Abstract Objective: To present an updated and evidence-based guideline for the use of dual-energy x-ray absorptiometry (DXA) to assess body composition in clinical practice. Materials and methods: This Official Position was developed by the Scientific Committee of the Brazilian Association of Bone Assessment and Metabolism ( Associação Brasileira de Avaliação Óssea e Osteometabolismo , ABRASSO) and experts in the field who were invited to contribute to the preparation of this document. The authors searched current databases for relevant publications in the area of body composition assessment. In this second part of the Official Position, the authors discuss the interpretation and reporting of body composition parameters assessed by DXA and the use of DXA for body composition evaluation in special situations, including evaluation of children, persons with HIV, and animals. Conclusion: This document offers recommendations for the use of DXA in body composition evaluation, including indications, interpretation, and applications, to serve as a guiding tool in clinical practice and research for health care professionals in Brazil.

Resumo Osteoporose, uma doença metabólica caracterizada por baixa massa óssea, deterioração da microarquitetura do tecido ósseo e aumento da suscetibilidade a fraturas, é comumente vista como um problema de saúde feminino. Essa visão tem fundamentos: em comparação com os homens as mulheres têm densidade mineral óssea menor, têm vida mais longa e perdem massa óssea mais rapidamente, principalmente após a menopausa, devido à diminuição acentuada dos níveis séricos de estrógeno. Entretanto, nos últimos 20 anos a osteoporose no homem tem sido reconhecida como um problema de saúde pública devido à ocorrência cada vez maior de fraturas por fragilidade. Cerca de 30% de todas as fraturas de quadril ocorrem em homens. Estudos recentes mostram que a probabilidade de fratura por fragilidade do quadril, vértebra ou punho em homens brancos após os 50 anos, pelo resto de suas vidas, situa-se em torno de 13%, 40% nas mulheres. Os homens apresentam perda de massa óssea e fraturas mais tardiamente do que as mulheres. Embora os homens mais idosos tenham maior risco de fratura, cerca de metade das fraturas de quadril ocorre antes dos 80 anos. A expectativa de vida tem aumentado para ambos os sexos no Brasil e em todo o mundo, porém em uma velocidade maior para homens do que para mulheres. Esta Diretriz foi baseada em uma revisão sistemática da literatura com relação a prevalência, etiologia, diagnóstico e tratamento da osteoporose em homens.

Abstract Osteoporosis, a metabolic disease characterized by low bone mass, deterioration of the bone tissue microarchitecture and increased susceptibility to fractures, is commonly regarded as a women's health problem. This point of view is based on the fact that compared with men, women have lower bone mineral density and longer lifespans and lose bone mass faster, especially after menopause, due to a marked decrease in serum estrogen levels. However, in the last 20 years, osteoporosis in men has become recognized as a public health problem due to the occurrence of an increasingly higher number of fragility fractures. Approximately 30% of all hip fractures occur in men. Recent studies show that the probability of fracture due to hip, vertebral or wrist fragility in Caucasian men older than fifty years, for the rest of their lives, is approximately 13% versus a 40% probability of fragility fractures in women. Men show bone mass loss and fractures later than women. Although older men have a higher risk of fracture, approximately half of all hip fractures occur before the age of 80. Life expectancy is increasing for both sexes in Brazil and worldwide, albeit at a higher rate for men than for women. This Guideline was based on a systematic review of the literature on the prevalence, etiology, diagnosis and treatment of osteoporosis in men.

Resumo A osteoporose é a principal causa de fraturas na população acima de 50 anos. É uma doença silenciosa que afeta especialmente as mulheres na pós-menopausa e idosos e tem elevada taxa de morbimortalidade. O principal objetivo do tratamento da osteoporose é a prevenção das fraturas. A identificação dessa população de risco através do diagnóstico e tratamento precoces é de fundamental importância. A última diretriz brasileira para tratamento da osteoporose em mulheres na pós-menopausa foi elaborada em 2002. Desde então foram desenvolvidas novas estratégias de diagnóstico da osteoporose, bem como fármacos com novos mecanismos de ação foram adicionados ao arsenal terapêutico. A Comissão de Osteoporose e Doenças Osteometabólicas da Sociedade Brasileira de Reumatologia em conjunto com a Associação Médica Brasileira e sociedades afins desenvolveu esta atualização da diretriz do tratamento da osteoporose em mulheres na pós-menopausa de acordo com as melhores evidências científicas disponíveis. Esta atualização é destinada aos profissionais das várias especialidades médicas e da área da saúde envolvidos no tratamento da osteoporose, médicos em geral e organizações relacionadas à saúde.

Abstract Osteoporosis is the leading cause of fractures in the population older than 50 years. This silent disease affects primarily postmenopausal women and the elderly, and the morbidity and mortality rates are high. The main goal of treating osteoporosis is the prevention of fractures. The identification of populations at risk through early diagnosis and treatment is essential. The last Brazilian guideline for the treatment of postmenopausal osteoporosis was elaborated in 2002. Since then, new strategies for diagnosis and risk stratification have been developed, and drugs with novel action mechanisms have been added to the therapeutic arsenal. The Osteoporosis and Osteometabolic Diseases Committee of the Brazilian Society of Rheumatology, in conjunction with the Brazilian Medical Association and other Societies, has developed this update of the guidelines for the treatment of postmenopausal osteoporosis according to the best scientific evidence available. This update is intended for professionals in many medical and health specialties involved in the treatment of osteoporosis, for physicians in general and for health-related organizations.

ABSTRACT OBJECTIVE: To evaluate bone mass accrual and determine the influence of clinical, anthropometric, dietary and biochemical parameters on bone mass. METHODS: A cohort study including 35 prepubertal HIV-infected children, between 7 and 12 years, attended at a referral center. At time 1 (T1) and time 2 (T2), patients were assessed according to clinical, anthropometric, dietary, biochemical parameters and bone mineral density (BMD). At T2, patients were divided into prepubertal and pubertal. RESULTS: Despite the increase in bone mass absolute values, there was no improvement in lumbar spine BMD (LSBMD) Z-score (p = 0.512) and worsening in total body BMD (TBMD) Z-score (p = 0.040). Pubertal patients (n = 19) showed higher bone mineral content (BMC) (p = 0.001), TBMD (p = 0.006) and LSBMD (p = 0.002) compared to prepubertal patients. After multivariate linear regression analysis, the predictors of bone mass in T1 were age, BMI and HAZ-scores for BMC; BMI Z-score, adequate serum magnesium concentration and dietary calcium intake for TBMD; adequate serum concentration of magnesium, BMI and HAZ-scores for LSBMD. In T2, age, total body fat and lean body mass (kg) for BMC; BMI Z-score and puberty for TBMD; dietary fat intake, BMI Z-score for BMD and puberty for LSBMD. CONCLUSION: HIV-infected children have compromised bone mass and the presence of puberty seems to provide suitability of these parameters. Adequate intake of calcium and fat appears to be protective for proper bone mass accumulation factor, as well as monitoring nutritional status and serum magnesium concentration.

OBJECTIVE: To identify lipodystrophy in prepubertal HIV-infected children using anthropometric parameters and body composition assessment. METHODS: Cross-sectional study including 40 prepubertal HIV-infected children of both genders seen at the Care Center of the Division of Pediatric Infectious Diseases - Universidade Federal de São Paulo, São Paulo city, Brazil, was carried out from August to December 2008. Age, clinical and immunological status, prophylaxis, transmission and highly active antiretroviral therapy were recorded. Body mass index z-score and height-for-age z-score were calculated to characterize the nutritional status. Circumferences were measured with flexible tape and skinfolds were assessed by an adipometry. Fat mass and lean mass were determined by dual-energy X-ray absorptiometry. Presence of clinical signs of lipodystrophy was assessed by a trained clinician. Data were analyzed using SPSS 12.0 software. RESULTS: The mean age and standard deviation were 9.8 (1.2) years, 50% were girls and 82.5% children from B and C categories. Clinical lipodystrophy and dislypidemia were present in 27.5% and 70%, respectively. The trunk to arm ratio and the limb to trunk ratio had positive association with lipodystrophy. Patients with lipodystrophy had short stature, higher triglycerides values and lower HDL-cholesterol. CONCLUSION: The ratios obtained by skinfolds and dual-energy X-ray absorptiometry measurements can be considered as indicators of preclinical lipodystrophy. The cutoff points have not been determined yet; however, continuous assessment may be useful to identify early body composition changes.

OBJETIVOS: investigar o conhecimento de profissionais médicos brasileiros a respeito da osteoporose, estratégias de prevenção e tratamento e o acesso à informação em osteoporose, utilizando-se um questionário desenvolvido para avaliar o conhecimento de profissionais médicos em relação à importância da osteoporose e suas estratégias de tratamento. PACIENTES E MÉTODOS: o questionário foi divulgado a11 mil médicos afiliados à Sociedade Brasileira de Clínica Médica (SBCM). Realizou-se a divulgação da pesquisa e do questionário por meio de anúncios publicados no Jornal do Clínico. Inicialmente, foi disponibilizado na home-page e, em seguida, diretamente enviado via e-mail aos sócios cadastrados da SBCM. RESULTADOS: um total de 329 questionários retornou aos pesquisadores. A maioria dos médicos (55,3%) tinha tempo de graduação superior a 10 anos. Pouco mais que a metade dos profissionais médicos pesquisados (55%) relatou ter fácil acesso à densitometria óssea. A maioria (99%) dos participantes acredita que é importante ou muito importante prevenir a osteoporose. Da mesma forma, 73% dos médicos pesquisados acreditam que a osteoporose possa ser prevenida e 63% deles discutem o assunto com os seus pacientes. Por outro lado, mais da metade dos médicos pesquisados não crê que seus pacientes venham a mudar hábitos de vida e cerca de 50% deles não acreditam que seus pacientes venham a aderir ao tratamento da doença em longo prazo. Apenas 35% dos médicos pesquisados acreditam que os tratamentos para osteoporose sejam efetivos. Cerca de 82% fazem uso da densitometria óssea. Médicos com 10 anos ou mais de graduação utilizam a densitometria óssea mais freqüentemente que seus colegas com menos tempo de graduação. CONCLUSÃO: os autores acreditam que as informações obtidas no presente estudo poderiam ser úteis para o início do desenvolvimento de estratégias educacionais efetivas para a prevenção e o tratamento de pacientes com osteoporose.

OBJECTIVES: Brazilian physicians' knowledge on osteoporosis prevention and treatment strategies was investigated in this cross-sectional study. A specific structured questionnaire was designed to evaluate physicians' knowledge regarding osteoporosis prevention and treatment as well as osteoporosis information access. PATIENTS AND METHODS: the questionnaire was made available to around 11,000physicians affiliated to the Brazilian Society of Internal Medicine (BSIM). The questionnaire was initially presented at the BSIM home-page and subsequently sent by e-mail to all BSIM members. RESULTS: a total of 329 answered questionnaires returned to the researchers. Most of the physicians that answered the questionnaire (55.3%) had time since graduation lougher than 10 years and half of them (55%) reported having easy access to bone densitometry. The great majority of the physicians (99%) believe that preventing osteoporosis is important or very important. Accordingly, 73% of the physicians believe that osteoporosis can be prevented and around 63% of them discuss the issue with their patients regularly. On the other hand, most of the physicians that answered the questionnaire do not believe that their patients are able to change life habits or will adhere to the treatment in the long-term. Only 35% of the physicians believe that current osteoporosis treatment is effective. Around 82% of the physicians make use of bone densitometry to evaluate osteoporosis. Physicians with time since graduation higher than 10 years reported using bone densitometry more often than their colleagues with less time since graduation. CONCLUSION: our results demonstrate that educational programs aiming at the general practitioner are needed in order to provide better care in terms of prevention and treatment of skeletal fragility syndromes.

A prevalência de incapacidade e dependência funcional é maior em idosos e está intimamente associada à redução da massa muscular, que ocorre, até mesmo, em indivíduos saudáveis. A sarcopenia parece decorrer da interação complexa de distúrbios da inervação, diminuição de hormônios, aumento de mediadores inflamatórios e alterações da ingestão protéico-calórica que ocorrem durante o envelhecimento. A perda de massa e força muscular é responsável pela redução de mobilidade e aumento da incapacidade funcional e dependência. Quando associada à fragilidade, esta perda gera custos econômicos e sociais. Neste artigo, pretende-se avaliar aspectos relacionados à gênese da sarcopenia, bem como analisar possíveis opções terapêuticas e de prevenção.

The high prevalence of inability and functional dependence is an important problem in elderly people. It is closely related with aging decrease of lean muscle mass that occurs even in healthy subjects. Skeletal muscle mass deficiency, or sarcopenia, results from complex interactions between innervations disturbances, hormones deficiency, inflammatory cytokines and restriction in caloric-proteic ingestion. Loss of skeletal muscle mass and strength results in disability and functional dependency that are associated to frailty in many elderly people. These conditions represent enormous economic and social budget. In this article, we evaluate pathogenesis of sarcopenia and discuss potential therapies.

OBJETIVO: atividades de promoção de saúde e prevenção direcionadas para osteoporose podem ajudar a reduzir a taxa de fraturas osteoporóticas na população idosa. MÉTODOS: para avaliar se mulheres com osteoporose modificam seus hábitos de vida após a fratura, selecionamos 518 mulheres idosas caucasianas de nosso Serviço Ambulatorial de Reumatologia (122 com fratura), que foram seguidas por um ano. O questionário de avaliação foi baseado no European Vertebral Osteoporosis Study (EVOS) e contém tópicos relacionados com queda, massa óssea e fratura. Radiografias lateral da coluna torácica e lombar foram realizadas de acordo com protocolo padrão para verificar fratura vertebral. Densidade mineral óssea foi medida por meio de densitômetro Lunar DPX, Madison, WI. O comportamento das mulheres foi analisado antes e após a fratura. RESULTADOS: antes da fratura, 34% das mulheres tinham pior percepção da saúde, 40,2% caminhavam pelo menos meia hora por dia, 14,7% usavam bengalas, 56,6% queixavam-se de tonturas, 59,6% possuíam tapetes espalhados pela casa, 78,9% usavam transporte público, 21,1% utilizavam transporte privado (carro) e 36,8% usavam solado de couro e não de borracha. Após a fratura, 66,4% das mulheres tinham pior percepção da saúde; 69,7% ficaram mais sedentárias, 27,9% usavam mais bengalas, 63,4% queixavam-se de mais tonturas, 38,3% tinham retirado os tapetes de casa, 68,1% trocaram o transporte público por privado e 55,7% modificaram o solado dos sapatos de couro para borracha. Fatores de risco relacionados com a massa óssea não foram modificados após a fratura. CONCLUSÕES: estes achados sugerem que mulheres idosas modificam somente os hábitos de vida relacionados com quedas, mas não aqueles relacionados com a massa óssea após a fratura por osteoporose. Pesquisas são necessárias a fim de avaliar quais estratégias de intervenção podem ocasionar melhores resultados na prevenção de fraturas por osteoporose.

OBJECTIVE: health promotion and disease prevention activities directed to osteoporosis might help to reduce the rate of osteoporotic fractures among elderly people. METHODS: in order to check whether osteoporotic women modify their habits after the fracture, 518 postmenopausal white Brazilian elderly women were recruited from the outpatient clinic of the Rheumatology Division (122 of them with fracture) and were followed for one year. Questionnaire of evaluation was based on the European Vertebral Osteoporosis Study (EVOS) and inquiries about topics related to falls, bone mass and fracture. Lateral thoracic and lumbar radiographs were taken according to a standard protocol in order to verify vertebral fracture. Bone mineral density was measured using a bone densitometer (Lunar DPX, Madison, WI). Women's behavior was analyzed before and after the fracture. RESULTS: before the fracture, 34% of them had poor health perception, 40.2% walked at least half an hour per day, 14.7% used canes, 56.6% complained of dizziness, 59.6% scattered rugs, 78.9% used public transportation, 21.1% used car, and 36.8% wore leather instead of rubber sole. After the fracture, 66.4% of those women had worse health perception; 69.7% became more sedentary, 27.9% used more canes, 63.4% complained of more dizziness, 38.3% removed rugs, 68.1% changed from public to private car transportation, and 55.7% modified their shoes from leather to rubber sole. Risk factors related to bone mass did not change before and after the fractures. CONCLUSIONS: these findings suggested that women modify only lifestyle habits related to falls but not those related to bone mass after osteoporotic fracture. Further research is needed in order to check which intervention strategies may lead to better results in preventing osteoporotic fractures.