Regular cannabis use modulates the impact of HIV on the neural dynamics serving cognitive control.

BACKGROUND: Cannabis use and HIV are independently associated with decrements in cognitive control. However, the combined effects of HIV and regular cannabis use on the brain circuitry serving higher-order cognition are unclear. AIMS: Investigate the interaction between cannabis and HIV on neural interference effects during the flanker task and spontaneous activity in regions underlying higher-order cognition. METHODS: The sample consisted of 100 participants, including people with HIV (PWH) who use cannabis, PWH who do not use cannabis, uninfected cannabis users, and uninfected nonusers. Participants underwent an interview regarding their substance use history and completed the Eriksen flanker task during magnetoencephalography (MEG). MEG data were imaged in the time-frequency domain and oscillatory maps depicting the neural flanker interference effect were probed for group differences. Voxel time series were then assessed for group-level differences in spontaneous activity. RESULTS: Group differences in behavioral performance were identified along with group differences in theta and alpha neural interference responses in higher-order regions across the cortex, with nonusers with HIV generally exhibiting the most aberrant responses. Likewise, time series analyses indicated that nonusers with HIV also had significantly elevated spontaneous alpha activity in the left inferior frontal and dorsolateral prefrontal cortices (dlPFC). Finally, we found that spontaneous and oscillatory alpha activity were significantly coupled in the inferior frontal cortex and dlPFC among cannabis users, but not nonusers. CONCLUSIONS: Regular cannabis use appears to suppress the impact of HIV on spontaneous and oscillatory alpha deficits in the left inferior frontal cortex and dlPFC.

Gray matter volumes discriminate cognitively impaired and unimpaired people with HIV.

BACKGROUND: Current diagnostic criteria of HIV-associated neurocognitive disorders (HAND) rely on neuropsychological assessments. The aim of this study was to evaluate if gray matter volumes (GMV) can distinguish people with HAND, neurocognitively unimpaired people with HIV (unimpaired PWH), and uninfected controls using linear discriminant analyses. METHODS: A total of 231 participants, including 110 PWH and 121 uninfected controls, completed a neuropsychological assessment and an MRI protocol. Among PWH, HAND (n = 48) and unimpaired PWH (n = 62) designations were determined using the widely accepted Frascati criteria. We then assessed the extent to which GMV, corrected for intracranial volume, could accurately distinguish the three groups using linear discriminant analysis. Sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, area under the curve (AUC), and accuracy were computed for each model using the classification results based on GMV compared to the neuropsychological assessment. RESULTS: The best performing model was comprised of bilaterally combined GMV and was stratified by sex. Among males, sensitivity was 85.2% (95% CI: 66.3%-95.8%), specificity was 97.0% (95% CI: 91.6%-99.4%), and the AUC was 0.91 (95% CI: 0.83-0.99). Among females, sensitivity was 100.0% (95% CI: 83.9%-100.0%), specificity was 98.8% (95% CI: 93.4%-100.0%), and the AUC was 0.99 (95% CI: 0.98-1.00). CONCLUSIONS: GMV accurately discriminated HAND from unimpaired PWH and controls. Measures of GMV may be highly sensitive to HAND, and revisions to the Frascati criteria should consider including GMV in conjunction with a neuropsychological assessment to diagnose HAND.

A pharmacist-led medication switch protocol in an academic HIV clinic: patient knowledge and satisfaction.

BACKGROUND: Tenofovir alafenamide (TAF) is associated with less renal and bone toxicity compared with tenofovir disoproxil (TDF). TAF's recent FDA approval has spurred HIV providers to consider switching antiretroviral therapy (ART) regimens containing TDF to TAF to minimize long term risks. Patient views on the process of such medication switches have not been explored. METHODS: Patients taking elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate (E/C/F/TDF) following the Food and Drug Administration's (FDA) approval of elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide (E/C/F/TAF) received medication education from an HIV pharmacist prior to switching to the tenofovir alafenamide (TAF) formulation. Patients were asked to complete a cross-sectional survey assessing satisfaction with the switch process and knowledge about the new medication 4 to 8 weeks post-switch. RESULTS: Sixty five patients completed the switch and 57 (88%) completed a follow-up survey. Most (86%) reported understanding why the switch was made, while 91% correctly identified that TAF is associated with reduced renal toxicity, and 73% correctly identified that TAF is associated with reduced bone toxicity. No statistically significant difference was found in satisfaction with or understanding of why the medication switch was made when assessed by sex, age, race, or education, but there was a trend toward significance in the distribution of answers based on education level with those with a high school diploma, General Educational Development (GED) or less being more likely to be satisfied with the medication switch (p = 0.074). CONCLUSIONS: Education from an ambulatory clinic-based HIV pharmacist resulted in high rates of patient satisfaction and understanding of the switch from TDF to TAF-containing ART.

A new reference method for the validation of the nutrient profiling schemes using dietary surveys.

Nutrient profiles of foods are increasingly used as the scientific basis of nutritional labeling, health claims, or nutritional education. Nutrient profiling schemes are based on sets of rules, scores, or thresholds applied to the nutritional composition of foods. However, there is a lack of scientific validation of nutritional profiling schemes. To develop a reference method using existing dietary surveys, to define a set of indicator foods that are positively or negatively associated with a "healthy diet." Such indicator foods can be used both for establishing relevant nutrient profiles and for the validation of existing or future nutrient profiling schemes. The proposed validation method is based on food and nutrient intakes of adults participating in national dietary surveys in five EU countries: Belgium (n = 2,507), Denmark (n = 3,151), France (n = 1,474), Ireland (n = 1,379), and Italy (n = 1,513). The characterization of indicator foods is divided in two steps. First, "healthy diets" of individuals are identified in the five national dietary surveys by comparison to the Eurodiet reference intakes. Second, indicator foods associated positively or negatively to the "healthy diets" are determined. With a P-value of 10(-3) for the test of comparison of food intakes between the "most healthy eaters" and the "less healthy eaters," it was possible to identify 294 indicator foods out of 1,669 foods tested in the five countries. In all the countries except Italy, there were more indicator foods positively associated than indicator foods negatively associated with the "healthy diet." The food categories of these indicator foods were in good agreement with Food Based Dietary Guidelines like the USDA dietary guideline for Americans. A new reference method for the validation of profiling schemes was developed based on dietary intake data from using dietary surveys in five European countries. Only a minority of foods consumed in these dietary surveys could be used as indicator foods of healthy or unhealthy diets in order to subsequently test nutritional profiling schemes. Further work is needed to build a list of indicator foods that could be considered as a "gold standard."

Comparison of different nutrient profiling schemes to a new reference method using dietary surveys.

A new EU regulation on nutrition and health claims made on foods has entered into force in January 2007. The regulation provides for the use of nutrient profiles to determine which foods may bear claims but does not specify what the profiles should be or how they should be developed. Several nutrient profiling schemes have already been established. Therefore, it is necessary to develop approaches to test if the existing profiling schemes could fulfil the new regulation needs. The aim of the present study is to investigate how reference "indicator foods" derived from national dietary surveys in five different countries, are classified according to three existing nutrient profiling schemes: The UK Food Standards Agency (FSA) model, The Dutch Tripartite classification model and the US FDA model used for regulating health claims. "Indicator foods" that have been shown to be positively or negatively associated with healthy diets in adults in five EU countries were classified according to each of the three profiling schemes. The performance and effectiveness of each profiling scheme in correctly classifying the "indicator foods" were assessed using sensitivity and specificity ratios. The sensitivity and the specificity ratios of the three profiling schemes tested were relatively good. There were only small differences of performance between the three systems. A significant negative correlation between sensitivity and specificity was observed. The level of concordance between the classification of the "indicator foods" that have been selected because of being positively or negatively associated with a healthy diet and the classification by each of the three profiling methods tested was quite good. However, further improvement of the "indicator foods" approach is needed if it is to serve as a "gold standard".