Source: DGNews  |  Posted 2 years ago

By Ed Susman

SAN FRANCISCO -- February 21, 2010 -- Fragility fractures of the hip or the vertebrae occur more frequently among veterans with HIV, according to a study presented here at the 17th Conference on Retroviruses and Opportunistic Infections (CROI).

“I don’t think we’re at a point yet where we can really answer the question of why infection with HIV is associated with fragility fractures -- those that occur in the absence of trauma,” said Julie Womack, PhD, Yale School of Medicine and the Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut, in a presentation on February 18.

She speculated that the relationship between HIV and the increase risk of fractures could be related to chronic inflammation caused by the virus.

Dr. Womack and colleagues accessed records of more than 119,000 veterans and observed that HIV was associated with a 38% increase in the risk of fragility fractures, even after adjustment for other risk factors. Of the records they analysed, 34% of the patients were HIV-positive; the remainder were age-matched HIV-negative veterans.

Initially, the researchers were looking at fractures of the wrist, hip, and vertebrae, but wrist fractures tended to decrease with older age, suggesting they were usually the result of trauma. For that reason, the final analysis included only hip and backbone fractures.

In this study, 952 fractures occurred -- 644 hip fractures and 308 vertebral fractures -- during a median follow-up of 8 years. Mean age at fracture was 55 years. This translated to about 2% of patients having such fractures during the study period, from 1997 to 2009. The rate was slightly increased among those with HIV -- 2.3% versus 1.7%. When the model was adjusted to account for other known risk factors -- such as decreased bone mineral density, white race, or stroke -- the hazard ratio fell to 1.38, but remained significant.

“This suggests that HIV infection adds a modest increased risk for fragility fracture,” said Dr. Womack, although the increase is less than those associated with other risk factors.

She said the study’s strengths include its large size, and the ability to record fracture incidence and to adjust for possible covariates. Also, patients were, in general, older than in many other HIV cohorts.

On the other hand, she said, the study had no information on smoking -- a major risk factor for fracture -- or on parental history of hip fracture. The researchers also could not eliminate all trauma-related fractures, she said.

Although it is known that HIV is associated with decreased bone mineral density, said Dr. Womack, most of the people in the study did not have osteoporosis. For such patients, preventive measures -- such as weight-bearing exercise, smoking cessation, and adequate vitamin D and calcium -- should be part of regular care.

[Presentation title: HIV-infection and Fragility Fracture Risk Among Male Veterans. Abstract 129]