1. www.ias2013.org Kuala Lumpur, Malaysia, 30 June - 3 July 2013 Longitudinal Study of Bone Mineral Density and Vitamin D Levels Among Perinatally HIV-infected Thai Adolescents Receiving Long Term Antiretroviral Therapy Surapong Tanchaweng, MD a Thanyawee Puthanakit, MD b, c, Rachanee Saksawad, MD a, Chantapat Brukesawan MD a, Alan Maleesatharn, MBA a, Kulkanya Chokephaibulkit, MD a,* a Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand, 10700. b Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand 10330. c HIV-NAT/Thai Red Cross AIDS Research, 104 Ratchadamri Road, Pathumwan, Bangkok Thailand 10330. MOPDB0103 A 2 times DXA study at 12-24 months apart with life style modification education, without calcium and vitamin D supplement

2. www.ias2013.org Kuala Lumpur, Malaysia, 30 June - 3 July 2013 Results N(%) P=0.001 P<0.001 P=0.013 P<0.001 46 adolescents with median age 14.5 yrs at 1 st measurement Receiving TDF 41.3% and 54.3% at 1 st and 2 nd measurement respectively Intervention : life style modification education, no calcium and vitamin D supplement Being male was associated with worsening of BMD (OR 4.8, 95%CI 1.1-20.7) p=0.022

3. www.ias2013.org Kuala Lumpur, Malaysia, 30 June - 3 July 2013  We found worsening of BMD over 12-24 months in Thai HIV- infected adolescents.  Educational counseling improve vitamin D levels, but not BMD.  Decrease BMD over 12-24 months was associated with being male but not associated with receiving of PIs, NNRTI or TDF. Conclusions Acknowledgements We would like to thank all our patients the TREAT Asia/amfAR, All the expert assistance provided by the Division of Pediatric endocrinology and Division of Infectious Diseases Department of Pediatrics Faculty of Medicine Siriraj Hospital Mahidol University, Thailand