Low body weight is responsible for osteopenia and osteoporosis, according to a newly reported study in the Journal of Clinical Endocrinology and Metabolism. These results challenge those of other studies indicating that HIV is primarily responsible for the increased risk of low bone mineral density, which can lead to hip fractures and spinal problems, in people living with the virus.

Mark Bolland, MBChB, of the department of medicine at the University of Auckland in New Zealand, and his colleagues analyzed data from all previously reported studies evaluating the prevalence of osteopenia and osteoporosis in HIV-positive people. They reviewed nine published studies and one abstract from a conference that included body weight data.

Consistent with the original research, Dr. Bolland’s team concluded that people with HIV were more likely than HIV-negative patients. However, they also found that the average body weight was lower among the HIV-positive compared with the HIV-negative volunteers. When the study authors adjusted the data to reflect the differences in body weight, the difference between the two groups of patients in terms of bone mineral density shrank considerably, leading them to conclude that HIV is not an independent risk factor for osteopenia or osteoporosis.