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, b Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand c HIV-NAT/Thai Red Cross AIDS Research, 104 Ratchadamri Road, Pathumwan, Bangkok Thailand MOPDB0103 A 2 times DXA study at months apart with life style modification education, without calcium and vitamin D supplement

Kuala Lumpur, Malaysia, 30 June - 3 July 2013 Results N(%) P=0.001 P<0.001 P=0.013 P< 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 ) p=0.022

Kuala Lumpur, Malaysia, 30 June - 3 July 2013  We found worsening of BMD over months in Thai HIV- infected adolescents.  Educational counseling improve vitamin D levels, but not BMD.  Decrease BMD over 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