Association of serum BDNF concentration with high-intensity interval training / 体力科学

To evaluate the association of serum BDNF concentration with high-intensity interval training, 12 healthy male volunteers, aged 28-48 years, completed 16-week high-intensity interval training (HIIT) using ergometer. Training program consisted of >90% VO₂ peak for 60 sec separated by 60 sec active rest period for 8-12 sets twice weekly for 16-week. Maximal exercise tolerance tests were performed before (0-week), 4-week, and 16-week after the intervention program. VO₂ peak as well as peak watt was linearly increased after 4-week (9% for both VO₂ peak and peak watt) and 16-week HIIT training (15% for VO₂ peak and 18% for peak watt, p<0.01). However, there was no change in serum BDNF concentration by HIIT. On the other hand, there was a positive association of serum BDNF concentration at baseline with % increase in peak watt after the intervention (ρ=0.60, p<0.05). The association between BDNF and exercise training is still unclear, and more studies are needed to clarify the above positive association.

Effects of Risedronate on Osteoarthritis of the Knee

The purpose of the present study was to discuss the effects of risedronate on osteoarthritis (OA) of the knee by reviewing the existing literature. The literature was searched with PubMed, with respect to prospective, double-blind, randomized placebo-controlled trials (RCTs), using the following search terms: risedronate, knee, and osteoarthritis. Two RCTs met the criteria. A RCT (n = 231) showed that risedronate treatment (15 mg/day) for 1 year improved symptoms. A larger RCT (n = 1,896) showed that risedronate treatment (5 mg/day, 15 mg/day, 35 mg/week, and 50 mg/week) for 2 years did not improve signs or symptoms, nor did it alter radiological progression. However, a subanalysis study (n = 477) revealed that patients with marked cartilage loss preserved the structural integrity of subchondral bone by risedronate treatment (15 mg/day and 50 mg/week). Another subanalysis study (n = 1,885) revealed that C-terminal crosslinking telopeptide of type II collagen (CTX-II) decreased with risedronate treatment in a dose-dependent manner, and levels reached after 6 months were associated with radiological progression at 2 years. The results of these RCTs show that risedronate reduces the marker of cartilage degradation (CTX-II), which could contribute to attenuation of radiological progression of OA by preserving the structural integrity of subchondral bone. The review of the literature suggests that higher doses of risedronate (15 mg/day) strongly reduces the marker of cartilage degradation (CTX-II), which could contribute to attenuation of radiological progression of OA by preserving the structural integrity of subchondral bone.

Comparison of the Effect of Vitamin K2 and Risedronate on Trabecular Bone in Glucocorticoid-Treated Rats: A Bone Histomorphometry Study

PURPOSE: To compare the effect of vitamin K2 and risedronate on trabecular bone in glucocorticoid (GC)-treated rats. MATERIALS AND METHODS: Forty-eight Sprague-Dawley female rats, 3 months of age, were randomized by the stratified weight method into 5 groups according to the following treatment schedule: age-matched control, GC administration, and GC administration with concomitant administration of vitamin K2, risedronate, or vitamin K2 + risedronate. GC (methylprednisolone sodium succinate, 5.0 mg/kg) and risedronate (10 microgram/kg) were administered subcutaneously three and five times a week, respectively. Vitamin K2 (menatetrenone, 30 mg/kg) was administered orally three times a week. At the end of the 8-week experiment, bone histomorphometric analysis was performed on trabecular bone of the tibial proximal metaphysis. RESULTS: GC administration decreased trabecular bone mass compared with age-matched controls because of decreased bone formation (mineralizing surface, mineral apposition rate, and bone formation rate) and increased bone erosion. Vitamin K2 attenuated GC-induced trabecular bone loss by preventing GC-induced decrease in bone formation (mineralizing surface) and subsequently reducing GC-induced increase in bone erosion. Risedronate prevented GC-induced trabecular bone loss by preventing GC-induced increase in bone erosion although it also suppressed bone formation (mineralizing surface, mineral apposition rate, and bone formation rate). Vitamin K2 mildly attenuated suppression of bone formation (mineralizing surface) and bone erosion caused by risedronate without affecting trabecular bone mass when administered in combination. CONCLUSION: The present study showed differential effect of vitamin K2 and risedronate on trabecular bone in GC-treated rats.

Influence of Ovariectomy on Bone Turnover and Trabecular Bone Mass in Mature Cynomolgus Monkeys

PURPOSE: To examine the influence of ovariectomy (OVX) on bone turnover and trabecular bone mass at the 3 clinically important skeletal sites in mature cynomolgus monkeys. MATERIALS AND METHODS: Six female cynomolgus monkeys, aged 17-21 years, were randomized into 2 groups by the stratified weight: the OVX and sham-operation groups (n = 3 in each group). The experimental period was 16 months. Lumbar bone mineral density (BMD) in vivo and serum and urinary bone turnover markers were longitudinally measured, and peripheral quantitative computed tomographic and bone histomorphometric analyses were performed on trabecular bone of the lumbar vertebra, femoral neck, and distal radius at the end of the experiment. RESULTS: OVX induced in a reduction in lumbar BMD compared with the sham controls and the baseline, as a result of increased serum levels of bone-specific alkaline phosphatase and urinary levels of cross-lined N- and C-terminal telopeptides of type I collagen. Furthermore, OVX induced reductions in trabecular volumetric BMD and trabecular bone mass compared with the sham controls, with increased bone formation rate at the lumbar vertebra, femoral neck, and distal radius. CONCLUSION: The results indicated that OVX in mature cynomolgus monkeys (17-21 years of age) increased bone turnover and induced trabecular bone loss at the three skeletal sites compared with the sham controls. Thus, mature cynomolgus monkeys could be utilized for preclinical studies to examine the effects of interventions on bone turnover and trabecular bone mass at the 3 clinically important skeletal sites.

Comparison of the Effects of Alendronate and Alfacalcidol on Hip Bone Mineral Density and Bone Turnover in Japanese Men Having Osteoporosis or Osteopenia with Clinical Risk Factors for Fractures

PURPOSE: The comparative effects of alendronate and alfacalcidol on bone mineral density (BMD) and bone turnover have already been established in postmenopausal women with osteoporosis. An open-labeled prospective study was conducted to compare the treatment effects of alendronate and alfacalcidol on hip BMD and bone turnover in Japanese men with osteoporosis or osteopenia with clinical risk factors for fractures. MATERIALS AND METHODS: One hundred twelve men with osteoporosis or osteopenia with clinical risk factors for fractures (mean age: 71.4 years) were randomly divided into two groups of 56 patients each: the alendronate (5 mg daily) and alfacalcidol (1 microgram daily) groups. The BMD of the total hip, urinary level of cross-linked N-terminal telopeptides of type I collagen (NTX), and serum levels of bone-specific alkaline phosphatase (BSAP) were measured during the 12-month-treatment period. RESULTS: Forty-five patients in the alendronate group and 42 patients in the alfacalcidol group completed the trial. Alendronate increased BMD (+2.3% at 12 months) following reductions in the urinary level of NTX (-46.4% at 3 months) and serum level of BSAP (-34.1% at 12 months), while alfacalcidol sustained BMD (-1.9% at 12 months) as well as the urinary level of NTX (+13.2% at 3 months) and serum level of BSAP (+1.8% at 12 months). CONCLUSION: The present study confirmed that alendronate has better efficacy than alfacalcidol (active control) in increasing hip BMD and reducing bone turnover in Japanese men with osteoporosis or osteopenia with clinical risk factors for fractures.

Comparison of the Effects of Alendronate and Alfacalcidol on Hip Bone Mineral Density and Bone Turnover in Japanese Men Having Osteoporosis or Osteopenia with Clinical Risk Factors for Fractures

PURPOSE: The comparative effects of alendronate and alfacalcidol on bone mineral density (BMD) and bone turnover have already been established in postmenopausal women with osteoporosis. An open-labeled prospective study was conducted to compare the treatment effects of alendronate and alfacalcidol on hip BMD and bone turnover in Japanese men with osteoporosis or osteopenia with clinical risk factors for fractures. MATERIALS AND METHODS: One hundred twelve men with osteoporosis or osteopenia with clinical risk factors for fractures (mean age: 71.4 years) were randomly divided into two groups of 56 patients each: the alendronate (5 mg daily) and alfacalcidol (1 microgram daily) groups. The BMD of the total hip, urinary level of cross-linked N-terminal telopeptides of type I collagen (NTX), and serum levels of bone-specific alkaline phosphatase (BSAP) were measured during the 12-month-treatment period. RESULTS: Forty-five patients in the alendronate group and 42 patients in the alfacalcidol group completed the trial. Alendronate increased BMD (+2.3% at 12 months) following reductions in the urinary level of NTX (-46.4% at 3 months) and serum level of BSAP (-34.1% at 12 months), while alfacalcidol sustained BMD (-1.9% at 12 months) as well as the urinary level of NTX (+13.2% at 3 months) and serum level of BSAP (+1.8% at 12 months). CONCLUSION: The present study confirmed that alendronate has better efficacy than alfacalcidol (active control) in increasing hip BMD and reducing bone turnover in Japanese men with osteoporosis or osteopenia with clinical risk factors for fractures.

Comparison of Effects of Alendronate and Raloxifene on Lumbar Bone Mineral Density, Bone Turnover, and Lipid Metabolism in Elderly Women with Osteoporosis

PURPOSE: To compare the effects of alendronate and raloxifene on lumbar bone mineral density (BMD), bone turnover, and lipid metabolism in elderly women with osteoporosis. Subjects and Methods: One hundred twenty-two postmenopausal women with osteoporosis (mean age: 69.4 years) were randomly divided into 2 groups of 61 patients: the alendronate group and the raloxifene group. BMD of the lumbar spine, urinary level of cross-linked N-terminal telopeptides of type I collagen (NTX), and serum levels of alkaline phosphatase (ALP), total cholesterol (TC), high and low density lipoprotein cholesterols (LDL-C and HDL-C, respectively), and triglycerides (TG) were measured during the 12-month-treatment period. RESULTS: The trial in 50 patients in the alendronate group and 52 patients in the raloxifene group could be completed. Both alendronate and raloxifene increased lumbar BMD (+8.0% and +2.4% at 12 months, respectively), followed by reductions of urinary NTX level and serum ALP level; however, the effects of alendronate were more pronounced than those of raloxifene. Only raloxifene reduced the serum levels of TC and LDL-C (-3.9% and -7.7% at 12 months, respectively), without any significant effect on the serum HDL-C and TG levels. CONCLUSION: The present study confirmed the efficacy of alendronate greater than raloxifene in increasing lumbar BMD through its effect on marked reduction of the bone turnover more than by raloxifene, and some beneficial effects of raloxifene on lipid metabolism in elderly women with osteoporosis.