PubMed Health⌕ Search

Biomedical subjects

J Iwamoto

Publications and source records attributed to J Iwamoto.

At least 19 recordsLinked to original sources

Synergistic effect of vitamin K2 and prostaglandin E2 on cancellous bone mass in hypophysectomized young rats.

Hypophysectomy (HX) results in cessation of bone growth and cancellous osteopenia in rats. It has been reported that prostaglandin E2 (PGE2) improves cortical and cancellous bone mass in HX rats. The purpose of the present study was to examine whether combined administration of vitamin K2 and PGE2 would have a more beneficial effect on bone than single administration of either alone in HX rats. Forty-three female Sprague-Dawley rats, 6 weeks of age, were randomized by the stratified weight method into five groups: intact controls, HX, HX + vitamin K2 (30 mg/kg, p.o., daily), HX + PGE2 (0.83 mg/kg, i.m., 5 days a week), and HX + vitamin K2 + PGE2. The duration of the experiment was 4 weeks. There was a reduction in cancellous bone volume/total tissue volume (BV/TV) of the proximal tibial metaphysis and a reduction in total tissue area and cortical area (Ct.Ar) of the tibial diaphysis. Vitamin K2 did not affect cancellous BV/TV or Ct.Ar. On the other hand, PGE2 attenuated the loss of cancellous BV/TV in association with higher bone formation rate/bone surface (BFR/BS) and eroded surface (ES)/BS compared with intact controls. PGE2 also increased percent Ct.Ar compared with nontreated HX rats as a result of attenuation of a decrease in periosteal BFR/BS. Vitamin K2 had a synergistic effect with PGE2 on cancellous BV/TV as a result of the suppression of an increase in ES/BS observed by PGE2 treatment. These results suggested that PGE2 had an anabolic action on cancellous and cortical bone and that despite no apparent effect of vitamin K2 on bone, it had a synergistic effect with PGE2 on cancellous bone mass in young HX rats.

Animals↗

Raloxifene and vitamin K2 combine to improve the femoral neck strength of ovariectomized rats.

We evaluated the skeletal effects of two osteoporosis therapies in an ovariectomized rat model, raloxifene and vitamin K2, as well as the vitamin K2 plus raloxifene (K + Ral) combination. In two studies, 6-month-old rats were ovariectomized, except for sham-ovariectomy controls (Sham), and dosed orally with vehicle, 30 mg/kg vitamin K2, 1 mg/kg raloxifene, or the combination of K + Ral for 6 weeks following surgery. Vitamin K2 had no effect on serum estrogen, low-density lipoprotein cholesterol (LDL-C), or urinary deoxypyridinoline levels, but slightly increased osteocalcin levels compared to Ovx. Raloxifene lowered total cholesterol, LDL-C, osteocalcin, and urinary deoxypyridinoline levels to below Ovx levels, while having no effect on estrogen levels. Raloxifene, but not vitamin K2, prevented ovariectomy-induced loss of bone in the distal femoral metaphysis and proximal tibial metaphysis, as did the K + Ral combination. Raloxifene, but not vitamin K2, partially prevented, loss of vertebral bone mineral density (BMD), whereas K + Ral had BMD greater than that of Ovx. Vitamin K2 increased bone formation rate to above Ovx, whereas raloxifene and K + Ral reduced bone formation rate to Sham levels. Vitamin K2 had no effect on eroded surface compared to Ovx, while raloxifene and K + Ral reduced eroded surface to Sham levels. Groups were not different in the BMD of femoral midshaft; however vitamin K2 was observed to increase periosteal mineralizing surface of the tibial shaft to above Ovx, while raloxifene reduced periosteal mineralizing surface toward Sham levels. Femoral neck strength was not different between groups, indicating no significant beneficial effect of either raloxifene or vitamin K2 at this site. However, K + Ral had reproducibly greater femoral neck strength than Ovx or Sham. Raloxifene, but not vitamin K2, partially prevented loss of lumbar vertebra strength; but K + Ral was not different from Sham or Ovx. Therefore, raloxifene and vitamin K2 had complementary effects on bone resorption and formation activities, respectively, resulting in a reproducible, significant improvement of femoral neck strength. These rat data suggest interesting therapeutic possibilities that may require clinical verification.

Administration, Oral↗

New quantitative methods for evaluation of dynamic changes in QT interval on 24 hour Holter ECG recordings: QT interval in idiopathic ventricular fibrillation and long QT syndrome.

OBJECTIVES: To introduce a nomogram of the normal QT interval at various heart rates measured from 24 hour Holter ECG recordings in healthy subjects with respect to age and sex and to use the nomogram to characterise dynamic changes in QT interval in patients with idiopathic ventricular fibrillation (IVF) and the long QT syndrome (LQT). METHODS: The study group consisted of 422 subjects: 249 healthy men ranging in age from 21-88 years (mean (SD) 47 (20) years) and 173 healthy women ranging in age from 21-85 years (47 (19) years). In addition, seven men with IVF ranging in age from 33-53 years (43 (9) years) and five women with LQT ranging in age from 20-55 years (37 (14) years) were studied. For each subject, QT interval and heart rate were determined automatically from 24 hour Holter ECG digital data-namely, QT interval was measured from signal averaged ECG waves obtained by averaging consecutive sinus beats during each 15 second period over 24 hours. Data were grouped and averaged at an interval of 5 beats/min for heart rates ranging from 46-120 beats/min. RESULTS: In healthy subjects aged < 50 years and > or = 50 years QT intervals were longer in women than in men. QT intervals were longer in both men and women aged > or = 50 years than in ages < 50 years. From these findings a nomogram of QT interval at varying heart rates adjusted for age (younger group aged < 50 years or older group aged > or = 50 years) and sex was determined. In patients with IVF, QT intervals were significantly shorter at slower heart rates than normal values obtained from the nomogram. In patients with LQT, QT intervals were significantly longer at both faster and slower heart rates than normal values. CONCLUSIONS: The nomogram of QT interval at varying heart rates adjusted for sex and age could be used to assess dynamic changes of QT interval of various pathological conditions. For example, patients with IVF had shorter QT interval at slower heart rates, a finding suggestive of arrhythmogenicity of this specific syndrome at night. Patients with LQT had prolonged QT interval at specific heart rate ranges depending on their genotype.

Adult↗

Effects of vitamin K2 administration on calcium balance and bone mass in young rats fed normal or low calcium diet.

OBJECTIVE: The purpose of this study was to examine the effects of vitamin K2 administration on calcium balance and bone mass in young rats fed a normal or low calcium diet. METHODS: Forty female Sprague-Dawley rats, 6 weeks of age, were randomized by stratified weight method into four groups with 10 rats in each group: 0.5% (normal) calcium diet, 0.1% (low) calcium diet, 0.5% calcium diet + vitamin K2 (menatetrenone, 30 mg/100 g chow diet), and 0.1% calcium diet + vitamin K2. After 10 weeks of feeding, serum calcium and calciotropic hormone levels were measured, and intestinal calcium absorption and renal calcium reabsorption were evaluated. Bone histomorphometric analyses were performed on cortical bone of the tibial shaft and cancellous bone of the proximal tibia. RESULTS: Feeding a low calcium diet induced hypocalcemia, increased serum parathyroid hormone (PTH) and 1,25-dihydroxyvitamin D [1,25(OH)2D] levels with decreased serum 25-hydrovyvitamin D [25(OH)D] level, stimulated intestinal calcium absorption and renal calcium reabsorption, and reduced cortical bone mass as a result of decreased periosteal bone gain and enlarged marrow cavity, but did not significantly influence cancellous bone mass. Vitamin K2 administration in rats fed a low calcium diet stimulated renal calcium reabsorption, retarded the abnormal elevation of serum PTH level, increased cancellous bone mass, and retarded cortical bone loss, while vitamin K2 administration in rats fed a normal calcium diet stimulated intestinal calcium absorption by increasing serum 1,25(OH)2D level, and increased cortical bone mass. CONCLUSION: This study clearly shows the differential response of calcium balance and bone mass to vitamin K2 administration in rats fed a normal or low calcium diet.

Animals↗

Relationship between radiographic abnormalities of lumbar spine and incidence of low back pain in high school rugby players: a prospective study.

The purpose of this study was to examine the relationship between prevalent radiographic abnormalities of the lumbar spine and the incidence of low back pain in high school rugby players. Three hundred and twenty-seven incoming high school rugby players (15-16 years of age) were recruited between 1986 and 1994. All of them underwent athletic physical examination before participation in high school athletics. The relationship between prevalent radiographic abnormalities of the lumbar spine in the pre-participation athletic physical examination and the incidence of low back pain during a 1-year period after the start of participation in athletics was analyzed. Radiographic abnormalities assessed were spondylolysis, disc space narrowing, spinal instability, Schmorl's node, balloon disc, and spina bifida occulta. The frequency of respective radiographic abnormalities was 15.6%, 13.1%, 32.7%, 14.1%, 11.6%, and 30.6%. Two hundred and forty-three players (74.3%) had at least one of these radiographic abnormalities. The incidence of low back pain was 44.0% in players with no such radiographic abnormalities and 41.2% in those with at least one radiographic abnormality. The incidence of low back pain in players with the respective radiographic abnormalities was 72.5%, 46.5%, 46.7%, 39.1%, 34.2%, and 41.0%, and only players with spondylolysis had a significantly higher incidence of low back pain than those with no radiographic abnormalities. This study shows that a radiographic abnormality, specifically spondylolysis, is a significant radiological risk factor for low back pain in high school rugby players.

Adolescent↗

Effects of vitamin D supplementation on calcium balance and bone growth in young rats fed normal or low calcium diet.

OBJECTIVE: We examined the effect of vitamin D supplementation on bone growth in young rats fed a normal or low calcium diet. METHODS: Fifty female Sprague-Dawley rats, 6 weeks of age, were randomized by stratified weight method into five groups with 10 rats in each group: baseline control, 0.5% (normal) or 0.1% (low) calcium diet, and 0.5 or 0.1% calcium diet + vitamin D (25 microg/100 g, food intake). Duration of the experiment was 10 weeks. RESULTS: Vitamin D supplementation stimulated intestinal calcium absorption and increased urinary calcium excretion in rats fed a low or normal calcium diet. Vitamin D supplementation prevented the reduction in periosteal bone gain but enhanced enlargement of the marrow cavity and reduced the maturation-related cancellous bone gain in rats fed a low calcium diet, and increased the maturation-related cancellous and cortical bone gains in rats fed a normal calcium diet. CONCLUSION: This study shows the differential effects of vitamin D supplementation on born growth in young rats fed a normal or low calcium diet.

Animals↗

Conservative treatment of isolated posterior cruciate ligament injury in professional baseball players: a report of two cases.

Conservative treatment is currently recommended for most isolated posterior cruciate ligament (PCL) injuries in athletes. However, it is not known whether conservative treatment is applicable even in high performance athletes with isolated PCL injury. The results in two extremely high performance athletes, professional baseball players with isolated acute PCL injury treated conservatively are reported. A catcher and an out fielder, who were regular players, hurt their knees in baseball games. Magnetic resonance images of the knee detected complete PCL rupture. Following a carefully guided physical therapy program, a 3-week period of immobilization of the knee in full extension was achieved with a knee brace, while performing hard quadriceps muscle strengthening exercise, and then running exercise was started. Six to eight weeks after injury, they were able to return fully to their original sporting activity despite tibial posterior translation on posterior drawer test, and to sustain this activity over 2 years. Switching of weight-bearing to non-weight-bearing in a deep knee flexion is considered to contribute to subjective instability in athletes with PCL-deficiency. Probably because our cases, even though extremely high performance athletes were infrequently subjected to such a situation while playing baseball, they were able to return to their pre-injury level of athletic performance without severe subjective instability through conservative treatment.

Adult↗

Returning athletes with severe low back pain and spondylolysis to original sporting activities with conservative treatment.

The purpose of this study was to clarify the efficacy of conservative treatment in athletes with severe low back pain and spondylolysis, especially focusing on returning to original sporting activities. One hundred and four athletes (96 males and eight females), who consulted our sports medicine clinic during the 11-year period between September 1991 and October 2002 because of low back pain with an apparent defect of the pars interarticularis on plain radiographs, were subjected to conservative treatment. The mean age of the patients was 20.7 years. Of all the patients, 40 (38.5%) discontinued sporting activities due to severe low back pain, and were conservatively treated with activity restriction and antilordotic lumbosacral bracing, aimed at relieving low back pain by achieving stability of the fracture partly associated with fibrous union. After their low back pain was markedly reduced, the brace was removed and then individual training to return to the original sporting activities was started. Thirty-five patients (87.5%) could return to their original sporting activities in an average of 5.4 months (range: 1.0-11.5 months) after the onset of treatment, and could continue the activities for at least 6 months despite non-bony union. These results suggest that the outcome of conservative treatment with activity restriction and bracing appears to be satisfactory in controlling symptoms and returning to original sporting activities. Randomized controlled trials or comparative follow-up studies are needed to confirm our results.

Adolescent↗

Does compensatory hyperparathyroidism predispose to ischemic stroke?

BACKGROUND: Parathyroid hormone (PTH) is vasoactive, and the endothelium is one of the target tissues of this hormone. Hyperparathyroidism is frequently associated with hypertension. OBJECTIVE: To determine if hyperparathyroidism, which develops particularly in elderly women as a compensatory mechanism to osteoporosis, may be a risk factor for ischemic stroke. METHODS: Serum PTH levels and bone mineral density (BMD) in 107 elderly patients with ischemic stroke (>or=65 years old) were assessed on the day of onset. The control group consisted of 107 healthy volunteers matched for age and sex. RESULTS: BMD was significantly lower and serum PTH higher in female stroke patients than in control subjects; there was a negative correlation between these two measurements. One-third of the female stroke patients had a serum PTH level higher than the mean + 2 SD of the control subjects (high PTH group), and the interval between menopause and the stroke was significantly longer in the high PTH group than in the normal PTH group. Multiple logistic analyses revealed hypertension and ischemic heart disease were more prevalent in the high PTH group. BMD and PTH were normal in male stroke patients. CONCLUSION: High serum PTH level may be associated with high incidence of ischemic stroke in women, possibly through the increased incidence of hypertension.

Absorptiometry, Photon↗

Urinary cross-linked N-telopeptides of type I collagen levels in patients with rheumatoid arthritis.

Osteoclastic activation rather than suppression of bone formation has been suggested to be the dominant process leading to bone loss in rheumatoid arthritis (RA). Although many studies have already shown the correlation of urinary pyridinoline (PYD) and deoxypyridinoline (DPD) levels with RA-related bone loss, urinary cross-linked N-telopeptides of type I collagen (NTx), a more specific marker of bone-derived type I collagen fragments in urine than urinary PYD and DPD in RA, has not been adequately studied. The purpose of the present study was to determine clinical factors that are associated with an increase in urinary NTx levels in patients with RA. One hundred and eighty-four patients with RA and 185 sex- and age-matched controls were enrolled in the study: 71 men, 37-68 years of age (RA: 31, controls: 40); 129 premenopausal women, 30-48 years of age (RA: 67, controls: 62), and 169 postmenopausal women, 48-69 years of age (RA: 86, controls: 83). The correlations of urinary NTx levels, measured by enzyme-linked immunosorbent assay with anatomic grade in the wrist, functional class, duration of disease, steroid use, modified health assessment questionnaire (HAQ) score for the upper and lower extremities, the levels of serum c-reactive protein and rheumatoid factor (RF), erythrocyte sedimentation rate, and/or years since menopause were examined by multiple regression analysis. Urinary NTx levels (nmol BCE/mmol Cr) did not differ significantly between men with RA and controls (53.2 +/- 29.6 vs 41.0 +/- 19.6, respectively), whereas urinary NTx levels were significantly higher in pre- and postmenopausal women with RA than in respective controls (premenopausal women: 57.1 +/- 36.6 vs 42.3 +/- 21.3, P <0.01; women: 76.2 +/- 27.3 vs 57.1 +/- 28.3, P <0.001). In men with RA, no clinical factors were significantly correlated with urinary NTx levels. In premenopausal women with RA, functional class, HAQ score for the upper extremities, and RF were significantly correlated with urinary NTx levels (all P <0.05); in postmenopausal women with RA, functional class and RF were significantly correlated with urinary NTx levels (both P <0.05). These findings suggest that urinary NTx levels were significantly higher only in women with RA than in age-matched controls, and a RA-related increase in urinary NTx levels may be associated with physical inactivity and disease activity.

Adult↗

RETRACTED: Comparative effects of vitamin K and vitamin D supplementation on prevention of osteopenia in calcium-deficient young rats.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. The Journal has been made aware of concerns regarding the integrity of the data, authorship and ethical approval for this study. Despite repeated attempts to contact the co-authors we have been unable to confirm the authorship of this paper.

Animals↗

Effect of etidronate on bone in orchidectomized and sciatic neurectomized adult rats.

The purpose of the present study was to determine whether etidronate treatment could prevent bone loss caused by orchidectomy (ORX) and unilateral sciatic neurectomy (NX) in adult male rats. Seventy-four male Wistar rats, aged 10 months, were randomly divided into eight groups: baseline controls (n = 10); age-matched sham-operated controls (AMC; n = 9); ORX (n = 9); NX (n = 10); ORX + NX (n = 9); ORX + etidronate treatment (ORX + E; n = 7); NX + E (n = 10); and ORX + NX + E (n = 10). Etidronate treatment (10 mg/kg per day subcutaneously) was initiated 2 weeks after surgery and was continued for 2 weeks. Four weeks after surgery, bone mineral density (BMD) of the proximal and middle tibia (PT and MT, respectively), distal and middle femur (DF and MF, respectively), and fourth lumbar vertebral body (LVB) was measured by dual-energy X-ray absorptiometry (Model DCS-600, Aloka, Tokyo, Japan). The mechanical properties of the MF and third LVB were measured by three-point bending and compression tests, respectively. Levels of urinary deoxypyridinoline (Dpd) and serum osteocalcin (Oc) were also measured by enzyme-linked immunosorbent assay. Four weeks of aging had no significant effects on BMD, bone mechanical properties, or bone markers. ORX significantly increased the levels of urinary Dpd and serum Oc, which resulted in significant decreases in BMD of the PT, MT, DF, MF, and fourth LVB, as well as the mechanical strength (maximum load) of the MF and third LVB. NX significantly increased levels of urinary Dpd and decreased levels of serum Oc, resulting in a significant decrease in BMD of the PT, DF, and fourth LVB. The ORX-induced decrease in BMD of the PT was more pronounced when combined with NX. Etidronate treatment for NX, ORX, and ORX + NX rats significantly decreased levels of urinary Dpd and serum Oc, resulting in complete prevention of loss of BMD and/or bone mechanical strength. The present study demonstrates the efficacy of etidronate treatment for prevention of bone loss caused by testosterone deficiency and immobilization in adult male rats.

Age Factors↗

Forearm bone mineral density in postmenopausal women with rheumatoid arthritis.

Osteoporosis in cases of rheumatoid arthritis (RA) is multifactorial, and the pathogenesis of bone loss induced by RA in postmenopausal women is not fully understood. The purpose of the present study was to determine the factors that affect forearm bone mineral density (BMD) in postmenopausal women with RA. In total, 839 postmenopausal women aged 46-90 years, were enrolled in the study; 470 patients with RA and 369 healthy controls (CON). Forearm (distal radius) BMD, measured by DXA using a DTX-200 (Osteometer, MediTech, CA, USA), was significantly lower in the RA group than in the CON group (P < 0.0001), even when adjusted for age, height, body weight, body mass index, and years since menopause (YSM) (P < 0.01). On multiple regression analysis, in the CON group, age and YSM were significantly correlated with BMD (P < 0.01 and P < 0.05, respectively). On the other hand, in the RA group, in addition to YSM, anatomic grade in the wrist, modified health assessment questionnaire (HAQ) score for the upper extremities, and erythrocyte sedimentation rate were each significantly correlated with BMD (P < 0.0001, P < 0.001, P < 0.0001, and P < 0.001, respectively), whereas functional class, duration of disease, dose of prednisolone used, modified HAQ score for the lower extremities, and the levels of c-reactive protein and rheumatoid factor were not. The present study with a large number of subjects shows that in addition to YSM, disuse (anatomic grade) of the wrist, arm function, and disease activity appear to be significant determinants of forearm BMD in postmenopausal women with RA.

Absorptiometry, Photon↗

Effect of menatetrenone on bone mineral density and incidence of vertebral fractures in postmenopausal women with osteoporosis: a comparison with the effect of etidronate.

The purpose of the present study was to compare the effects of etidronate and menatetrenone on bone mineral density (BMD) and the incidence of vertebral fractures in postmenopausal women with osteoporosis. Seventy-two osteoporotic women, more than 5 years after menopause, 53-78 years of age, were randomly divided into three administration groups: E group; intermittent cyclical etidronate (200 mg/day, 14 days per 3 months; n = 25); M group; menatetrenone (45 mg/day, daily; n = 23); and C group (control); calcium lactate (2 g/day, daily; n = 24). Forearm BMD was measured by dual-energy X-ray absorptiometry at 0, 6, 12, 18, and 24 months after the treatment started. There were no significant differences in age, body mass index, years since menopause, and initial BMD among the three groups. One-way analysis of variance (ANOVA) with repeated measurements showed a significant decrease in BMD in the C group (P < 0.0001). Two-way ANOVA with repeated measurements showed a significant increase in BMD in the M group compared with that in the C group (P < 0.0001), and a significant increase in BMD in the E group compared with that in the C and M groups (P < 0.0001 and P < 0.01, respectively). The indices of new vertebral fractures/1000 patient-years in the E and M groups were significantly higher than that in the C group (chi(2) = 47.7; P < 0.0001 and chi(2) = 42.4; P < 0.0001, respectively), and did not differ significantly between the E and M groups. The present preliminary study provides evidence to suggest that, despite the lower increase in BMD produced by menatetrenone, this agent, as well as etidronate, may have the potential to reduce osteoporotic vertebral fractures in postmenopausal women with osteoporosis.

Absorptiometry, Photon↗

Relationships between physical activity and metacarpal cortical bone mass and bone resorption in hemiplegic patients.

The aim of the present study was to investigate the relationships between physical activity and metacarpal cortical bone mineral density (BMD) and bone resorption in hemiplegic patients. Seventy-two male hemiplegic patients with cerebrovascular disease (mean age, 67.0 years; range 48-83 years) were recruited. Metacarpal cortical BMD in bilateral hands was measured by computed X-ray densitometry, and the levels of urinary cross-linked N-telopeptides of type I collagen (NTx), as a bone resorption marker, were measured by an enzyme-linked immunosorbent assay (ELISA). BMD (mean +/- SD) in the paralyzed hand was significantly lower than that in the nonparalyzed hand (2.52 +/- 0.46 and 2.64 +/- 0.45 mmAl; P < 0.05). On multiple regression analysis, BMD was significantly positively correlated with Brunnstrom stage (assessment of degree of paralysis) in the hand (P < 0.05), whereas urinary NTx levels were significantly negatively correlated with Brunnstrom stage in the hand, arm, and leg, and with walking ability (P < 0.05, P < 0.05, P < 0.01, and P < 0.01, respectively). These findings suggest that, in male hemiplegic patients, although metacarpal cortical BMD may be affected by only local physical activity, urinary NTx appears to be responsive to local and general physical activity.

Aged↗

Effect of administration of lipoprostaglandin E(1) on physical activity and bone resorption in patients with neurogenic intermittent claudication.

The effect of the systemic administration of prostaglandin (PG) E(1) on physical activity and bone resorption was examined in patients with intermittent claudication (gait disturbance). Twenty male patients (age, 67.2 +/- 7.8 years; mean +/- SD) with neurogenic intermittent claudication caused by lumbar spinal canal stenosis were included in the study. Lipo-PG E(1) was administered intravenously, at a daily dose of 10 microg, on 3 days a week, for 6 months in all patients. Clinical symptoms, levels of urinary cross-linked N-telopeptides of type I collagen (NTx), and metacarpal cortical bone mineral density (BMD) were assessed before and just after the 6 months of treatment. Subjective symptoms, including leg pain and/or tingling and gait disturbance, and restrictions of the activities of daily living were significantly improved. However, no significant changes were observed in either urinary NTx levels or metacarpal cortical BMD. These findings suggest that the systemic administration of PG E(1) appears to improve subjective symptoms and activities of daily living in elderly male patients with neurogenic intermittent claudication, but does not affect either bone resorption or metacarpal cortical BMD. Short-term systemic administration of PG E(1) and increased physical activity in elderly male patients with gait disturbance caused by lumbar spinal canal stenosis may not affect bone resorption.

Aged↗

Effect of exercise training and detraining on bone mineral density in postmenopausal women with osteoporosis.

We examined the effect of exercise training and detraining on bone mineral density (BMD) in postmenopausal women with osteoporosis. Thirty-five postmenopausal women with osteoporosis, aged 53-77 years, were randomly assigned to three groups: a control group (n = 20), a 2-year exercise training group (n = 8), and an 1-year exercise training plus 1-year detraining group (n = 7). Exercise training consisted of daily brisk walking and gymnastic training. Calcium lactate, 2.0 g, and 1alpha-hydroxyvitamin D3, 1 microg were supplied daily to all subjects. No significant differences in initial lumbar BMD, measured by dual-energy X-ray absorptiometry (DXA) were found among the three groups. The mean percent change in BMD compared with the baseline was significantly higher at 1 and 2 years in the exercise training group and at 1 year in the detraining group than in the control group, and did not differ significantly at 2 years between the detraining and control groups. These findings indicate that our exercise training program led to a significant increase in lumbar BMD in postmenopausal women with osteoporosis compared with the control, but that the BMD reverted toward a level that was not significantly different from the control with detraining. Continued exercise training is needed to maintain the bone mass gained through exercise training.

Aged↗