Co-infection with hepatitis B or C is a risk factor for reduced bone mineral density among women with HIV

Co-infection with hepatitis B or C is associated with reduced bone mineral density (BMD) in women living with HIV, French investigators report in the online edition of the Journal of Acquired Immune Deficiency Syndromes. The investigators compared bone mineral density between people with HIV infection alone and people with chronic viral hepatitis co-infection.

“The hypothesis of an epidemiological association between viral hepatitis and osteoporosis was the central aim of our study and was only confirmed in our HIV-infected female patients,” write the authors. “Further longitudinal studies are needed to elucidate the relationship between osteoporosis and chronic viral hepatitis, including inflammatory processes accelerating bone mass loss.”

A substantial body of research has shown a high prevalence of reduced bone mineral density in people living with HIV. The exact causes are uncertain but may include traditional reasons such as ageing and smoking, the damage caused by untreated HIV infection and the side-effects of some antiretroviral drugs.

Glossary

bone mineral density (BMD)

The higher your bone mineral content, the denser your bones are. And the denser your bones, the stronger they are and the less likely they are to break. A bone density test uses X-rays to measure how many grams of calcium and other bone minerals are packed into a segment of bone. The bones that are most commonly tested are in the spine, hip and sometimes the forearm. 

body mass index (BMI)

Body mass index, or BMI, is a measure of body size. It combines a person's weight with their height. The BMI gives an idea of whether a person has the correct weight for their height. Many BMI calculators can be found on the internet.

epidemiology

The study of the causes of a disease, its distribution within a population, and measures for control and prevention. Epidemiology focuses on groups rather than individuals.

hypothesis

A tentative explanation for an observation, phenomenon, or scientific problem. The purpose of a research study is to test whether the hypothesis is true or not.

longitudinal study

A study in which information is collected on people over several weeks, months or years. People may be followed forward in time (a prospective study), or information may be collected on past events (a retrospective study).

A large number of people living with HIV are co-infected with hepatitis B or hepatitis C. The prevalence of osteoporosis in people with chronic liver disease has been shown to be as high as 56% in some studies. This prompted investigators in southern France to hypothesise that people with both HIV and chronic viral hepatitis would have an especially high risk of osteoporosis. They therefore designed a study comparing the bone mineral density of people with these co-infections and people with HIV infection alone.

Participants were recruited between 2004-05 and 2008-09. Scans were used to measure bone mineral density in the lumbar spine, femoral neck (hip) and total body.

The study population consisted of 626 people, 269 of whom had chronic viral hepatitis co-infection (208 with hepatitis C, 45 with hepatitis B and 16 with both).

Overall, the study participants had a median age of 44 years and 27% were female (31% postmenopausal). The majority of participants (71%) had an undetectable viral load and the median CD4 cell count was 506 cells/mm3.

Rates of osteopenia (mild reduction in bone mineral density) were similar between people who had co-infection and HIV-monoinfection (49 vs 53%).

However, prevalence of osteoporosis was significantly higher among those with viral hepatitis co-infection (35 vs 26%, p = 0.03).

Factors associated with low bone mineral density among male participants were increasing age (each additional ten years, OR = 2.0; 95% CI, 1.3-3.0; p < 0.001); being in the MSM (men who have sex with men) risk group (OR = 3.6; 95% CI, 1.6-8.2; p = 0.0021); and a body mass index (BMI) below 20 kg/m2 (OR = 12.1; 95% CI, 2.6-56.2; p = 0.0015). Viral hepatitis co-infection was not a risk factor.

Among women, the risk factors were older age (each additional ten years, OR =15.2; 95% CI, 3.6-65.5); BMI below 20 kg/m2 (OR = 18.4; 95% CI, 1.6-217.9; p = 0.0208) and viral hepatitis co-infection (OR = 19; 95% CI, 1.0=349.8; p = 0.0474).

“Our study strongly suggests that chronic viral hepatitis is associated with osteoporosis in HIV-infected women,” comment the authors.

They believe their findings have implications for patient care. “For osteopenic and osteoporotic co-infected patients, preventive programs to reduce the BMD decline and the risk of fracture may be considered, while considering the specific needs of women, and should take into account well-known risk-factors (low BMI and older age).”

References

Lawson-Ayayi S et al. Chronic viral hepatitis is associated with low bone mineral density in HIV-infected patients, ANRS CO 3 Aquitaine cohort. J Acquir Immune Defic Syndr, online edition. DOI: 10.1097/QAI.0b013e3182845d88, 2013.