There is an
increased prevalence of osteoporosis and osteopenia in young HIV-positive men,
Spanish researchers report in the online edition of the Journal of Acquired Immune Deficiency Syndromes. The study also
showed that a low nadir CD4 cell count and therapy with a protease inhibitor
were associated with lower peak bone mass.
showed lower hip T score and a higher prevalence of osteopenia and osteoporosis
than HIV-uninfected controls,” write the authors. “Peak bone mass was inversely
associated with nadir CD4 T-cell counts and the use of protease inhibitors, but
directly associated with fat and lean mass.”
Low bone mineral
density is a recognised complication of HIV infection. Causes are thought to
include traditional risk factors such as smoking and drug use, the inflammatory
effects of HIV itself, and the side-effects of some antiretroviral drugs.
Bone mass reaches
a peak at the end of skeletal maturation. Up to 90% of bone mass is acquired by
the age of 18 in females and the age of 20 in males. By age 30, everyone has
reached their peak bone mass. It is well known
that low peak bone mass is associated with an increased risk of osteoporosis
and bone fractures.
accumulating evidence that HIV infection is associated with low bone mineral
density and an increased risk of fractures, a team of Spanish investigators
designed an observational study comparing bone mineral density and T-scores in
the lumbar spine and femur between HIV-positive young adults and age- and
sex-matched HIV-negative controls. They also examined
the risk factors for low bone mineral density in the HIV-positive participants.
density was measured using dual-energy X-ray absorptiometry (DEXA) scanning.
population comprised 232 HIV-positive participants and 75 HIV-negative controls.
All were aged between 20 and 30 years and approximately three-quarters were
male. Individuals with a very low (16 kg/m2 or below) or a very high (above
28 kg/m2) body mass index were excluded from participation, as
were those with comorbidities known to increase the risk of bone metabolism
risk factors for low bone mineral density were available for 50% of the
participants and 40% of the controls. As expected, individuals with HIV were more
likely to be smokers than the HIV-negative controls (57 vs 13%, p =0.012), and
were also were more likely to use drugs (15 vs 3%) and drink alcohol (20 vs
3%, p = 0.04). HIV-positive women were more likely to report the use of
hormonal contraception (20 vs 0%, p = 0.05). Similar proportions of HIV-positive and HIV-negative participants
reported regular exercise (48 vs 40%), which is known to protect
again low bone mineral density.
Two-thirds of the
HIV-positive participants were gay men and 94% were receiving antiretroviral
No differences in
bone mineral density were found at any site between the HIV-positive and the
HIV-negative individuals. The authors were “surprised” by this finding.
However, the mean
total T-score in the femur was significantly lower in the HIV-positive participants
than in the controls (-0.2 standard deviation [SD] vs +0.05 SD, p = 0.018).
present in 11% of the patients and 4% of controls. Osteopenia was detected in
57% of individuals with HIV infection and in 51% of the uninfected controls.
mineral density was present in only a third of the HIV-positive participants, which
was significantly lower than the prevalence in the controls (45%, p = 0.019).
numbers of children and adults are affected by low BMD [bone mineral density],
probably because secondary forms are becoming more common as a result of
lifestyle, diet, chronic illness and medication,” note the investigators.
Analysis of the
results according to gender showed that osteoporosis was more common in
HIV-positive men compared to control men (12 vs 6%, p = 0.033), as was
osteopenia (57 vs 46%, p = 0.014).
Mean total femoral
T-score was -0.3 SD in HIV-infected men compared to +0.1 SD in the control men
(p = 0.03).
density, T-score and the prevalence of osteopenia and osteoporosis were similar
between the HIV-positive and HIV-negative women.
A low nadir CD4
cell count and therapy with a protease inhibitor were associated with lower
peak bone mass in the lumbar spine and total femor (p = 0.022 and p = 0.005,
suggest the “negative effect of low nadir CD4 T-cell count on BMD could be
explained by the high levels of immune activation and inflammation usually
associated with severe immunodeficiency”.
lean mass and total fat mass were associated with increased bone density at all
“Since lean mass
is strongly related to physical activity, it is clear that exercise is an
important component in the prevention of bone loss,” the researchers comment
and they suggest exercise should be “strongly recommended in HIV-infected
patients from the very early stages of the infection”.
“Considering that this young population will be living with HIV infection for
many years, risk factors for osteoporosis should be modified, if possible.”