Tag Archives: human

Inulin Increases Calcium Absorption and Bone Mineralization in Adolescents

Abstract

A combination of prebiotic short- and long-chain inulin-type fructans enhances calcium absorption and bone mineralization in young adolescents.

Short-term studies in adolescents have generally shown an enhancement of calcium absorption by inulin-type fructans (prebiotics). Results have been inconsistent; however, and no studies have been conducted to determine whether this effect persists with long-term use. The objective was to assess the effects on calcium absorption and bone mineral accretion after 8 wk and 1 y of supplementation with an inulin-type fructan.
Pubertal adolescents were randomly assigned to receive 8 g/d of a mixed short and long degree of polymerization inulin-type fructan product (fructan group) or maltodextrin placebo (control group). Bone mineral content and bone mineral density were measured before randomization and after 1 y. Calcium absorption was measured with the use of stable isotopes at baseline and 8 wk and 1 y after supplementation. Polymorphisms of the Fok1 vitamin D receptor gene were determined.
Calcium absorption was significantly greater in the fructan group than in the control group at 8 wk (difference: 8.5 +/- 1.6%; P < 0.001) and at 1 y (difference: 5.9 +/- 2.8%; P = 0.04). An interaction with Fok1 genotype was present such that subjects with an ff genotype had the least initial response to fructan. After 1 y, the fructan group had a greater increment in both whole-body bone mineral content (difference: 35 +/- 16 g; P = 0.03) and whole-body bone mineral density (difference: 0.015 +/- 0.004 g/cm(2); P = 0.01) than did the control group.
Daily consumption of a combination of prebiotic short- and long-chain inulin-type fructans significantly increases calcium absorption and enhances bone mineralization during pubertal growth. Effects of dietary factors on calcium absorption may be modulated by genetic factors, including specific vitamin D receptor gene polymorphisms.

Abrams SA, Griffin IJ, Hawthorne KM, Liang L…
Am. J. Clin. Nutr. Aug 2005
PMID: 16087995 | Free Full Text

Cissus May Increase Local IGF-1 in Osteoblasts

Abstract

Cissus quadrangularis augments IGF system components in human osteoblast like SaOS-2 cells.

Osteoporosis is a public health problem which is associated with significant morbidity and mortality. Growth factors are produced locally in the bone and control cellular events such as induction of bone growth. Signaling through the Insulin-like growth factor (IGF)-I receptor (IGF-IR) by locally synthesized IGF-I or IGF-II in osteoblast is considered crucial for normal development and for bone remodeling. Traditional use of Cissus quadrangularis (C. quadrangularis) in the treatment of bone disorders have been documented, however its regulatory effects on IGF system components remain largely unknown. The present study is employed to delineate the effects of ethanolic extract of C. quadrangularis on the regulation of IGF system components in human osteoblast like SaOS-2 cells. RT-PCR analysis revealed an increase in the mRNA expression of IGF-I, IGF-II, IGF-IR in cells treated with C. quadrangularis when compared with control cells. The mRNA expression of IGF binding protein-3 (IGFBP-3) did not differ significantly between control and C. quadrangularis treated cells. Immunoradiometric analysis revealed increased levels of IGF-I, IGF-II and IGFBP-3 in the conditioned medium of C. quadrangularis treated cultures when compared with control. Western blotting analysis revealed increase in protein levels of IGF-IR in cells treated with C. quadrangularis. These results indicate positive regulation of C. quadrangularis on the IGF system components of human osteoblast like SaOS-2 cells.

Muthusami S, Ramachandran I, Krishnamoorthy S, Govindan R…
Growth Horm. IGF Res. Dec 2011
PMID: 22015109

Cissus Anabolic Actions on Bone Cells

Abstract

Effects of Cissus quadrangularis on the proliferation, differentiation and matrix mineralization of human osteoblast like SaOS-2 cells.

Osteoporosis is a public health problem which is associated with significant morbidity and mortality. The repair of bone defect is still a big challenge for orthopedic surgeons. Traditional use of Cissus quadrangularis (C. quadrangularis) in the treatment of bone disorders has been documented. The present study was employed to delineate the effects of ethanolic extract of C. quadrangularis on the proliferation, differentiation and matrix mineralization of human osteoblast like SaOS-2 cells. Lactate dehydrogenase assayed in the conditioned medium of control and C. quadrangularis treated cells did not differ significantly indicating that ethanolic extract of C. quadrangularis is nontoxic to osteoblastic cells. [(3)H] Thymidine incorporation assay revealed that C. quadrangularis treatment has increased the DNA synthesis of human osteoblastic SaOS-2 cells indicating increased proliferation of these cells. The data on alizarin red and ALP staining revealed increased matrix mineralization of human osteoblast like SaOS-2 cells. The study also revealed that the anabolic actions of ethanolic extract of C. quadrangularis in human osteoblast like cells are mediated through increased mRNA and protein expression of Runx2, a key transcription factor involved in the regulation of bone matrix proteins. Chromatin immunoprecipitation analysis revealed increased transcriptional activity of Runx2 on the promoter of osteocalcin after C. quadrangularis treatment. These results indicate positive regulation of C. quadrangularis on the proliferation, differentiation, and matrix mineralization of human osteoblast like SaOS-2 cells.

Muthusami S, Senthilkumar K, Vignesh C, Ilangovan R…
J. Cell. Biochem. Apr 2011
PMID: 21308732

Review: Milk + Resistance Training

Abstract

Impact of milk consumption and resistance training on body composition of female athletes.

Resistance exercise (RE) preceding the provision of high-quality dairy protein supports muscle anabolism. Milk contains bioactive components, including two high-quality protein fractions, calcium and vitamin D, each of which has been shown modulate body composition (increasing lean mass and decreasing fat mass) under energy balance and hypoenergetic conditions. These dairy nutrients are also essential for skeletal health. Acutely, no study of RE and milk/whey consumption has been undertaken exclusively in female athletes, let alone women, nevertheless, studies with both men and women show increased lean mass accretion following milk/whey compared to soy/placebo. Currently, no longer-term RE studies with milk supplementation have been done in female athletes. However, trials in young recreationally active women demonstrated augmented increases in lean mass and decreases in fat mass with RE and milk or whey protein consumption. The amount of protein consumed post-exercise is also important; two trials using yogurt (5 g protein/6 oz) failed to demonstrate a positive change in body composition compared to placebo. For bone health, RE plus dairy improved bone mineral density at clinically important sites and reduced bone resorption. With energy restriction, in one study, higher dairy plus higher protein resulted in greater fat loss, lean mass gain and improved bone health in overweight women. In another study, milk and calcium supplementation showed no greater benefit. Neither trial exclusively utilized RE. Overall, RE and milk/dairy consumption positively impact body composition in women by promoting losses in fat, gains or maintenance of lean mass and preservation of bone. Future studies in female athletes and under energy restriction with RE alone are warranted.

Josse AR, Phillips SM
Med Sport Sci 2012
PMID: 23075559

Review: Exercise Program Design

Abstract

Exercise for patients with osteoporosis: management of vertebral compression fractures and trunk strengthening for fall prevention.

Maintenance of bone health and quality requires mechanical strain, but the mechanical force needs to be within the bone’s biomechanical competence. In osteoporosis, compression of vertebral bodies can be insidious. Therefore, absence of pain does not necessarily indicate absence of vertebral microfracture and deformity. Further, patients with previous vertebral fractures are at risk for further vertebral fractures and their associated morbidity. Exercise is a part of the comprehensive management of patients with osteoporosis and has been associated with improvement of quality of life and lowered risk of future fracture. The exercise prescription needs to match the needs of the patient. If exercise is not prescribed properly, then it may have negative consequences. In general, an exercise program, therapeutic or recreational, needs to address flexibility, muscle strength, core stability, cardiovascular fitness, and gait steadiness. As with pharmacotherapy, therapeutic exercises need to be individualized on the basis of musculoskeletal status and an individual’s exercise interest. In osteoporosis, axial strength and stability are of primary importance. In particular, a spinal extensor strengthening program should be performed with progressive measured resistance as tolerated. To address falls and fractures, an exercise program should also include balance and lower extremity strength training. Proper dosing of oral cholecalciferol and calcium supplements can enhance the effect of strengthening exercises. Finally, a coordinated approach, such as the Spinal Proprioception Extension Exercise Dynamic (SPEED) program, can improve back extensor strength, the level of physical activity, and locomotion, and reduce back pain and fear and risk of falls.

Sinaki M
PM R Nov 2012
PMID: 23174554

Alendronate + Exercise Prevents All Bone Loss During Spaceflight

Abstract

Bisphosphonates as a supplement to exercise to protect bone during long-duration spaceflight.

We report the results of alendronate ingestion plus exercise in preventing the declines in bone mass and strength and elevated levels of urinary calcium and bone resorption in astronauts during 5.5 months of spaceflight.
This investigation was an international collaboration between NASA and the JAXA space agencies to investigate the potential value of antiresorptive agents to mitigate the well-established bone changes associated with long-duration spaceflight.
We report the results from seven International Space Station (ISS) astronauts who spent a mean of 5.5 months on the ISS and who took an oral dose of 70 mg of alendronate weekly starting 3 weeks before flight and continuing throughout the mission. All crewmembers had available for exercise a treadmill, cycle ergometer, and a resistance exercise device. Our assessment included densitometry of multiple bone regions using X-ray absorptiometry (DXA) and quantitative computed tomography (QCT) and assays of biomarkers of bone metabolism.
In addition to pre- and post-flight measurements, we compared our results to 18 astronauts who flew ISS missions and who exercised using an early model resistance exercise device, called the interim resistance exercise device, and to 11 ISS astronauts who exercised using the newer advanced resistance exercise device (ARED). Our findings indicate that the ARED provided significant attenuation of bone loss compared with the older device although post-flight decreases in the femur neck and hip remained. The combination of the ARED and bisphosphonate attenuated the expected decline in essentially all indices of altered bone physiology during spaceflight including: DXA-determined losses in bone mineral density of the spine, hip, and pelvis, QCT-determined compartmental losses in trabecular and cortical bone mass in the hip, calculated measures of fall and stance computed bone strength of the hip, elevated levels of bone resorption markers, and urinary excretion of calcium.
The combination of exercise plus an antiresoptive drug may be useful for protecting bone health during long-duration spaceflight.

Leblanc A, Matsumoto T, Jones J, Shapiro J…
Osteoporos Int Jul 2013
PMID: 23334732

Biking May Help Bones Affected by High Cortisol

Abstract

Effect of physiological exercise on osteocalcin levels in subjects with adrenal incidentaloma.

In the present study, we have evaluated whether physical exercise affect low osteocalcin concentrations observed in patients with subclinical hypercortisolism.
Sixteen patients (10 men and 6 women, age 38-55 yr) with adrenal incidentaloma were studied. Fifteen healthy volunteers matched for age (range 35-47 yr) were used as controls. Subjects were submitted to a 8-week exercise-training program with cycle-ergometer for 1 h/day 3-4 days/week at 60% of their individual VO2 max. Before and after this period, resting venous serum osteocalcin and GH concentrations were measured in the same batch. The blood sampling after 8 weeks of the training program were performed after resting for one day. All patients and controls underwent also the following endocrine evaluation: serum cortisol, plasma ACTH.
Our results demonstrate a significant increase of osteocalcin after physical exercise and a positive correlation between osteocalcin and GH. This later might suggest a role of GH in the increased osteocalcin secretion.
The data of the present study suggest a positive effect of physical exercise on bone metabolism in patients with adrenal incidentaloma.

Coiro V, Volpi R, Cataldo S, Magotti MG…
J. Endocrinol. Invest. Apr 2012
PMID: 22652825

It is surprising the exercise helped considering the form of exercise was cycling – a non-weight bearing exercise.

Resistance Exercise Prevents Bone Loss During Spaceflights

Abstract

Benefits for bone from resistance exercise and nutrition in long-duration spaceflight: Evidence from biochemistry and densitometry.

Exercise has shown little success in mitigating bone loss from long-duration spaceflight. The first crews of the International Space Station (ISS) used the “interim resistive exercise device” (iRED), which allowed loads of up to 297 lb(f) (or 1337 N) but provided little protection of bone or no greater protection than aerobic exercise. In 2008, the Advanced Resistive Exercise Device (ARED), which allowed absolute loads of up to 600 lb(f) (1675 N), was launched to the ISS. We report dietary intake, bone densitometry, and biochemical markers in 13 crewmembers on ISS missions from 2006 to 2009. Of these 13, 8 had access to the iRED and 5 had access to the ARED. In both groups, bone-specific alkaline phosphatase tended to increase during flight toward the end of the mission (p = 0.06) and increased 30 days after landing (p < 0.001). Most markers of bone resorption were also increased in both groups during flight and 30 days after landing (p < 0.05). Bone densitometry revealed significant interactions (time and exercise device) for pelvis bone mineral density (BMD) and bone mineral content (p < 0.01), hip femoral neck BMD (p < 0.05), trochanter BMD (p < 0.05), and total hip BMD (p < 0.05). These variables were unchanged from preflight only for ARED crewmembers, who also returned from flight with higher percent lean mass and lower percent fat mass. Body mass was unchanged after flight in both groups. All crewmembers had nominal vitamin D status (75 ± 17 nmol/L) before and during flight. These data document that resistance exercise, coupled with adequate energy intake (shown by maintenance of body mass determined by dual-energy X-ray absorptiometry [DXA]) and vitamin D, can maintain bone in most regions during 4- to 6-month missions in microgravity. This is the first evidence that improving nutrition and resistance exercise during spaceflight can attenuate the expected BMD deficits previously observed after prolonged missions.

Smith SM, Heer MA, Shackelford LC, Sibonga JD…
J. Bone Miner. Res. Sep 2012
PMID: 22549960

Physical Activity Associated with Higher Bone Density in Chinese Women

Abstract

[Physical activity and bone mineral density in postmenopausal women].

To test the association of total and physical activity (PA) intensity levels with bone mineral density (BMD) and bone mineral content (BMC) in postmenopausal women.
315 postmenopausal women (50-70 y) were recruited for this cross-sectional study from community residents in Guangzhou, China. PA and related covariates including general characteristics and dietary intakes were assessed using a face-to-face interview. BMD and BMC were determined by a dual energy x-ray absorptiometry, at the whole body, lumbar spine (L1-AL4), total hip and its sub-sites.
The participants were tertiled according to metabolic equivalent (MET) of PA. Analysis of covariance showed that greater PA tended to correlated to better BMD and BMC at various sites. Mean (S) BMDs at the whole body were (1.045 +/- 0.008), (1.043 +/- 0.008), (1.068 +/- 0.008) g/cm2 in the tertile I, II and III of total PA. BMD was significantly higher in the tertile III than those in the tertile I (P = 0. 049) and II (P = 0.028). No significant difference was observed at other sites. Mean BMC was significantly higher in the of highest total PA group than those in the other two groups at total femur, femoral neck, shaft femur and ward’s triangle (P = 0. 004-0. 042). The association was differed by PA intensity levels. BMD tended to be increased with less light-intensity PA, more moderate-intensity PA and moderate vigorous-intensity PA.
Greater total PA and moderate-intensity PA, and moderate vigorous-intensity PA might improve bone mass in postmenopausal women.

Zhong W, Li J, Huang Z, Yang X…
Wei Sheng Yan Jiu Mar 2012
PMID: 22611928

A Positive Study on Vibration With or Without Exercise

Abstract

Whole-body vibration effects on bone mineral density in women with or without resistance training.

Whole-body vibration exposure may translate into improved bone mass in young adult women. The primary focus of this study was to examine the effects of graded whole-body vibration or vibration exposure plus resistance training on bone mineral density (BMD), hematological measures for bone remodeling, and exercise metabolism in young women.
There were 51 healthy active women [mean (SD) age, 21.02 (3.39) yr; height, 165.66 (6.73) cm; body mass 66.54 (13.39) kg] who participated in the intervention. Subjects were randomly assigned to whole-body vibration (WBV), whole-body vibration plus resistance training (WBV+RT), or control (CONT) groups for 16 wk.
A repeated-measure ANOVA found no significant (P < 0.05) group differences in BMD at the completion of 16 wk. A significant within group change was apparent for the WBV (2.7% femoral neck) and WBV+RT (femoral neck 1.9%; vertebra 0.98%). WBV and WBV+RT experienced a significant (P < 0.05) 60% and 58% increase in adiponectin, 48% and 30% in transforming growth factor-beta1, and 17% and 34% in nitric oxide with an accompanying 50% and 36% decrease in osteopontin, 19% and 34% in interleukin-1beta, and 38% and 39% in tumor necrosis factor-alpha.
The results indicate graded whole-body vibration exposure may be effective in improving BMD by increasing bone deposition while also decreasing bone resorption. Whole-body vibration may also provide an efficient stratagem for young women to achieve peak bone mass and help stave off osteoporosis later in life and provide a novel form of physical training.

Humphries B, Fenning A, Dugan E, Guinane J…
Aviat Space Environ Med Dec 2009
PMID: 20027849