULTS

The mean (SD) serum 25D level of the 1,384 participants in both surveys was 23.4 ng/mL (6.5). The annual cumulative incidences of osteoporosis at L2-4 and the femoral neck were 0.76 and 1.83%/year, respectively. The incidences of knee osteoarthritis and lumbar spondylosis were 3.3 and 11.4%/year, respectively. After adjusting for potential associated factors, logistic regression analyses revealed that the odds ratio for the occurrence of femoral neck osteoporosis significantly decreased as serum 25D levels increased (+1 SD; odds ratio 0.67; 95% confidence interval 0.49-0.92; p = 0.014).

CONCLUSIONS

Higher serum 25D levels may prevent the occurrence of osteoporosis at the femoral neck, but not knee osteoarthritis, lumbar spondylosis, or osteoporosis at L2-4.

Prevalence and progression of radiographic ossification of the posterior longitudinal ligament and associated factors in the Japanese population: a 3-year follow-up of the ROAD study

SUMMARY

The prevalence of radiographic cervical ossification of the posterior longitudinal ligament (OPLL) in 1,562 Japanese from a population-based cohort was 1.9 %. The presence of OPLL showed a significant association with the femoral neck bone mineral density (BMD), presence of diffuse idiopathic skeletal hyperostosis (DISH) and plasma pentosidine levels. Only one new case of radiographic OPLL was detected, but OPLL progressed in all affected subjects.

INTRODUCTION

The purpose of this study was to clarify the prevalence and progression of radiographic OPLL and the associated factors, using the population-based cohort Research on Osteoarthritis/osteoporosis Against Disability (ROAD).

METHODS

In the ROAD study, 1,690 participants underwent X-ray examination of the entire spine and both knees. Radiographic OPLL, lumbar spondylosis, knee osteoarthritis and DISH were diagnosed by a single, well-experienced orthopaedic surgeon. An interviewer-administered questionnaire and tests for anthropometric measurements were administered, and the BMDs of the lumbar spine and proximal femur were determined. A new OPLL case was considered if heterotopic ossification in the posterior longitudinal ligament was absent at baseline but present during follow-up. Progression was defined as an increase in the maximum length or width of the ossification at follow-up over that at baseline.

RESULTS

Radiographic OPLL was detected in 30 (17 men, 13 women) of 1,562 individuals who underwent X-ray examination of the cervical spine (prevalence = 1.9 %). Its prevalence was significantly higher in men than in women (p = 0.007), but no association with age was observed. In a logistic regression analysis, OPLL showed a significant association with the femoral neck BMD, presence of DISH and plasma pentosidine levels. Only one new case of radiographic OPLL was detected, but OPLL progressed in all affected subjects.

CONCLUSION

This population-based study clarified the prevalence of radiographic OPLL in the Japanese population as well as its progression. OPLL showed significant association with plasma pentosidine levels, BMD and DISH.

Exercise habits during middle age are associated with lower prevalence of sarcopenia: the ROAD study

SUMMARY

The present cross-sectional study investigated the prevalence of sarcopenia and clarified its associated factors in 1,000 elderly participants of Japanese population-based cohorts. Exercise habit in middle age was associated with low prevalence of sarcopenia in older age, suggesting that it is a protective factor against sarcopenia in older age.

INTRODUCTION

The present study investigated the prevalence of sarcopenia using the European Working Group on Sarcopenia in Older People (EWGSOP) definition, and clarified the association of sarcopenia with physical performance in the elderly participants of Japanese population-based cohorts of the Research on Osteoarthritis/osteoporosis Against Disability (ROAD) study.

METHODS

We enrolled 1,000 participants (aged ≥65 years) from the second visit of the ROAD study who had completed assessment of handgrip strength, gait speed, and skeletal muscle mass measured by bioimpedance analysis. Presence of sarcopenia was determined according to the EWGSOP algorithm. Information collected included exercise habits in middle age.

RESULTS

Prevalence of sarcopenia was 13.8 % in men and 12.4 % in women, and tended to be significantly higher according to increasing age in both sexes. Factors associated with sarcopenia, as determined by logistic regression analysis, were chair stand time (odds ratio [OR], 1.09; 95 % confidence interval [CI], 1.04-1.14), one-leg standing time (OR, 0.97; 95 % CI, 0.96-0.99), and exercise habit in middle age (OR, 0.53; 95 % CI, 0.31-0.90). Exercise habit in middle age was associated with low prevalence of sarcopenia in older age. Furthermore, linear regression analysis revealed that exercise habits in middle age were significantly associated with grip strength (P < .001), gait speed (P < .001), and one-leg standing time (P = .005) in older age.

CONCLUSIONS

This cross-sectional study suggests that exercise habit in middle age is a protective factor against sarcopenia in older age and effective in maintaining muscle strength and physical performance in older age.

Prevalence and distribution of intervertebral disc degeneration over the entire spine in a population-based cohort: the Wakayama Spine Study

OBJECTIVES

The purposes of this study were to investigate the prevalence and distribution of intervertebral disc degeneration (DD) over the entire spine using magnetic resonance imaging (MRI), and to examine the factors and symptoms potentially associated with DD.

DESIGN

This study included 975 participants (324 men, mean age of 67.2 years; 651 women, mean age of 66.0 years) with an age range of 21-97 years in the Wakayama Spine Study. DD on MRI was classified into Pfirrmann's system (grades 4 and 5 indicating DD). We assessed the prevalence of DD at each level in the cervical, thoracic, and lumbar regions and the entire spine, and examined DD-associated factors and symptoms.

RESULTS

The prevalence of DD over the entire spine was 71% in men and 77% in women aged <50 years, and >90% in both men and women aged >50 years. The prevalence of an intervertebral space with DD was highest at C5/6 (men: 51.5%, women: 46%), T6/7 (men: 32.4%, women: 37.7%), and L4/5 (men: 69.1%, women: 75.8%). Age and obesity were associated with the presence of DD in all regions. Low back pain was associated with the presence of DD in the lumbar region.

CONCLUSION

The current study established the baseline data of DD over the entire spine in a large population of elderly individuals. These data provide the foundation for elucidating the causes and mechanisms of DD.

Profiles of vitamin D insufficiency and deficiency in Japanese men and women: association with biological, environmental, and nutritional factors and coexisting disorders: the ROAD study

Assessments of serum 25-hydroxyvitamin D levels in 1,683 Japanese from a population-based cohort revealed prevalences of vitamin D insufficiency and deficiency were 81.3 and 1.2%, respectively. Vitamin D deficiency was significantly associated with female sex, examined month, current smoking, lack of regular walking, higher intact parathyroid hormone (iPTH), and poor daily vitamin D intake.

INTRODUCTION

To clarify the characteristics of subjects with vitamin D insufficiency and deficiency among men and women in the general Japanese population.

METHODS

We initiated research on osteoarthritis/osteoporosis against disability (ROAD), a large-scale population-based cohort study, in 2005-2007. Blood examination was performed to measure serum 25-hydroxyvitamin D (25D) and iPTH levels and biochemical markers of bone turnover in 1,683 participants (595 men, 1,088 women). Participants completed an interviewer-administered questionnaire, measurements of bone mineral density, and x-ray examination. Vitamin D deficiency and insufficiency were defined by serum 25D levels <10 and ≥10 but <30 ng/mL, respectively.

RESULTS

The prevalence of vitamin D insufficiency and deficiency was 81.3 and 1.2%, respectively. Multinominal logistic regression analyses using potentially confounding variables revealed vitamin D insufficiency was significantly associated with age (+1 year, relative risk ratio, 0.98; 95% confidence interval, 0.96-0.99), gender (women vs. men, 2.28; 1.59-3.30), residing areas (coastal area vs. mountainous area, 0.58; 0.41-0.81), examined month (October, November, December vs. January, 0.51; 0.34-0.76), and serum levels of iPTH (+1 pg/mL, 1.02; 1.01-1.03). Vitamin D deficiency was significantly characterised by female sex (20.5; 3.1-136.7), examined month (0.28; 0.09-0.95), current smoking habit (6.39; 1.78-23.0), lack of regular outside walking (3.96; 1.34-11.7), higher iPTH (1.02; 1.01-1.03) and poor daily vitamin D intake (+10 μg/day, 0.48; 0.24-0.93).

CONCLUSIONS

A high prevalence of vitamin D insufficiency and a low prevalence of vitamin D deficiency were found in Japanese men and women, and the characteristics of vitamin D status were clarified.

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.

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.

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.

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.

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.

Epidemiology of lumbar osteoporosis and osteoarthritis and their causal relationship--is osteoarthritis a predictor for osteoporosis or vice versa?: the Miyama study

SUMMARY

In a 10-year follow-up of a population-based cohort of Japanese subjects, incidences of and causal relationships between osteoporosis (OP) and osteoarthritis (OA) at the lumbar spine were clarified. OP might reduce the risk of subsequent OA at the spine in women, but not in men.

INTRODUCTION

The aim of this study is to clarify the contribution of osteoarthritis (OA) to osteoporosis (OP) and vice versa.

METHODS

A population-based, epidemiological study was conducted in a Japanese rural community. From 1,543 participants aged 40-79 years, 200 men and 200 women were selected and followed up for 10 years. Bone mineral density measurements were repeated after 3, 7, and 10 years, and X-rays were repeated after 10 years.

RESULTS

The incidence of lumbar OP per 10,000 person-years for persons in their 40s, 50s, 60s, and 70s was 0, 0, 109.5, and 151.1 for men and 124.2, 384.0, 227.3, and 239.5 for women, respectively. The cumulative incidence of lumbar OA over 10 years aged 40-79 years was 25.8% in men and 45.2% in women. Cox's proportional hazards model showed no significant relationship between the presence of lumbar OA at the baseline and incidence of lumbar and femoral neck OP in both genders. A significant relationship was demonstrated between the presence of lumbar OP, not femoral neck OP, at the baseline and cumulative incidence of lumbar OA in women (odds ratio, 0.20; 95% confidence interval, 0.05-0.80; P = 0.02).

CONCLUSION

OP in women appears to reduce the future incidence of OA at the lumbar spine.

Fully automatic quantification of knee osteoarthritis severity on plain radiographs

OBJECTIVE

Although knee osteoarthritis (OA) is a major public health issue causing chronic disability, there is no objective or accurate method for measurement of the structural severity in general clinical practice. Here we have established a fully automatic program KOACAD (knee OA computer-aided diagnosis) to quantify the major OA parameters on plain knee radiographs, validated the reproducibility and reliability, and investigated the association of the parameters with knee pain.

METHODS

KOACAD was programmed to measure joint space narrowing at medial and lateral sides, osteophyte formation, and joint angulation. Anteroposterior radiographs of 1979 knees of a large-scale cohort population were analyzed by KOACAD and conventional categorical grading systems.

RESULTS

KOACAD automatically measured all parameters in less than 1s without intra- or interobserver variability. All parameters, especially medial joint space narrowing, were significantly correlated with the conventional gradings. In the parameters, osteophyte formation was associated with none of the joint space parameters, suggesting different etiologic mechanisms between them. Multivariate logistic regression analysis after adjustment for age and confounding factors revealed that medial joint space narrowing and varus angulation of knee joints were risk factors for the presence of pain (594/1979 knees), while neither lateral joint space nor osteophyte area was.

CONCLUSION

KOACAD was shown to be useful for objective, accurate, simple and easy evaluation of the radiographic knee OA severity in daily clinical practice. This system may also serve as a surrogate measure for the development of disease-modifying drugs for OA, just as bone mineral density does in osteoporosis.

Prevalence of radiographic lumbar spondylosis and its association with low back pain in elderly subjects of population-based cohorts: the ROAD study

OBJECTIVES

Although lumbar spondylosis is a major cause of low back pain and disability in elderly people, few epidemiological studies have been performed. The prevalence of radiographic lumbar spondylosis was investigated in a large-scale population study and the association with low back pain was examined.

METHODS

From a nationwide cohort study (Research on Osteoarthritis Against Disability; ROAD), 2288 participants aged > or =60 years (818 men and 1470 women) living in urban, mountainous and coastal communities were analysed. The radiographic severity at lumbar intervertebral levels from L1/2 to L5/S was determined by Kellgren/Lawrence (KL) grading.

RESULTS

In the overall population the prevalence of radiographic spondylosis with KL> or =2 and > or =3 at the severest intervertebral level was 75.8% and 50.4%, respectively, and that of low back pain was 28.8%. Although KL> or =2 spondylosis was more prevalent in men, KL> or =3 spondylosis and low back pain were more prevalent in women. Age and body mass index were risk factors for both KL > or =2 and KL> or =3 spondylosis. Although KL = 2 spondylosis was not significantly associated with low back pain compared with KL = 0 or 1, KL> or =3 spondylosis was related to the pain only in women.

CONCLUSIONS

This cross-sectional study in a large population revealed a high prevalence of radiographic lumbar spondylosis in elderly subjects. Gender seems to be distinctly associated with KL> or =2 and KL> or =3 lumbar spondylosis, and disc space narrowing with or without osteophytosis in women may be a risk factor for low back pain.

Association between height loss and bone loss, cumulative incidence of vertebral fractures and future quality of life: the Miyama study

INTRODUCTION

The study aimed to clarify associations between height loss, bone loss and the quality of life (QOL) score among general inhabitants of Miyama, a rural Japanese community. This population-based epidemiological study was conducted in Miyama, a village located in a mountain area in Wakayama Prefecture, Japan.

METHODS

A list of all inhabitants comprising 1,543 inhabitants (716 men, 827 women) born in this village between 1910-1949 was compiled. From the above whole cohort, a subcohort to measure bone mineral density (BMD) was recruited, consisting of 400 participants, divided into four groups of 50 men and 50 women each, and stratified into age decades by decade of birth-year (1910-1919, 1920-1929, 1930-1939 or 1940-1949). BMD measurement, physical measurements of height (cm) and body weight (kg) were taken, and body mass index (BMI; kg/m(2)) were calculated. BMD and anthropometric measurements were repeated on the same participants at 3, 7 and 10 years after baseline measurement (1993, 1997 and 2000).

RESULTS AND DISCUSSION

Among 299 of 400 participants, changes in height over 10 years for men in their 40s, 50s, 60s and 70s were -0.7 cm, -0.5 cm, -1.2 cm and -1.5 cm, respectively, compared with -0.7 cm, -1.4 cm, -2.1 cm and -3.7 cm in women, respectively. No significant relationships between change in height and rate of change in BMD at the lumbar spine and femoral neck after adjustment for age in men (lumbar spine, beta = 0.058, standard error of the mean (SE) = 0.031, P = 0.501, R(2) = 0.038; femoral neck, beta = 0.100, SE = 0.038, P = 0.228, R(2) = 0.121) were identified. By contrast, among women, a significant positive association was identified between height change and change rate of BMD at the lumbar spine after adjusting for age (beta = 0.221, SE = 0.039, P = 0.012, R(2) = 0.069), while no significant relationship was found between height change and change rate at the femoral neck (beta = 0.107, SE = 0.039, P = 0.229, R(2) = 0.048). No significant relationship was noted between vertebral fractures (VFx) and height at baseline in men and women (men: odds ratio (OR) 0.93, 95% confidence interval (CI) 0.81-1.05, P = 0.24; women: OR 0.97, 95% CI 0.87-1.08, P = 0.58) or between VFx and height loss (men: OR 1.31, 95% CI 1.00-1.71, P = 0.051; women: OR 1.20, 95% CI 0.94-1.53, P = 0.14). In both men and women, no significant relationship was identified between utility of the EuroQol EQ5D questionnaire and height at baseline (men: beta = -0.148, SE = 0.003, P = 0.202, R(2) = 0.076; women: beta = 0.127, SE = 0.004, P = 0.235, R(2) = 0.048), and height change (men: beta = -0.078, SE = 0.008, P = 0.452, R(2) = 0.065; women: beta = 0.053, SE = 0.010, P = 0.608, R(2) = 0.038).

[Thoracic surgery for the penetrating lung or tracheal trauma]

Seven cases suffered from a chest trauma (stab wound in 6 and impalement injury in 1) were emergently transferred to our hospital. Open thoracotomy was performed for the intolerable bleeding immediately after admission. Injured lung was treated by lobectomy in 1 patient, lingual segmentectomy in 2, lower basal segmentectomy in 2, partial resection in 4 and direct suture in 2. The penetrating trachea was carefully repaired by direct suture with additional midsternal thoracotomy. To accomplish appropriate partial resection of the injured lung, a metallic straight suction tube inserted into a pulmonary stab wound was retracted and a stapling instrument was applied underneath the suction tube. With the segmentectomy and the partial resection, the volume of the residual lung was maximally saved. As a result, all 7 patients were successfully alive.

[Prevention of acute exacerbation of interstitial pneumonia in the patients operated for lung cancer]

Eight patients with interstitial pneumonia (IP) underwent pulmonary surgery for lung cancer. The first patient died due to postoperative exacerbation, but the subsequent 7 patients had good postoperative course without exacerbation by the following careful management. 1) Avoidance of administration of high concentration of oxygen keeping the PO2 about 100 mmHg during the operation. 2) Short-term administration of low-dose steroid before the operation. 3) Administration of erythromycin, tocopherol acetate, and inhalation of N-acetylcysteine before and after the operation. 4) Long-term drainage of the postoperative thoracic discharge to release the local cytokines. These treatments inhibit secretion of the inflammatory cytokines which influence exacerbation of IP.

[Removal of the intrapleural hematoma after extrapleural pneumonectomy]

Three cases of pleuropneumonectomy, which have been performed in our institution between 1996 and 2003, are studied. All of them received re-thoracotomy to remove intrapleural hematoma for prolonged high fever, anemia and high level of CRP. Post re-operative courses were satisfactory without any signs of infection. The residual intrapleural hematoma sometimes causes pyothorax and would be an obstacle to the intrapleural instillation of anticancer medications. The removal of the hematoma should be scheduled at an early period after the pleuropneumonectomy.

[Utility of the perfusion-assist for beating heart coronary artery bypass surgery]

During off-pump coronary artery bypass surgery, concern remains about the possible myocardial injury associated with the transient occlusion and stabilization of the target vessels. To try to minimize myocardial ischemia and achieve hemodynamic stability, we utilized a coronary perfusion catheter combined with the perfusion-assisted direct coronary artery bypass system that enables active and modified coronary perfusion of the target vessel throughout the duration of multiple grafting (modified PADCAB). In the series of 10 patients, perfusion of the target coronary systems averaged 2,072.8 +/- 649.7 ml over 92.9 +/- 26.1 minutes under a constant infusion pressure of 120 mmHg. Nitroglycerin (100 micrograms/l of flow) was delivered directly into the coronary arteries as an additive in all patients. Hemodynamic instability was notably absent in all cases, even in cases that required difficult anastomosis with a relatively long time for the anastomosis. There were no perioperative complications and no detectable myocardial damage (i.e., impairment of myocardial wall motion indicated by echocardiography findings or by > 0.25 ng/ml of troponin-T release compared to the preoperative level) in this series of patients.

[Antegrade selective cerebral perfusion for extended total arch replacement using separated graft technique; reassessment from the type of aneurysms and dissections]

One hundred eighty two patients with thoracic aortic aneurysms or dissections who required total arch replacement (TAR) were operated on with separated graft technique and selective cerebral perfusion (SCP) between 1991 and 2000. These patients were divided into 4 groups according to the pathology as follows: group 1; acute type A dissection, group 2; chronic type A dissection, group 3; distal arch aneurysm and group 4; proximal arch aneurysm. For SCP, both the innominate artery and the left common carotid artery were cannulated when the patient was cooled to a rectal temperature of 22 degrees C. Hospital mortalities were 27% in group 1, 14% in group 2, 19% in group 3, and 8% in group 4. Independent predictors of hospital mortality were shock, visceral, and leg ischemia in group 1, and circulatory arrest time of the lower half body to be more than 1 hour and cardiopulmonary bypass time to be more than 5 hours in group 3. Permanent neurological complication occurred in 3% in group 1 and 8% in group 3. Hospital mortality was affected by the type of aneurysms and dissections. It is necessary to give careful consideration to the indication of TAR with SCP, especially in acute type A dissection and distal arch aneurysm.

Age-related pattern of body density and body composition of Japanese men and women 18-59 years of age

Age-related patterns of body size and composition were studied in a cross-sectional sample of Japanese adults 18-59 years of age. Height, weight, the body mass index (BMI), body density (BD), percentage body fat (%Fat), fat mass (FM), fat-free mass (FFM), and the sum of seven skinfold thicknesses (SF) of 288 men and 552 women were considered. Body density was measured by underwater weighing densitometry. Mean values of height, weight, BMI, BD, %Fat, FM, FFM, and SF of males were 169.0 cm, 65.3 kg, 22.8 kg/m(2), 1.0600 g/ml, 17.0%, 11.4 kg, 53.9 kg, and 95.0 mm, respectively, while corresponding values for females were 157.4 cm, 52.9 kg, 21.4 kg/m(2), 1.0420 g/ml, 24.4%, 13.1 kg, 39.7 kg, and 128.2 mm, respectively. Height, BD, and FFM correlated negatively with age in both sexes, while weight, BMI, %Fat, FM, and SF correlated positively with age. The highest BD and the lowest %Fat were observed in males ages 20 to <25 years (G20) and in females 25 to <30 years (G25). The lowest BD and highest %Fat were observed in G50 in both sexes. Correlations among parameters of body size and composition were stable with age in each sex. Height correlated negatively with BMI and %Fat in females, but not in males. In males, FM started to increase between G20 and G25 and continued to increase until G50, while SF and BMI remained stable during this period. In females, FM accumulation started around 30 years of age and continued until G50 and was accompanied by increases in SF and BMI.

[Minimal incision abdominal aortic aneurysm repair]

OBJECTIVE

The use of a limited incision for abdominal aortic aneurysm (AAA) repair was evaluated, and its outcome was analyzed in comparison to standard open repair.

PATIENTS AND METHODS

Between February 2000 and August 2001, 20 patients with an AAA underwent minimal incision repair (MINI) for tube graft implantation. The minimal skin incision was made after localization of aneurysm neck and aortic bifurcation by CT and DSA. For repair of the upper part of the AAA the abdominal incision was retracted toward the head of the patient who was in a jackknife decubitus position. Conversely, when the peripheral portion of the AAA was treated, the abdominal incision was retracted caudally with the patient in a flat or slightly bent decubitus position. The operation itself was performed using the standard conventional technique. The length of the abdominal incision was 10 cm. Clinical characteristics and in-hospital outcome of this procedure were compared to a group of patients who underwent repair of AAA by means of a standard open technique (OPEN).

RESULTS

Patients age in the MINI and OPEN groups were similar (69 +/- 11 vs. 69 +/- 9 years). However, there were significant differences between the MINI and OPEN groups in the time for starting oral intake of food (2,4 +/- 1,2 vs. 7,4 +/- 5,5 postoperative days, p = 0,003), time for starting to walk outside the room (2,2 +/- 0,7 vs. 4,6 +/- 2,2 postoperative days, p = 0,01) and operation times (197 +/- 37 vs. 294 +/- 83 min, p = 0,0004).

CONCLUSION

Minimal incision repair is technically feasible and combines the benefits of a minimal incision with those of conventional open repair, reducing patient recovery time.

Age-related pattern of body density and body composition in Japanese males and females, 11 and 18 years of age

The age-related pattern of body density and body composition in Japanese males (n = 266) and females (n = 318), 11.00 to 18.99 years of age was studied. Body density (BD) as well as height, body weight, and seven skinfold thicknesses were measured. Percentage fat (%Fat) was calculated using the age- and sex-specific equation of Lohman. Fat mass (FM), fat-free mass (FFM), and the body mass index (BMI) were calculated. The trend for BD in males was lowest at 11 years (1.0530 g/ml) and increased to 1.0695 g/ml at 14 years, and then decreased slightly at 15 to 17 years. In female, BD decreased from 1.0530 g/ml at 13 years to 1.0424 g/ml at 17 years. Mean %Fat was highest in males at 11 years (15.8%), and lowest at 14 years (10.1%). The highest mean %Fat in females occurred at 16 years (22.8%), and the lowest at age 11 years (15.2%). Overall, only 6.8% of males and 3.1% of females were classified as obese. Between 11 and 18 years, FFM of males differed by 20.7 kg or 67.9%, whereas females showed a difference of only 10.8 kg or 34.7%. Consequently, age effects explained approximately 60% of the male variance of FFM but only 26% in females. Body density of each sex and age group in this study did not differ significantly from previous Japanese studies, and the pooled BD data for 1,457 Japanese including the present study are reported as a reference.

Retinotopic hemodynamic activation of the human V5/MT area during optokinetic responses

To detect retinotopic activation in the human V5/MT, we obtained fMRI signals during optokinetic responses (OKR). We used two types of patterns, consisting of random dots plotted in either the central or peripheral regions, to stimulate the central and peripheral visual fields, respectively. These patterns moved at a constant speed of 20 degrees/s rightward and leftward alternately. Subjects were required to track the patterns with their eyes. The two types of visual stimuli elicited different patterns of brain activation; the area with the most significant response to central visual field stimuli was located posteriorly to that responding to peripheral visual field stimuli.

Brief pretreatment of radial artery conduits with phenoxybenzamine prevents vasoconstriction long term

BACKGROUND

Radial artery bypass conduits are prone to early vasospasm or "string sign" with use of vasopressor therapy intraoperatively and postoperatively, causing increased resistance in coronary artery grafts. Current intraoperative treatment with papaverine fails to provide sustained inhibition of vasoconstriction. We tested the hypothesis that a 30-minute pretreatment of radial artery segments with the alpha-adrenergic antagonist phenoxybenzamine (PB) or the putative protein phosphatase 2,3-butadione monoxime (BDM) attenuates vasoconstriction induced by the vasopressors phenylephrine or norepinephrine for as long as 48 hours compared with papaverine.

METHODS

Canine radial arteries were harvested, incubated in control buffer or solutions of papaverine 10(-6) M, BDM 10(-6) M or phenoxybenzamine 10(-6) M for 30 minutes, washed, and stored in drug-free culture medium for 2, 24, or 48 hours. After storage, constriction was induced by norepinephrine at incremental concentrations ranging from 0.7 to 3.5 micromol/L or by phenylephrine (0.300 to 1.5 micromol/L) with or without the inhibitors, and the degree of vasoconstriction was quantified in organ chambers. Responses to norepinephrine or phenylephrine were compared to constriction with receptor-independent potassium chloride KC1 (30 mmol/L).

RESULTS

Maximum responses to phenylephrine and norepinephrine were comparable at 2, 24, and 48 hours after harvest in the control group (phenylephrine: 67% +/- 4%, 62% +/- 6%, 65% +/- 6% of KC1 response; norepinephrine: 75% +/- 4%, 62% +/- 1%, 58% +/- 7%, respectively). Papaverine failed to attenuate constriction to phenylephrine and norepinephrine 2, 24, or 48 hours posttreatment. Pretreatment with BDM did not reduce vasoconstriction responses to phenylephrine or norepinephrine 2 hours after incubation but did reduce constriction responses thereafter. In contrast, phenoxybenzamine completely attenuated constriction to both phenylephrine (19% +/- 8%, 1% +/- 4%, -12% +/- 4%) and norepinephrine (7.1% +/- 1%, -5% +/- 5%, -20% +/- 5%) at 2, 24, and 48 hours posttreatment, respectively. Phenoxybenzamine did not alter endothelial function relative to controls at any time point.

CONCLUSIONS

Thirty-minute pretreatment of RA conduits with 10(-6) M phenoxybenzamine completely inhibits vasoconstriction to phenylephrine and norepinephrine for as long as 48 hours. Soaking radial artery grafts briefly in phenoxybenzamine solution before implantation may be effective in preventing postoperative vasospasm caused by two common alpha-adrenergic agonists used in postoperative hemodynamic management.

All-blood (miniplegia) versus dilute cardioplegia in experimental surgical revascularization of evolving infarction

BACKGROUND

The advantages of blood cardioplegia include the oxygen-carrying capacity, superior oncotic and buffering properties, and endogenous antioxidants contained in blood. However, the partial dilution of blood in 4:1 (blood:crystalloid) cardioplegic solutions may nullify these advantages and progressively dilute blood during continuous retrograde delivery. This study tested the hypothesis that all-blood (66:1) cardioplegia provides superior myocardial protection compared with dilute (4:1) cardioplegia delivered in a continuous retrograde modality during surgical reperfusion of evolving myocardial infarction.

METHODS AND RESULTS

After 60 minutes of left anterior descending coronary artery (LAD) occlusion, anesthetized canines were placed on cardiopulmonary bypass and randomized to either all-blood cardioplegia (AB group) or dilute blood cardioplegia (Dil group). After cross clamping, arrest was induced with 5 minutes of tepid (30 degrees C) antegrade potassium all-blood or dilute blood cardioplegia and maintained with tepid retrograde coronary sinus cardioplegia for a total of 1 hour. The LAD was released after 30 minutes of arrest, simulating revascularization. The cardioplegia hematocrit for the Dil group was lower than that for the AB group (7+/-1% versus 12+/-2%, P<0.05); at the end of bypass, systemic hematocrit was lower in the Dil group than in the Ab group (15+/-1% versus 20+/-1%, P<0.05). Infarct size (triphenyltetrazolium chloride staining) was comparable between the AB and Dil groups (29.6+/-2.9% versus 30.3+/-3.9% of area at risk), and there was no difference in area-at-risk myocardium systolic shortening (by sonomicrometry, -0.3+/-1% versus -0.4+/-1%). Tissue edema after bypass tended to be greater in the Dil group compared with the AB group in the heart (82+/-0% versus 81+/-1%), lung (79+/-1% versus 78+/-1%), liver (75+/-1% versus 74+/-0%), and skeletal muscle (76+/-1% versus 73+/-2%) and was significantly greater in the duodenum (80+/-1% versus 79+/-1%, P<0.05) and kidney (82+/-1% versus 79+/-1%, P<0.05). Postexperimental endothelial function (relaxation of acetylcholine) was impaired in LADs of the AB group versus the Dil group (59+/-6% versus 77+/-5%, P<0.05).

CONCLUSIONS

Both all-blood cardioplegia and dilute cardioplegia have disadvantages, but these do not have an impact on the pathogenesis of infarct size or recovery of regional contractile function.

Electroplegia: an alternative to blood cardioplegia for arresting the heart during conventional (on-pump) cardiac operation

BACKGROUND

Aortic cross-clamping is contraindicated in patients with severe atherosclerosis of the ascending aorta, and administration of chemical cardioplegia may be cumbersome in these patients. In this study, we demonstrate an alternative method of achieving cardioplegia by electrical stimulation of the vagus nerve.

METHODS

In anesthetized canines, the left anterior descending coronary artery was reversibly ligated for 90 minutes, followed by cardiopulmonary bypass (CPB) and randomization to three groups (n = 8 each): (1) BCP group: 1 hour of intermittent hypothermic (4 degrees C) blood cardioplegia infusion; (2) CPB group: 1 hour of CPB alone; (3) EP group (group receiving electroplegia): 1 hour of intermittent vagal stimulation (total of 60 20-second electrical stimuli at 40 Hz, 6 to 10 V) with adjunctive pyridostigmine (0.5 mg/kg), verapamil (50 microg/kg), and propranolol (80 microg/kg) to potentiate hyperpolarization and suppress ectopic escape beats.

RESULTS

The EP group achieved consistent intervals of arrest with 3.8 +/- 1.2 escape beats per 20-second stimulation period. After 2 hours of reperfusion off CPB, the left anterior descending coronary artery segmental shortening was reduced from baseline in all groups, but the segmental shortening recovered to a greater extent in the EP group than in either the CPB or BCP group (2.4% +/- 1.4% versus -1.3% +/- 1.3% versus -4.0% +/- 0.8%, p < 0.05). Infarct size (TTC stain, percentage of area at risk) was comparable among groups (EP: 20.9% +/- 4.7%; CPB: 29.6% +/- 3.2%; BCP: 25.1% +/- 5.7%). Postischemic left anterior descending coronary artery endothelial function (percent maximum relaxation to acetylcholine) was depressed in the EP group (68.6% +/- 7.6% versus 102.3% +/- 6.4%, p < 0.05), but was comparable versus nonischemic circumflex function in the BCP group (77.1% +/- 11.9% versus 100.4% +/- 10.0%, p = 0.15) and the CPB group (93.8% +/- 6.6% versus 93.3% +/- 6.6%).

CONCLUSIONS

Electroplegia achieves elective intermittent cardiac arrest, avoids hypothermia, chemical cardioplegia, and aortic cross-clamping, with physiological outcomes comparable to blood cardioplegia.

Decrease in the Ca2+-activated K+ current of pulmonary arterial smooth muscle in pulmonary hypertension rats

Pulmonary hypertension exhibits acute elevation of vascular tone and hyperreactivity of pulmonary vasculature, which are closely related to patient mortality. In the present study, we investigated the characteristics of membrane currents of isolated pulmonary artery smooth muscle cells taken from rats with monocrotaline-induced pulmonary hypertension. Male Wistar rats were given a single subcutaneous injection of monocrotaline or saline, and then sacrificed between 18 to 21 days after the injection. The membrane currents in the smooth muscle cells from both groups of rats were compared using the whole-cell patch clamp technique. With 0.1 mM EGTA in the pipette, the densities of outward currents in monocrotaline-injected rats were smaller than those in control rats. When EGTA in patch pipettes was increased to 10 mM, the densities of the outward currents in monocrotaline-injected rats were equal to those of control rats. The Ca2+-activated K+ channel blockers (TEA, iberiotoxin) and nisoldipine were less effective on the outward currents of monocrotaline-injected rats. In the current clamp mode, a depolarization of membrane potential induced by 4-aminopyridine was greater in monocrotaline-injected rats than in control rats because of the reduced activity of the Ca2+-activated K+ channels. The Ca2+-activated K+ channels were decreased in pulmonary hypertension. The reduced activity of the currents may be related to the vascular hyperreactivity in pulmonary hypertension.

Characteristics of body heat balance of paraplegics during exercise in a hot environment

The purpose of this investigation was to clarify the characteristics of body temperature regulation in paraplegics due to spinal cord injury (SCI) during an arm cranking exercise in a hot environment. Twelve paraplegics with lesions located between Th3 and L1,2 and seven able-bodied subjects (AB) participated in this study. The subjects were exposed to a hot (33 degrees C) or a moderate temperature (25 degrees C) environment for one hour and during the last 10 min of the exposure, the subjects performed arm cranking exercises at an exercise intensity of 40 W. The skin temperatures at the chest, the upper arm, the thigh and the calf, the tympanic membrane temperature (Tty), and the skin blood flow of the thigh (SBFT) were continuously monitored during the experiment. Although no systematical variation was found in the Tty at 25 degrees C, the Tty at 33 degrees C in paraplegics during exercise was significantly greater than that at rest (P < 0.01), which indicated a pronounced heat stress for paraplegics at 33 degrees C. SBFT of paraplegics with high lesions of the SCI remained unchanged during the experiment at 25 degrees C and 33 degrees C, while paraplegics with low lesions in this study showed consecutive increases in SBFT during exercise in both environmental conditions similar to AB. The increased core temperature in paraplegics with high lesions was considered to be due to a lack of sweat response and vasomotor activity in the paralyzed area. On the basis of the findings in this study, it can be suggested that high core temperature without any increment of SBFT may be characterized as body heat balance of paraplegics with high lesions during exercise in a hot environment.

Experimental off-pump coronary artery revascularization with adenosine-enhanced reperfusion

OBJECTIVE

Although beating heart coronary artery bypass grafting has recently gained popularity, it eliminates the protective strategies (ie, cardioplegia) developed for use in conventional cardiac operations. We recently introduced the technique of perfusion-assisted direct coronary artery bypass to perfuse the grafted vessels during multivessel off-pump coronary artery bypass grafting. In the present study we tested the hypothesis that intracoronary reperfusion with the cardioprotective agent adenosine during simulated perfusion-assisted direct coronary artery bypass attenuates reperfusion injury.

METHODS

In anesthetized dogs the heart was exposed, and the left anterior descending coronary artery was ligated for 75 minutes. Reperfusion was achieved through a catheter in the left anterior descending coronary artery by means of a computer-controlled pump. Intracoronary left anterior descending coronary artery perfusion pressure was continuously matched to mean arterial blood pressure. In one group (adenosine group) 10 micromol/L adenosine was added to the blood during the first 30 minutes of reperfusion, whereas another group (vehicle group) received a comparable volume of saline solution.

RESULTS

During the first 30 minutes of reperfusion, blood flow through the left anterior descending coronary artery was significantly greater (P <.05) in the adenosine group than in the vehicle group (150.6 +/- 21.9 vs 50.2 +/- 11.3 mL/min at 15 minutes of reperfusion). Although there were no group differences in postischemic wall motion, infarct size was significantly smaller in the adenosine group than in the vehicle group (11.1% +/- 3.0% vs. 28.0% +/- 4.0% of area at risk, P <.05). Myeloperoxidase activity in the necrotic tissue, an index of neutrophil accumulation, tended to be lower in the adenosine group than in the vehicle group (58.6 +/- 14.2 vs. 91.0 +/- 21.6 DeltaAbs Units x min(-1) x g(-1) tissue). In isolated postischemic left anterior descending coronary artery rings, the maximal relaxation response to the endothelium-dependent vasodilator acetylcholine was significantly greater in the adenosine group than in the vehicle group (97.9% +/- 5.6% vs. 64.7% +/- 6.5%, P<.05).

CONCLUSION

This novel reperfusion strategy for off-pump coronary artery bypass grafting can be used not only in cases requiring multiple grafting but also to attenuate necrosis and endothelial dysfunction in acute evolving infarction.

[Development of three-dimensional stereo viewer for high-resolution data]

In order to visualize high-resolution three-dimensional (3D) data as a stereogram, a real-time volume-rendering system using a hardware graphic board and conventional PC was developed. A 256(3) data set could be visualized at a redrawing rate of 12 Hz, and a 512(3) data set at a rate of 2.5 Hz. It was demonstrated that stereogram visualization using volume graphic hardware architecture potentially enables rapid examination of high-resolution 3D data by changing visualization parameters such as level, window, transfer function for opacity, and color map or coordinate direction.

Adenosine attenuates reperfusion-induced apoptotic cell death by modulating expression of Bcl-2 and Bax proteins

This study tests the hypothesis that infarct reduction with adenosine (Ado) is associated with inhibition of apoptotic cell death by modulating expression of anti-apoptotic Bcl-2 and pro-apoptotic Bax proteins and reducing neutrophil accumulation. In three groups of dogs, the left anterior descending coronary artery was occluded for 60 min and reperfused for 6 h. Either saline (Control, n=8), Ado (140 microg/kg/min, n=8) or CGS21680, an adenosine A2A receptor analogue, (0.2 microg/kg/min, n=7) were infused during the first 2 h of reperfusion. Myocardial apoptosis was detected by histological TUNEL staining and DNA laddering. Expression of Bcl-2 and Bax proteins was analyzed using Western blot assay. Neutrophil localization was detected by immunohistochemistry with monoclonal anti-neutrophil CD18 antibody. There was no group difference in collateral blood flow (colored microspheres) during ischemia. Intra-left atrial administration of Ado and CGS21680 significantly decreased infarct size from 26+/-2% in Control to 13+/-1%* and 16+/-3%*, respectively. TUNEL positive cells in the peri-necrotic zone of the ischemic myocardium were also significantly reduced from 16+/-2% in Control group to 9+/-1%* and 10+/-2%*, respectively, consistent with the absence of DNA laddering in these two groups. Densitometrically, Ado and CGS21680 at reperfusion significantly increased the expression (% of normal myocardium) of downregulated Bcl-2 from 45+/-6% in Control group to 78+/-12%* and 69+/-10%*, respectively, and attenuated expression of upregulated Bax from 198+/-16% in Control group to 148+/-10%* and 158+/-12%*, respectively. Furthermore, the number of positive CD18 cells (mm(2) myocardium), which was significantly correlated with TUNEL positive cells in peri-necrotic zone, was significantly reduced from 403+/-42 in Control group to 142+/-18* in Ado group and 153+/-20%* in CGS21680 group, respectively. In conclusion, the present study suggests that inhibition of apoptosis by Ado at reperfusion involves alterations in anti-apoptotic Bcl-2 and pro-apoptotic Bax proteins and neutrophil accumulation, primarily mediated by an adenosine A2A receptor. * P<0.05 v Control group.