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Bone Loss in HIV-Positive
Women
A Canadian Study
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(Continued
from page 2)
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The World Health Organization
uses “T-scores” to compare BMD to predicted values. The T score compares
BMD to expected peak bone mass at 30 years of age whereas the “Z score”
compares BMD to age-matched norms. Osteopenia is defined as greater than
or equal to (>) 1 standard deviation (SD) below T score (that is less than
or equal to ({<} -1), while osteoporosis is > 2.5 SD below T score (<
-2.5). Severe osteoporosis is > 2.5 SD plus bone fracture.
Bone turnover is assessed
by measuring indicators of bone formation, including serum osteocalcin
(a protein that is used to strengthen the protein matrix), and bone alkaline
phosphatase. Other ways to look at the rate of changes in bone structure
include bone resorption and the rate of turnover by checking urinary d-pyridinolines.
People with HIV can have a greater loss of bone mass than would be expected
for their age (Figure 2). (2)
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The Oak
Tree Clinic, Children and Women’s Health Centre of BC is leading a
Canadian multicenter trial that is investigating bone disorders among HIV-positive
women. The objective of this study is to determine the prevalence of low
BMD in HIV- positive women, look at contributory factors and compare data
to population-based, age and ethnicity matched controls from the Canadian
Multicentre Osteoporosis Study (CaMOS). Data was collected from a sequential
sample of HIV-positive women (Table 1). |
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Table
1. First Study Group Characteristics
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Total
Group
(n= 49)
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Normal
BMD (n=28)
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Low
BMD (n=21)
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Age
in Years
(range)
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38
(19-56)
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38
(19-52)
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40
(25-56)
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CD
4 T-cells
(range)
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240
(10-1000)
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275
(10-680)
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225
(20-1000)
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Duration
of HIV in years (range)
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7
(1-16)
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7
(2-16)
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9
(1-16)
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Table
2, notes ART history and duration of infection. The investigators are
looking at the role of ART, especially protease inhibitors (PI’s), as well
as the role of diet, lifestyle, family history, reproductive history and
other potential risk factors for low bone mineral density.
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| Table
2. Antiretroviral History |
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Total
Group
(n= 49)
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Normal
BMD
(n=28)
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Low
BMD
(n=21)
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| ART
Naïve |
8
(16)
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4
(14)
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4
(19)
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| ART
Exposed |
41
(84)
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24
(86)
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17
(81)
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| PI
Exposed |
30/41
(73%)
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15/24
(63%)
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15/17
(88)
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| Duration
ART (years/range) |
4
(.5-9.0)
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4
(.5-7.0)
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5
(.5-9.0)
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