First published on May 22, 2017
The analysis involved men in the Multicenter AIDS Cohort Study (MACS), an ongoing evaluation of gay and bisexual men with HIV and a similar group of HIV-negative men in four U.S. cities. MACS members make study visits twice a year to get checkups and answer health questionnaires, which include reporting new fractures. MACS researchers calculated the new-fracture rate (incidence) for:
- all fractures except those of the face, skull, and fingers or toes.
- fragility fractures, defined as fractures of the spinal column, wrist, or long bones in the upper leg (femur) or upper arm (humerus). Fragility fractures are those likely to result from low bone density.
The study focused on 1,221 men with HIV and 1,408 without HIV. The HIV group had higher proportions of nonwhites (41% versus 27%), smokers (38% versus 31%), and people with HCV infection (10% versus 6%).The researchers divided men into three age groups: 40 to 49, 50 to 59, and 60 or older. To figure fracture incidence, they used a statistical method that accounts for several risk factors, including race, weight, hypertension, diabetes, hepatitis C virus (HCV) infection, kidney function, smoking, and alcohol use. This method estimates fracture incidence by age and HIV status, regardless of whatever other risk factors a person has.
The new-fracture rate for all fractures (incidence) was higher in men with HIV (12.8 versus 10.0 per 1000 person-years), revealing that about 13 of every 1,000 men living with HIV had a fracture each year. Age-group analysis traced this difference to a doubled risk of all fractures in 50- to 59-year-old men with HIV (adjusted incidence rate ratio [aIRR] 2.06). Adjusted incidence did not differ significantly between the status groups in the 40-to-49 age group or the 60-or-older age group. Hypertension boosted all-fracture risk about one-third (aIRR 1.32).
Fragility fracture incidence was also higher in men with HIV (4.6 versus 3.4 per 1000 person-years). Fragility fracture risk was twice as high in 50- to 59-year-old men with HIV (aIRR 2.06). But fragility fracture risk did not differ significantly by HIV status in 40- to 49-year-old men or men 60 or older. Total use of anti-HIV protease inhibitors or Viread (tenofovir) did not affect incidence of fragility fractures. In an analysis limited to men with HIV, fragility fracture incidence was almost twice as high in 50- to 59-year-old men than in men 40 to 49 years old. Fragility fracture incidence was slightly more than double in men 60 or older than in the 40-to-49 group.
The researchers conclude that their results support current guidelines calling for bone mineral density testing in HIV-positive men 50 or older. Some risk factors for low bone mineral density — like older age and race — cannot be controlled. HIV-positive men and women, especially those over 50, should be aware of bone risk factors they can control: lack of exercise, smoking, drinking too much alcohol, getting too little calcium or vitamin D, and weighing less than normal.
Mark Mascolini writes about HIV infection.