You have reached the HIVandHepatitis.com legacy site. Please visit our new site at hivandhepatitis.com

  
 HIV and Hepatitis.com Coverage of the
XVIII International AIDS Conference
(AIDS 2010)  July 18 - 23, 2010, Vienna, Austria
HIV/HCV Coinfected People More Likely to Sustain Fractures Related to Bone Loss

SUMMARY: HIV/HCV coinfected individuals people appear more likely than to develop osteoporosis (bone loss) and experience fractures of the wrist, hips, and spine than people with either virus alone, according to a study presented this week at the XVIII International AIDS Conference in Vienna. These findings suggest that bone loss associated with aging may be a particular concern for the coinfected population, which accounts for up to one-third of people with HIV.

By Liz Highleyman

Considerable research has shown that HIV positive people tend to have lower bone mineral density on average and a higher risk of osteoporosis and fractures compared with their HIV negative counterparts. Hepatitis C virus (HCV) infection is also associated with bone problems, especially when it progresses to liver cirrhosis.

Osteoporosis may be caused by toxic damage to the bones or metabolic changes that lead to an imbalance of bone production and resorption. Bone mineral density normally declines with age and is linked to hormone and vitamin D levels. It is not yet fully understood whether accelerated bone loss in people with HIV or HCV is attributable to the viruses themselves, drugs used to treat them, or some other factors.

In the present study, Roger Bedimo from the Veterans Administration North Texas Healthcare System in Dallas retrospectively assessed the incidence of osteoporotic fractures among 56,660 HIV positive patients enrolled in the Veterans Affairs' Clinical Case Registry between 1988 and 2009; 17,281, or 31%, were coinfected with hepatitis C.

Most (98%) were men and the average age was 45 years. About two-thirds had taken antiretroviral therapy (ART), for an average duration of about 4 years. Participants were followed for about 5 years on average, contributing a total 305,237 person-years of observation.

Using ICD9 diagnostic codes from medical records, the researchers identified all patients who experienced osteoporotic fractures of the wrist, hip, or vertebrae (bones of the spine) after HIV diagnosis. A limitation of the study is that they only looked at fractures and not measures of bone mineral density, which could reveal earlier stages of bone loss.

They compared fracture rates between HIV monoinfected and HIV/HCV coinfected people and looked at the influence of other factors associated with bone loss including age, race/ethnicity, body weight, ART exposure, diabetes, chronic kidney disease, and smoking; they were unable to determine alcohol or drug use from available data.

Results

951 patients sustained at least 1 osteoporotic fracture during the observation period:
 
Wrist: 451 fractures;
Hip: 308 fractures;
Vertebrae: 106 fractures.
HIV/HCV coinfected patients had a fracture rate of 3.25 per 1000 person-years, compared with 2.54 per 1000 person-years among HIV monoinfected people.
Restricting the analysis to the combination ART era (1996-2009), the corresponding fracture rates were 4.06 vs 2.86 per 1000 person-years, respectively.
Looked at another way, half of the patients (50.5%) who sustained fractures were HIV/HCV coinfected versus one-third (31.0%) of those without fractures.
HCV coinfection was a significant independent predictor of osteoporotic fractures:
 
Univariate analysis: hazard ratio (HR) 1.27, or 27% increased risk;
Multivariate analysis: HR 1.43, or 43% increased risk.
Other factors significantly associated with higher risk of fracture in the multivariate analysis included:
 
White race/ethnicity: HR 1.75;
Older age: HR 1.50 per additional 10 years;
Tobacco use: 1.48;
Body mass index < 20: HR 1.40.
Chronic kidney diseases and diabetes were associated with fractures in the univariate analysis, but were no longer significant predictors after adjusting for other factors.
Use of antiretroviral was associated with a reduced risk of fractures (HR 0.44).
During the ART era, having an osteoporotic fracture increased the risk of death by 77%.

Based on these findings, the investigators concluded, "HCV coinfection is associated with higher risk of osteoporotic fractures among HIV-infected patients."

"Risk of osteoporotic fractures appears to be increasing in the HAART era among HIV/HCV patients," they continued.

The researchers suggested that exposure to ART "appears to be protective" against osteoporotic fractures, but noted that high overall mortality in the pre-HAART era may not have allowed patients to survive long enough to develop fractures.

It is possible that ART is not actually protective, but rather is "a surrogate measures of patients with better care."

Investigator affiliations: VA North Texas Healthcare System, Medicine, Dallas, TX; University of Alabama at Birmingham, Birmingham, AL; University of Texas Southwestern Medical Center, Medicine, Dallas, TX.

7/23/10

Reference
R Bedimo, A Westfall, H Drechsler, and N Maalouf. HCV co-infection is associated with a high risk of osteoporotic fractures among HIV-infected patients. XVIII International AIDS Conference. Vienna, July 18-23, 2010. Abstract TUAB0104.


 

 

 

 

 

 

 

 

 

 

 



    Google Custom Search