Prevalence and risk factors of low bone mineral density among perinatally HIV-infected Thai adolescents receiving antiretroviral therapy.

Background: Low bone mineral density (BMD) has been reported among 10%-54% of HIV-infected adolescents in developed countries. We studied the prevalence and predictors of low BMD among HIV-infected Thai adolescents receiving antiretroviral therapy.

Methods: A cross-sectional study of lumbar spine (L2-L4) BMD as measured by dual-energy X-ray absorptiometry in Thai HIV-infected adolescents aged 12-20 years was performed. The BMD Z score was analyzed using age-matched healthy Thai children as a reference. Serum 25-hydroxyvitamin D was performed. Osteopenia was defined as BMD Z score ≤ -2.

Results: From October 2010 to February 2011, 101 adolescents, 50% male, with a median age of 14.3 (range: 13.0-15.7) years were enrolled. The median [interquartile range (IQR)] current CD4 T-cell count was 646 (506-796) cells per cubic millimeter and 90% had plasma HIV-1 RNA <50 copies per milliliter. The mean BMD among HIV-infected adolescents and controls were 0.855 and 0.980 g/cm (P < 0.001). The median (IQR) L2-L4 spine BMD Z score was -1.0 (-1.9 to -0.1), of which 24% had BMD Z score ≤ -2.0. The median (IQR) of 25-hydroxyvitamin D level was 24.8 (20.0-31.4) ng/mL, of which 25% had vitamin D level < 20 ng/mL. In multivariate analysis, the height for age Z score < -1.5 (adjusted odds ratio: 6.2; 95% confidence interval: 2.2 to 17.7) and history of World Health Organization clinical stage 4 before antiretroviral therapy (adjusted odds ratio: 3.7; 95% confidence interval: 1.3 to 10.7) were significantly associated with osteopenia.

Conclusion: One fourth of HIV-infected Thai adolescents have osteopenia. Children with history of advanced-staging or having low height for age are at risk of osteopenia. Preventive measures to prevent osteopenia should be incorporated in routine care for these adolescents.