A study examining bone mineral density among HIV-infected and non-infected women has highlighted the severity of bone loss among HIV-positive women with low body weight. The degree of bones loss was much higher than that previously found in the female HIV-positive population, according to findings published in the June edition of the Journal of Acquired Immune Deficiency Syndromes.
The findings indicate that such women are at increased risk of fractures, particularly of the lumbar spine. Part of the mechanism of bone loss seems related to low androgen levels, so the researchers suggest that testosterone replacement might be a useful treatment in such cases.
Recent studies have suggested that bone loss occurs among HIV-infected women. Risk factors for bone loss in the general population include age, race, weight, smoking status, and hormonal changes. Women with HIV may be at particular risk because of hormonal changes and changes in body weight.
Therefore Sara Dolan and colleagues from Harvard Medical School (Boston, MA, USA) examined the effects of weight changes, body composition, androgen levels, and menstrual dysfunction on bone mineral density at various sites assessed by dual X-ray absorptiometry. The study included 124 HIV-infected women of normal weight, 28 HIV-infected women with low body weight (
HIV-infected women with low weight had significantly lower lean and total fat mass (p
Among the HIV-infected subjects, lumbar bone density correlated with proportion of ideal body weight (p
Clinical risk factors for osteopenia and osteoporosis in the HIV population in univariate analysis included low free testosterone (p = 0.0007), low weight (p = 0.014), and reduced frequency of menstrual periods (p = 0.0006), while smoking was not a risk factor. In a multivariate regression analysis, race, menstrual status, and lean mass were most significantly associated with lumbar bone density but testosterone was not significantly associated, despite the fact that 20% of the HIV-positive women had reduced free testosterone.
Importantly, the authors report: “Using the WHO osteoporosis and osteopenia categorization, a significantly larger percentage of HIV-infected women with low weight have osteoporosis and/or osteopenia . . . Our data suggest that bone loss is also seen among normal-weight HIV-infected women but not to the degree seen in HIV-infected women with low weight.”
The findings also indicate that androgen deficiency is linked with increased osteopenia and osteoporosis, although the fact that the association of testosterone with bone density disappeared in a multivariate analysis suggests that androgen deficiency may be reducing bone density indirectly, through reduction of lean body mass.
“Furthermore”, the authors note, “data derived from the current study support the generally held notion that weight loss is an important factor for androgen deficiency in HIV-infected women.”
The team concludes that measurement of free testosterone is an important part of the clinical evaluation of HIV-positive women, while “androgen replacement is a potential treatment strategy among androgen-deficient HIV-infected women to improve bone density and lean body mass as well as other features of androgen deficiency”. Other potential treatment strategies that need evaluation are normalisation of menstrual function with oestrogen, and treatments to block bone resorption.
Dolan SE at al. Effects of weight, body composition, and testosterone on bone mineral density in HIV-infected women. J Acquir Immune Defic Syndr 45: 161-67, 2007.