Association between Sex, CD4 Cell Counts, Antiretroviral Medications, and Olfactory and Gustatory Functions of HIV-Infected Adults

Salt Taste and Salt Sensitive Hypertension in HIV

PURPOSE OF REVIEW

To provide a summary of current literature and propose potential mechanistic models to help us understand the role of HIV infection/antiretroviral therapy (ART), salt taste sensitivity (STS), and salt sensitivity of blood pressure (SSBP) in hypertension development.

RECENT FINDINGS

The epithelial sodium channel (ENaC) is the main protein/sodium channel for recognizing Na + in the tongue and mediates preference to low-medium salt concentrations in animals and humans. Considering the pressor response to oral salt in individuals with SSBP, poor STS may worsen blood pressure. Specific genetic variants in ENaC are linked to salt taste perception and hypertension. HIV infection, some ART, and specific antihypertensive drugs are associated with reduced STS and an increased liking for salty foods. Persons with HIV (PWH) on ART may have a decreased STS and are at a higher risk of developing salt-sensitive hypertension. Inflammation mediated by dietary salt is one of the drivers of poor STS and salt-sensitive hypertension among PWH.

Olfactory Dysfunction in Aging African American and Caucasian Men With HIV: A Pilot Study

ABSTRACT

As people age with HIV, olfactory dysfunctions may become more pronounced, especially for African Americans who are predisposed to declines in olfaction. In this cross-sectional study, 34 middle-age and older African American and 17 Caucasian men living with HIV were administered two objective olfactory measures (UPSIT). In the Smell Threshold Test, compared to the HIV-negative age norms, adults living with HIV were significantly less able to detect a lower threshold smell. In the University of Pennsylvania Smell Identification Test, compared to the HIV-negative age norms, adults living with HIV were significantly less able to correctly identify odors; furthermore, using such norms, African Americans with HIV were less likely to correctly identify odors compared to Caucasians with HIV. Since the literature indicates that African Americans have a stronger attraction for salty and sweet foods, such olfactory dysfunction may contribute to poor eating habits, potentially predisposing this population to additional health problems.

Dysgeusia: A review in the context of COVID-19

Background

Taste disorders in general, and dysgeusia in particular, are relatively common disorders that may be a sign of a more complex acute or chronic medical condition. During the COVID-19 pandemic, taste disorders have found their way into the realm of general as well as specialty dentistry, with significance in screening for patients who potentially may have the virus.

Types of Studies Reviewed

The authors searched electronic databases (PubMed, Embase, Web of Science, Google Scholar) for studies focused on dysgeusia, ageusia, and other taste disorders and their relationship to local and systemic causes.

Results

The authors found pertinent literature explaining the normal physiology of taste sensation, proposals for suggested new tastes, presence of gustatory receptors in remote tissues of the body, and etiology and pathophysiology of taste disorders, in addition to the valuable knowledge gained about gustatory disorders in the context of COVID-19. Along with olfactory disorders, taste disorders are one of the earliest suggestive symptoms of COVID-19 infection.

Conclusions

Gustatory disorders are the result of local or systemic etiology or both. Newer taste sensations, such as calcium and fat tastes, have been discovered, as well as taste receptors that are remote from the oropharyngeal area. Literature published during the COVID-19 pandemic to date reinforces the significance of early detection of potential patients with COVID-19 by means of screening for recent-onset taste disorders.

Practical Implications

Timely screening and identification of potential gustatory disorders are paramount for the dental care practitioner to aid in the early diagnosis of COVID-19 and other serious systemic disorders.

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.

Systemic diseases and disorders

Alterations in the ability to smell or taste are of considerable consequence, impacting quality of life, safety, nutrition, and dietary activities. These primary senses are influenced by a wide range of systemic diseases and disorders that commonly involve the entire body. These include viral, bacterial, fungal, protozoal, cestode, and nematode infections that can spread throughout the gastric, lymphatic, neural, or circulatory systems as well as classic autoimmune disorders, collagen diseases, diabetes, and hypertension, and others. Although a considerable literature has evolved in which the function of both taste and smell has been assessed in a number of such disorders, quantitative chemosensory testing is still relatively rare with many disorders not receiving empirical assessment. Incongruent findings are not uncommon. This chapter reviews what is known about the influences of a wide spectrum of systemic diseases and disorders on the abilities to taste and smell.