Methamphetamine Injection Among Young Men Who Have Sex With Men: Risk for Human Immunodeficiency Virus Transmission in a Los Angeles Cohort

Association of Partnership-Level Methamphetamine Use on Inconsistent PrEP Care Engagement Among GBMSM in Los Angeles County

There are limited quantitative studies describing the association between meth use in the context of male-male sexual partnerships and PrEP care engagement. We assessed the longitudinal relationship between individual and partnership level meth use with inconsistent PrEP engagement among young gay, bisexual and other men who have sex with men (GBMSM) in Los Angeles. The primary exposure was meth use at the partnership level with a ternary variable (neither partner nor participant used meth, either used meth, or both used meth). Generalized estimating equations were used to assess odds of inconsistent PrEP engagement at different levels of partner-participant meth use, adjusting for age at visit, number of recent male partners and partner intimacy. Among inconsistent PrEP engagement, 61% (n = 84, vs. 79.5%, n = 346 continuous) reported that neither they nor their partner used meth, 22% (n = 31, vs. 18%, n = 56) reported that either partner or participant used meth and 17% (n = 24, vs. 8%, n = 33) reported that both partner and participant used meth (P < 0.01). There were increased odds of inconsistent PrEP engagement when both partner and participant reported meth use (aOR: 3.82; 95%CI: 1.83-7.99) and when either partner or participant reported meth use (aOR: 2.46; 95%CI: 1.28-4.75). Meth use plays an important role in consistent PrEP engagement among GBMSM in mSTUDY. PrEP users who use meth with partners may benefit from integrated interventions addressing both meth use and PrEP engagement.

Drug Use, Family Support, and Depressive Symptoms Among Latinx Sexual Minority Men: A Longitudinal Analysis

Family rejection has negative health consequences for Latinx sexual minority men (LSMM). However, LSMM often reconcile with their families, a phenomenon cross-sectional studies miss. We analyzed longitudinal data from the Healthy Young Men's Study in Los Angeles. We used individual fixed-effects Poisson regression to model changes over time in the associations among family support, drug use, and depressive symptoms. We found that (1) the initiation of drug use was associated with a 7.2% (Ratio=1.072, 95% CI 1.006 - 1.142, p = 0.03) increase in family support among LSMM who reported high depressive symptoms (depression subscale T-score ≥ 63) in at least one data wave; (2) a 1-unit increase in family support was associated with a 4.7% (RR = ;0.953, 95% CI 0.931 - 0.976, p < 0.001) decrease in the probability of high depressive symptoms; and (3) no significant association between a change in drug use and a change in high depressive symptoms. Over time, LSMM appear to benefit from the health effects of family support associated with Latinx family structures.

Neuroprotective effect of histamine H3 receptor blockade on methamphetamine-induced cognitive impairment in mice

OBJECTIVE

Methamphetamine (METH) exposure is commonly believed to result in cognitive impairment. Histamine H3 receptor (H3R) antagonists reportedly have potential applications for treating cognitive impairment accompanied by various neuropsychiatric disorders. The present study aimed to investigate the effect of H3R blockade by Thioperamide (THIO) on METH-induced cognitive impairment and the underlying mechanism.

METHODS

In Experiment 1, C57BL/6 mice received daily injections of saline or 5 mg/kg METH for 5 consecutive days. The Novel Object Recognition (NOR) and Morris water maze (MWM) tasks were used to assess cognitive functions of mice. H3R protein expression and apoptosis were subsequently measured in the hippocampus. In Experiment 2, HT22 cells were first treated with ddH₂O or 3 mM METH. The cell survival rate and H3R protein level were subsequently assessed. In Experiment 3, the animals were first treated with saline or 20 mg/kg THIO for 7 days, followed by co-administration of either saline or 5 mg/kg METH for an additional 5 days. The remaining experiments were carried out in the same manner as Experiment 1. In Experiment 4, HT22 cells were pretreated with either ddH₂O or 5 mM THIO for 2 h, followed by ddH₂O or 3 mM METH treatment for an additional 12 h. The remaining experiments were carried out in the same manner as Experiment 2. In Experiment 5, the changes in MEK1/2, p-MEK1/2, ERK1/2 and p-ERK1/2 protein levels were examined in the hippocampus of all mice from Experiment 3 and HT22 cells from Experiment 4.

RESULTS

METH-treated mice showed significantly worsened NOR and MWM performance, along with markably hippocampal apoptosis. A significantly lower cell survival rate was observed in METH-treated HT22 cells. Increased levels of H3R protein were found in both METH-treated mice and HT22 cells. THIO significantly improved METH-induced cognitive impairment in mice and toxicity in HT22 cells. METH significantly increased the level of p-MEK1/2 and p-ERK1/2 proteins in the hippocampus of mice and HT22 cells, which was reversed by THIO pretreatment.

CONCLUSION

Our findings reveal that H3R blockade by THIO yields a neuroprotective effect against METH-induced cognitive impairment in mice and toxicity in HT22 cells via the raf-MEK-ERK signaling pathway.

The State of the Research on Opioid Outcomes Among Lesbian, Gay, Bisexual, Transgender, Queer, and Other Sexuality- and Gender-Diverse Populations: A Scoping Review

Purpose: Research on opioid misuse, opioid use disorder (OUD), and overdose (i.e., opioid outcomes) among lesbian, gay, bisexual, transgender, queer, and other populations within the LGBTQ umbrella (LGBTQ+) remains sparse. The purpose of this scoping review was to characterize the state of the research on opioid outcomes among LGBTQ+ populations, and identify gaps in the extant literature and areas for future research. Methods: We conducted a scoping review of peer-reviewed, English language articles published between 2011 and 2020 that examined opioid outcomes among LGBTQ+ populations in the CINAHL, Embase, PubMed, and PsycINFO databases. We extracted data from articles that focused on opioid outcomes within their specific aims or purpose. We include a general summary for articles that secondarily described opioid outcomes among LGBTQ+ populations. Results: Of 113 published studies that examined opioid outcomes among LGBTQ+ populations, 10% (n = 11) were specifically designed to focus on this topic. Across studies, bisexual populations, particularly women, were at highest risk for opioid misuse and OUD. Few studies examined opioid outcomes by more than one dimension of sexual orientation (n = 3, 27%), race and/or ethnicity (n = 3, 27%), or age (n = 5, 45%). Only two included transgender or gender diverse samples; only one explicitly measured gender identity. Conclusions: Future research is needed to understand the impact of the opioid epidemic on LGBTQ+ people, particularly transgender and other gender diverse individuals, and the intersectional role of race, ethnicity, and age in opioid disparities among LGBTQ+ individuals. Additional research could contribute to the development of much-needed affirming OUD treatment and other services for LGBTQ+ people.