Treatment for bone mineral loss: alendronate safe and effective in HIV

Treatment with alendronate, calcium and vitamin D results in improved bone mineral density in HIV-positive people with osteoporosis or osteopenia, researchers from Washington University, St Louis, United States, report in the April 1^st edition of the Journal of Acquired Immune Deficiency Syndromes

Osteopenia refers to reduced bone mineral density and osteoporosis refers to a more severe reduction in bone mineral density which results in a fracture risk for to five times the level found in the general population.

Osteoporosis and osteopenia appear to be frequent metabolic complications in people with HIV disease, but the cause of reduced bone mineral density is still unclear. Although some studies have correlated the development of osteoporosis with duration of antiretroviral therapy, others have found no association, leading some researchers to suggest that thinning of the bones is a long-term complication of HIV infection rather than antiretroviral therapy.

A prior history of wasting, steroid use, hypogonadism or immobilisation due to chronic illness may also increase the risk of osteoporosis in HIV-positive individuals.

Alendronate is the only product approved for the treatment of osteoporosis in men and women, but its use in HIV-positive people has not been evaluated previously.

Researchers at Washington University School of Medicine, St Louis, one of the leading centres of research into osteoporosis in HIV infection, recruited 31 HIV-positive patients with osteopenia or osteoporosis. Patients were randomised to receive or not receive 70mg of alendronate each week for 48 weeks. All participants received a calcium supplement of 1000mg daily, with 400 IU of vitamin D.

Participants had an average age of 44 years and 87% were male. Sixty-one per cent were receiving protease inhibitor-based therapy. At baseline the median t-score in the lumbar spine was -1.52 and -1.02 in the hip.

After 48 weeks of treatment, the alendronate group had experienced a 5.2% increase in lumbar spine bone mineral density, compared to a 1.3% increase in the calcium and vitamin D alone group (p=0.007). A significant difference had emerged by week 24. Significant differences in bone mineral density were not observed at other sites, such as the hip, at week 48. The authors note that in order to see changes at those sites, a larger and longer study would be necessary; the lumbar spine region is usually the first site to show improvements in bone mineral density during alendronate treatment.

“The increases in bone mineral density did not correlate with baseline t-score,” note the authors, “suggesting that the beneficial effects of alendronate were similar among different degrees of osteopenia/osteoporosis at baseline.”

Alendronate treatment was well tolerated and did not appear to cause interactions with antiretroviral drugs.

“Our study should not be interpreted as a recommendation for treatment of all HIV-positive patients with osteopenia…treatment recommendations for HIV-infected patients, in the absence of large trials, should be consistent with…guidelines. Current guidelines for the treatment of osteoporosis in women recommend treatment of individuals with 1 major or 2 minor risk factors for osteoporosis plus a t- score lower than -1.5 on a DEXA scan.”