Prior J et al. (2007) Fragility fractures and bone mineral density in HIV positive women: a case–control population-based study. Osteoporos Int 18: 1345–1353

Risk factors for osteoporosis, including low BMI, weight loss, cigarette, alcohol and drug use, low blood-cell counts and disturbed menstruation, tend to be more prevalent in HIV-positive women than in the general population; HIV-positive women are therefore thought to have increased fracture risk. To assess fracture risk in HIV-positive women, Prior et al. conducted a case–control study that compared osteoporosis risk factors and fracture incidence in 138 HIV-positive women from the Canadian Women's HIV+ Study with those in 402 age-matched and region-matched controls from the Canadian Multicentre Osteoporosis Study. Of the 138 HIV-positive women, 100 had received antiretroviral therapy.

Significantly more HIV-positive women than controls had experienced fragility fractures (26.1% vs 17.3%). HIV-positive women were more likely than controls to smoke or use injection drugs, be treated with glucocorticoids, and have oligomenorrhea, and reported more weight-cycling of 10 kg or more. There was, however, no difference in BMI or BMD between the two groups.

The authors suggest that the increased fracture risk associated with HIV, despite apparently normal BMD, might be due to HIV-associated structural differences in bone microarchitecture that are not reflected in BMD changes. Bone-structure studies of HIV-positive women are planned. The relationship between antiretroviral therapy and osteoporosis will also be the subject of future study.