Chemosensory Declines in Older Adults with HIV: Identifying Interventions

The Association Between Olfactory Function and Cognition in Aging African American and Caucasian Men With HIV: A Pilot Study

Older adults and people living with HIV have been shown to experience disproportionately more olfactory dysfunction. Some neurological studies suggest that olfactory dysfunction may be a precursor to cognitive dysfunction. The purpose of our study was to determine whether olfactory dysfunction was predictive of cognition. In our cross-sectional study, 51 African American and Caucasian men living with HIV (ages ≥ 40 years) were administered a cognitive performance battery and two objective olfactory measures (the University of Pennsylvania Smell Identification Test and the Smell Threshold Test). The strongest cognitive associations to the University of Pennsylvania Smell Identification Test performance were found in the Hopkins Verbal Learning Test, a measure of verbal learning and verbal memory. These findings were consistent with previous research, demonstrating a relationship between decreased olfactory function and poorer cognitive performance. An important clinical implication from these results is the potential use of olfactory dysfunction as a prodromal biomarker for HIV-associated neurocognitive disorder.

The olfactory function in patients with common variable immunodeficiency

AIMS

To determine the incidence of olfactory dysfunction in common variable immunodeficiency patients. To evaluate the correlation between olfactory dysfunction and chronic rhinosinusitis in this class of patients.

MATERIALS AND METHODS

Fifty patients, with a diagnosis of common variable immunodeficiency and under immunoglobulin replacement therapy, were submitted to an otolaryngology physical examination and a CT scan of the craniofacial structures in order to show the presence of signs of chronic rhinosinusitis. An olfactory function evaluation was executed using the Sniffin' Sticks Test, with assessment of olfactory threshold, discrimination, identification and overall composite scores (TDI: threshold-discrimination-identification score).

RESULTS

An olfactory dysfunction was found in 23 (46%) common variable immunodeficiency patients, with hyposmia and anosmia respectively present in 65% and 38% of them. The mean TDI score in the study group was 27.7. Common variable immunodeficiency patients with CRS presented a more suggestive increase of the olfactory threshold, discrimination and identification compared to those without chronic rhinosinusitis.

CONCLUSION

In conclusion, patients with common variable immunodeficiency seem to suffer from olfactory disorders more than healthy people. One of the causal factors could be considered the presence of rhinosinusal pathologies.

Impaired sense of smell and altered olfactory system in RAG-1(-∕-) immunodeficient mice

Immune deficiencies are often associated with a number of physical manifestations including loss of sense of smell and an increased level of anxiety. We have previously shown that T and B cell-deficient recombinase activating gene (RAG-1)(-∕-) knockout mice have an increased level of anxiety-like behavior and altered gene expression involved in olfaction. In this study, we expanded these findings by testing the structure and functional development of the olfactory system in RAG-1 (-∕-) mice. Our results show that these mice have a reduced engagement in different types of odors and this phenotype is associated with disorganized architecture of glomerular tissue and atrophy of the main olfactory epithelium. Most intriguingly this defect manifests specifically in adult age and is not due to impairment in the patterning of the olfactory neuron staining at the embryo stage. Together these findings provide a formerly unreported biological evidence for an altered function of the olfactory system in RAG-1 (-∕-) mice.

The synergistic effects of HIV, diabetes, and aging on cognition: implications for practice and research

Thanks to highly active antiretroviral therapy, many people infected with HIV will likely live into old age. Although this is a welcome prognosis, new issues are emerging that may complicate the ability to successfully age in this clinical population. HIV and aging independently are related to cognitive impairments, so there are concerns that those aging with HIV may be more at risk of such cognitive impairments. Moreover, highly active antiretroviral therapy itself can create metabolic disorders, such as prediabetes and/or frank type 2 diabetes, which have also been linked to poorer cognitive functioning. Thus, concerns increase that, as people age with HIV and develop comorbid metabolic disorders that may lead to type 2 diabetes, they will be at triple risk of developing cognitive impairments that can impair everyday functioning and reduce quality of life. This article explores these issues and provides implications for practice and research.

Prevention, Rehabilitation, and Mitigation Strategies of Cognitive Deficits in Aging with HIV: Implications for Practice and Research

Highly active antiretroviral therapy has given the chance to those living with HIV to keep on living, allowing them the opportunity to age and perhaps age successfully. Yet, there are severe challenges to successful aging with HIV, one of which is cognitive deficits. Nearly half of those with HIV experience cognitive deficits that can interfere with everyday functioning, medical decision making, and quality of life. Given that cognitive deficits develop with more frequency and intensity with increasing age, concerns mount that as people age with HIV, they may experience more severe cognitive deficits. These concerns become especially germane given that by 2015, 50% of those with HIV will be 50 and older, and this older cohort of adults is expected to grow. As such, this paper focuses on the etiologies of such cognitive deficits within the context of cognitive reserve and neuroplasticity. From this, evidence-based and hypothetical prevention (i.e., cognitive prescriptions), rehabilitation (i.e., speed of processing training), and mitigation (i.e., spaced retrieval method) strategies are reviewed. Implications for nursing practice and research are posited.