HIV treatment does not increase the risk of bone fractures, French investigators report in the May edition of AIDS. Nor did the researchers find any association between CD4 cell count and viral load and an increased risk of fractures. Their analysis showed that the only factors associated with fractures were excess alcohol consumption and co-infection with hepatitis C virus.
Bone complications such as osteoporosis (reduced bone mineral density) and osteonecrosis (bone death) are more common in patients with HIV than the general population. A number of possible causes for this have been suggested, including the direct effects of HIV, the side-effects of antiretroviral therapy, and lifestyle factors such as smoking and alcohol use.
There is little information on the risk of bone fractures for HIV-positive individuals. Investigators from the French ANRS CO8 APROCO-COPILOTE study therefore undertook long-term analysis of patients who initiated HIV treatment based on a protease inhibitor between 1997 and 1999. Their aim was to determine the incidence of bone fractures and their risk factors.
A total of 1281 HIV-positive individuals were included in the study. These individuals were followed for a median of seven years. During this time, there were a total of 27 bone fractures in 26 patients that caused hospitalisation or severely limited an individual’s functioning.
The incidence of bone fractures was 3.3 per 1000 patient years. Most of the fractures (81%) were the result of a trauma such as a fall, an accident, a blow or assault. In 19% of cases, fractures occurred when the patient was drunk.
Osteoporosis was present in four patients experiencing a bone fracture.
Individuals experiencing a fracture were no different to HIV-positive patients who did not - in terms of age (median, 36 years), gender (77% male), diagnosis with AIDS (20%), baseline viral load (31,000 copies/ml), body mass index (median, 22 kg2) or type of protease inhibitor first used.
However, patients who experienced a fracture were more likely to drink five or more units of alcohol a day (44% vs 20%) and to be co-infected with hepatitis C virus (48% vs 25%).
In statistical analysis that controlled for possible confounding factors, the investigators found that the incidence of bone fractures was 2.9-fold higher (95% CI = 1.3-6.5) in patients who drank excessive amounts of alcohol and 3.6-fold higher (95% CI = 1.6-8.1) in those who were co-infected with hepatitis C.
The investigators note that the incidence of bone fractures revealed by their study was in line with that observed in the general French population (5 to 10 per 1000 patient years).
Both alcohol use and infection with hepatitis C virus have been associated with an increased risk of bone fractures in earlier research, note the researchers. This is because alcohol “increase[s] both osteoporosis and risky behaviours”, they comment. Liver disease may contribute to loss of bone density because of its effect on vitamin D, they suggest.
“Specific information, monitoring of HCV/HIV-co-infected patients and active promotion of alcohol cessation programs in HIV-infected patients are to be recommended for the prevention of bone fractures”, conclude the investigators.
Collin F et al. Ten-year incidence and risk-factors of bone fractures in a cohort of treated HIV-1-infected adults. AIDS 23: 1021-23, 2009.