While the large, global START trial has officially proved that starting HIV treatment soon after diagnosis is preferable to waiting, early treaters do experience more bone loss than those who defer taking antiretrovirals (ARVs) until HIV disease has progressed. Nevertheless, this difference, as seen in a substudy of the START trial, did not translate to an increased risk of a fracture or osteoporosis, at least during the study’s follow-up period, aidsmap reports.

Researchers conducted a bone mineral density (BMD) sub-study of the global START trial, including 193 of those who were randomized to start ARVs with CD4s above 500 and 204 of those set to begin treatment after their CD4s fell below 350 or they developed AIDS-defining conditions. Results were presented at the 15th European AIDS Conference in Barcelona, Spain.

During an average follow-up period of 2.2 years, spine BMD fell an average of 1.6 percentage points more and hip BMD fell an average of 1.5 percentage points more among those in the immediate treatment group compared with the deferred treatment group. Then the researchers compared BMD percentage point change between those who took ARVs and those who did not—as opposed to the group into which they were randomized, since those in the immediate group did not have to begin treatment and many in the deferred group did eventually go on ARVs (which they were permitted to do at any time and for any reason). The mean change was a 2.2 percentage point drop in spine BMD and a 2.1 percentage point drop in hip BMD.

After adjusting for various factors, the researchers found that the only significant risk factor for greater bone loss was if a study participant took a protease inhibitor in his or her first ARV regimen.

To read the aidsmap article, click here.