Umberto Tarantino

Effects of different sports on bone density and muscle mass in highly trained athletes

PURPOSE It is known that participating in sports can have a beneficial effect on bone mass. However, it is not well established which sport is more beneficial for increased bone mineral density (BMD) and appendicular muscle mass (AMM). This study investigated the effects of different high-intensity activities on BMD and AMM in highly trained athletes. MATERIALS AND METHODS Sixty-two male subjects aged 18--25 yr participated in the study. The sample included judo (J; N = 21), karate (K; N = 14), and water polo (W; N = 24) athletes who all competed at national and international level. Twelve age-matched nonathletic individuals served as the control group (C). All athletes exercised regularly for at least 3 h x d(-1), 6 d x wk(-1). Segmental, total BMD, and AMM were measured with a dual-energy x-ray (DXA) absorptiometry (Lunar Corp., Madison, WI). DXA analysis also includes bone mineral content (BMC) and fat and lean masses. RESULTS Total BMD(C) was significantly lower (mean +/- SD: 1.27 +/- 0.06 g x cm(-2), P < 0.05) than either judo or karate athletes (total BMD(J) (1.4 +/- 0.06 g x cm(-2)) and total BMD(K) (1.36 +/- 0.08 g x cm(-2))) but not different from the W athletes (total BMD(W) (1.31 +/- 0.09 g x cm(-2))). AMM was significantly lower in the C group compared with the three athletic groups (P < 0.05). Fat mass was higher in the W versus J and K athletes but not different from the C group (P < 0.05). CONCLUSIONS This cross-sectional study has shown that athletes, especially those engaged in high-impact sports, have significantly higher total BMD and AMM than controls. These results suggest that the type of sport activity may be an important factor in achieving a high peak bone mass and reducing osteoporosis risk.

Body composition assessment by dual-energy X-ray absorptiometry (DXA)

Body composition (BC) assessment is indispensable to evaluate nutritional status and thus health, both at the population and individual level, and to assess the efficacy of primary and secondary preventive nutritional strategies. Changes in BC, including the regional distribution of body fat, largely occur during pubertal transition, with marked differences between genders. They may, however, also occur in the elderly, who experience significant changes in the ratio between body fat and muscle with aging. The development and implementation of more sophisticated techniques (e.g. BC assessment at the molecular and atomic levels) could provide a major contribution to determining BC at different levels. This review discusses the application of dual-energy X-ray absorptiometry (DXA) on BC determination, given that DXA has the potential to provide overall and regional assessment of BC in terms of fat, lean mass and bone. DXA is widely used in many clinical settings primarily diagnosis osteoporosis. This article describes the use of whole-body DXA in assessing BC in patients with chronic diseases (e.g. metabolic syndrome) as well as in different sport activities to evaluate the effects of exercise.RiassuntoLa valutazione della composizione corporea, da qui in avanti denominata con il termine anglosassone di body composition (BC), è un metodo essenziale per analizzare lo stato di salute in termini nutrizionali, sia a livello di popolazione sia a livello individuale, come pure per indagare l’efficacia delle strategie nutrizionali preventive primarie e secondarie. I cambiamenti della BC, inclusa la distribuzione distrettuale del grasso corporeo, avvengono in larga parte durante il periodo puberale e si diversificano in base al sesso. Questi tuttavia possono manifestarsi anche nel soggetto anziano, per il quale il trascorrere degli anni può causare significativi cambiamenti nel rapporto tra grasso corporeo e muscolo. Per misurare la composizione corporea esistono numerose tecniche; alcune semplici, ma con margini di errore ancora elevati, altre invece costose e sofisticate (come per esempio la valutazione a livello atomico e molecolare della BC) ma più affidabili nel rilevamento dei risultati a vari livelli. Questa revisione della letteratura riguarda l’applicazione della tecnica dual-Energy X-ray absorptiometry (DXA) per la determinazione della composizione corporea, in quanto tale metodica permette di misurare sia in maniera totale che segmentale, per singoli distretti, i vari componenti quali: massa grassa, massa magra e tessuto osseo. Attualmente la DXA è principalmente usata per fare diagnosi di osteoporosi e/o per controllare la risposta alla terapia farmacologia. In questo articolo verranno descritte le altre possibili indicazioni, tra cui lo studio della BC nei pazienti con sindromi metaboliche croniche e l’applicazione in condizioni fisiologiche, quali per esempio nello sportivo, per valutare l’effetto dell’esercizio fisico sulla massa corporea.

Multinational survey of osteoporotic fracture management

Osteoporosis is characterized by a decreased bone mass and an increased bone fragility and susceptibility to fracture. Patients with a fragility fracture at any site have an increased risk of sustaining future fractures. Orthopedic surgeons manage most of these fractures and are often the only physician seen by the patient. Mounting evidence that orthopedic surgeons are not well attuned to osteoporosis led the Bone and Joint Decade (BJD) and the International Osteoporosis Foundation (IOF) to survey 3,422 orthopedic surgeons in France, Germany, Italy, Spain, the United Kingdom, and New Zealand. The majority of the respondents in all countries had the opinion that the orthopedic surgeon should identify and initiate the assessment of osteoporosis in patients with fragility fractures. Heterogeneous practice pattern exist in different countries; however, identification and treatment of the osteoporotic patient seems to be insufficient in many areas: half of the orthopedic surgeons surveyed received little or no training in osteoporosis. Only approximately one in four orthopedic surgeons in France, the UK and New Zealand regarded themselves as knowledgeable about treatment modalities. Less than one-fifth of the orthopedic surgeons arranged for a surgically treated patient with a fragility fracture to have a bone mineral density (BMD) test. Twenty percent said that they never refer a patient after a fragility fracture for BMD. Only half of the orthopedic surgeons in southern Europe know about the importance of some external risk factors for hip fractures (cataracts, poor lighting, pathway obstacles, poor balance). In summary, this survey clearly indicates that many orthopedic surgeons still neglect to identify, assess and treat patients with fragility fractures for osteoporosis. More educational opportunities need to be offered to orthopedic surgeons through articles, web-based learning and educational seminars. Development of a simple clinical pathway from evidence-based guidelines is an important step to ensure that optimal care is provided for patients with fragility fractures.

Transglutaminase-2 differently regulates cartilage destruction and osteophyte formation in a surgical model of osteoarthritis

Osteoarthritis is a progressive joint disease characterized by cartilage degradation and bone remodeling. Transglutaminases catalyze a calcium-dependent transamidation reaction that produces covalent cross-linking of available substrate glutamine residues and modifies the extracellular matrix. Increased transglutaminases-mediated activity is reported in osteoarthritis, but the relative contribution of transglutaminases-2 (TG2) is uncertain. We describe TG2 expression in human femoral osteoarthritis and in wild-type and homozygous TG2 knockout mice after surgically-induced knee joint instability. Increased TG2 levels were observed in human and wild-type murine osteoarthritic cartilage compared to the respective controls. Histomorphometrical but not X-ray investigation documented in osteoarthritic TG2 knockout mice reduced cartilage destruction and an increased osteophyte formation compared to wild-type mice. These differences were associated with increased TGFβ-1 expression. In addition to confirming its important role in osteoarthritis development, our results demonstrated that TG2 expression differently influences cartilage destruction and bone remodeling, suggesting new targeted TG2-related therapeutic strategies.

Osteoporosis and sarcopenia: the connections

Osteoporosis and sarcopenia are the most frequent musculoskeletal disorders affecting older people. Osteoporosis is a widespread disorder affecting millions of individuals of all ethnic backgrounds worldwide, particularly among older women. It is characterized by reduced bone mass and microarchitectural deterioration of bone tissue, with a consequent increase in the risk of fracture. Sarcopenia is considered to be one of the major factors responsible for functional limitations and motor dependency in elderly persons. In age-related muscle atrophy, a decrease in muscle fiber size and number, and a preferential loss of type II fibers have been reported. A decrease in the circulating levels of specific hormones (e.g., estrogen, testosterone, growth hormone, and insulin-like growth factor-1) has been shown to be associated with sarcopenia and this appears to play an important role in its pathogenesis.

Sarcopenia and fragility fractures: molecular and clinical evidence of the bone-muscle interaction

➤ Bone and muscle tissues are in close relationship, and the aging process is a factor involved in the loss of the functionality of both bones and muscles.➤ Sarcopenia and osteoporosis are linked from a biological and functional perspective and are related to an increased fracture risk in the elderly.➤ The increased fracture risk in sarcopenic and osteoporotic subjects is due to the decline of muscle mass and strength, the decrease in bone mineral density, and limited mobility.

A correlation between knee cartilage degradation observed by arthroscopy and synovial proteinases activities

OBJECTIVE A novel study has been carried out to characterize the amount and activity levels of metalloproteinases (i.e., MMP-1, MMP-2, MMP-3, MMP-8, MMP-9 and MMP-13) and of their inhibitors (i.e., TIMP-1 and TIMP-2) in synovial fluid from patients (n = 56) with different degrees of either chondral lesions or knee arthritis identified and classified by arthroscopy. DESIGN AND METHODS Zymographies, Western blotting and ELISA tests have been used to correlate the disease stage, as determined by arthroscopy, and both the amount and the activation state of different MMPs and of their inhibitors. RESULTS Analysis of data obtained demonstrates that the degree of cartilage degradation, as seen by arthroscopy, is strictly related to the activity of some synovial MMPs, in particular MMP-2 and MMP-13 and on reduced inhibitory effect of MMP-2 by TIMP-2; in addition, a serine protease weighing about 125 kDa appears only in patients with severe cartilage degradation, i.e., with knee arthritis. CONCLUSIONS On the whole, this is the first study in which an analysis of synovial MMPs/other proteinases activity and TIMPs has been strictly related to arthroscopy results in patients with different degrees of osteoarthritis. Results indicate that an imbalance between specific MMP activities and the amount of TIMPs and of its inhibitory efficiency is crucial for the disease evolution and it is related to the disease stage.

Long-term effect of exercise on bone mineral density and body composition in post-menopausal ex-elite athletes: a retrospective study.

Objectives:The aim of this retrospective study was to determine the long-term effect of exercise on bone mineral density (BMD), bone mineral content (BMC) and body composition (BC) in post-menopausal women who were elite athletes during their youth compared with sedentary controls.Subjects/Methods:It is a retrospective study and carried out in an outpatient clinic. A total of 48 post-menopausal women (54–73 years of age) were enrolled. Ex-elite athletes with long-term (>20 years) histories of significant training and performance were divided into two groups: weight-bearing sports (runners, n=12) and non-weight-bearing sports (swimmers, n=12). The athletes were age matched with sedentary controls (n=24). BMD, BMC and BC were measured using dual-energy X-ray absorptiometry. Healthcare and sport activity histories were evaluated using a questionnaire.Results:No significant differences were found with regard to body weight, height, body mass index and hours of activity between the two groups of athletes. There were no significant differences in activity levels between athletes and controls at the time of this study. BMD and BMC were not significantly different between athletes; they were significantly higher in athletes than in controls (P<0.001). Although the ex-athletes did not significantly differ in BC, left and right lean arm mass and arm BMD were significantly higher in swimmers than in runners (P<0.0001).Conclusions:The high level of physical activity observed in female athletes is associated with improved muscle mass, BMD and BMC, and physical activity during youth seems to have a beneficial effect on bone mass and helps to prevent bone loss due to aging.

Irisin prevents and restores bone loss and muscle atrophy in hind-limb suspended mice

We previously showed that Irisin, a myokine released from skeletal muscle after physical exercise, plays a central role in the control of bone mass. Here we report that treatment with recombinant Irisin prevented bone loss in hind-limb suspended mice when administered during suspension (preventive protocol) and induced recovery of bone mass when mice were injected after bone loss due to a suspension period of 4 weeks (curative protocol). MicroCT analysis of femurs showed that r-Irisin preserved both cortical and trabecular bone mineral density, and prevented a dramatic decrease of the trabecular bone volume fraction. Moreover, r-Irisin protected against muscle mass decline in the hind-limb suspended mice, and maintained the fiber cross-sectional area. Notably, the decrease of myosin type II expression in unloaded mice was completely prevented by r-Irisin administration. Our data reveal for the first time that Irisin retrieves disuse‐induced bone loss and muscle atrophy. These findings may lead to development of an Irisin-based therapy for elderly immobile osteoporotic and physically disable patients, and might represent a countermeasure for astronauts subjected to microgravity-induced bone and muscle losses.

FXIIIA and TGF-β over-expression produces normal musculo-skeletal phenotype in TG2-/- mice

Transglutaminase (TGs) enzymes and proteins crosslinking have for long time been implicated in the formation of hard tissue development, matrix maturation and mineralization. Among the TGs family members, in the context of connective tissue formation, TG2 and Factor XIII are expressed in cartilage by hypertrophic chondrocytes. Here, we analyse the morphological consequences of TG2 deficiency, during the development of skeletal elements. When TG2 is absent, there are not gross abnormalities in the development of the skeletal system, probably from compensatory mechanisms resulting in increased expression of FXIIIA and TGF-ß 1. In vivo other TGs may be involved in promoting chondrocytes and osteoblast differentiation and matrix mineralisation