ABSTRACT
ABSTRACT BACKGROUND: Low bone mineral content (BMC) and bone mineral density (BMD) have been identified in human immunodeficiency virus (HIV)-infected children and adolescents. The direct adverse effects of HIV infection and combined antiretroviral therapy (ART) negatively contribute to bone metabolism. A direct relationship between muscle strength levels and BMD in HIV-infected adults and older adults has been described. However, it is unknown whether handgrip strength (HGS) is associated with bone mass in pediatric populations diagnosed with HIV. OBJECTIVE: To ascertain whether HGS levels are associated with BMC and BMD in HIV-infected children and adolescents. DESIGN AND SETTING: Cross-sectional study conducted in Florianãpolis, Brazil, in 2016. METHODS: The subjects were 65 children and adolescents (8-15 years) diagnosed with vertically-transmitted HIV. Subtotal and lumbar-spine BMC and BMD were obtained via dual-emission X-ray absorptiometry (DXA). HGS was measured using manual dynamometers. The covariates of sex, ART, CD4+ T lymphocytes and viral load were obtained through questionnaires and medical records. Sexual maturation was self-reported and physical activity was measured using accelerometers. Simple and multiple linear regression were used, with P < 0.05. RESULTS: HGS was directly associated with subtotal BMD (β = 0.002; R² = 0.670; P < 0.001), subtotal BMC (β = 0.090; R² = 0.734; P = 0.005) and lumbar-spine BMC (β = 1.004; R² = 0.656; P = 0.010) in the adjusted analyses. However, no significant association was found between HGS and lumbar-spine BMD (β = 0.001; R² = 0.464; P = 0.299). CONCLUSION: HGS was directly associated with BMD and BMC in HIV-infected children and adolescents.
Subject(s)
Humans , Child , Adolescent , Aged , Bone Density , HIV Infections/drug therapy , Cross-Sectional Studies , Hand Strength , Lumbar VertebraeABSTRACT
O objetivo do presente estudo foi apresentar um conjunto de orientações para a utilização de acelerômetros no Brasil. O método consistiu na revisão e síntese de artigos que utilizaram acelerômetros como instrumento de medida objetiva da atividade física. Com base nesses estudos, buscou-se apresentar orientações para as fases pré-coleta (seleção do acelerômetro; testagem da calibração dos acelerômetros, atualização de firmware; estudo piloto; e definição de protocolo), coleta (distribuição dos acelerômetros; contato com participantes; e devolução dos acelerômetros) e pós-coleta (processamento; transformação e interpretação dos dados; e comparabilidade dos dados) do uso de acelerômetros. São descritos procedimentos para facilitar as tomadas de decisões relacionadas ao uso desses dispositivos, bem como para obtenção de dados de acelerometria válidos e reprodutíveis. As orientações são uma iniciativa de pesquisadores da área a fim de proporcionar um avanço metodológico nas medidas objetivas da atividade física. A adoção das orientações pode facilitar a padronização dos procedimentos empregados e a comparabilidade de resultados entre estudos com acelerômetros no Brasil.
The aim of this study was to develop instructions for using accelerometers to measure physical activity in Brazil. This manuscript is a review and synthesis of scientific papers that have used accelerometers for objective physical activity assessment in different age groups as well as studies providing directions for using activity monitors in large-scale studies. In this study, we present instructions for the pre-data collection (selection of monitor; unit calibration, firmware update, pilot study, protocol definition), data collection (monitor distribution, contacting participants, monitor return) and post-data collection (data processing, transformation and interpretation) phases. We describe procedures for facilitating decision making related to using accelerometers, as well as for obtaining valid and reliable accelerometer physical activity data. This set of instructions is an initiative of a group of physical activity researchers with the purpose of contributing to methodologically advance the field of objective physical activity measurement in Brazil. The current set of instructions intend to facilitate the standardization of procedures for collecting physical activity data with accelerometers in Brazil and, thus, for ascertaining future comparability of data collected in different studies.