Vitamin D, muscle and bone: Integrating effects in development, aging and injury

Efficacy and utility of a tool for both measurement of vitamin B6, B12, D, folate and iron status and assessment of diet quality in athletes

NutriProfiel® is a tool to measure micronutrient status and to assess diet quality. It consists of measurement of micronutrient status in blood and a short food frequency questionnaire (FFQ) ('Eetscore-FFQ'). Based on the results, individuals receive a dietary advice. In this study, we evaluated the application of NutriProfiel in athletes ('NutriProfiel-Sport') by assessing the coverage of nutrient intake of the Eetscore-FFQ (part 1) and by evaluating athlete's dietary behaviour after using NutriProfiel-Sport and their satisfaction with this tool (part 2). For part 1, data of 419 athletes were used. We evaluated the coverage of nutrient intake of the Eetscore-FFQ using first and second MOMents (MOM1 and MOM2) sum scores of food items in the questionnaire. Forty-eight athletes were involved in part 2. They gave blood samples for micronutrient status measurement and were asked to complete the Eetscore-FFQ at baseline and after 3 months, as well as a questionnaire on their satisfaction with NutriProfiel-Sport. Results showed that for most nutrients, MOM1 and MOM2 scores were above 80 %, meaning that nutrient intake was sufficiently covered by the Eetscore-FFQ. No difference in diet quality was observed between baseline and after 3 months. Nevertheless, a majority of athletes reported the NutriProfiel-Sport results and advice as useful. On a scale from 0 to 10, NutriProfiel-Sport was graded with a mean (±sd) score of 7⋅6 (±0⋅8). In conclusion, NutriProfiel-Sport is a potential valuable and appreciated tool for athletes and the Eetscore-FFQ as part of this tool sufficiently covers nutrient intake in athletes.

Vitamin D Metabolites: Analytical Challenges and Clinical Relevance

Recent research activities have provided new insights in vitamin D metabolism in various conditions. Furthermore, substantial progress has been made in the analysis of vitamin D metabolites and related biomarkers, such as vitamin D binding protein. Liquid chromatography tandem mass spectrometric (LC-MS/MS) methods are capable of accurately measuring multiple vitamin D metabolites in parallel. Nevertheless, only 25(OH)D and the biologically active form 1,25(OH)2D are routinely measured in clinical practice. While 25(OH)D remains the analyte of choice for the diagnosis of vitamin D deficiency, 1,25(OH)2D is only recommended in a few conditions with a dysregulated D metabolism. 24,25(OH)2D, free and bioavailable 25(OH)D, and the vitamin D metabolite ratio (VMR) have shown promising results, but technical pitfalls in their quantification, limited clinical data and the lack of reference values, impede their use in clinical practice. LC-MS/MS is the preferred method for the measurement of all vitamin D related analytes as it offers high sensitivity and specificity. In particular, 25(OH)D and 24,25(OH)2D can accurately be measured with this technology. When interpreted together, they seem to provide a functional measure of vitamin D metabolism beyond the analysis of 25(OH)D alone. The determination of VDBP, free and bioavailable 25(OH)D is compromised by unresolved analytical issues, lacking reference intervals and insufficient clinical data. Therefore, future research activities should focus on analytical standardization and exploration of their clinical value. This review provides an overview on established and new vitamin D related biomarkers including their pathophysiological role, preanalytical and analytical aspects, expected values, indications and influencing conditions.

Osteosarcopenia and type 2 diabetes mellitus in post-menopausal women: a case-control study

BACKGROUND

Osteosarcopenia has been defined as the concomitance of low bone density (osteopenia/osteoporosis) and sarcopenia. Osteoporosis is characterized by alterations in bone microarchitecture and decrease of bone mineral density (BMD), whereas sarcopenia is the progressive decrease of both muscle mass and function that increase the risk of falls. Type 2 diabetes mellitus (T2DM) is associated with poor bone strength and muscle wasting.

OBJECTIVE

The aim of this study is to analyze the association between osteosarcopenia and T2DM in post-menopausal women (PMW).

METHODS

We performed an age matched case-control study (1:2 ratio), considering as cases PMW affected by T2DM, and PMW without T2DM as control group. For all patients a DXA evaluation to investigate bone density and body composition measures were performed. Moreover, we carried out muscle strength and performance assessments. Outcome measures were femoral neck and lumbar spine BMD T-scores, appendicular lean mass (ALM), handgrip strength and the Short Physical Performance Battery (SPPB). Data from both groups were analyzed and compared.

RESULTS

Thirty-six PMW (12 T2DM vs 24 non-T2DM) were recruited. The frequency of osteosarcopenia was significantly higher in the T2DM group compared to controls (50% vs 17%; OR 5.0, 95% CI 1.05 to 23.79, p = 0.043). Handgrip strength was significantly lower in the T2DM group (10.09 ± 4.02 kg vs 18.40 ± 6.83 kg; p = 0.001).

CONCLUSIONS

Post-menopausal women with T2DM have a 5 times higher risk to have osteosarcopenia compared to non-diabetic ones. Further studies on larger cohorts are required to confirm these findings.

Roles of nutrition in muscle health of community-dwelling older adults: evidence-based expert consensus from Asian Working Group for Sarcopenia

General muscle health declines with age, and in particular, sarcopenia-defined as progressive loss of muscle mass and strength/physical performance-is a growing issue in Asia with a rising population of community-dwelling older adults. Several guidelines have addressed early identification of sarcopenia and management, and although nutrition is central to treatment of sarcopenia, there are currently few guidelines that have examined this specifically in the Asian population. Therefore, the Asian Working Group for Sarcopenia established a special interest group (SIG) comprising seven experts across Asia and one from Australia, to develop an evidence-based expert consensus. A systematic literature search was conducted using MEDLINE on the topic of muscle health, from 2016 (inclusive) to July 2021, in Asia or with relevance to healthy, Asian community-dwelling older adults (≥60 years old). Several key topics were identified: (1) nutritional status: malnutrition and screening; (2) diet and dietary factors; (3) nutritional supplementation; (4) lifestyle interventions plus nutrition; and (5) outcomes and assessment. Clinical questions were developed around these topics, leading to 14 consensus statements. Consensus was achieved using the modified Delphi method with two rounds of voting. Moreover, the consensus addressed the impacts of COVID-19 on nutrition, muscle health, and sarcopenia in Asia. These statements encompass clinical expertise and knowledge across Asia and are aligned with findings in the current literature, to provide a practical framework for addressing muscle health in the community, with the overall aim to encourage and facilitate broader access to equitable care for this target population.

From the Bench to the Bedside: Branched Amino Acid and Micronutrient Strategies to Improve Mitochondrial Dysfunction Leading to Sarcopenia

With extended life expectancy, the older population is constantly increasing, and consequently, so too is the prevalence of age-related disorders. Sarcopenia, the pathological age-related loss of muscle mass and function; and malnutrition, the imbalance in nutrient intake and resultant energy production, are both commonly occurring conditions in old adults. Altered nutrition plays a crucial role in the onset of sarcopenia, and both these disorders are associated with detrimental consequences for patients (e.g., frailty, morbidity, and mortality) and society (e.g., healthcare costs). Importantly, sarcopenia and malnutrition also share critical molecular alterations, such as mitochondrial dysfunction, increased oxidative stress, and a chronic state of low grade and sterile inflammation, defined as inflammageing. Given the connection between malnutrition and sarcopenia, nutritional interventions capable of affecting mitochondrial health and correcting inflammageing are emerging as possible strategies to target sarcopenia. Here, we discuss mitochondrial dysfunction, oxidative stress, and inflammageing as key features leading to sarcopenia. Moreover, we examine the effects of some branched amino acids, omega-3 PUFA, and selected micronutrients on these pathways, and their potential role in modulating sarcopenia, warranting further clinical investigation.

The risk factors for developing clustered vertebral compression fractures: a single center study

OBJECTIVE

Vertebral compression fractures (VCFs) are common among elderly individuals, but clustered VCFs (C-VCFs) are rare and more severe. The risk factors for C-VCFs remain unclear. Thus, we investigated the clinical characteristics of C-VCFs to identify the imminent fracture risk and to improve the treatment for such patients.

METHODS

We reviewed records of VCF patients at a single medical center between January 2011 and September 2020. Patients who had four or more VCFs within one year were categorized into the C-VCF group, and the remaining patients were paired into the control group at a ratio of 2:1. We collected demographic, clinical, laboratory, and radiological information regarding these patients. Univariate analyses, stratified analyses, and multivariate logistic regression were performed to identify the risk factors for C-VCFs.

RESULTS

A total of 156 patients were enrolled, of whom 52 were C-VCF patients. C-VCF patients had more severe fractures and pain, with fractures occurring at uncommon sites of the spine. The independent risk factors for C-VCFs included glucocorticoid treatment (P<0.001, HR: 12.7), recent fracture history (P=0.021, HR: 5.5), and lower trabecular bone score (TBS, P=0.044, HR: 1.6). TBS and bone mineral density had greater predictive values in patients without glucocorticoid treatment (P<0.001). Sex, age, and bone turnover biomarkers were not independent risk factors for C-VCFs.

CONCLUSION

C-VCFs are rare adverse consequences of severe osteoporosis, for which glucocorticoid treatment, recent fracture history, and lower TBS are unique risk factors that are valuable for the early identification and prevention of C-VCFs.

Experimental study protocol of the project "MOtor function and VItamin D: Toolkit for motor performance and risk Assessment (MOVIDA)"

Musculoskeletal injuries, a public health priority also in the military context, are ascribed to several risk factors, including: increased reaction forces; low/reduced muscle strength, endurance, body mass, Vitamin D level, and bone density; inadequate lifestyles and environment. The MOVIDA Project-funded by the Italian Ministry of Defence-aims at developing a transportable toolkit (assessment instrumentation, assessment protocols and reference/risk thresholds) which integrates motor function assessment with biological, environmental and behavioural factors to help characterizing the risk of stress fracture, stress injury or muscle fatigue due to mechanical overload. The MOVIDA study has been designed following the STROBE guidelines for observational cross-sectional studies addressing healthy adults, both militaries and civilians, with varying levels of physical fitness (sedentary people, recreational athletes, and competitive athletes). The protocol of the study has been designed and validated and is hereby reported. It allows to collect and analyse anamnestic, diagnostic and lifestyle-related data, environmental parameters, and functional parameters measured through portable and wearable instrumentation during adapted 6 minutes walking test. The t-test, one and two-way ANOVA with post-hoc corrections, and ANCOVA tests will be used to investigate relevant differences among the groups with respect to biomechanical parameters; non-parametric statistics will be rather used for non-normal continuous variables and for quantitative discrete variables. Generalized linear models will be used to account for risk and confounding factors.

Muscle-specific deletion of the vitamin D receptor in mice is associated with diaphragm muscle weakness

Diseases or conditions where diaphragm muscle (DIAm) function is impaired, including chronic obstructive pulmonary disease, cachexia, asthma, and aging, are associated with an increased risk of pulmonary symptoms, longer duration of hospitalizations, and increasing requirements for mechanical ventilation. Vitamin D deficiency is associated with proximal muscle weakness that resolves following therapy with vitamin D₃. Skeletal muscle expresses the vitamin D receptor (VDR), which responds to the active form of vitamin D, 1,25-dihydroxyvitamin D₃ by altering gene expression in target cells. In knockout mice without skeletal muscle VDRs, there is marked atrophy of muscle fibers and a change in skeletal muscle biochemistry. We used a tamoxifen-inducible skeletal muscle Cre recombinase in Vdr^fl/fl mice (Vdr^fl/fl actin.iCre+) to assess the role of muscle-specific VDR signaling on DIAm-specific force, fatigability, and fiber type-dependent morphology. Vdr^fl/fl actin.iCre+ mice treated with vehicle and Vdr^fl/fl mice treated with tamoxifen served as controls. Seven days following the final treatment, mice were euthanized, the DIAm was removed, and isometric force and fatigue were assessed in DIAm strips using direct muscle stimulation. The proportion and cross-sectional areas of DIAm fiber types were evaluated by immunolabeling with myosin heavy chain antibodies differentiating type I, IIa and IIx, and/or IIb fibers. We show that in mice with skeletal muscle-specific VDR deletion, maximum specific force and residual force following fatigue are impaired, along with a selective atrophy of type IIx and/or IIb fibers. These results show that the VDR has a significant biological effect on DIAm function independent of systemic effects on mineral metabolism.NEW & NOTEWORTHY Vitamin D deficiency and vitamin D receptor (VDR) polymorphisms are associated with adverse pulmonary and diaphragm muscle (DIAm)-associated respiratory outcomes. We used a skeletal muscle-specific tamoxifen-inducible VDR knockout to investigate DIAm dysfunction following reduced VDR signaling. Marked DIAm weakness and atrophy of type IIx and/or IIb fibers are present in muscle-specific tamoxifen-induced VDR knockout mice compared with controls. These results show that the VDR has a significant biological effect on DIAm function independent of systemic effects on mineral metabolism.

Overuse-Related Injuries of the Musculoskeletal System: Systematic Review and Quantitative Synthesis of Injuries, Locations, Risk Factors and Assessment Techniques

Overuse-related musculoskeletal injuries mostly affect athletes, especially if involved in preseason conditioning, and military populations; they may also occur, however, when pathological or biological conditions render the musculoskeletal system inadequate to cope with a mechanical load, even if moderate. Within the MOVIDA (Motor function and Vitamin D: toolkit for risk Assessment and prediction) Project, funded by the Italian Ministry of Defence, a systematic review of the literature was conducted to support the development of a transportable toolkit (instrumentation, protocols and reference/risk thresholds) to help characterize the risk of overuse-related musculoskeletal injury. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) approach was used to analyze Review papers indexed in PubMed and published in the period 2010 to 2020. The search focused on stress (overuse) fracture or injuries, and muscle fatigue in the lower limbs in association with functional (biomechanical) or biological biomarkers. A total of 225 Review papers were retrieved: 115 were found eligible for full text analysis and led to another 141 research papers derived from a second-level search. A total of 183 papers were finally chosen for analysis: 74 were classified as introductory to the topics, 109 were analyzed in depth. Qualitative and, wherever possible, quantitative syntheses were carried out with respect to the literature review process and quality, injury epidemiology (type and location of injuries, and investigated populations), risk factors, assessment techniques and assessment protocols.

Vitamin D Supplementation and Impact on Skeletal Muscle Function in Cell and Animal Models and an Aging Population: What Do We Know So Far?

Aging is associated with impairment in skeletal muscle mass and contractile function, predisposing to fat mass gain, insulin resistance and diabetes. The impact of Vitamin D (VitD) supplementation on skeletal muscle mass and function in older adults is still controversial. The aim of this review was to summarize data from randomized clinical trials, animal dietary intervention and cell studies in order to clarify current knowledge on the effects of VitD on skeletal muscle as reported for these three types of experiments. A structured research of the literature in Medline via PubMed was conducted and a total of 43 articles were analysed (cells n = 18, animals n = 13 and humans n = 13). The results as described by these key studies demonstrate, overall, at cell and animal levels, that VitD treatments had positive effects on the development of muscle fibres in cells in culture, skeletal muscle force and hypertrophy. Vitamin D supplementation appears to regulate not only lipid and mitochondrial muscle metabolism but also to have a direct effect on glucose metabolism and insulin driven signalling. However, considering the human perspective, results revealed a predominance of null effects of the vitamin on muscle in the ageing population, but experimental design may have influenced the study outcome in humans. Well-designed long duration double-blinded trials, standardised VitD dosing regimen, larger sample sized studies and standardised measurements may be helpful tools to accurately determine results and compare to those observed in cells and animal dietary intervention models.

Effects of marathon race on selected myokines and sclerostin in middle-aged male amateur runners

In recent years, there has been increasing interest in the homeostatic response to extreme exercises, especially in the integrated function of muscle and bone. The aim of this study was to evaluate the effects of a marathon race on selected myokines and sclerostin in 10 male recreational runners (mean age 41 ± 7.7 years). Body composition, bone mineral density (BMD), and the serum concentration of myostatin, irisin, sclerostin, osteoprotegerin (OPG), 25-hydroxyvitamin D (25(OH)D), parathyroid hormone (PTH), high-sensitivity interleukin-6 (hsIL-6), tumor necrosis factor α (TNFα), high-sensitivity C-reactive protein (hsCRP) and myoglobin, were determined 24 h before and 24 h and 72 h after a marathon race. Post-marathon increases were observed in the levels of myostatin (1.2-fold), OPG (1.5-fold), and PTH (1.3-fold), hsIL-6 (1.9-fold), myoglobin (4.1-fold), hsCRP (fivefold), TNFα (2.6-fold), after 24 h; and in myostatin (1.2-fold), irisin (1.1-fold), sclerostin (1.3-fold), OPG (1.3-fold), and PTH (1.4-fold), hsIL-6 (1.4-fold), TNFα (1.9-fold), after 72 h compared to the baseline level. The results show that in response to the marathon run, a complex network of endocrine interactions is initiated. Further research is needed to fully elucidate the long-term impact of prolonged high intensity exercise on the human body.

Association of Vitamin D Status with Lower Limb Muscle Strength in Professional Basketball Players: A Cross-Sectional Study

Vitamin D deficiency in athletes may play a role in influencing fracture risk and athletic performance. This study aimed to examine the vitamin D status of basketball players and determine its correlation with muscle strength. We included 36 male professional basketball players (mean age, 22.6 ± 3.2 years) categorized by vitamin D status. We examined the muscle strength of knee extension/flexion and ankle dorsiflexion/plantarflexion using an isokinetic dynamometer. Eleven (30.5%), fifteen (41.7%), and ten (27.8%) players had deficient (<20 ng/mL), insufficient (20–32 ng/mL), and sufficient vitamin D levels (>32 ng/mL), respectively. In the dominant side, there were no significant correlations of vitamin D level with knee extension/flexion strength (r = 0.134, p = 0.436; r = −0.017, p = 0.922, respectively), or with plantarflexion/dorsiflexion ankle strength (r = −0.143, p = 0.404; r = 1.109, p = 0.527, respectively). Moreover, the isokinetic lower limb strengths were not significantly different between the three groups in all settings (all p > 0.05). In conclusion, professional basketball players had a high prevalence of vitamin D insufficiency. Though it may not be associated with muscle strength, maintaining adequate vitamin D levels by micronutrients monitoring, regular dietician consultation, and supplementation is still a critically considerable strategy to enhance young athletes’ health.

Vitamin D status, nutrition and growth in HIV-infected mothers and HIV-exposed infants and children in Botswana

BACKGROUND

Poor vitamin D status is a global health problem and common in patients with human immunodeficiency virus (HIV) in high-income countries. There is less evidence on prevalence of vitamin D deficiency and nutrition and growth in HIV-infected and -exposed children in low- and middle-income countries.

OBJECTIVES

To determine the vitamin D status in Batswana HIV-infected mothers and their children, differences among HIV-infected mothers and between HIV-exposed and -infected infants and children, and associations between vitamin D and disease-related outcomes, nutrition, and growth.

METHODS

This was a cross-sectional study of HIV+ mothers and HIV-exposed infants and unrelated children (1-7.9 years). Serum 25-hydroxyvitamin D (25(OH)D) was measured, among other nutritional indicators, for mothers, infants and children. Vitamin D status for HIV-infected mothers and children, and an immune panel was assessed. History of HIV anti-retroviral medications and breastfeeding were obtained. Data were collected prior to universal combination antiretroviral therapy in pregnancy.

RESULTS

Mothers (n = 36) had a mean serum 25(OH)D of 37.2±12.4ng/mL; 11% had insufficient (<20ng/mL), 17% moderately low (20.0-29.9ng/mL) and 72% sufficient (≥30ng/mL) concentrations. No infants (n = 36) or children (n = 48) were vitamin D insufficient; 22% of HIV- and no HIV+ infants had moderately low concentrations and 78% of HIV- and 100% of HIV+ infants had sufficient status, 8% of HIV- and no HIV+ children had moderately low concentrations and 92% of HIV- and 100% HIV+ children had sufficient concentrations. HIV+ children had significantly lower length/height Z scores compared to HIV- children. Length/height Z score was positively correlated with serum 25(OH)D in all children (r = 0.33, p = 0.023), with a stronger correlation in the HIV+ children (r = 0.47 p = 0.021). In mothers, serum 25(OH)D was positively associated with CD4% (r = 0.40, p = 0.016).

CONCLUSIONS

Results showed a low prevalence of vitamin D insufficiency in Botswana. Growth was positively correlated with vitamin D status in HIV-exposed children, and HIV+ children had poorer linear growth than HIV- children.

Bone Control of Muscle Function

Bone and muscle represent a single functional system and are tightly connected to each other. Indeed, diseases characterized by alterations of muscle physiology have effects on bone remodeling and structure and vice versa. Muscle influence on bone has been deeply studied, and recent studies identified irisin as new molecule involved in this crosstalk. Muscle regulation by bone needs to be extensively investigated since in the last few years osteocalcin was recognized as a key molecule in the bone–muscle interaction. Osteocalcin can exist in two forms with different degrees of carboxylation. The undercarboxylated form of osteocalcin is a hormone released by the bone matrix during the osteoclast bone resorption and can bind its G-protein coupled receptor GPRC6A expressed in the muscle, thus regulating its function. Recently, this hormone was described as an antiaging molecule for its ability to regulate bone, muscle and cognitive functions. Indeed, the features of this bone-related hormone were used to test a new therapeutic approach for sarcopenia, since injection of osteocalcin in older mice induces the acquirement of physical abilities of younger animals. Even if this approach should be tested in humans, osteocalcin represents the most surprising molecule in endocrine regulation by the skeleton.

Response to fatigue observed through magnetic resonance imaging on the quadriceps muscle in postmenopausal women

OBJECTIVES

Menopause marks the end of women's reproductive period and can lead to sarcopenia and osteoporosis (OP), increasing the risk of falls and fractures. The aim of this study is to evaluate the influence of normal and low bone mineral density (BMD) on muscular activity, observed through inflammatory edema when mapping using magnetic resonance imaging (MRI) on the quadriceps muscle of postmenopausal women.

METHODS

This was a cross-sectional study involving 16 older women, who were divided into two groups: osteoporosis group (OG), older women with OP, and control group (CG), older women without OP. The groups were evaluated in terms of nuclear MRI exam before and after carrying out fatigue protocol exercises using an isokinetic dynamometer and squatting exercises.

RESULTS

The results of the present study showed that in intragroup comparisons, for both groups, there was a significant increase (p<0.05) in the T2 signal of the nuclear MRI in the quadriceps muscle after carrying out exercises using both thighs. In the intergroup comparison, no statistically significant difference was observed between the OG and CG, pre- (p=0.343) and postexercise (p=0.874).

CONCLUSION

The acute muscular activation of the quadriceps evaluated by T2 mapping on nuclear MRI equipment is equal in women with and without OP in the postmenopausal phase. BMD did not interfere with muscle response to exercise when muscle fatigue was reached.

Role of vitamin D receptor in the regulation of CYP3A gene expression

Vitamin D₃ (VD₃) is a multifunctional nutrient which can be either synthesized or absorbed from the diet. It plays a pivotal role in systemic calcium and phosphate homeostasis, as well as in various physiological and pathological processes. VD₃ is converted to the active form, 1α,25-dihydroxyvitamin D₃ (1,25-D3), by cytochrome P450 2R1 (CYP2R1)/CYP27A1 and CYP27B1 sequentially, and deactivated by multiple enzymes including CYP3A4. On the other hand, 1,25-D3 is capable of activating the transcription of CYP3A genes in humans, mice and rats. The vitamin D receptor (VDR)-mediated transactivation of human CYP3A4 and CYP3A5 resembles that known for pregnane X receptor (PXR). Activated VDR forms a heterodimer with retinoid X receptor α (RXRα), recruits co-activators, translocates to the cell nucleus, binds to the specific vitamin D responsive elements (VDRE), and activates the gene transcription. In mice, intestinal Cyp3a11 mRNA levels, but not those of hepatic CYP3As, were induced by in vivo administration of VDR and PXR agonists. In rats, intestinal Cyp3a1 and Cyp3a2 mRNAs were induced by 1,25-D3 or lithocholic acid (LCA), whereas hepatic Cyp3a2, but not Cyp3a1 and Cyp3a9, was modulated to 1,25-D3 treatment. In general, the VDR-mediated regulation of CYP3A presents species and organ specificity.

Impact of Serum Source on Human Mesenchymal Stem Cell Osteogenic Differentiation in Culture

Human mesenchymal stem cells (MSCs) show promise for musculoskeletal repair applications. Animal-derived serum is extensively used for MSC culture as a source of nutrients, extracellular matrix proteins and growth factors. However, the routine use of fetal calf serum (FCS) is not innocuous due to its animal antigens and ill-defined composition, driving the development of alternatives protocols. The present study sought to reduce exposure to FCS via the transient use of human serum. Transient exposure to animal serum had previously proved successful for the osteogenic differentiation of MSCs but had not yet been tested with alternative serum sources. Here, human serum was used to support the proliferation of MSCs, which retained surface marker expression and presented higher alkaline phosphatase activity than those in FCS-based medium. Addition of osteogenic supplements supported strong mineralisation over a 3-week treatment. When limiting serum exposure to the first five days of treatment, MSCs achieved higher differentiation with human serum than with FCS. Finally, human serum analysis revealed significantly higher levels of osteogenic components such as alkaline phosphatase and 25-Hydroxyvitamin D, consistent with the enhanced osteogenic effect. These results indicate that human serum used at the start of the culture offers an efficient replacement for continuous FCS treatment and could enable short-term exposure to patient-derived serum in the future.

X-ray densitometric indices of proximal phalanx, medial phalanx and ungular pelvic limb bones as criteria for age diagnosis of cattle in forensic veterinary expertise

Morphological parameters of biological material are extremely informative in diagnostic studies, in particular, to determine the species, sex, time of death, the term of burial. The most informative object for these tasks is the skeleton, because changes in the bones are stored for a long time, while soft tissue is subjected to rotting. Bone tissue is the most durable, but at the same time, it is very labile and reacts to all metabolic processes in the body. The object of the study was proximal phalanx, medial phalanx and ungular bone of the pelvic limb of cattle ranging in age from newborn to 12 years old. Radiography of the proximal phalanx, medial phalanx and ungular bones of the pelvic limb was performed on the Arman apparatus. The bones were subjected to X-ray in the lateromedial projection. The inner and outer sections of the tubular bone were determined. The mathematical modeling of the interaction of X-rays and the cortical layer of bones of fingers (proximal phalanx, medial phalanx and ungular) of cattle was carried out in this work. It is established that this process is described by Bouger's law. The physico-mathematical model of proximal phalanx, medial phalanx and ungular bones has been calculated, on the basis of which it was possible to calculate the X-ray densitometric indices of these bones of cattle. The age features of dynamics of X-ray densitometric indices of the proximal phalanx, medial phalanx and ungular bones were established and a method of determining the age of cattle according to this criterion was proposed. A mathematical model for the proximal phalanx, medial phalanx and ungular bones of the pelvic limbs of cattle that can be applied in X-ray densitometry uses: for the average third proximal phalanx – section of heterogeneous tubular structure modeled by a semicircle; for a medial phalanx bone – a section of a triangular shape; for the ungular bone – a heterogeneous structure, the plantar surface is inscribed in a rectangle. The process of interaction of X-rays with the bone structure of the examined pelvic limb bones can be described by Bouguer's law. The developed mathematical modeling of this interaction and the algorithm for its analysis is the basis for determining the age of cattle for X-ray densitometric indices of the proximal phalanx, medial phalanx and ungular bones of pelvic limbs. By X-ray densitometry of the proximal phalanx and medial phalanx bones of the pelvic limbs extremities one can diagnose the age of bovine animals from birth to 5 years, but according to ungular bones – from birth to 10 years. X-ray densitometry of medial phalanx and ungular bones of pelvic limbs can be used for diagnosing bovine cattle in a complex with other morphological, chemical and physical methods of investigation.

Effect of vitamin D supplementation on upper and lower limb muscle strength and muscle power in athletes: A meta-analysis

BACKGROUND

Vitamin D may play a role in skeletal muscle because of the discovery of VDR in skeletal muscle. However, vitamin D deficiency is a global problem, including athletes. Studies examining the effect of vitamin D supplementation on muscle function in athletes have inconsistent results. Therefore, we aimed to quantitatively summarize the evidence for the effect of vitamin D supplementation on skeletal muscle strength and explosive power of athletes using a meta-analysis.

METHODS

PubMed, EMBASE, Cochrane Library, and Web of Science were searched for studies to identify randomized controlled trials or controlled trials meeting the inclusion criteria. By a meta-analysis, effect sizes (standardized mean differences, SMD) with 95% confidence intervals (CI) was calculated to compare reported outcomes across studies, I2 index was used to assessing heterogeneity, and heterogeneity factors were identified by regression analysis. The potential publication and sensitivity analyses were also assessed.

RESULTS

Eight RCTs involving 284 athletes were included. The protocols used to evaluate the muscle strength of athletes were inconsistent across the included studies, and muscle explosive power was assessed via vertical jump tests. The results indicated that vitamin D supplementation had no impact on overall muscle strength outcomes (SMD 0.05, 95% CI: -0.39 to 0.48, p = 0.84). In subgroup analysis, vitamin D supplementation had an effect on lower-limb muscle strength (SMD 0.55, 95% CI:0.12 to 0.98, p = 0.01) but not upper-limb muscle strength (SMD -0.19, 95% CI:-0.73 to 0.36, p = 0.50) or muscle explosive power (SMD 0.05, 95% CI:-0.24 to 0.34, p = 0.73). Vitamin D supplementation was more effective for athletes trained indoors (SMD 0.48, 95% CI:0.06 to 0.90, p = 0.02).

CONCLUSIONS

Vitamin D supplementation positively affected lower limb muscle strength in athletes, but not upper limb muscle strength or muscle power. Different muscle groups and functions may respond differently to vitamin D supplementation. Additional studies should focus on determining the appropriate vitamin D supplementation methods and optimal serum 25(OH)D levels for athletes.

REGISTRATION

The protocol for our study is registered in the international prospective register of systematic reviews (PROSPERO registration number CRD42016045872).

Transcriptomic Response to 1,25-Dihydroxyvitamin D in Human Fibroblasts with or without a Functional Vitamin D Receptor (VDR): Novel Target Genes and Insights into VDR Basal Transcriptional Activity

The vitamin D receptor (VDR) mediates vitamin D actions beyond bone health. While VDR activation by 1,25-dihydroxyvitamin D (1,25D) leads to robust transcriptional regulation, less is known about VDR actions in the absence of 1,25D. We analyzed the transcriptomic response to 1,25D in fibroblasts bearing a severe homozygous hereditary vitamin D resistant rickets-related p.Arg30* VDR mutation (MUT) and in control fibroblasts (CO). Roughly 4.5% of the transcriptome was regulated by 1,25D in CO fibroblasts, while MUT cells without a functional VDR were insensitive to 1,25D. Novel VDR target genes identified in human fibroblasts included bone and cartilage factors CILP, EFNB2, and GALNT12. Vehicle-treated CO and MUT fibroblasts had strikingly different transcriptomes, suggesting basal VDR activity. Indeed, oppositional transcriptional effects in basal conditions versus after 1,25D activation were implied for a subset of target genes mostly involved with cell cycle. Cell proliferation assays corroborated this conjectured oppositional basal VDR activity, indicating that precise 1,25D dosage in target tissues might be essential for modulating vitamin D actions in human health.

Targeting Cell Senescence for the Treatment of Age-Related Bone Loss

PURPOSE OF REVIEW

We review cell senescence in the context of age-related bone loss by broadly discussing aging mechanisms in bone, currently known inducers and markers of senescence, the senescence-associated secretory phenotype (SASP), and the emerging roles of senescence in bone homeostasis and pathology.

RECENT FINDINGS

Cellular senescence is a state of irreversible cell cycle arrest induced by insults or stressors including telomere attrition, oxidative stress, DNA damage, oncogene activation, and other intrinsic or extrinsic triggers and there is mounting evidence for the role of senescence in aging bone. Cellular aging also instigates a SASP that exerts detrimental paracrine and likely systemic effects. With aging, multiple cell types in the bone microenvironment become senescent, with osteocytes and myeloid cells as primary contributors to the SASP. Targeting undesired senescent cells may be a favorable strategy to promote bone anabolic and anti-resorptive functions in aging bone, with the possibility of improving bone quality and function with normal aging and/or disease.

Higher dietary intake of vitamin D may influence total cholesterol and carbohydrate profile independent of body composition in men with Chronic Spinal Cord Injury

STUDY DESIGN

A case-control design.

OBJECTIVES

To determine the effects of dietary vitamin D intake on insulin sensitivity (Si), glucose effectiveness (Sg), and lipid profile in individuals with spinal cord injury (SCI).

METHODS

20 male, paraplegic (T3-L1) with chronic (> one year) motor complete SCI (AIS A or B) were recruited. Three-day dietary records were analyzed for dietary vitamin D (calciferol), and participants were assigned to one of two groups, a high vitamin D intake group and a low vitamin D intake group based on the mid-point of vitamin D frequency distribution. Individuals in both groups were matched based on age, weight, time since injury and level of injury. Sg, Si and lipid profiles were measured of the two groups.

RESULTS

The high vitamin D group had an average intake of 5.33 ± 4.14 mcg compared to low vitamin D group, 0.74 ± 0.24 mcg. None of the 20 participants met the recommended guidelines for daily vitamin D intake. The higher vitamin D group had a significantly lower (P = 0.035) total cholesterol (148.00 ± 14.12 mg/dl) than the lower vitamin D group (171.80 ± 36.22 mg/dl). Vitamin D adjusted to total dietary intake was positively correlated to improvement in Si and Sg (P<0.05).

CONCLUSION

The findings suggest that persons with SCI consume much less than the recommended guidelines for daily vitamin D intake. However, a higher dietary intake of vitamin D may influence total cholesterol and carbohydrate profile as demonstrated by a significant decrease in total cholesterol and improvement in glucose homeostasis independent of body composition changes after SCI.

Classes of vitamin D status and functional outcome after hip fracture: a prospective, short-term study of 1350 inpatients

BACKGROUND

Vitamin D depletion is associated with unfavourable outcomes after hip fracture. However, the classes of vitamin D status currently in use, which are defined according to serum calcifediol levels, have not been validated for their predictive capability of the functional recovery.

AIM

To investigate the association between serum calcifediol categorized into 4 classes and the functional recovery after hip fracture.

DESIGN

Prospective, short-term observational study.

SETTING

Rehabilitation hospital in Italy.

POPULATION

We evaluated 1350 of 1412 inpatients with hip fracture.

METHODS

Serum calcifediol was measured by an immunoenzymatic assay 14.7±4.4 (mean±SD) days after surgery and categorized into 4 classes: I class <12 ng/mL; II class 12-20 ng/mL; III class 21-29 ng/mL; IV class ≥30ng/mL. The functional outcome was assessed by using the Barthel Index.

RESULTS

We found a significant difference in Barthel index scores at the end of inpatient rehabilitation across the 4 classes of vitamin D status: χ2 (3, N.=1350) 27.2; P<0.001. The difference persisted after adjustment for 8 covariates (P=0.004). By comparing pairs of classes, we found that Barthel index scores were lower in the 829 patients of the I class than in the 275 of the II (P=0.005) who had in turn Barthel index scores lower than the 132 patients of the III class (P=0.038). Conversely, no significant differences emerged between the patients of the III class and the 114 patients of the IV class (P=0.421). The results did not materially change when Barthel Index effectiveness was substituted for Barthel Index scores as the outcome measure.

CONCLUSIONS

Calcifediol levels below 12ng/mL were associated with a worse recovery than those between 12 and 20ng/mL that were in turn associated with a worse recovery than those between 21 and 29 ng/mL. Conversely, no significant differences were found between the patients with calcifediol between 21 and 29ng/mL and those with calcifediol ≥30 ng/mL.

CLINICAL REHABILITATION IMPACT

Despite caution due to the observational design, our study suggests that vitamin D depletion should be treated after hip fracture to optimize the functional outcome, with a target level for serum calcifediol of 21-29ng/mL and no further advantages associated with calcifediol levels of 30ng/mL or higher.

Was the calf circumference associated with serum vitamin D level in obesity and non-obesity adults

PURPOSED

This study examined the associations between 25-hydroxyvitamin D [25(OH)D] and common anthropometric parameters.

METHODS

The data were derived from the National Health and Nutrition Examination Survey from 2001 through 2004. We divided all subjects into two groups with a cut-off point for body mass index set at 30. The primary outcome was the potential relationship between the anthropometric parameters and 25(OH)D status.

RESULTS

A positive association was found between the 25(OH)D levels and calf circumference (CC) in all of the designed models (P < 0.001). The adjusted β coefficient of the 25(OH)D levels for the CC was 0.542 (95% confidence intervals (CI), 0.376-0.708, P < 0.001) after adjusting for all covariates. An increasing linear tendency for 25(OH)D was present in non-obese participants. Additionally, subjects in the higher tertiles of CC tended to have higher 25(OH)D levels with a significant correlation (P for trend <0.001).

CONCLUSION

A positive association between 25(OH)D concentration and CC in non-obese individuals was observed.

Cathepsin K activity controls cardiotoxin-induced skeletal muscle repair in mice

BACKGROUND

Cathepsin K (CatK) is a widely expressed cysteine protease that has gained attention because of its enzymatic and non-enzymatic functions in signalling. Here, we examined whether CatK-deficiency (CatK^-/- ) would mitigate injury-related skeletal muscle remodelling and fibrosis in mice, with a special focus on inflammation and muscle cell apoptosis.

METHODS

Cardiotoxin (CTX, 20 μM/200 μL) was injected into the left gastrocnemius muscle of male wild-type (CatK^+/+ ) and CatK^-/- mice, and the mice were processed for morphological and biochemical studies.

RESULTS

On post-injection Day 14, CatK deletion ameliorated muscle interstitial fibrosis and remodelling and performance. At an early time point (Day 3), CatK^-/- reduced the lesion macrophage and leucocyte contents and cell apoptosis, the mRNA levels of monocyte chemoattractant protein-1, toll-like receptor-2 and toll-like receptor-4, and the gelatinolytic activity related to matrix metalloproteinase-2/-9. CatK deletion also restored the protein levels of caspase-3 and cleaved caspase-8 and the ratio of the BAX to the Bcl-2. Moreover, CatK deficiency protected muscle fibre laminin and desmin disorder in response to CTX injury. These beneficial muscle effects were mimicked by CatK-specific inhibitor treatment. In vitro experiments demonstrated that pharmacological CatK inhibition reduced the apoptosis of C2C12 mouse myoblasts and the levels of BAX and caspase-3 proteins induced by CTX.

CONCLUSIONS

These results demonstrate that CatK plays an essential role in skeletal muscle loss and fibrosis in response to CTX injury, possibly via a reduction of inflammation and cell apoptosis, suggesting a novel therapeutic strategy for the control of skeletal muscle diseases by regulating CatK activity.

International Clinical Practice Guidelines for Sarcopenia (ICFSR): Screening, Diagnosis and Management

OBJECTIVES

Sarcopenia, defined as an age-associated loss of skeletal muscle function and muscle mass, occurs in approximately 6 - 22 % of older adults. This paper presents evidence-based clinical practice guidelines for screening, diagnosis and management of sarcopenia from the task force of the International Conference on Sarcopenia and Frailty Research (ICSFR).

METHODS

To develop the guidelines, we drew upon the best available evidence from two systematic reviews paired with consensus statements by international working groups on sarcopenia. Eight topics were selected for the recommendations: (i) defining sarcopenia; (ii) screening and diagnosis; (iii) physical activity prescription; (iv) protein supplementation; (v) vitamin D supplementation; (vi) anabolic hormone prescription; (vii) medications under development; and (viii) research. The ICSFR task force evaluated the evidence behind each topic including the quality of evidence, the benefit-harm balance of treatment, patient preferences/values, and cost-effectiveness. Recommendations were graded as either strong or conditional (weak) as per the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. Consensus was achieved via one face-to-face workshop and a modified Delphi process.

RECOMMENDATIONS

We make a conditional recommendation for the use of an internationally accepted measurement tool for the diagnosis of sarcopenia including the EWGSOP and FNIH definitions, and advocate for rapid screening using gait speed or the SARC-F. To treat sarcopenia, we strongly recommend the prescription of resistance-based physical activity, and conditionally recommend protein supplementation/a protein-rich diet. No recommendation is given for Vitamin D supplementation or for anabolic hormone prescription. There is a lack of robust evidence to assess the strength of other treatment options.

Changes in vitamin D endocrinology during aging in adults

Worldwide, vitamin D deficiency is a common finding. Within individuals 25-hydroxyvitamin D (25OH)D) concentrations remain fairly stable over time although large differences in individual longitudinal changes exist. During aging vitamin D metabolism and activity changes in several different ways. Intestinal resistance to 1,25(OH)2D develops which hampers intestinal calcium uptake. Vitamin D receptor number decreases with aging in several organs involved in calcium metabolism and 1alpha-hydroxylase activity decreases mainly due to a decrease in renal function reducing vitamin D activation. Effects of 1,25(OH)2D on cell proliferation and differentiation may influence potential anti-cancer effects whereas regulation of telomere length may result in longevity. In older individuals, vitamin D supplementation has positive effects on fracture risk, number of falls and physical function. Supplementation in older populations warrants specific attention. Effects on "non-classical" outcomes may be revealed by ongoing large randomized clinical trials with high doses of vitamin D.

Effect of Vitamin D Deficiency on Voice

PURPOSE

The purpose of this article was to investigate the relationship between low level of vitamin D, phonatory symptoms, and acoustic findings.

METHOD

A total of 38 subjects presenting to the endocrinology clinic were enrolled in 2 groups: 19 with vitamin D deficiency who were not on treatment, and 19 with normal vitamin D level who were on treatment. Demographic data included age, gender, and history of smoking. All patients were asked about the presence or absence of dysphonia, degree of phonatory effort, and vocal fatigue. Acoustic analysis and perceptual evaluation using the grade, roughness, breathiness, asthenia, and strain scale were performed on all subjects.

RESULTS

The mean age of the total group was 47.29 ± 13.52 years. The difference in the mean and frequency of phonatory effort, vocal fatigue, and dysphonia, and in the mean of the acoustic variables, perceptual parameters, and the score of the Voice Handicap Index-10 was not statistically significant between patients with low vitamin D levels compared with controls.

CONCLUSION

The results of this study revealed no significant difference in the prevalence of phonatory symptoms in patients with vitamin D deficiency compared with patients with no vitamin D deficiency. A larger study is needed to substantiate the difference in the prevalence of phonatory systems between the 2 groups.

Betaine promotes cell differentiation of human osteoblasts in primary culture

BACKGROUND

Betaine (BET), a component of many foods, is an essential osmolyte and a source of methyl groups; it also shows an antioxidant activity. Moreover, BET stimulates muscle differentiation via insulin like growth factor I (IGF-I). The processes of myogenesis and osteogenesis involve common mechanisms with skeletal muscle cells and osteoblasts sharing the same precursor. Therefore, we have hypothesized that BET might be effective on osteoblast cell differentiation.

METHODS

The effect of BET was tested in human osteoblasts (hObs) derived from trabecular bone samples obtained from waste material of orthopedic surgery. Cells were treated with 10 mM BET at 5, 15, 60 min and 3, 6 and 24 h. The possible effects of BET on hObs differentiation were evaluated by real time PCR, western blot and immunofluorescence analysis. Calcium imaging was used to monitor intracellular calcium changes.

RESULTS

Real time PCR results showed that BET stimulated significantly the expression of RUNX2, osterix, bone sialoprotein and osteopontin. Western blot and immunofluorescence confirmed BET stimulation of osteopontin protein synthesis. BET stimulated ERK signaling, key pathway involved in osteoblastogenesis and calcium signaling. BET induced a rise of intracellular calcium by means of the calcium ions influx from the extracellular milieu through the L-type calcium channels and CaMKII signaling activation. A significant rise in IGF-I mRNA at 3 and 6 h and a significant increase of IGF-I protein at 6 and 24 h after BET stimulus was detected. Furthermore, BET was able to increase significantly both SOD2 gene expression and protein content.

CONCLUSIONS

Our study showed that three signaling pathways, i.e. cytosolic calcium influx, ERK activation and IGF-I production, are enhanced by BET in human osteoblasts. These pathways could have synergistic effects on osteogenic gene expression and protein synthesis, thus potentially leading to enhanced bone formation. Taken together, these results suggest that BET could be a promising nutraceutical therapeutic agent in the strategy to counteract the concomitant and interacting impact of sarcopenia and osteoporosis, i.e. the major determinants of senile frailty and related mortality.

Changes in pro-inflammatory markers and leucine concentrations in response to Nordic Walking training combined with vitamin D supplementation in elderly women

Mechanisms underpinning age-related decreases in muscle strength and muscle mass relate to chronic inflammation. Physical activity induces an anti-inflammatory effect, but it is modulated by additional factors. We hypothesized that vitamin D, which has also anti-inflammatory activity will modify adaptation to exercise and reduce inflammation in elderly women. Twenty-seven women aged 67 ± 8 years were included and divided into groups with baseline vitamin D concentration more than 20 ng mL⁻¹ (MVD) and less than 20 ng mL⁻¹ (LVD). Both groups performed 1 h Nordic Walking (NW) training combined with vitamin D supplementation for 12 weeks. Serum concentrations of inflammation markers, branched amino acids, vitamin D, muscle strength and balance were assessed at the baseline and three days after intervention. The training caused the significant decrease in concentration of pro-inflammatory proteins HMGB1 (30 ± 156%; 90% CI) and IL-6 (−10 ± 66%; 90% CI) in MVD group. This effects in group MVD were moderate, indicating vitamin D as one of the modifiers of these exercise-induced changes. Rise of myokine irisin induced by exercise correlated inversely with HMGB1 and the correlation was more pronounced at the baseline as well as after training among MVD participants. Although the intervention caused the leucine level to rise, a comparison of the recorded response between groups and the adjusted effect indicated that the effect was 20% lower in the LVD group. Overall the applied training program was effective in reducing HMGB1 concentration. This drop was accompanied by the rise of myokine irisin and better uptake of leucine among women with higher baseline vitamin D.

Vitamin D3 transactivates the zinc and manganese transporter SLC30A10 via the Vitamin D receptor

Vitamin D3 regulates genes critical for human health and its deficiency is associated with an increased risk for osteoporosis, cancer, diabetes, multiple sclerosis, hypertension, inflammatory and immunological diseases. To study the impact of vitamin D3 on genes relevant for the transport and metabolism of nutrients and drugs, we employed next-generation sequencing (NGS) and analyzed global gene expression of the human-derived Caco-2 cell line treated with 500nM vitamin D3. Genes involved in neuropeptide signaling, inflammation, cell adhesion and morphogenesis were differentially expressed. Notably, genes implicated in zinc, manganese and iron homeostasis were largely increased by vitamin D3 treatment. An ∼10-fold increase in ceruloplasmin and ∼4-fold increase in haptoglobin gene expression suggested a possible association between vitamin D and iron homeostasis. SLC30A10, the gene encoding the zinc and manganese transporter ZnT10, was the chiefly affected transporter, with ∼15-fold increase in expression. SLC30A10 is critical for zinc and manganese homeostasis and mutations in this gene, resulting in impaired ZnT10 function or expression, cause manganese intoxication, with Parkinson-like symptoms. Our NGS results were validated by real-time PCR in Caco-2 cells, as well as in duodenal biopsies taken from healthy human subjects treated with 0.5μg vitamin D3 daily for 10 days. In addition to increasing gene expression of SLC30A10 and the positive control TRPV6, vitamin D3 also increased ZnT10 protein expression, as indicated by Western blot and cytofluorescence. In silico identification of potential vitamin D responsive elements (VDREs) in the 5'-flanking region of the SLC30A10 promoter and dual-luciferase reporter assay showed enhanced promoter activity in the presence of vitamin D receptor (VDR) and retinoid X receptor (RXR) constructs, as well as vitamin D3, but not when one of these factors was absent. Electrophoretic mobility shift assay (EMSA) and competition EMSA revealed binding of select sequences, namely, nt -1623/-1588 and nt -1758/-1723 relative to the transcription start site, to VDR-containing nuclear extracts. In conclusion, we have shown that vitamin D3 transactivates the SLC30A10 gene in a VDR-dependent manner, resulting in increased ZnT10 protein expression. Because SLC30A10 is highly expressed in the small intestine, it is possible that the control of zinc and manganese systemic levels is regulated by vitamin D3 in the intestine. Zinc, manganese and vitamin D are important for bone metabolism and brain health. Future examination of a possible role for supplementation or chelation of zinc and manganese, alongside vitamin D3 administration, will further our understanding of its potential benefit in the treatment of specific illnesses, such as osteoporosis and Parkinson's disease.

Revisiting the Debate: Does Exercise Build Strong Bones in the Mature and Senescent Skeleton?

Traditional exercise programs seem to be less osteogenic in the mature and post-mature skeleton compared to the young skeleton. This is likely because of the decline in sensitivity of bone to mechanical loading that occurs with advancing age. Another factor contributing to the apparently diminished benefit of exercise in older adults is failure of widely used measurement techniques (i.e., DXA) to identify changes in 3-dimensional bone structure, which are important determinants of bone strength. Moreover, although hormonal contributors to bone loss in the elderly are well-recognized, the influence of age-related increases in sympathetic nervous system activity, which impacts bone metabolism, is rarely considered. In this Perspective, we cite evidence from animal and human studies demonstrating anabolic effects of exercise on bone across the lifespan and we discuss theoretical considerations for designing exercise regimens to optimize bone health. We conclude with suggestions for future research that should help define the osteogenic potential of exercise in older individuals.

Diabetes and disordered bone metabolism (diabetic osteodystrophy): time for recognition

Diabetes and osteoporosis are rapidly growing diseases. The link between the high fracture incidence in diabetes as compared with the non-diabetic state has recently been recognized. While this review cannot cover every aspect of diabetic osteodystrophy, it attempts to incorporate current information from the First International Symposium on Diabetes and Bone presentations in Rome in 2014. Diabetes and osteoporosis are fast-growing diseases in the western world and are becoming a major problem in the emerging economic nations. Aging of populations worldwide will be responsible for an increased risk in the incidence of osteoporosis and diabetes. Furthermore, the economic burden due to complications of these diseases is enormous and will continue to increase unless public awareness of these diseases, the curbing of obesity, and cost-effective measures are instituted. The link between diabetes and fractures being more common in diabetics than non-diabetics has been widely recognized. At the same time, many questions remain regarding the underlying mechanisms for greater bone fragility in diabetic patients and the best approach to risk assessment and treatment to prevent fractures. Although it cannot cover every aspect of diabetic osteodystrophy, this review will attempt to incorporate current information particularly from the First International Symposium on Diabetes and Bone presentations in Rome in November 2014.

Markers of Bone Metabolism in Patients With Chronic Pancreatitis and Pancreatic Ductal Adenocarcinoma

There are no studies comparing some of the most important markers, such as vitamin D, parathormone, osteocalcin, bone alkaline phosphatase, and calcium, in patients with chronic benign and malignant pancreatic diseases. Our objective was to comparatively evaluate serum markers of bone metabolism in patients with chronic pancreatitis and in those with ductal pancreatic adenocarcinoma. Sixty-three consecutive subjects were studied: 30 patients with a firm diagnosis of chronic pancreatitis and 33 having histologically confirmed pancreatic adenocarcinoma. Serum 25-hydroxyvitamin D, bone alkaline phosphatase, osteocalcin, parathormone, and calcium were determined using commercially available kits. Taking into consideration the clinical variables of all 63 patients studied, 25-hydroxyvitamin D was inversely correlated with only the body mass index (P = 0.007), whereas it was not correlated with age (P = 0.583) or fecal elastase-1 concentrations (P = 0.556). Regarding the other substances studied, parathormone was positively correlated with only the age of the patients (P = 0.015). Of the 5 substances studied, only bone alkaline phosphates were significantly different (P < 0.001) between patients with chronic pancreatitis and those with pancreatic ductal adenocarcinoma. Within the 2 groups of patients, the 23 patients with chronic pancreatitis without diabetes mellitus had serum concentrations of 25-hydroxyvitamin D significantly lower (P = 0.045) than those with chronic pancreatitis having diabetes mellitus, whereas smokers with pancreatic ductal adenocarcinoma had serum concentrations of calcium significantly higher (P < 0.001) as compared to nonsmokers. Altered bone metabolism seems to be associated with chronic diseases of the pancreas; however, the mechanism should be better elucidated.