MUSCLE STRENGTH AND ENDURANCE IN CHILDREN LIVING WITH HIV

Potterton J1,2, Shiau S2,3,4, Van Aswegen T2, Strehlau R2, Patel F2, Thurman C3, Burke M2, Yin M5, Kuhn L2,3,4, Arpadi S2,3,4,61University of the Witwatersrand, Physiotherapy, Johannesburg, South Africa, 2Empilweni Services and Research Unit, Rahima Moosa Mother and Child Hospital, Department of Paediatrics and Child Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa, 3Gertrude H. Sergievsky Center, College of Physicians and Surgeons, Columbia University, New York, United States, 4Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, United States, 5Department of Medicine, Division of Infectious Diseases, College of Physicians & Surgeons, Columbia University, New York, United States, 6Department of Pediatrics, College of Physicians & Surgeons, Columbia University, New York, United StatesBackground: Myopathy and muscle weakness has been described in HIV-infected adults but little research has been done investigating muscle strength and physical endurance in children infected with HIV. HIV infection is associated with intestinal protein malabsorption, depletion of the body's protein reserves, and abnormal protein metabolism. These abnormalities can lead to decreased muscle bulk which may affect muscle strength and subsequently delay gross motor development.Purpose: The aim of this study is to determine the muscle strength and endurance levels of children infected with HIV and initiated on antiretroviral treatment at an early age.Methods: The CHANGES Bone Study follows 219 HIV-infected children and 219 HIV-uninfected children in Johannesburg, South Africa. At a cross-sectional visit, 175 HIV-infected and 171 HIV-uninfected children were assessed for endurance and muscle strength. Endurance was assessed using the Six Minute Walk Test. The American Thoracic Society guidelines for administering the test were adhered to. Blood pressure, heart rate and oxygen saturation were monitored pre- and post-test. Muscle strength was assessed using a hand held dynamometer using a 'make' test. Measurements included shoulder abduction, shoulder forward flexion, elbow flexion, elbow extension, hip flexion, hip extension, knee flexion, knee extension, ankle plantarflexion and ankle dorsiflexion. Each measurement was taken three times and the maximum reading was recorded. Shoulder and elbow values were summed to give an overall upper limb score and hip, knee and ankle scores were summed to give a lower limb score. Clinical and anthropometric data were extracted from the child's clinical file. We compared measurements of HIV-infected to HIV-uninfected children.Results: The results for 175 HIV positive and 171 HIV negative children were analysed. The two groups were well matched for age (p=0.88) and sex (p=0.23). There were no significant differences between the two groups for pre- and post- test blood pressure or oxygen saturation. The HIV infected group had significantly higher pre test (p=0.007 and post test (p=0.006) heart rates than the HIV uninfected group. The distance walked on the Six Minute walk test was similar in both groups but markedly lower than reported in other studies. There were no significant differences between the two groups for muscle strength in either the upper (p=0.984) or lower (p=0.845) limbs.Conclusion(s): The muscle strength and submaximal endurance of young children infected with HIV may be similar to that of HIV uninfected children. The HIV infected children in this study were all initiated on antiretroviral treatment early in life and their disease was well controlled. The fact that both groups had relatively poor levels of endurance in comparison to international studies warrants further investigation.Implications: The results of this study suggest that children infected with HIV who are well managed have the potential to perform well in assessments of muscle strength and submaximal endurance compared to their uninfected peers. The endurance levels of children, both infected and uninfected, in this community need to be investigated further.Keywords: Paediatric HIV, muscle strength, enduranceFunding acknowledgements: Eunice Kennedy Shriver National Institute of Child Health and Human Development (HD 073977, HD 073952); National Research Foundation, South AfricaTopic: Paediatrics; Oncology, HIV & palliative care; Disability & rehabilitationEthics approval required: YesInstitution: University of the WitwatersrandEthics committee: Human Research Ethics Committee (medical)Ethics number: M120871All authors, affiliations and abstracts have been published as submitted.