PTH improves titanium implant fixation more than pamidronate or renutrition in osteopenic rats chronically fed a low protein diet

SUMMARY

We evaluated the effects of parathyroid hormone (PTH), pamidronate, or renutrition on osseointegration of titanium implants in the proximal tibia of rats subject to prolonged low-protein diets. PTH improved mechanical fixation, microarchitecture, and increased pull-out strength. Pamidronate or renutrition had lesser effects. PTH can thus improve implant osseointegration in protein-malnourished rats.

INTRODUCTION

Protein malnutrition impairs implant osseointegration in rats. PTH and pamidronate prevent deleterious effects of protein restriction introduced just prior to implantation. Whether these treatments improve osseointegration after chronic protein deprivation, i.e., in osteopenic bone at time of implantation, is unknown. We evaluated effects of PTH, pamidronate, or renutrition on resistance to pull-out of titanium rods implanted into the rat tibiae following isocaloric low-protein intake.

METHODS

Forty-one adult female rats received normal or isocaloric low-protein diets. Six weeks later, implants were surgically inserted into proximal tibiae. Following implantation, rats on low-protein diets were treated with PTH (1-34), pamidronate, saline vehicle, or normal protein diets, for another 8 weeks. Tibiae were removed for micro-computerised tomographic morphometry and evaluation of pull-out strength.

RESULTS

Pull-out strength decreased in rats on isocaloric low-protein diets compared with normal protein group (-33.4%). PTH increased pull-out strength in low-protein group, even compared to controls from the normal protein group. PTH and pamidronate increased bone volume/tissue volume, bone-to-implant contact, and trabecular thickness, whilst trabecular separation was reduced, with a shift to more plate-like bone surrounding the implants.

CONCLUSIONS

PTH reversed the deleterious effects of long-term protein undernutrition on mechanical fixation and bone microarchitecture and improved implant osseointegration more than pamidronate or renutrition, likely through changes to structure model index.

Administration of growth hormone in selectively protein-deprived rats decreases BMD and bone strength

INTRODUCTION

Isocaloric protein undernutrition is associated with decreased bone mass and decreased bone strength, together with lower IGF-I levels. It remains unclear whether administration of growth hormone (GH) corrects these alterations in bone metabolism.

MATERIALS AND METHODS

Six-month-old female rats were fed isocaloric diets containing either 2.5% or 15% casein for 2 weeks. Bovine growth hormone (bGH, 0.5 or 2.5mg/kg of body weight) or vehicle was then administered as subcutaneous injections, twice daily, to rats on either diet for 4 weeks. At the proximal tibia, analysis of bone mineral density (BMD), maximal load and histomorphometry were performed. In addition, urinary deoxypyridinoline, plasma osteocalcin and IGF-I concentrations were measured. Weight was monitored weekly.

RESULTS

bGH caused a dose-dependent increase in plasma IGF-I regardless of the dietary protein content. However, bGH dose-dependently decreased BMD and bone strength in rats fed the low-protein diet. There was no significant effect of bGH on BMD in rats fed the normal protein diet within this short-term treatment period, however bone formation as detected by histomorphometry was improved in this group but not the low-protein group. Osteoclast surface was increased in the low-protein bGH-treated animals only. Changes in bone turnover markers were detectable under both normal and low-protein diets.

CONCLUSION

These results emphasize the major importance of dietary protein intake in the bone response to short-term GH administration, and highlight the need for further investigation into the effects of GH treatment in patients with reduced protein intake.

Strontium ranelate and alendronate have differing effects on distal tibia bone microstructure in women with osteoporosis

The structural basis of the antifracture efficacy of strontium ranelate and alendronate is incompletely understood. We compared the effects of strontium ranelate and alendronate on distal tibia microstructure over 2 years using HR-pQCT. In this pre-planned, interim, intention-to-treat analysis at 12 months, 88 osteoporotic postmenopausal women (mean age 63.7 ± 7.4) were randomized to strontium ranelate 2 g/day or alendronate 70 mg/week in a double-placebo design. Primary endpoints were changes in microstructure. Secondary endpoints included lumbar and hip areal bone mineral density (aBMD), and bone turnover markers. This trial is registered with http://www.controlled-trials.com, number ISRCTN82719233. Baseline characteristics of the two groups were similar. Treatment with strontium ranelate was associated with increases in mean cortical thickness (CTh, 5.3%), cortical area (4.9%) and trabecular density (2.1%) (all P < 0.001, except cortical area P = 0.013). No significant changes were observed with alendronate. Between-group differences in favor of strontium ranelate were observed for CTh, cortical area, BV/TV and trabecular density (P = 0.045, 0.041, 0.048 and 0.035, respectively). aBMD increased to a similar extent with strontium ranelate and alendronate at the spine (5.7% versus 5.1%, respectively) and total hip (3.3% versus 2.2%, respectively). No significant changes were observed in remodeling markers with strontium ranelate, while suppression was observed with alendronate. Within the methodological constraints of HR-pQCT through its possible sensitivity to X-ray attenuation of different minerals, strontium ranelate had greater effects than alendronate on distal tibia cortical thickness and trabecular volumetric density.

Treatment of osteoporosis: recognizing and managing cutaneous adverse reactions and drug-induced hypersensitivity

Cutaneous adverse reactions are reported for many treatments including antiosteoporotic agents. This position paper includes an algorithm for their recognition. With early recognition and proper management, including immediate and permanent withdrawal of the culprit agent, accompanied by hospitalization, rehydration, and systemic corticosteroids, if necessary, the prognosis is good.

INTRODUCTION

Cutaneous adverse reactions are reported for many therapeutic agents and observed in between 0% and 8% of treated patients depending on the drug. The antiosteoporotic agents are reputed to be safe in terms of cutaneous effects; however, there have been a number of case reports of cutaneous adverse reactions, which merit consideration. This was the subject of a Working Group meeting of the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis in April 2009, to focus on the impact of cutaneous adverse reactions and drug-induced hypersensitivity in the management of postmenopausal osteoporosis. We prepared this position paper following these discussions, and include an algorithm for their recognition.

METHODS

We reviewed cutaneous adverse reactions observed with antiosteoporotic agents, including information from case reports, regulatory documents, and pharmacovigilance.

RESULTS

The cutaneous adverse reactions range from benign reactions including exanthematous or maculopapular eruption (drug rash), photosensitivity, and urticaria to the severe and potentially life-threatening reactions, angioedema, drug rash with eosinophilia and systemic symptoms (DRESS), Stevens Johnson syndrome (SJS), and toxic epidermal necrolysis (TEN). Review of available evidence shows that cutaneous adverse reactions occur with all commonly used antiosteoporotic agents. Notably, there are reports of SJS and TEN for bisphosphonates, and of DRESS and TEN for strontium ranelate. These severe reactions remain very rare (<1 in 10,000 cases).

CONCLUSION

With early recognition and proper management, including immediate and permanent withdrawal of the culprit agent, accompanied by hospitalization and rehydration and systemic corticosteroids if necessary, the prognosis is good.

Strontium ranelate improves implant osseointegration

INTRODUCTION

Endosseous implantation is a frequent procedure in orthopaedics and dentistry, particularly in the aging population. The incidence of implant failure, however, is high in situations where the bone at the site of implantation is not of optimal quality and quantity. Alterations of bone turnover and changes in intrinsic bone tissue quality have potentially negative effects on optimal osseointegration. Strontium ranelate, which acts on both resorption and formation, and improves biomaterial properties, is hypothesized to improve osseointegration and this hypothesis was tested here.

MATERIALS AND METHODS

Titanium implants were inserted into the proximal tibias of thirty 6-month-old Sprague-Dawley female rats. During the 8 weeks following implantation, animals received orally strontium ranelate (SrRan) 5 days a week (625 mg/kg/day) or saline vehicle. Pull-out strength, microCT and nanoindentation were assessed on the implanted tibias.

RESULTS

SrRan significantly increased pull-out strength compared to controls (+34%). This was associated with a significant improvement of bone microarchitecture around the implant (BV/TV+36%; Tb.Th+13%; Conn.D+23%) with a more plate-shape structure and an increase in bone-to-implant contact (+19%). Finally, strontium ranelate had a significant beneficial effect on parameters of bone biomaterial properties at both cortical (modulus+11.6%; hardness+13%) and trabecular areas (modulus+7%; hardness+16.5%).

CONCLUSIONS

SrRan is an antiosteoporotic agent that increased mechanical fixation of the implant. The improvement of pull-out strength was associated with an improvement of implant osseointegration with both a positive effect on bone microarchitecture and on bone biomaterial properties in the vicinity of the implant. These current results may support potential benefits of strontium ranelate in orthopaedic and dental surgery to enhance osseointegration.

The need for a transparent, ethical, and successful relationship between academic scientists and the pharmaceutical industry: a view of the Group for the Respect of Ethics and Excellence in Science (GREES)

This paper provides recommendations for fair and unbiased relationship between academic scientists and the pharmaceutical industry.

INTRODUCTION

Real or perceived problems in the relationship between academics and the industry have been the subject of much recent debate. It has been suggested that academic clinicians should sever all links with the industry-a view that is rarely challenged.

METHODS

Academic experts and members of the pharmaceutical industry were invited to an expert consensus meeting to debate this topic. This meeting was organized by the Group for the Respect of Ethics and Excellence in Science. Conflict of interest, competing interest, right and duties of academic scientist, authorship, and staff and student education were discussed.

RESULTS

Guidelines for a transparent, ethical, strong, and successful partnership between the academic scientist and the pharmaceutical industry have been provided.

CONCLUSIONS

The Group support interactions between the industry and clinicians provided that it is transparent and ethical.

FRAX assessment of osteoporotic fracture probability in Switzerland

SUMMARY

A Swiss-specific FRAX model was developed. Patient profiles at increased probability of fracture beyond currently accepted reimbursement thresholds for bone mineral density (BMD) measurement by dual X-ray absorptiometry (DXA), and osteoporosis treatment were identified.

INTRODUCTION

This study aimed to determine which constellations of clinical risk factors, alone, or combined with BMD measurement by DXA, contribute to improved identification of Swiss patients with increased probability of fracture.

METHODS

The 10-year probability of hip and any major osteoporotic fracture was computed for both sexes, based on Swiss epidemiological data, integrating fracture risk and death hazard, in relation to validated clinical risk factors, with and without BMD values.

RESULTS

Fracture probability increased with age, lower body mass index (BMI), decreasing BMD T-score, and all clinical risk factors used alone or combined. Several constellations of risk factor profiles were identified, indicating identical or higher absolute fracture probability than risk factors currently accepted for DXA reimbursement in Switzerland. With identical sex, age and BMI, subjects with parental history of hip fracture had as high a probability of any major osteoporotic fracture as patients on oral glucocorticoids or with a prevalent fragility fracture. The presence of additional risk factors further increased fracture probability.

CONCLUSIONS

The customised FRAX model indicates that a shift from the current DXA-based intervention paradigm, toward a fracture risk continuum based on the 10-year probability of any major osteoporotic fracture may improve identification of patients at increased fracture risk.

Proximal tibia volumetric bone mineral density is correlated to the magnitude of local acceleration in male long-distance runners

The beneficial effect of physical exercise on bone mineral density (BMD) is at least partly explained by the forces exerted directly on the bones. Male runners present generally higher BMD than sedentary individuals. We postulated that the proximal tibia BMD is related to the running distance, as well as to the magnitude of the shocks (while running) in male runners. A prospective study (three yearly measurements) included 81 healthy male subjects: 16 sedentary lean subjects, and 3 groups of runners (5-30 km/wk, n = 19; 30-50 km/wk, n = 29; 50-100 km/wk, n = 17). Several measurements were performed at the proximal tibia level: volumetric BMD (vBMD) and cortical index (CI), i.e., an index of cortical bone thickness and peak accelerations (an index of shocks during heel strike) while running (measured by a three-dimensional accelerometer). A general linear model assessed the prediction of vBMD or CI by 1) simple effects (running distance, peak accelerations, time); and 2) interactions (for instance, if vBMD prediction by peak acceleration depends on running distance). CI and vBMD 1) increase with running distance to reach a plateau over 30 km/wk; and 2) are positively associated with peak accelerations over 30 km/wk. Running may be associated with high peak accelerations to have beneficial effects on BMD. More important strains are needed to be associated with the same increase in BMD during running sessions of short duration than those of long duration. CI and vBMD are associated with the magnitude of the shocks during heel strike in runners.

Maximizing bone mineral mass gain during growth for the prevention of fractures in the adolescents and the elderly

Bone mass is a key determinant of fracture risk. Maximizing bone mineral mass during childhood and adolescence may contribute to fracture risk reduction during adolescence and possibly in the elderly. Although more than 60% of the variance of peak bone mass (PBM), the amount of bone present in the skeleton at the end of its maturation process, is genetically determined, the remainder is likely influenced by factors amenable to positive intervention, such as adequate dietary intake of dairy products as a natural source of calcium and proteins, vitamin D, and regular weight-bearing physical activity. Low calcium and vitamin D intakes are associated with negative effects on bone, including suboptimal PBM acquisition. As suggested by intervention studies, regular intake of dairy products may have positive and possibly sustained effects on bone mineral mass gain, contributing thereby to fracture risk reduction. Further evidence from intervention studies suggests that weight-bearing physical activities, such as jumping, may contribute to bone mineral mass gain in children. Optimizing PBM acquisition through dietary and physical exercise measures may represent a valuable primary method for the prevention of fractures.

[Osteoporosis]

Fracture risk could be evaluated with FRAX. Vitamin D administration decreases the rate of falls and deaths. Denosumab reduces the risk of fracture in postmenopausal women with osteoporosis and shows positive effects in case of breast and prostate cancers with hormone deprivation therapies. Zoledronate and teriparatide alone are more effective than risedronate and alendronate respectively in treatment of glucocorticoids induced osteoporosis. The association zoledronate and teriparatide may be promising. Vertebroplasty is not the first line treatment for symptomatic osteoporotic vertebral fractures. Osteonecrosis of the jaw and subtrochanteric femoral fractures are still events to consider in case of treatments with bisphosphonates.

Bisphosphonate-associated osteonecrosis of the jaw: a key role of inflammation?

Osteonecrosis of the jaw (ONJ) can be associated with nitrogen-containing bisphosphonates (NBPs) therapy. Various mechanisms of NBP-associated ONJ have been proposed and there is currently no consensus of the underlying pathogenesis. The detailed medical and dental histories of 30 ONJ patients treated with NBPs for malignant diseases (24) or osteoporosis (6) were analyzed. The necrotic bone was resected and analyzed histologically after demineralization. In 10 patients the perinecrotic bone was also resected and processed without demineralization. Alveolar bone samples from 5 healthy patients were used as controls. In 14 ONJ patients, serial technetium-99m-methylene diphosphonate scintigraphic scans were also available and confronted to the other data. Strong radionuclide uptake was detected in some patients several months before clinical diagnosis of ONJ. The medullary spaces of the necrotic bone were filled with bacterial aggregates. In the perinecrotic bone, the bacteria-free bone marrow characteristically showed an inflammatory reaction. The number of medullary inflammatory cells taken as an index of inflammation allowed us to discriminate two inflammation grades in the ONJ samples. Low-grade inflammation, characterized by marrow fibrosis and low inflammatory cells infiltration, increased numbers of TRAP(+) mono- and multineacleated cells was seen in patients with bone exposure<2 cm(2). High-grade inflammation, associated with larger lesions, showed amounts of tartrate-resistant acid phosphatase(+)/calcitonin receptor(-) mono- and multinucleated cells, osteocyte apoptosis, hypervascularization and high inflammatory cell infiltration. The clinical extent of ONJ was statistically linked to the numbers of inflammatory cell. Taken together these data suggest that bone necrosis precedes clinical onset and is an inflammation-associated process. We hypothesize that from an initial focus, bone damage spreads centrifugally, both deeper into the jaw and towards the mucosa before the oral bone exposure and the clinical diagnosis of ONJ.

Management of osteoporosis in the elderly

BACKGROUND

Osteoporosis is predominantly a condition of the elderly, and the median age for hip fracture in women is approximately 83 years. Osteoporotic fracture risk is multifactorial, and often involves the balance between bone strength and propensity for falling.

OBJECTIVE

To present an overview of the available evidence, located primarily by Medline searches up to April, 2009, for the different management strategies aimed at reducing the risk of falls and osteoporotic fractures in the elderly.

RESULTS

Frailty is an independent predictor of falls, hip fractures, hospitalisation, disability and death in the elderly that is receiving increasing attention. Non-pharmacological strategies to reduce fall risk can prevent osteoporotic fractures. Exercise programmes, especially those involving high doses of exercise and incorporating balance training, have been shown to be effective. Many older people, especially the very elderly and those living in care institutions, have vitamin D inadequacy. In appropriate patients and given in sufficient doses, vitamin D and calcium supplementation is effective in reducing both falls and osteoporotic fractures, including hip fractures. Specific anti-osteoporosis drugs are underused, even in those most at risk of osteoporotic fracture. The evidence base for the efficacy of most such drugs in the elderly is incomplete, particularly with regard to nonvertebral and hip fractures. The evidence base is perhaps most complete for the relatively recently introduced drug, strontium ranelate. Non-adherence to treatment is a substantial problem, and may be exacerbated by the requirements for safe oral administration of bisphosphonates.

CONCLUSION

Evidence-based strategies are available for reducing osteoporotic fracture risk in the elderly, and include exercise training, vitamin D and calcium supplementation, and use of evidence-based anti-osteoporotic drugs. A positive and determined approach to optimising the use of such strategies could reduce the burden of osteoporotic fractures in this high-risk group.

The influence of pubertal timing on bone mass acquisition: a predetermined trajectory detectable five years before menarche

BACKGROUND

Later menarcheal age (MENA) is a risk factor for osteoporosis. It is associated with low peak bone mass (PBM). Like PBM, MENA is under strong genetic influence. We hypothesized that MENA-related bone mass differences could be predetermined before puberty.

METHODS

We tested this hypothesis in 124 healthy subjects followed from age 7.9 to 20.4 yr with dual-energy x-ray absorptiometry assessment at mean ages of 8.9, 10.0, 12.4, and 16.4 yr. Six sites were measured: radial metaphysis, radial diaphysis, femoral neck, trochanter, femoral diaphysis, and L2-L4. Mean MENA (+/-SD) was 13.0 +/- 1.2 yr. The cohort was segregated by the median of MENA into LATER (14.0 +/- 0.7 yr) and EARLIER (12.1 +/- 0.7 yr) subgroups.

RESULTS

At 20.4 +/- 0.6 yr, areal bone mineral density (aBMD) was lower in the LATER than the EARLIER subgroup at all six sites, with a mean difference of -0.31 Z-score (P = 0.022). Lower Z-scores in the LATER than in the EARLIER subgroup were observed at all sites at mean ages of 10.0, 12.4, and 16.4 yr, and before pubertal maturation, i.e. at 8.9 yr with a mean Z-score difference of -0.34 (P = 0.016). From mean age 8.9 to 20.4 yr, aBMD gains of all sites were similar in LATER and EARLIER subgroups, with mean of +301 and +308 mg/cm(2) (P = 0.402), respectively.

CONCLUSIONS

In prepubertal girls who will experience later menarche, a deficit in aBMD can already be observed before the onset of pubertal maturation, with no further accumulated deficit until PBM compared to girls with earlier menarche. This suggests that shorter estrogen exposure from prepuberty to PBM is not the main factor for increased osteoporosis risk associated with later menarche. Rather common genetic determinants of low bone mass and later puberty could be involved.

Early serum IGF-I response to oral protein supplements in elderly women with a recent hip fracture

BACKGROUND & AIMS

In patients with recent hip fracture, reduced serum IGF-I in relation to protein undernutrition is frequent. Elevation of circulating IGF-I in response to a daily oral supplement of 20 g of casein was observed after 6 months. This study determined if the response to casein as compared to whey protein can be observed as early as after one week.

METHODS

45 women were randomized after recent hip fracture in 3 groups receiving a preparation of 20 g of casein, an isocaloric supplement of 20 g of whey protein or an isocaloric supplement of 15 g of whey protein combined with 5 g of essential amino acids (a.a.).

RESULTS

A similar significant elevation of serum IGF-I was already observed after 7 days for casein (+37.3 microg/L), whey (+29.4) and for whey+a.a. (+34.3). From day 7-28, no further significant rise in IGF-I was recorded.

CONCLUSION

After one week of protein supplementation, the percent increase of IGF-I was of similar magnitude to that previously observed after 6 months of protein supplementation. It suggests that in hip fracture patients, long-term effects of various protein preparations on IGF-I could be predicted from changes observed as early as 7 days after the onset of supplementation.

Age and gender distribution of primary hyperparathyroidism and incidence of surgical treatment in a European country with a particularly high life expectancy

OBJECTIVE

Primary hyperparathyroidism (PHPT) is a frequently encountered endocrine disease in the elderly, but little is known about ist epidemiology in the aging European population. This study investigates the age- and sex-dependence of PHPT and the incidence of parathyroidectomy (PTX) in Switzerland, a country with a particularly high life expectancy.

DESIGN

A population-based study was performed using data from the Swiss Federal Statistical Office covering years 2000 to 2004. Anonymised hospital discharge codes for PHPT and PTX were analysed, and the hospitalisation rate for PHPT and incidence of PTX were calculated.

RESULTS

The mean annual hospitalisation rate of patients with PHPT was 8.3/100,000 inhabitants. The rate was approximately three times higher in women than in men, with the highest estimate found in women > or = 80 years (63.7/ 100,000). The population-adjusted annual incidence of PTX was 3.8/100,000 inhabitants. PTX incidence was higher in individuals > or = 50 years than in younger persons (8.7/100,000 vs 1.3/100,000), with a peak in patients aged 70-74 years.

CONCLUSIONS

In a European population with high life expectancy, the hospitalisation rate of PHPT is higher in women and increases continuously with age. Incidence of PTX is highest in patients aged 70-74 years. These findings underscore the need for further research on the impact of population aging on the treatment patterns of PHPT.

Remaining lifetime and absolute 10-year probabilities of osteoporotic fracture in Swiss men and women

SUMMARY

Remaining lifetime and absolute 10-year probabilities for osteoporotic fractures were determined by gender, age, and BMD values. Remaining lifetime probability at age 50 years was 20.2% in men and 51.3% in women and increased with advancing age and decreasing BMD. The study validates the elements required to populate a Swiss-specific FRAX model.

INTRODUCTION

Switzerland belongs to high-risk countries for osteoporosis. Based on demographic projections, burden will still increase. We assessed remaining lifetime and absolute 10-year probabilities for osteoporotic fractures by gender, age and BMD in order to populate FRAX algorithm for Switzerland.

METHODS

Osteoporotic fracture incidence was determined from national epidemiological data for hospitalised fractured patients from the Swiss Federal Office of Statistics in 2000 and results of a prospective Swiss cohort with almost 5,000 fractured patients in 2006. Validated BMD-associated fracture risk was used together with national death incidence and risk tables to determine remaining lifetime and absolute 10-year fracture probabilities for hip and major osteoporotic (hip, spine, distal radius, proximal humerus) fractures.

RESULTS

Major osteoporotic fractures incidence was 773 and 2,078 per 100,000 men and women aged 50 and older. Corresponding remaining lifetime probabilities at age 50 were 20.2% and 51.3%. Hospitalisation for clinical spine, distal radius, and proximal humerus fractures reached 25%, 30% and 50%, respectively. Absolute 10-year probability of osteoporotic fracture increased with advancing age and decreasing BMD and was higher in women than in men.

CONCLUSION

This study validates the elements required to populate a Swiss-specific FRAX model, a country at highest risk for osteoporotic fractures.

The importance and relevance of peak bone mass in the prevalence of osteoporosis

Bone mass and strength achieved at the end of the growth period, simply designated as 'Peak Bone Mass (PBM)', plays an essential role in the risk of osteoporotic fractures occurring in adulthood. It is considered that an increase of PBM by one standard deviation would reduce the fracture risk by 50%. As estimated from twin studies, genetics is the major determinant of PBM, accounting for about 60 to 80% of its variance. During pubertal maturation, the size of the bone increases whereas the volumetric bone mineral density remains constant in both genders. At the end of puberty, the sex difference is essentially due to a greater bone size in male than female subjects. This is achieved by larger periosteal deposition in boys, thus conferring at PBM a better resistance to mechanical forces in men than in women. Sex hormones and the IGF-1 system are implicated in the bone sexual dimorphism occurring during pubertal maturation. The genetically determined trajectory of bone mass development can be modulated to a certain extent by modifiable environmental factors, particularly physical activity, calcium and protein intakes. Prepuberty appears to be an opportune time to modify environmental factors that impinge on bone mineral mass acquisition.

[Fall prevention: a challenge in the strategy of fracture prevention in the elderly]

Fracture risk depends on density and quality of bone but also on fall risk. Besides the resultant fractures, the human and socio-economic burden of falls pose many challenges to the issue of prevention for the elderly. A systematic approach to falls prevention should be considered as a part of routine care. The identification of intrinsic and extrinsic risk factors is an essential initial step to falls prevention. Intervention should be multidisciplinary and multifactorial, targeting modifiable risk factors, especially for high risk patients. We report the experience of a multidisciplinary program designed to prevent falls and fractures, conducted at the Geneva University Hospital.

Zinc increases the effects of essential amino acids-whey protein supplements in frail elderly

Protein undernutrition is frequent in the elderly. It contributes to the development of osteoporosis, possibly via lower IGF-I. Dietary zinc can influence IGF-I production.

OBJECTIVES

To determine the influence of dietary zinc addition on IGF-I and bone turnover responses to essential amino acids-whey (EAA-W) protein supplements in frail elderly.

DESIGN AND SETTING

A daily oral protein supplement was given to hospitalized patients for 4 weeks. On a randomized, double-blind basis, patients received either an additional 30 mg/day of zinc or control.

PARTICIPANTS

Sixty-one hospitalized elderly aged 66.7 to 105.8, with a mini-nutritional assessment score between 17 and 24 were enrolled.

MEASUREMENTS

Activities of daily living; dietary intakes; serum IGF-I, IGF-BP3, CrossLapsTM, osteocalcin and zinc were measured before and after 1, 2 and 4 weeks of protein supplementation.

RESULTS

Serum IGF-I rapidly increased in both groups. Zinc accelerated this increase with changes of +48.2 +/- 14.3 and +22.4 +/- 4.7% (p < .05) by 1 week, in the zinc-supplemented and control groups, respectively. Zinc significantly decreased the serum bone resorption marker CrossLapsTM by already 1 week. Activities of daily living improved by +27.0 +/- 3.1 and +18.3 +/- 4.5% in zinc-supplemented and control groups, respectively.

CONCLUSION

In the elderly, zinc supplementation accelerated the serum IGF-I response to EAA-W protein by 1 week and decreased a biochemical marker of bone resorption.