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

The potential benefits and mechanisms of protein nutritional intervention on bone health improvement

Osteoporosis commonly occurs in the older people and severe patients, with the main reason of the imbalance of bone metabolism (the rate of bone resorption exceeding the rate of bone formation), resulting in a decrease in bone mineral density and destruction of bone microstructure and further leading to the increased risk of fragility fracture. Recent studies indicate that protein nutritional support is beneficial for attenuating osteoporosis and improving bone health. This review summarized the classical mechanisms of protein intervention for alleviating osteoporosis on both suppressing bone resorption and regulating bone formation related pathways (promoting osteoblasts generation and proliferation, enhancing calcium absorption, and increasing collagen and mineral deposition), as well as the potential novel mechanisms via activating autophagy of osteoblasts, altering bone related miRNA profiles, regulating muscle-bone axis, and modulating gut microbiota abundance. Protein nutritional intervention is expected to provide novel approaches for the prevention and adjuvant therapy of osteoporosis.

Loss of Muscle Mass and Strength After Hip Fracture: an Intervention Target for Nutrition Supplementation

PURPOSEOF REVIEW

To summarize what is known about the deleterious effect of hip fracture on muscle mass and strength as well as the scientific evidence for post-surgical nutrition supplementation to maintain muscle and improve function.

RECENT FINDINGS

This review provides a discussion of the relationship between muscle mass, strength, and physical function following hip fracture, briefly describes the approaches to measuring lean mass, discusses prevalence of sarcopenia and malnutrition among older men and women with hip fracture, and reviews the effects of essential amino acids on muscle. Loss of muscle mass and strength following hip fracture is substantial with consequences for recovery of functional independence. EAA-based nutrition supplementation, which directly effects muscle, has potential to improve outcomes.

Dietary Supplement Intake is Associated with Healthier Lifestyle Behaviors in College Students Attending a Regional University in the Southeast: A Cross-Sectional Study

The relationship between intake of dietary supplements and biomarkers such as insulin and insulin-like growth factor has not been well explored. The primary aim of this cross-sectional study was to investigate the associations between supplement intake and biological and lifestyle factors. We hypothesized that dietary supplement intake was associated with healthier lifestyle behaviors. College students attending a Southeast university were recruited between January 2018 and April 2019. Blood samples were collected to measure insulin, insulin-like growth factor 1 (IGF-1) and alanine aminotransferase (ALT). Statistical tests employed were linear regression and analysis of variance. Ninety-eight participants completed the study and 91% reported taking at least one supplement, while 5.1% reported taking 9+ supplements once per week. There were no differences in levels of insulin, IGF-1 and ALT by levels of dietary supplement intake. Although there were no differences in HEI-2015 score among the groups, those who consumed five or more supplements met a higher percentage of the recommended intake for fruits, performed aerobic exercise for longer duration, and had lower body fat percentage compared to participants who consumed two or less supplements at least once per week. These findings are consistent with previous studies and suggest that dietary supplement intake is highly prevalent in college students, and it may be related to healthy lifestyle behaviors. Future studies should employ mixed methodology to examine reasons by which college students consume dietary supplements and to assess perceived and direct health benefits associated with consumption.

Protein Supplement and Enhanced Recovery After Posterior Spine Fusion Surgery: A Randomized, Double-blind, Placebo-controlled Trial

STUDY DESIGN

This was a randomized, double-blind clinical trial study.

OBJECTIVE

The objective of this study was to evaluate the effect of protein supplementation on vertebral fusion and enhanced recovery after posterior spine fusion (PSF) surgery.

SUMMARY OF BACKGROUND DATA

Nonfusion is one of the most common complications of lumbar spine surgery. It has been shown that protein plays an important role in bone repair; however, its correlation to vertebral fusion following PSF surgery is unknown.

PATIENTS AND METHODS

In this randomized, double-blind clinical trial study, the intervention group received a diet with 1.2 g of protein plus high-protein supplement (36 g whey protein), and the control group received a similar diet, except for starch as a placebo from 48 hours before to 1 month after surgery.

RESULTS

The intervention group showed a significantly higher rate of vertebral fusion compared with the control group (P=0.019). Surgical site infection and pain were significantly lower in the intervention group. A significant difference was found in the wound healing rate in favor of the intervention group. The rates of decrease in serum high-sensitivity C-reactive protein levels and increase in serum levels of insulin-like growth factor 1, albumin, total protein, and alkaline phosphatase were greater in the intervention group than in the control group (P<0.001).

CONCLUSIONS

Increased protein intake improves vertebral fusion and enhances recovery in patients undergoing PSF. This was the first study to investigate the effect of protein on fusion and healing factors; as a result, further clinical trials are needed to confirm the current results.

The global approach to rehabilitation following an osteoporotic fragility fracture: A review of the rehabilitation working group of the International Osteoporosis Foundation (IOF) committee of scientific advisors

PURPOSE

To conduct a review of the current state of the evidence for rehabilitation strategies post-fragility fracture.

METHODS

Narrative review conducted by the Rehabilitation Working Group of the International Osteoporosis Foundation Committee of Scientific Advisors characterizing the range of rehabilitation modalities instrumental for the management of fragility fractures.

RESULTS

Multi-modal exercise post-fragility fracture to the spine and hip is strongly recommended to reduce pain, improve physical function, and improve quality of life. Outpatient physiotherapy post-hip fracture has a stronger evidence base than outpatient physiotherapy post-vertebral fracture. Appropriate nutritional care after fragility fracture provides a large range of improvement in morbidity and mortality. Education increases understanding of osteoporosis which in turn increases utilization of other rehabilitation services. Education may improve other health outcomes such as pain and increase a patient's ability for self-advocacy.

CONCLUSION

Rehabilitation interventions are inter-reliant, and research investigating the interaction of exercise, nutrition, and other multi-modal therapies may increase the relevance of rehabilitation research to clinical care.

Stimulating effect of whey protein hydrolysate on bone growth in MC3T3-E1 cells and a rat model

This study was conducted to investigate the effect of whey protein hydrolysate (WPH) on osteogenic cell differentiation and its growth-promoting effects in rats. Alkaline phosphatase (ALP) activity and calcium deposition were measured by treating MC3T3-E1 cells with WPH, and mRNA and protein levels of factors related to osteoblast differentiation were assessed. ALP activity and calcium deposition were significantly increased in the WPH group (p < 0.001). These findings were confirmed by the upregulation of ALP, bone morphogenic protein, bone sialoprotein, and collagen at the mRNA and protein levels. Furthermore, to confirm the growth-promoting effect of WPH, bone growth was analyzed by administering 3-week-old Sprague-Dawley rats with whey protein or WPH. Moreover, serum levels of calcium, ALP, and insulin-like growth factor-1 (IGF-1) were analyzed, bone analysis was performed using micro-CT, and the size of the growth plate was measured by Cresyl violet staining. When rats were administered with a high dose of WPH (600 mg per kg per day), calcium levels decreased significantly, while ALP levels (1.14-fold; p < 0.01), IGF-1 levels, tibia length, and growth plate height increased significantly compared to those in the control group. Collectively, WPH has shown to be effective in bone differentiation and bone growth.

Undernutrition, Sarcopenia, and Frailty in Fragility Hip Fracture: Advanced Strategies for Improving Clinical Outcomes

Geriatric patients with hip fractures often experience overlap in problems related to nutrition, including undernutrition, sarcopenia, and frailty. Such problems are powerful predictors of adverse responses, although few healthcare professionals are aware of them and therefore do not implement effective interventions. This review aimed to summarize the impact of undernutrition, sarcopenia, and frailty on clinical outcomes in elderly individuals with hip fractures and identify successful strategies that integrate nutrition and rehabilitation. We searched PubMed (MEDLINE) and Cochrane Central Register of Controlled Trials (CENTRAL) for relevant literature published over the last 10 years and found that advanced interventions targeting the aforementioned conditions helped to significantly improve postoperative outcomes among these patients. Going forward, protocols from advanced interventions for detecting, diagnosing, and treating nutrition problems in geriatric patients with hip fractures should become standard practice in healthcare settings.

The Effects of Cow-Milk Protein Supplementation in Elderly Population: Systematic Review and Narrative Synthesis

BACKGROUND

To review currently available evidence on the effect of cow-milk proteins supplementation (CPS) on health in the elderly.

METHODS

Five electronic databases (Pubmed, Web of Science, Embase, Cochrane Library, ClinicalTrials.gov) were searched for studies about CPS among older people. All types of publications were included, with the exception of systematic reviews, meta-analyses, opinion letters, editorials, case reports, conference abstracts and comments. An additional search in Google Scholar and a manual review of the reference lists were performed.

RESULTS

Overall, 103 studies were included. Several studies explored the role of CPS in the preservation or improvement of muscle mass among healthy subjects (40 studies) and pre-frail, frail or sarcopenic patients (14), with evidence of beneficial effects. Other studies assessed the effect of CPS on bones (12), cardiovascular disease (8), inflamm-aging (7), chronic pulmonary disease (4), neurocognitive function (4), and vaccines (2), with weak evidence of positive effects. Seven studies in the field of protein metabolism investigated the role of CPS as an important contributor to nutritional needs. Other investigational areas are considered in the last five studies.

CONCLUSIONS

The beneficial effects of CPS in achieving aged-related nutritional goals, in preserving muscle mass and in recovering after hospitalization may be particularly relevant in the elderly.

Effectiveness of home based intervention program in reducing mortality of hip fracture patients: A non-randomized controlled trial

PURPOSE

The study was done to investigate whether a postoperative intervention program is effective in reducing mortality and improving mobility in two comparative hip fracture patients over one year postoperatively.

METHODS

A non-randomized controlled trial study with an intervention group of hip fracture patients and historical control group with 12 months follow up. One hundred twenty four admitted hip fracture patients to the Trauma Unit of Assiut University Hospitals, aged 50 years and older were included from 1st July to 31st December 2014. They were divided into 64 and 60 patients as intervention and control groups respectively. Weight, height and bone mineral density were measured and baseline characteristics were taken. The intervention was a postoperative care program in the form of education sessions with an explanatory leaflet on discharge for nutrition and physical exercise program at home. Follow up phone calls were done at 3 months, 6 months and one year postoperatively by one assessor. Physical mobility was assessed by 24 items Western Ontario And McMaster Universities Osteoarthritis Index (WOMAC).

RESULTS

Mortality was significantly higher in the control group, WOMAC score was significantly better among intervention group through follow up. By multivariate Cox survival analysis, advancing age, no intervention, osteoporosis, postoperative complications, chest infections and heart attacks were significant predictors for mortality.

CONCLUSION

A significant improvement in mobility and reduction of mortality was achieved by application of a postoperative care program that could be incorporated into the hip fracture patients' care pathway.

Effects of Fermented Milk Products on Bone

Fermented milk products like yogurt or soft cheese provide calcium, phosphorus, and protein. All these nutrients influence bone growth and bone loss. In addition, fermented milk products may contain prebiotics like inulin which may be added to yogurt, and provide probiotics which are capable of modifying intestinal calcium absorption and/or bone metabolism. On the other hand, yogurt consumption may ensure a more regular ingestion of milk products and higher compliance, because of various flavors and sweetness. Bone mass accrual, bone homeostasis, and attenuation of sex hormone deficiency-induced bone loss seem to benefit from calcium, protein, pre-, or probiotics ingestion, which may modify gut microbiota composition and metabolism. Fermented milk products might also represent a marker of lifestyle promoting healthy bone health.

Determinants of Functional Outcomes Using Clinical Pathways for Rehabilitation After Hip Fracture Surgery

Background

This study evaluated functional outcomes using newly established clinical pathways after hip fracture surgery in older adults and analyzed the major determinants of successful functional outcomes in rehabilitation programs using standardized clinical pathways.

Methods

This was a retrospective cohort study performed in a tertiary rehabilitation facility. A total of 220 patients who had received unilateral hip fracture surgery were followed up from immediately after surgery to 6 months postoperatively. Clinical pathways for rehabilitation included early, individualized rehabilitation, education for activities of daily living, review of general medical conditions, and arrangement of discharge settings. One rehabilitation specialist consecutively checked ambulatory function using 3-level grading, and patients were classified into good recovery and poor recovery groups based on ambulatory function at 6 months postoperatively. Logistic regression analysis was performed using 7 representative variables (age, sex, bone mineral density, Mini-Mental Status Examination [MMSE], Berg Balance Scale [BBS], premorbid ambulatory function, and length of hospital stay).

Results

A total of 86.8% of patients could walk with or without assistance at 6 months after surgery and 75.5% of patients involved in the rehabilitation program were classified into the good recovery group in this study. the good recovery group showed higher mmse and bbs scores compared with the poor recovery group. the factors in the model most strongly correlated with recovery were mmse and bbs.

Conclusion

This study showed that a well-designed rehabilitation program could improve ambulatory function in older patients after hip fracture surgery and that cognitive impairment and poor balance control may inhibit the recovery of ambulatory function.

Dietary Protein Intake above the Current RDA and Bone Health: A Systematic Review and Meta-Analysis

Dietary intake of protein is fundamental for optimal acquisition and maintenance of bone across all life stages; however, it has been hypothesized that intakes above the current recommended dietary allowance (RDA) might be beneficial for bone health. We utilized the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines when preparing and reporting this systematic review and meta-analysis. A literature search strategy through April 11, 2017, was developed for the following 3 databases: PubMed, Ovid Medline, and Agricola. Included studies were those randomized controlled trials and prospective cohort studies among healthy adults ages 18 and older that examined the relationships between varying doses of protein intake at or above the current U.S. RDA (0.8 g/kg/d or 10%-15% of total caloric intake) from any source on fracture, bone mineral density (BMD)/bone mineral content (BMC), and/or markers of bone turnover. Twenty-nine articles were included for data extraction (16 randomized controlled trials [RCTs] and 13 prospective cohort studies). Meta-analysis of the prospective cohort studies showed high vs low protein intakes resulted in a statistically significant 16% decrease in hip fractures (standardized mean difference [SMD] = 0.84, 95% confidence interval [CI], 0.73, 0.95; I² = 36.8%). Data from studies included in these analyses collectively lean toward the hypothesis that protein intake above the current RDA is beneficial to BMD at several sites. This systematic review supports that protein intakes above the current RDA may have some beneficial role in preventing hip fractures and BMD loss. There were no differences between animal or plant proteins, although data in this area were scarce. Larger, long-term, and more well-controlled clinical trials measuring fracture outcomes and BMD are needed to adequately assess whether protein intake above the current RDA is beneficial as a preventative measure and/or intervention strategy for osteoporosis. Key teaching points: • • Bone health is a multifactorial musculoskeletal issue, and optimal protein intakes are key in developing and maintaining bone throughout the life span. • • Dietary protein at levels above the current RDA may be beneficial in preventing hip fractures and BMD loss. • • Plant vs animal proteins do not seem to differ in their ability to prevent bone loss; however, data in this area are scarce. • • Larger, long-term RCTs using women not using hormone replacement therapy (HRT) are needed to adequately assess the magnitude of impact that protein intakes above the RDA have on preventing bone loss.

Peripheral skeleton bone strength is positively correlated with total and dairy protein intakes in healthy postmenopausal women

BACKGROUND

Bone mineral content (BMC) and bone mineral density (BMD) are positively correlated with dietary protein intakes, which account for 1-8% of BMC and BMD variances. However, the relation between bone strength and microstructure, which are variables that are not captured by areal bone mineral density (aBMD), and dietary protein intakes, particularly from specific dietary sources, has not been clearly established.

OBJECTIVE

We investigated the association between the peripheral skeleton-predicted failure load and stiffness, bone microstructure, and dietary protein intakes from various origins (animal, divided into dairy and nondairy, and vegetable origins) in healthy postmenopausal women.

DESIGN

In a cross-sectional study in 746 Caucasian women aged 65.0 ± 1.4 y, we measured the aBMD with the use of dual-energy X-ray absorptiometry, the distal radius and tibia bone microstructures with the use of high-resolution peripheral quantitative computerized tomography, and bone strength with the use of a finite element analysis, and we evaluated dietary protein and calcium with the use of a validated food-frequency questionnaire.

RESULTS

Mean dietary calcium and protein intakes were greater than recommended amounts for this class of age. The predicted failure load and stiffness at the distal radius and tibia were positively associated with total, animal, and dairy protein intakes but not with vegetable protein intake. Failure load differences were accompanied by modifications of the aBMD and of cortical and trabecular bone microstructures. The associations remained statistically significant after adjustment for weight, height, physical activity, menopause duration, calcium intake, and the interaction between calcium and protein intake. A principal component analysis of the volumetric BMD and bone microstructure indicated that trabecular bone mainly contributed to the positive association between protein intakes and bone strength.

CONCLUSIONS

These results, which were recorded in a very homogeneous population of healthy postmenopausal women, indicate that there is a beneficial effect of animal and dairy protein intakes on bone strength and microstructure. Specifically, there is a positive association between the bone failure load and stiffness of the peripheral skeleton and dietary protein intake, which is mainly related to changes in the trabecular microstructure. This trial was registered at www.controlled-trials.com as ISRCTN11865958.

Nutritional supplementation for hip fracture aftercare in older people

BACKGROUND

Older people with hip fractures are often malnourished at the time of fracture, and subsequently have poor food intake. This is an update of a Cochrane review first published in 2000, and previously updated in 2010.

OBJECTIVES

To review the effects (benefits and harms) of nutritional interventions in older people recovering from hip fracture.

SEARCH METHODS

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register, CENTRAL, MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, Embase, CAB Abstracts, CINAHL, trial registers and reference lists. The search was last run in November 2015.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials of nutritional interventions for people aged over 65 years with hip fracture where the interventions were started within the first month after hip fracture.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, extracted data and assessed risk of bias. Where possible, we pooled data for primary outcomes which were: all cause mortality; morbidity; postoperative complications (e.g. wound infections, pressure sores, deep venous thromboses, respiratory and urinary infections, cardiovascular events); and 'unfavourable outcome' defined as the number of trial participants who died plus the number of survivors with complications. We also pooled data for adverse events such as diarrhoea.

MAIN RESULTS

We included 41 trials involving 3881 participants. Outcome data were limited and risk of bias assessment showed that trials were often methodologically flawed, with less than half of trials at low risk of bias for allocation concealment, incomplete outcome data, or selective reporting of outcomes. The available evidence was judged of either low or very low quality indicating that we were uncertain or very uncertain about the estimates.Eighteen trials evaluated oral multinutrient feeds that provided non-protein energy, protein, vitamins and minerals. There was low-quality evidence that oral feeds had little effect on mortality (24/486 versus 31/481; risk ratio (RR) 0.81 favouring supplementation, 95% confidence interval (CI) 0.49 to 1.32; 15 trials). Thirteen trials evaluated the effect of oral multinutrient feeds on complications (e.g. pressure sore, infection, venous thrombosis, pulmonary embolism, confusion). There was low-quality evidence that the number of participants with complications may be reduced with oral multinutrient feeds (123/370 versus 157/367; RR 0.71, 95% CI 0.59 to 0.86; 11 trials). Based on very low-quality evidence from six studies (334 participants), oral supplements may result in lower numbers with 'unfavourable outcome' (death or complications): RR 0.67, 95% CI 0.51 to 0.89. There was very low-quality evidence for six studies (442 participants) that oral supplementation did not result in an increased incidence of vomiting and diarrhoea (RR 0.99, 95% CI 0.47 to 2.05).Only very low-quality evidence was available from the four trials examining nasogastric multinutrient feeding. Pooled data from three heterogeneous trials showed no evidence of an effect of supplementation on mortality (14/142 versus 14/138; RR 0.99, 95% CI 0.50 to 1.97). One trial (18 participants) found no difference in complications. None reported on unfavourable outcome. Nasogastric feeding was poorly tolerated. One study reported no cases of aspiration pneumonia.There is very low-quality evidence from one trial (57 participants, mainly men) of no evidence for an effect of tube feeding followed by oral supplementation on mortality or complications. Tube feeding, however, was poorly tolerated.There is very low-quality evidence from one trial (80 participants) that a combination of intravenous feeding and oral supplements may not affect mortality but could reduce complications. However, this expensive intervention is usually reserved for people with non-functioning gastrointestinal tracts, which is unlikely in this trial.Four trials tested increasing protein intake in an oral feed. These provided low-quality evidence for no clear effect of increased protein intake on mortality (30/181 versus 21/180; RR 1.42, 95% CI 0.85 to 2.37; 4 trials) or number of participants with complications but very low-quality and contradictory evidence of a reduction in unfavourable outcomes (66/113 versus 82/110; RR 0.78, 95% CI 0.65 to 0.95; 2 trials). There was no evidence of an effect on adverse events such as diarrhoea.Trials testing intravenous vitamin B1 and other water soluble vitamins, oral 1-alpha-hydroxycholecalciferol (vitamin D), high dose bolus vitamin D, different oral doses or sources of vitamin D, intravenous or oral iron, ornithine alpha-ketoglutarate versus an isonitrogenous peptide supplement, taurine versus placebo, and a supplement with vitamins, minerals and amino acids, provided low- or very low-quality evidence of no clear effect on mortality or complications, where reported.Based on low-quality evidence, one trial evaluating the use of dietetic assistants to help with feeding indicated that this intervention may reduce mortality (19/145 versus 36/157; RR 0.57, 95% CI 0.34 to 0.95) but not the number of participants with complications (79/130 versus 84/125).

AUTHORS' CONCLUSIONS

There is low-quality evidence that oral multinutrient supplements started before or soon after surgery may prevent complications within the first 12 months after hip fracture, but that they have no clear effect on mortality. There is very low-quality evidence that oral supplements may reduce 'unfavourable outcome' (death or complications) and that they do not result in an increased incidence of vomiting and diarrhoea. Adequately sized randomised trials with robust methodology are required. In particular, the role of dietetic assistants, and peripheral venous feeding or nasogastric feeding in very malnourished people require further evaluation.

Nutrition and Inflammation in Older Individuals: Focus on Vitamin D, n-3 Polyunsaturated Fatty Acids and Whey Proteins

Chronic activation of the inflammatory response, defined as inflammaging, is the key physio-pathological substrate for anabolic resistance, sarcopenia and frailty in older individuals. Nutrients can theoretically modulate this phenomenon. The underlying molecular mechanisms reducing the synthesis of pro-inflammatory mediators have been elucidated, particularly for vitamin D, n-3 polyunsaturated fatty acids (PUFA) and whey proteins. In this paper, we review the current evidence emerging from observational and intervention studies, performed in older individuals, either community-dwelling or hospitalized with acute disease, and evaluating the effects of intake of vitamin D, n-3 PUFA and whey proteins on inflammatory markers, such as C-Reactive Protein (CRP), interleukin-1 (IL-1), interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α). After the analysis, we conclude that there is sufficient evidence for an anti-inflammatory effect in aging only for n-3 PUFA intake, while the few existing intervention studies do not support a similar activity for vitamin D and whey supplements. There is need in the future of large, high-quality studies testing the effects of combined dietary interventions including the above mentioned nutrients on inflammation and health-related outcomes.

Nutrition and bone health in women after the menopause

Osteoporosis affects one out of three postmenopausal women. Their remaining lifetime risk of fragility fractures exceeds that of breast cancer. The risk of osteoporosis and/or fragility fractures can be reduced through healthy lifestyle changes. These include adequate dietary intakes of calcium, vitamin D and protein, regular weight-bearing exercise, reduction in alcohol intake and smoking cessation. European guidance for the diagnosis and management of osteoporosis in postmenopausal women recommends a daily intake of at least 1000 mg/day for calcium, 800 IU/day for vitamin D and 1 g/kg body weight of protein for all women aged over 50 years. The development of programs that encourage lifestyle changes (in particular balanced nutrient intakes) are therefore essential for the reduction of osteoporosis risk.

Zinc Supplementation Increases Procollagen Type 1 Amino-Terminal Propeptide in Premenarcheal Girls: A Randomized Controlled Trial

BACKGROUND

Data have shown that healthy children and adolescents have an inadequate intake of zinc, an essential nutrient for growth. It is unclear whether zinc supplementation can enhance bone health during this rapid period of growth and development.

OBJECTIVE

The primary aim of this study was to determine the effect of zinc supplementation on biochemical markers of bone turnover and growth in girls entering the early stages of puberty. The secondary aim was to test moderation by race, body mass index (BMI) classification, and plasma zinc status at baseline.

METHODS

One hundred forty seven girls aged 9-11 y (46% black) were randomly assigned to a daily oral zinc tablet (9 mg elemental zinc; n = 75) or an identical placebo (n = 72) for 4 wk. Fasting plasma zinc, procollagen type 1 amino-terminal propeptide (P1NP; a bone formation marker), carboxy-terminal telopeptide region of type 1 collagen (ICTP; a bone resorption marker), and insulin-like growth factor I (IGF-I) were assessed at baseline and post-test. Additional markers of bone formation (osteocalcin) and resorption (urinary pyridinoline and deoxypyridinoline) were also measured.

RESULTS

Four weeks of zinc supplementation increased plasma zinc concentrations compared with placebo [mean change, 1.8 μmol/L (95% CI: 1.0, 2.6) compared with 0.2 μmol/L (95% CI: -0.3, 0.7); P < 0.01]. Zinc supplementation also increased serum P1NP concentrations compared with placebo [mean change, 23.8 μmol/L (95% CI: -14.9, 62.5) compared with -31.0 μmol/L (95% CI: -66.4, 4.2); P = 0.04). There was no effect from zinc supplementation on osteocalcin, ICTP, pyridinoline, deoxypyridinoline, or IGF-I. There was no moderation by race, BMI classification, or plasma zinc status at baseline.

CONCLUSIONS

Our data suggest that 4 wk of zinc supplementation increases bone formation in premenarcheal girls. Further studies are needed to determine whether supplemental zinc can improve childhood bone strength. This trial was registered at clinicaltrials.gov as NCT01892098.

Understanding the gastrointestinal tract of the elderly to develop dietary solutions that prevent malnutrition

Although the prevalence of malnutrition in the old age is increasing worldwide a synthetic understanding of the impact of aging on the intake, digestion, and absorption of nutrients is still lacking. This review article aims at filling the gap in knowledge between the functional decline of the aging gastrointestinal tract (GIT) and the consequences of malnutrition on the health status of elderly. Changes in the aging GIT include the mechanical disintegration of food, gastrointestinal motor function, food transit, chemical food digestion, and functionality of the intestinal wall. These alterations progressively decrease the ability of the GIT to provide the aging organism with adequate levels of nutrients, what contributes to the development of malnutrition. Malnutrition, in turn, increases the risks for the development of a range of pathologies associated with most organ systems, in particular the nervous-, muscoskeletal-, cardiovascular-, immune-, and skin systems. In addition to psychological, economics, and societal factors, dietary solutions preventing malnutrition should thus propose dietary guidelines and food products that integrate knowledge on the functionality of the aging GIT and the nutritional status of the elderly. Achieving this goal will request the identification, validation, and correlative analysis of biomarkers of food intake, nutrient bioavailability, and malnutrition.

Nutritional aspects of bone health

Bone mass, geometry and microstructure, and bony tissue material level properties determine bone strength, hence the resistance to fracture. At a given age, all these variables are the consequence of the amount accumulated and of the structure developed during growth, up to the so-called peak bone mass, and of the bone loss and microstructure degradation occurring later in life. Genetic factors primarily contribute to the variance of the determinants of bone strength. Nutritional intakes are environmental factors that influence both processes, either directly by modifying modelling and remodelling, or indirectly through changes in calcitropic hormone secretion and action. Some effects of nutrition on the offspring bone could take place during foetal life. There are interplays between genetic factors, nutritional intakes and physical exercise. Among the nutrients, sufficient dietary intakes of calcium and protein are necessary for bone health in childhood and adolescence as well as later in life.

Biochemical markers for assessment of calcium economy and bone metabolism: application in clinical trials from pharmaceutical agents to nutritional products

Nutrition plays an important role in osteoporosis prevention and treatment. Substantial progress in both laboratory analyses and clinical use of biochemical markers has modified the strategy of anti-osteoporotic drug development. The present review examines the use of biochemical markers in clinical research aimed at characterising the influence of foods or nutrients on bone metabolism. The two types of markers are: (i) specific hormonal factors related to bone; and (ii) bone turnover markers (BTM) that reflect bone cell metabolism. Of the former, vitamin D metabolites, parathyroid hormone, and insulin-like growth factor-I indicate responses to variations in the supply of bone-related nutrients, such as vitamin D, Ca, inorganic phosphate and protein. Thus modification in bone remodelling, the key process upon which both pharmaceutical agents and nutrients exert their anti-catabolic or anabolic actions, is revealed. Circulating BTM reflect either osteoclastic resorption or osteoblastic formation. Intervention with pharmacological agents showed that early changes in BTM predicted bone loss and subsequent osteoporotic fracture risk. New trials have documented the influence of nutrition on bone-tropic hormonal factors and BTM in adults, including situations of body-weight change, such as anorexia nervosa, and weight loss by obese subjects. In osteoporosis-prevention studies involving dietary manipulation, randomised cross-over trials are best suited to evaluate influences on bone metabolism, and insight into effects on bone metabolism may be gained within a relatively short time when biochemical markers are monitored.

Management of osteoporosis of the oldest old

This consensus article reviews the diagnosis and treatment of osteoporosis in geriatric populations. Specifically, it reviews the risk assessment and intervention thresholds, the impact of nutritional deficiencies, fall prevention strategies, pharmacological treatments and their safety considerations, the risks of sub-optimal treatment adherence and strategies for its improvement.

INTRODUCTION

This consensus article reviews the therapeutic strategies and management options for the treatment of osteoporosis of the oldest old. This vulnerable segment (persons over 80 years of age) stands to gain substantially from effective anti-osteoporosis treatment, but the under-prescription of these treatments is frequent.

METHODS

This report is the result of an ESCEO (European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis) expert working group, which explores some of the reasons for this and presents the arguments to counter these beliefs. The risk assessment of older individuals is briefly reviewed along with the differences between some intervention guidelines. The current evidence on the impact of nutritional deficiencies (i.e. calcium, protein and vitamin D) is presented, as are strategies to prevent falls. One possible reason for the under-prescription of pharmacological treatments for osteoporosis in the oldest old is the perception that anti-fracture efficacy requires long-term treatment. However, a review of the data shows convincing anti-fracture efficacy already by 12 months.

RESULTS

The safety profiles of these pharmacological agents are generally satisfactory in this patient segment provided a few precautions are followed.

CONCLUSION

These patients should be considered for particular consultation/follow-up procedures in the effort to convince on the benefits of treatment and to allay fears of adverse drug reactions, since poor adherence is a major problem for the success of a strategy for osteoporosis and limits cost-effectiveness.

Whey-reduced weight gain is associated with a temporary growth reduction in young mice fed a high-fat diet

Whey protein consumption reportedly alleviates parameters of the metabolic syndrome. Here, we investigated the effects of whey protein isolate (whey) in young mice fed a high-fat diet. We hypothesized that whey as the sole protein source reduced early weight gain associated with retarded growth and decreased concentration of insulin-like growth factor-1. Moreover, we hypothesized that these changes were explained by increased nitrogen loss via elevated urea production and/or increased energy expenditure. Male 5-week-old C57BL/6 mice were fed high-fat diets with the protein source being either whey, casein or a combination of both for 5 weeks. After 1, 3 or 5 weeks, respectively, the mice were subjected to a meal challenge with measurements of blood and urinary urea before and 1 and 3 h after eating a weighed meal of their respective diets. In a subset of mice, energy expenditure was measured by indirect calorimetry during the first week of dietary intervention. Observed exclusively during the first week of intervention, whey significantly reduced body length (P<.01) and weight gain (P<.001) correlating positively with plasma concentrations of insulin-like growth factor-1. The combination diet displayed intermediate results indicating an interactive effect. Urea production, urea cycle activity, food intake and energy expenditure were unaffected by protein source. In conclusion, whey decreased growth-related parameters exclusively during the first week of dietary intervention. The early effect of whey could not be explained by food intake, energy expenditure, urea production or urea cycle activity but was correlated with plasma levels of insulin-like growth factor-1.

Dairy products, yogurts, and bone health

Fracture risk is determined by bone mass, geometry, and microstructure, which result from peak bone mass (the amount attained at the end of pubertal growth) and from the amount of bone lost subsequently. Nutritional intakes are an important environmental factor that influence both bone mass accumulation during childhood and adolescence and bone loss that occurs in later life. Bone growth is influenced by dietary intake, particularly of calcium and protein. Adequate dietary calcium and protein are essential to achieve optimal peak bone mass during skeletal growth and to prevent bone loss in the elderly. Dairy products are rich in nutrients that are essential for good bone health, including calcium, protein, vitamin D, potassium, phosphorus, and other micronutrients and macronutrients. Studies supporting the beneficial effects of milk or dairy products on bone health show a significant inverse association between dairy food intake and bone turnover markers and a positive association with bone mineral content. Fortified dairy products induce more favorable changes in biochemical indexes of bone metabolism than does calcium supplementation alone. The associations between the consumption of dairy products and the risk of hip fracture are less well established, although yogurt intake shows a weakly positive protective trend for hip fracture. By consuming 3 servings of dairy products per day, the recommended daily intakes of nutrients essential for good bone health may be readily achieved. Dairy products could therefore improve bone health and reduce the risk of fractures in later life.

Nutrition and bone health: turning knowledge and beliefs into healthy behaviour

Primary osteoporosis prevention requires healthy behaviours, such as regular physical exercise and adequate dietary intakes of calcium, vitamin D and protein. Calcium and vitamin D can decrease postmenopausal bone loss and prevent fracture risk. However, there is still a high prevalence of calcium and vitamin D insufficiency in women aged 50+ years. Dietary sources of these nutrients are the preferred choice, and dairy products represent a valuable dietary source of calcium due to the high content, high absorptive rate and relatively low cost. Furthermore, dairy products also contain other key nutrients including vitamin D, phosphorus and protein that contribute to bone health. Studies of women's beliefs and behaviours with respect to osteoporosis highlight poor knowledge of the importance of dietary nutrient intakes and low concern regarding bone health. Osteoporosis educational programmes exist to help women change behaviours relevant to bone health. Such programmes can have positive influences on women's knowledge, attitudes, perceived norms, motivation and behaviours. Increased awareness of the consequences of low calcium and vitamin D intakes may promote women's attitudes towards dietary sources, in particular dairy products, and lead to better adherence to health recommendations. Increasing dietary nutrient intakes through educational initiatives should be further developed to aid the prevention of osteoporosis and the efficacy of osteoporosis management.

Effect of GH/IGF-1 on Bone Metabolism and Osteoporsosis

Background. Growth hormone (GH) and insulin-like growth factor (IGF-1) are fundamental in skeletal growth during puberty and bone health throughout life. GH increases tissue formation by acting directly and indirectly on target cells; IGF-1 is a critical mediator of bone growth. Clinical studies reporting the use of GH and IGF-1 in osteoporosis and fracture healing are outlined. Methods. A Pubmed search revealed 39 clinical studies reporting the effects of GH and IGF-1 administration on bone metabolism in osteopenic and osteoporotic human subjects and on bone healing in operated patients with normal GH secretion. Eighteen clinical studies considered the effect with GH treatment, fourteen studies reported the clinical effects with IGF-1 administration, and seven related to the GH/IGF-1 effect on bone healing. Results. Both GH and IGF-1 administration significantly increased bone resorption and bone formation in the most studies. GH/IGF-1 administration in patients with hip or tibial fractures resulted in increased bone healing, rapid clinical improvements. Some conflicting results were evidenced. Conclusions. GH and IGF-1 therapy has a significant anabolic effect. GH administration for the treatment of osteoporosis and bone fractures may greatly improve clinical outcome. GH interacts with sex steroids in the anabolic process. GH resistance process is considered.

Essential amino acid enriched high-protein enteral nutrition modulates insulin-like growth factor-1 system function in a rat model of trauma-hemorrhagic shock

Background

Nutrition support for critically ill patients supplemented with additional modular protein may promote skeletal muscle protein anabolism in addition to counteracting acute nitrogen loss. The present study was designed to investigate whether the essential amino acid (EAA) enriched high-protein enteral nutrition (EN) modulates the insulin-like growth factor-1 (IGF-1) system and activates the mammalian target of rapamycin (mTOR) anabolic signaling pathway in a trauma-hemorrhagic shock (T-HS) rat model.

Methodology/Principal Findings

Male Sprague-Dawley rats (n = 90, 278.18±0.94 g) were randomly assigned to 5 groups: (1) normal control, (2) pair-fed, (3) T-HS, (4) T-HS and standard EN, and (5) T-HS and EAA enriched high-protein EN. Six animals from each group were harvested on days 2, 4, and 6 for serum, gastrocnemius, soleus, and extensor digitorum longus sample collection. T-HS significantly reduced muscle mass. Nutrition support maintained muscle mass, especially the EAA enriched high-protein EN. Meanwhile, a pronounced derangement in IGF-1-IGFBPs axis as well as impaired mTOR transduction was observed in the T-HS group. Compared with animals receiving standard EN, those receiving EAA enriched high-protein EN presented 18% higher serum free IGF-1 levels following 3 days of nutrition support and 22% higher after 5 days. These changes were consistent with the concomitant elevation in serum insulin and reduction in corticosterone levels. In addition, phosphorylations of downstream anabolic signaling effectors - including protein kinase B, mTOR, and ribosomal protein S6 kinase1 - increased significantly in rats receiving EAA enriched high-protein EN.

Conclusion/Significance

Our findings firstly demonstrate the beneficial effect of EAA enriched high-protein EN on the metabolic modulation of skeletal muscle protein anabolism by regulating the IGF-1 system and downstream anabolic signaling transduction.

Increased energy intake in hip fracture patients affects nutritional biochemical markers

BACKGROUND AND AIMS

We have previously shown that nutritional guidelines decreased the incidence of pressure ulcers in hip fracture patients. In the present study, we evaluate whether the nutritional biochemical markers S-IGF-1 (Insulin-like Growth Factor 1), S-Transthyretin and S-Albumin are affected by patients' energy intake, and whether the markers are useful as predictors of postoperative complications.

MATERIAL AND METHODS

Quasi-experimental design, with one intervention and one control group, as well as pre- and post-study measurements. Eighty-eight hip fracture patients were included: 42 in the control group and 46 in the intervention group. The control group received regular nutritional support pre- and postoperatively, while the intervention group received nutritional support that followed new, improved clinical guidelines from admission to five days postoperatively. S-Albumin, S-Transthyretin, C-Reactive Protein (S-CRP) and S-IGF-1 were analysed at admission and five days postoperatively as well as complications like pressure ulcer and infection.

RESULTS

The intervention group had a significantly higher energy intake; for example, 1636 kcal versus 852 kcal postoperative day 1. S-IGF-1 levels decreased significantly in the control group, while no decrease in the intervention group. S-Albumin and S-Transthyretin decreased and S-CRP increased significantly in both groups, indicating that those markers were not affected short-term by a high-energy intake. There was no correlation between short-term post-operative complications and S-IGF-1, S-Transthyretin or S-Albumin at admission.

CONCLUSION

The results of our study showed that S-IGF-1 can be used as a short-term nutritional biochemical marker, as it was affected by a five-day high-energy regimen. However, neither S-IGF-1, S-Transthyretin or S-Albumin were useful in predicting postoperative complications within five days postoperatively.

A systematic review of growth hormone for hip fractures

OBJECTIVE

To evaluate the clinical effectiveness of growth hormone (GH) for hip fractures.

DESIGN

Based on the principles and methods of Cochrane systematic reviews, we searched the Cochrane Library (2011, 3 issue), PubMed (1966 to October 2011), EMBASE (1974 to October 2011), OVID database (1963 to October 2011), Chinese Bio-medicine database (1978 to October 2011), China Journal Full-text Database (1979 to October 2011), and VIP database (1989 to October 2011). Randomized controlled trials (RCTs) of GH treatment for hip fractures were included. We assessed the quality of included trials according to the Cochrane Handbook for Systematic Reviews of Interventions Version. The Cochrane Collaboration's software RevMan 5.0 was used for meta-analysis.

RESULTS

3 RCTs with a total of 162 hip fractures patients were included. Results of GH compared to placebo treatment showed that IGF-I levels significantly increased in the short term, but no significant differences in the long term. Additionally, there was no statistical difference in adverse events. Only one trial reported the measurement of bone mineral content (BMC), which showed that GH group was unchanged while the placebo group lost BMC at both 4 weeks and 8 weeks. Only one study measuring BMC showed no significant differences in the change of the MBI scores between GH group and placebo group; however, the changes from baseline in the hGH group were less than that in the placebo group among the older than 75 years group. Owing to the difference of measurement indexes in those studies, we could not perform a meta-analysis.

CONCLUSIONS

With the low quality of current evidence, GH may be effective in hip fractures. More carefully designed, double-blinded and placebo-controlled randomized trials with large numbers of participants about GH in the treatment of hip fractures are required.

Selective osteoblast overexpression of IGF-I in mice prevents low protein-induced deterioration of bone strength and material level properties

Protein deficiency is frequently observed in elderly osteoporotic patients. Undernutrition leads to decreased levels of IGF-I, an important factor in regulating bone homeostasis throughout life. IGF-I is produced in the liver and locally in the skeleton. We hypothesized that increasing IGF-I expression in the osteoblasts, the bone forming cells, would protect the skeleton from the negative effects of a low-protein diet. To test our hypothesis, we employed a mouse model in which IGF-I was overexpressed exclusively in osteoblasts and fed either a 15% (normal) or a 2.5% (low) protein isocaloric diet to the transgenic (TG) mice and their wild-type (WT) littermates for 8 weeks. Blood was collected for biochemical determinations and weight was monitored weekly. Bones were excised for microstructural analysis (μCT), as well as biomechanical and material level properties. Histomorphometric analysis was performed for bone formation parameters. A low protein diet decreased body weight, circulating IGF-I and osteocalcin levels regardless of genotype. Overexpression of IGF-I in the osteoblasts was, however, able to protect the negative effects of low protein diet on microstructure including tibia cortical thickness and volumetric density, and on bone strength. Overexpression of IGF-I in osteoblasts in these mice protected the vertebrae from the substantial negative effects of low protein on the material level properties as measured my nanoindentation. TG mice also had larger overall geometric properties than WT mice regardless of diet. This study provides evidence that while a low protein diet leads to decreased circulating IGF-I, altered microstructure and decreased bone strength, these negative effects can be prevented with IGF-I overexpression exclusively in bone cells.

Leptin is better than any other biological parameter for monitoring the efficacy of renutrition in hospitalized malnourished elderly patients

OBJECTIVE

Despite malnutrition being a major problem in hospitalized elderly patients, there is a lack of studies focusing on the comparative value of biological parameters for monitoring renutrition. The aim of this study was to determine which biological parameter(s) could best monitor successful renutrition in hospitalized malnourished elderly patients.

DESIGN

The objective of the study was to explore the impact of a 6-week renutrition process on anthropometric and biological parameters in elderly patients and to define the biological parameters associated with weight regain.

PATIENTS

A total of 72 hospitalized malnourished elderly patients admitted to a hospital-based geriatric rehabilitation unit.

MEASUREMENTS

Patients were evaluated at admission and at 6 weeks for anthropometric measurements of weight, sum of the four subcutaneous skinfold thicknesses, calf circumference and biological serum parameters including albumin, transthyretin, leptin, IGF-1, IGFBP-1 and IGFBP-3. Renutrition was considered successful if a patient gained at least 5% of body weight over 6 weeks.

RESULTS

Leptin was the only biological parameter that increased at 6 weeks in successful renutrition. Leptin variations were not influenced by C-reactive protein variations, in contrast to transthyretin which can be modified by the inflammatory states frequently encountered in geriatric patients.

CONCLUSIONS

Serum leptin is a more appropriate parameter than transthyretin for monitoring renutrition.

Nutritional approach for inhibiting bone resorption in institutionalized elderly women with vitamin D insufficiency and high prevalence of fracture

BACKGROUND

Nutritional approach to the deterioration of bone integrity and increased fracture risk appears to be particularly appropriate in elderly women living in nursing homes.

OBJECTIVE

To investigate the beneficial effect of the consumption of soft plain cheese on bone resorption markers in institutionalized elderly women.

DESIGN

Prospective, randomized crossover controlled study.

SETTING

Six French nursing homes or other institutions for elderly.

PARTICIPANTS

Institutionalized women ≥ 65 years old with low vitamin D status and calcium intake below 700 mg/day.

INTERVENTION

Consumption of soft plain cheese made of semi-skimmed milk which was fortified by both vitamin D3 (+1.25 µg/100g) and milk extracted Ca, thus achieving a total Ca content of 151 mg/100g as compared to about 118 mg/100g for standard fresh cheese. Two servings were taken every day during the 6 weeks that preceded or followed a period of 6 weeks without soft plain cheese consumption.

MEASUREMENTS

The primary end point was the change in serum carboxy terminal cross-linked telopeptide of type I collagen (CTX) selected as a marker of bone resorption.

RESULTS

29 women aged 73-94 yr were selected, 21 of them with mean age 87.2±6.1 years remained compliant. The intervention increased calcium and protein intakes by 51% (904±228 vs. 599±122 mg/d) and 33 % (74.2±17.1 vs. 55.6±12.7 g/d, mean±SD), respectively. The dietary intervention was associated with a statistically significant increase in serum levels of both 25OHD and IGF-I, while those of [corrected] CTX and TRAP5b were significantly reduced. Compliance was 93,4 %. The daily consumption of two servings of soft plain cheese was well accepted in terms of tastiness and appetite suited portion size.

CONCLUSION

This randomized crossover controlled trial demonstrates that in elderly women living in nursing homes, the consumption of soft plain cheese increasing the supply of vitamin D, calcium and proteins, could reduce bone resorption and thereby reduce the risk of incidental fragility fractures in the long term.

Extrinsic mechanisms involved in age-related defective bone formation

CONTEXT

Age-related bone loss is associated with progressive changes in bone remodeling characterized by decreased bone formation relative to bone resorption. Both trabecular and periosteal bone formation decline with age in both sexes, which contributes to bone fragility and increased risk of fractures. Studies in rodents and humans revealed that, independent of sex hormone deficiency, the age-related decline in bone formation is characterized by decreased osteoblast number and lifespan and reduced bone-forming capacity of individual osteoblasts. An important clinical question is to identify the mechanisms involved in the age-related defective bone formation.

EVIDENCE ACQUISITION

The mechanisms discussed in this review are based on a PubMed search and knowledge of the authors in the field.

EVIDENCE SYNTHESIS

Available basic and clinical studies indicate that multiple mechanisms are involved in the alterations of osteoblastogenesis and the resulting decline in bone formation with aging. Notably, the age-related osteoblast dysfunctions and defective bone formation are caused by a number of extrinsic clinical factors that inhibit anabolic signaling pathways in bone. Thus, targeting these pathways can abolish age-related bone loss.

CONCLUSIONS

The identification of extrinsic mechanisms involved in osteoblast dysfunctions associated with aging improves our knowledge of age-related bone loss and provides a basis for therapeutic intervention to improve bone formation and bone mass in the aging population.

Fatty acid consumption and risk of fracture in the Women's Health Initiative

BACKGROUND

Fatty acids (FAs) may be important dietary components that modulate osteoporotic fracture risk.

OBJECTIVE

The objective was to examine FA intake in relation to osteoporotic fractures.

DESIGN

The participants were postmenopausal women enrolled in the Women's Health Initiative (n = 137,486). Total fractures were identified by self-report; hip fractures were confirmed by medical record review. FA intake was estimated from baseline food-frequency questionnaires and standardized to total caloric intake. No data on omega-3 (n-3) FA supplements were available. Cox proportional hazard models were constructed to estimate risk of fracture.

RESULTS

Higher saturated FA consumption was associated with higher hip fracture risk [quartile 4 multivariate-adjusted hazard ratio (HR): 1.31; 95% CI: 1.11, 1.55; P for trend = 0.001]. Lower total fracture risk was associated with a higher monounsaturated FA intake (quartile 3 HR: 0.94; 95% CI: 0.89, 0.98; P for trend = 0.050) and polyunsaturated FA intake (quartile 4 HR: 0.95; 95% CI: 0.90, 0.99; P for trend = 0.019). Unexpectedly, higher consumption of marine n-3 FAs was associated with greater total fracture risk (quartile 4 HR: 1.07; 95% CI: 1.02, 1.12; P for trend = 0.010), whereas a higher n-6 FA intake was associated with a lower total fracture risk (quartile 4 HR: 0.94; 95% CI: 0.89, 0.98; P for trend 0.009).

CONCLUSIONS

These results suggest that saturated FA intake may significantly increase hip fracture risk, whereas monounsaturated and polyunsaturated FA intakes may decrease total fracture risk. In postmenopausal women with a low intake of marine n-3 FAs, a higher intake of n-6 FAs may modestly decrease total fracture risk. This trial was registered at clinicaltrials.gov as NCT00000611.