Background:  The simultaneous effects of weight, body composition, and androgen deficiency on bone mineral density have not been described in HIV-infected women.

Methods:  This investigation presents a comparative cohort analysis of 3 separate investigations to examine the effects of these variables on bone mineral density among 152 HIV-infected women of normal (n = 81) and low weight (n = 71), and 100 healthy control subjects. Free testosterone was determined by equilibrium dialysis. Bone density was determined by dual energy X-ray absorptiometry (DEXA). Abdominal fat was determined by single-slice CT scan at L4. A menstrual history was obtained.

Results:  A significant difference was seen in bone mineral density among all 3 groups at the lumbar spine (0.97±0.01 g/cm² vs 1.02±0.02 g/cm² vs 1.07±0.01 g/cm², p = <0.0001), total hip (0.88±0.01 g/cm² vs 0.95±0.02 g/cm² vs 0.98±0.01 g/cm², p = <0.0001), and femoral neck (0.78±0.01 g/cm² vs 0.83±0.02 g/cm² vs 0.87±0.01 g/cm², p = <0.0001) (HIV-infected low weight, HIV-infected normal weight, and healthy control subjects, respectively, for each comparison). Among the HIV-infected subjects, lumbar bone mineral density correlated with body mass index (r = 0.40, p = <0.0001, free testosterone (r = 0.16, p = 0.058), total body lean (r = 0.43, p = <0.0001), and total body fat (r = 0.35, p = <0.0001) and a significant correlation was seen for abdominal subcutaneous adipose tissue (r = 0.41, p = <0.0001) not visceral adipose tissue (r = 0.07, p = 0.417). Clinical risk factors for osteopenia and osteoporosis in the HIV population included low free testosterone (< 1.1 pg/mL [lower limit of the normal range of the free testosterone assay for women])(3.8 pmol/L) (p = 0.003), low weight (p = <0.0001), and oligiomenorrhea (p = 0.0006). 

Conclusions:  These data demonstrate that bone mineral density is abnormal among HIV-infected women, in association with low weight, reduced lean mass, reduced androgen levels, and abnormal menstrual function.