No association between bone mineral density and lipodystrophy in women receiving antiretroviral therapy
Polly Clayden, HIV i-Base
A number of studies have found an association between lipodystrophy and bone mineral density.
Rebecca Hicks presented data from a study of 47 HIV-positive women enrolled from the Maple Leaf Medical Clinic and Sunnybrook Health Services Clinic in Toronto. The study was conducted to examine the potential correlation between lipodystrophy and reduced bone mineral density (BMD) in women receiving antiretroviral treatment.
This was a cross-sectional study and participants were 18 years or older, on stable HAART for at least two months, not pregnant, and had a DXA BMD test.
The women completed a questionnaire that collected demographic data and information on the presence and severity of lipodystrophy. Lipodystrophy was diagnosed according to the HIV Outpatient Study criteria. Women were considered to have lipodystrophy if they had at least one severe symptom of fat redistribution, or at least two symptoms with one being of at least moderate severity.
Data on DXA BMD test results, osteoporosis risk factors and fracture history were collected from patient charts. A z-score was used to measure BMD (> 2.5 classified as low bone mass).
Almost half (25/47) of the women evaluated met the study definition for lipodystrophy. There were no significant differences in age, 42 vs 39 years, p=0.42; ethnicity 72 vs 68%, were black, p=0.73; duration of HIV infection, 7 vs 8 years, p=0.73, duration of HAART, 3 vs 4 years, p=0.75 or current CD4 count 500 vs 540 cells/mm3, between those with or without lipodystrophy respectively.
The investigators found similar BMD z-scores at the L1-L4 location, 0.60 vs 0.52, p=0.86; femoral neck 0.22 vs 0.05, p=0.44 and total hip 0.48 vs 0.58, p=0.83 in women with and without lipodystrophy.
Multivariate analysis adjusted for age (0.036, 95% CI 0.0940.023, per 10 years, p=0.222) and ethnicity (0.133, 95% CI 0.0360.231 for black vs other, p=0.009), in which only ethnicity remained significant, revealed no association between lipodystropy and femoral neck BMD z-scores (0.014, 95% CI 0.072-0.100) p=0.744.
The investigators suggested this finding that lipodystrophy and reduced BMD were not associated with each other in this study may have been due to reduced power caused by small sample size. They noted that as BMD was significantly associated with black ethnicity, with 70.2% of the sample population identifying as black, the results may have been skewed.
These data were hard to interpret, particularly as the investigators used a definition of lipodystrophy that did not differentiate between fat loss and fat gain.
Hicks R et al. Pilot study exploring the association between bone mineral density and lipodystrophy in HIV-positive women taking antiretroviral therapy. 1st International Workshop on HIV and Women. 1011 January 2011, Washington. Oral abstract O_15.