Revista de SIDA e investigación clínica

Brain Derived Neurotrophic Factor: From Neurobiology to Sexual Risk Prevention

Abstract

María José Míguez, Luis A Espinoza, Caroline Perez and Christopher Kahler

Objective: The authors’ draw on neurobiological theory to posit that sexual risks might be associated with neurological changes, specifically, those neuro-adaptive changes associated with addictions. We propose that low levels of brain-derived neurotrophic factor (BDNF), a signaling molecule involved in cognitive, emotional, and addiction behaviors, may play a key role in the expression of high-risk sexual behaviors.

Methods: In a prospective cohort of 400 people living with HIV (PLWH), information was collected regarding smoking (Fagerström Test for Nicotine Dependence), hazardous alcohol use (men >14 and women >7 drinks/week), sexual behaviors. To assess the role of BDNF, platelet poor plasma was obtained to measure BDNF levels and participants were dichotomized into Groups 1 (BDNF ≤ 5000 pg/mL) and 2 (BDNF >5000 pg/mL).

Results: Over two-thirds of the participants reported multiple risk behaviors, confirming our hypothesis that Group 1 would have a general risk-taking tendency. Individuals in Group 1 were more likely to smoke (p=0.0001) and to drink alcohol hazardously (HAU) more days per week (p=0.04), particularly hard liquor (p=0.001). In support of our hypothesis, Group 1 was also more likely to report sex under the influence of drugs/alcohol (p=0.003) and to exchange sex for money (p=0.03). Men from Group 1 had multiple partners (p=0.09), and engaged in unprotected anal sex (p=0.08) more than those in Group 2. The results from regressions showed that BDNF (p=0.05), use of antidepressants (p=0.003), hazardous alcohol use (p=0.0001) and the BDNF x gender interaction (p=0.022) were significant predictors of high-risk sexual behaviors. Further supporting our postulate, participants with low BDNF showed triple the risk of herpes (p=0.05).

Conclusion: This innovative approach demonstrated for the first time that substance abuse disorders (especially alcohol abuse), high-risk sexual behaviors, and sexually transmitted diseases occur more frequently in individuals with low BDNF levels. These findings suggest the importance of using BDNF modifiers in preventive interventions concerning people living with HIV. Given the limitations of the design, new studies among the general population are needed to confirm the generalizability of the findings.