Department of Psychiatry, University of California, San Diego, CA 92103, USA.
Neuropsychology. 2011 Sep;25(5):645-54. doi: 10.1037/a0023792.
Both the prevalence and incidence of HIV infection among older adults are on the rise. Older adults are at increased risk of HIV-associated neurocognitive disorders, which have historically been characterized as an inconsistent or "spotty" pattern of deficits. Dispersion is a form of intraindividual variability (IIV) that is defined as within-person variability in performance across domains and has been associated with poorer neurocognitive functioning and incipient decline among healthy older adults. To our knowledge, no studies have yet examined dispersion in an aging HIV-infected sample.
For the current study we examined the hypothesis that age and HIV infection have synergistic effects on dispersion across a battery of clinical and experimental cognitive tasks. Our well-characterized sample comprised 126 HIV-seropositive individuals (HIV+) and 40 HIV-seronegative comparison individuals (HIV-), all of whom were administered a comprehensive neuropsychological battery.
Consistent with our hypothesis, an age by HIV serostatus interaction was observed, with the older HIV+ group demonstrating a higher level of dispersion relative to older HIV- and younger HIV+ individuals, even when potentially confounding demographic and medical factors were controlled.
Our results demonstrate that older HIV+ adults produce greater dispersion, or intraindividual variability in performance across a range of tests, which may be reflective of cognitive dyscontrol to which this population is vulnerable, perhaps driven by the combined effects of aging and HIV infection on prefrontostriatal systems.
老年人中 HIV 感染的患病率和发病率都在上升。老年人感染 HIV 相关神经认知障碍的风险增加，而这些障碍在历史上一直被描述为不连贯或“斑驳”的缺陷模式。分散是个体内变异性（IIV）的一种形式，定义为个体在不同领域的表现中的个体内变异性，并且与健康老年人的认知功能较差和早期下降有关。据我们所知，尚无研究在衰老的 HIV 感染样本中检查分散。
在当前的研究中，我们检验了这样一个假设，即年龄和 HIV 感染对一系列临床和实验认知任务的分散具有协同作用。我们的特征良好的样本包括 126 名 HIV 阳性个体（HIV+）和 40 名 HIV 阴性对照个体（HIV-），所有个体均接受了全面的神经心理测试。
与我们的假设一致，观察到年龄与 HIV 血清状态的相互作用，与年轻的 HIV+个体相比，年龄较大的 HIV+组表现出更高水平的分散，即使在控制了潜在的混杂人口统计学和医学因素后也是如此。
我们的结果表明，年长的 HIV+成年人在一系列测试中表现出更大的分散性，或个体内的表现变异性，这可能反映了该人群易受认知失控的影响，可能是由衰老和 HIV 感染对额眶皮质系统的综合影响所致。
