Bone mineral loss through increased bone turnover in Hiv-infected children treated with highly active antiretroviral therapy

Objectives: To evaluate the occurrence and define the aetiology of osteopenia in children receiving highly active antiretroviral therapy (HAART). Methods: Bone mineral density (BMD) of total body and lumbar spine (L2-L4) was assessed by dual-energy X-ray absorptiometry in 40 children vertically infected with HIV: 35 taking HAART and five naive to any antiretroviral treatment (untreated). Six HAART-treated children showed clinical evidence of lipodystrophy. N-terminal propeptide of type-I procollagen (PINP), bone-specific alkaline phosphatase (BALP) and N-terminal telopeptide of type I collagen (NTx) were measured. Results were compared with those obtained in 314 healthy controls. Differences between HIV-positive and healthy children and within the HIV-positive group were assessed by multivariate analyses, controlling for confounding variables (age, sex, weight and height). Results: HAART-treated children showed lower spine BMD values than untreated (P= 0.045) and healthy (P= 0.004) children and lower total body BMD values than untreated (P = 0.012) and healthy (P < 0.0001) children. Spine and total body BMD were similar between untreated and healthy children. Total body BMD was lower (P< 0.005) in HAART-treated children with lipodystrophy than in untreated patients, while children on HAART but without lipodystrophy had intermediate values. BALP, PINP and NTx were similar among untreated and healthy children. HAART-treated children had higher BALP levels than healthy (P= 0.0007) and untreated (P= 0.045) children. PINP values showed the same trend as BALP. HAART-treated children had higher NTx urine levels than healthy (P < 0.0001) and untreated (P = 0.041) children. Conclusions: HAART seems a new risk factor for life-long osteoporosis in children. An increased rate of bone turnover causes BMD decrease. Severity of osteopenia seems to be related to lipodystrophy.