Bone mass loss and vitamin D metabolism impairment in HIV patients receiving highly active antiretroviral therapy

AIM: Given the few controversial data about the effect of highly active antiretroviral therapy (HAART) on bone mass in HIV patients, we investigated whether a relationship between osteopenia/osteoporosis risk and HAART exists. METHODS: In 172 HIV patients, 152 on HAART, 92 including and 60 not including protease inhibitors (PI), 20 naïve and 64 controls, we measured spine/femur bone mineral density (BMD) by DEXA, and assayed serum osteocalcin (O), bone alkaline phosphatase (BAP), 1,25(OH)2 D, parathormone (PTH), calcium (Ca) and urinary pyridinium cross-links (PYD & DPD). RESULTS: Following WHO BMD t-score criteria, osteopenia was ascertained in >35% of all HAART groups and in 30% of naive. Only HAART patients had osteoporosis, PI patients more frequently, significantly (p<0.03) in spine (21.7% vs 8.3%). Males, intravenous drug users and B-C stage patients have a higher risk for low bone mass. Mean t-score was significantly lower in both spine and femur and O and PYD & DPD higher in PI than non PI patients and controls; 1,25(OH)2 D was significantly lower in all HIV groups than controls, PI patients having the lowest values positively correlating with BMD and negatively with OC and PYD & DPD, and it decreased further in 27 non selected monitored patients continuing on HAART. PTH was higher and Ca lower in HAART patients than controls but not significantly, PTH negatively correlating with BMD. CONCLUSION: HAART could be associated with osteopenia, even osteoporosis, and it could aggravate the loss in bone mass due to HIV infection itself. We hypothesize that HAART may directly affect bone remodelling and/or may indirectly affect vitamin D metabolism.