The purpose of this prospective study was to determine whether moderate walking exercise in postmenopausal women with osteopenia/osteoporosis would affect bone metabolism. Fifty postmenopausal women, aged 49-75 years, with osteopenia/osteoporosis were recruited: 32 women entered the exercise program (the exercise group) and 18 served as controls (the control group). The exercise consisted of daily outdoor walking, the intensity of which was 50% of maximum oxygen consumption, with a duration of at least 1 h with more than 8000 steps, at a frequency of 4 days a week, over a 12-month period. Lumbar (L2-L4) bone mineral density (BMD) was measured at the baseline and every 6 months with dual-energy X-ray absorptiometry (DXA) in both groups. Serum bone-specific alkaline phosphatase (BAP) and urinary cross-linked N-terminal telopeptides of type I collagen (NTX) levels were measured at baseline and at months 1, 3, 6, 9, and 12 by EIA and ELISA, respectively, in the exercise group, and urinary NTX level was measured at the baseline and every 6 months in the control group. There were no significant differences in baseline characteristics including age, height, body weight, bone mass index, years since menopause, lumbar BMD, and urinary NTX level between the two groups. Although no significant changes were observed in lumbar BMD and the urinary NTX level in the control group, lumbar BMD in the exercise group was increased as compared with the control group, but was sustained from the baseline. In the exercise group, the urinary NTX level rapidly responded to walking exercise from month 3, and this reduction was sustained until month 12, followed by reduction in the serum BAP level. A moderately negative correlation was found between the percent change in the urinary NTX level at month 3 and that in lumbar BMD at month 12 in the exercise group. This study clearly demonstrates that the mechanism for the positive response of lumbar BMD to moderate walking exercise in postmenopausal women with osteopenia/osteoporosis appears to be the suppression of bone turnover, and that an early change in the urinary NTX level may be useful to predict the long-term response of increasing lumbar BMD to exercise, although its efficacy for lumbar BMD may be quite modest.

No abstract

The aim of this study was to investigate the possibility of using the atelocollagen honeycomb-shaped scaffold with a membrane seal (ACHMS-scaffold) for the culture of annulus fibrosus (AF) cells in tissue engineering procedures of intervertebral disc repair. AF cells from the intervertebral discs of Japanese white rabbits were cultured for up to 3 weeks in the ACHMS-scaffold to allow a high density, three-dimensional culture. Although the DNA content in the scaffold increased at a lower rate than in the monolayer culture, scanning electron microscopy data showed that the scaffold was filled with the grown AF cells and produced extracellular matrix on day 21. The amount of type II collagen and its mRNA expression by the scaffold cultured cells were determined using Western blotting and Northern blotting analyses, respectively, and remained at a higher level than in the monolayer cultured cells. Furthermore, glycosaminoglycan (GAG) accumulation in the scaffold culture was at a higher level than in the monolayer culture. Western blot analysis for extracted proteoglycans from the scaffold culture also exhibited a much higher proteoglycan accumulation than the monolayer culture. These results indicate that the AF cells are able to grow and remain phenotypically stable in the scaffold.

The aim of the present study was to examine the effects of exercise on bone mass, bone metabolism, and calciotropic hormones in young growing rats. Twenty 6-week-old female Wistar rats were randomized into the following four groups with 5 animals each: 7 weeks of exercise, 7 weeks of sedentary control, 11 weeks of exercise, and 11 weeks of sedentary control. The exercise regimen consisted of running on a treadmill at 25 m/min for 1 h each day on 5 days a week. After each period of exercise, the bone mineral content (BMC) of the tibia and fifth lumbar spine was measured by dual-energy X-ray absorptiometry, using a Lunar DPX-L instrument. The femoral length and levels of bone markers and calciotropic hormones were also assessed. Seven and 11 weeks of exercise increased the serum osteocalcin and 1,25-dihydroxyvitamin D(3) levels, and decreased the serum parathyroid level. Seven weeks of exercise decreased the urinary deoxypyridinoline level, and 11 weeks of exercise increased the serum alkaline phosphatase level and decreased the serum tartrate-resistant acid phosphatase level. As a result, 7 and 11 weeks of exercise increased the femoral length and tibial BMC, but did not alter the lumbar BMC. The present study demonstrates that treadmill exercise stimulates bone formation and suppresses bone resorption, increases the serum 1,25-dihydroxyvitamin D(3) level, and decreases the serum parathyroid hormone level, resulting in an increase in bone mass with stimulation of longitudinal bone growth, especially at weight-bearing sites, in young growing rats. Further studies with long-term exercise may be needed to obtain a positive effect on the lumbar BMC.

No abstract

Static and dynamic factors were related to the development of myelopathy in OPLL.

While bracing is the standard conservative treatment for acute osteoporotic compression fracture, the efficacy of different brace treatments has not been extensively studied. We aimed to clarify and compare the preventive effect of the different brace treatments on the deformity of the vertebral body and other clinical results in this patient cohort. This multicenter nationwide prospective randomized study included female patients aged 65–85 years with acute one-level osteoporotic compression fractures. We assigned patients within four weeks of injury to either a rigid-brace treatment or a soft-brace treatment. The main outcome measure was the anterior vertebral body compression percentage at 48 weeks. Secondary outcome measures included scores on the European Quality of Life-5 Dimensions (EQ-5D), visual analog scale (VAS) for lower back pain, and the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ). A total of 141 patients were assigned to the rigid-brace group, whereas 143 patients were assigned to the soft-brace group. There were no statistically significant differences in the primary outcome and secondary outcome measures between groups. In conclusion, among patients with fresh vertebral compression fractures, the 12-week rigid-brace treatment did not result in a statistically greater prevention of spinal deformity, better quality of life, or lesser back pain than soft-brace.

Dual-energy X-ray absorptiometry (DXA) was used to examine the effects of quantitative application of treadmill running exercise on bone mineral density (BMD) of the tibia and the fourth and fifth lumbar (L4 ؉ L5) vertebrae in mature osteopenic rats. Twenty 37-week-old rats with bone loss, resulting from feeding a relatively low calcium diet for 14 weeks after ovariectomy at the age of 23 weeks, were divided into four groups of five rats each according to the intensity and duration of the exercise: 12 m/minute, 1 h/day in group EX1; 18 m/minute, 1 h/day in group EX2; 12 m/minute, 2 h/day in group EX3; and sedentary control in group CON. With a standard calcium diet, the exercise was performed 5 days a week for 12 weeks, and the BMD of both the right tibia and the L4 ؉ L5 vertebrae was measured using DXA at weeks 0, 4, 8, and 12. At the end of 12 weeks of exercise, the right femur and the L5 vertebra were dissected and the mechanical strength was measured using a three-point bending test and a compression test, respectively. After 12 weeks of exercise, a significant increase in the tibial BMD was observed in only group EX1 compared with that in group CON (p ‫؍‬ 0.0039, by two-way analysis of variance). However, any significant increase in the L4 ؉ L5 vertebral BMD was not observed in any exercise groups compared with that in the control group. While a maximum breaking force of the femoral shaft in group EX1 was significantly greater than that in group CON (p < 0.05, by Mann-Whitney's U-test), that in groups EX2 and EX3 did not significantly differ from that in group CON. However, there was no significant difference in a maximum breaking force of the L5 vertebral body among all the exercise and control groups. These results indicated that the beneficial effects of treadmill running exercise under a standard calcium diet were recognized only in the weight-bearing bones of the mature osteopenic rats resulting from estrogen deficiency and inadequate calcium intake only when an optimal level of exercise was applied. (J Bone Miner Res 1998;13:1308-1317)