Brief Report: Rate of Nicotine Metabolism and Tobacco Use Among Persons With HIV: Implications for Treatment and Research

Robust tobacco smoking self-report in two cohorts: pregnant women or men and women living with or without HIV

Understanding the true burden of tobacco smoking on adverse pregnancy outcomes is critical in generating appropriate interventions to improve outcomes. Self-reporting of human behaviour that is associated with stigma is associated with underreporting in general and may bias the impact of smoking in studies; however, self-reporting is frequently the most practical method of gleaning this information. The objective of this study was to evaluate concordance between self-reported smoking and concentrations of plasma cotinine, a biomarker of smoking, among participants enrolled in two related HIV cohorts. A total of 100 pregnant women (76 living with HIV [LWH] and 24 negative controls) in their third trimester, and 100 men and non-pregnant women (43 LWH and 57 negative controls) were included. Among all participants, 43 pregnant women (49% LWH and 25% negative controls) and 50 men and non-pregnant women (58% LWH and 44% negative controls) were self-reported smokers. The odds of discordance between self-reported smoking and cotinine levels were not significantly different between self-reported smokers and non-smokers, nor between pregnant women and others, but were significantly increased, regardless of self-reported status, among people LWH compared to negative controls. The overall concordance between plasma cotinine and self-reported data among all participants was 94% with a sensitivity and specificity of 90% and 96%, respectively. Taken together, these data demonstrate that participant surveying in a non-judgemental context can lead to accurate and robust self-report smoking data among both persons LWH and not, including in the context of pregnancy.

A Cross-Sectional Analysis of the Nicotine Metabolite Ratio and Its Association with Sociodemographic and Smoking Characteristics among People with HIV Who Smoke in South Africa

The nicotine metabolite ratio (NMR) is associated with race/ethnicity but has not been evaluated among smokers in the African region. We conducted a cross-sectional analysis of baseline data from a large randomized, controlled trial for smoking cessation among people with HIV (PWH) in South Africa. Urine samples were analyzed for the NMR and evaluated as a binary variable using a cutoff value of the fourth quartile to determine the fastest metabolizers. The median NMR was 0.31 (IQR: 0.31, 0.32; range: 0.29, 0.57); the cut-point for fast metabolizers was ≥0.3174 ng/mL. A high NMR was not associated with the number of cigarettes per day (OR = 1.10, 95% CI: 0.71, 1.70, p = 0.66) but was associated with 40% lower odds of a quit attempt in the past year (OR = 0.69; 95% CI: 0.44, 1.07, p = 0.09) and alcohol use (OR = 0.59, 95% CI: 0.32, 1.06, p = 0.07). No association was seen with marijuana or HIV clinical characteristics. As we found only minimal variability in the NMR and minimal associations with intensity of smoking, NMR may be of limited clinical value in this population, although it may inform which individuals are less likely to make a quit attempt.

Brief Report: HIV Infection Does Not Explain Higher Nicotine Metabolism in People Living With HIV

BACKGROUND

Smoking contributes to significant morbidity and mortality in people with HIV. People with HIV have relatively high nicotine metabolism rates, as measured by the nicotine metabolite ratio (NMR, 3-hydroxycotinine/cotinine). A higher NMR is associated with difficulty quitting smoking. We hypothesized that HIV infection might upregulate nicotine metabolism.

SETTING

A retrospective study of male current smokers in the Multicenter AIDS Cohort Study who HIV seroconverted between 1985 and 1993.

METHODS

Eligibility included having plasma stored before and after confirmed HIV seroconversion and current tobacco use. Samples were selected from the closest available visits before (median 3.3 months) and after (median 9.4 months) seroconversion. Antiretroviral therapy use was exclusionary. Cotinine and 3-hydroxycotinine were measured using liquid chromatography-tandem mass spectrometry. We compared NMR from plasma pre-HIV and post-HIV infection using signed-rank tests. We targeted a sample size of 71 pairs to achieve 80% power to detect a 0.1 unit increase in NMR with P = 0.05.

RESULTS

We analyzed paired samples from 78 participants; the median age was 34.5 years [interquartile range (IQR 29-40 years)]. The median NMR pre-HIV and post-HIV was 0.45 (IQR 0.32-0.54) and 0.46 (IQR 0.34-0.56), respectively. The median change in NMR postseroconversion was +0.01 (IQR -0.05, +0.09), P = 0.25. Stratification of median change in NMR by timing between samples or time since HIV seroconversion did not alter this finding.

CONCLUSIONS

Acquiring HIV had no measurable effect on NMR. We postulate that upregulation of the NMR may be due to direct pharmacologic effects of HIV medications or metabolic changes in response to HIV infection.

Brief Report: Nicotine Metabolism Ratio Increases in HIV-Positive Smokers on Effective Antiretroviral Therapy: A Cohort Study

BACKGROUND

People with HIV (PWH) smoke tobacco at much higher rates than the general population. Previous research has shown that PWH have faster nicotine metabolism than HIV-uninfected individuals, which may underlie this disparity, but the cause is unknown. We investigated whether higher nicotine metabolite ratio (NMR; 3-hydroxycotinine:cotinine), a validated biomarker of nicotine metabolism through CYP2A6, was associated with antiretroviral use among HIV-infected smokers.

METHODS

We conducted a retrospective cohort study of HIV-positive smokers in the University of Pennsylvania Center for AIDS Research cohort. We compared the NMR before viral suppression (>10,000 copies/mL) and after viral suppression on antiretroviral therapy (<200 copies/mL). We used mixed-effects linear regression to analyze the change in NMR after viral suppression and assessed for effect modification by efavirenz use.

RESULTS

Eighty-nine individuals were included in the study. We observed effect modification by efavirenz use (interaction term for efavirenz use, P < 0.001). Among those on nonefavirenz regimens, the mean NMR increased by 0.14 (95% confidence interval: 0.05 to 0.23, P = 0.002). Among those on efavirenz-containing regimens, the mean NMR increased by 0.53 (95% confidence interval: 0.39-0.66, P < 0.001).

CONCLUSIONS

We observed a clinically and statistically significant increase in NMR after viral suppression among smokers with HIV, which more than doubled among those on efavirenz-based regimens. Higher NMR among HIV-positive smokers on antiretroviral therapy may help explain the higher rates of tobacco use and lower quit rates among PWH in care. These findings suggest that regimen choice and other modifiable factors may be targets for future attempts to increase success rates for tobacco cessation among PWH.

Persistent Disparities in Smoking Rates Among PLWH Compared to the General Population in Philadelphia, 2009-2014

Despite reductions in smoking rates in the general population, little is known about recent smoking trends among people living with HIV (PLWH). We compared the risk for smoking and temporal trends in smoking among PLWH and the general population in the Philadelphia metropolitan area between 2009 and 2014. We used weighted logistic regression to assess the relation between HIV and smoking, and examined temporal smoking trends. The adjusted odds ratio (OR) for smoking comparing PLWH to the general population was 1.80 (95% CI 1.55-2.09) after adjusting for socio-economic, demographic, and mental health diagnosis variables. Smoking prevalence decreased in both the PLWH and general populations during the study period, and we did not observe a significant difference in rates of decline between groups (P = 0.54). Despite overall progress in smoking cessation, a disparity persisted in smoking rates between PLWH and the general population, with and without adjustment for socio-economic, demographic, and mental health variables. Further research is needed to understand the mechanisms linking HIV and tobacco use in order to inform public health efforts to reduce smoking among PLWH.

Is It Feasible to Impact on Smoking Habits in HIV-Infected Patients? Mission Impossible From the STOPSHIV Project Cohort

OBJECTIVE

Assessment of the feasibility and effectiveness of a brief intervention for smoking cessation in people living with HIV (PLWH).

SETTING

Multicenter cohort prospective study involving PLWH from 10 Italian infectious disease centers.

METHODS

During routine HIV care, clinicians delivered the 5As brief intervention (Ask, Advise, Assess, Assist, Arrange) to each patient who enrolled in the study, following the European AIDS Clinical Society guidelines. At study end, participating clinicians evaluated their own adherence to intervention: "standard" if counseling was delivered in at least half of the follow-up visits, "soft" if less. The main outcome measure was smoking abstinence ≥6 months. Abstinence predictors were evaluated using a Cox-proportional hazard regression model.

RESULTS

One thousand eighty-seven PLWH-patients (age 47.9 ± 10.8, male 73.5%) were followed for a median of 23 months (interquartile range 21-25). At baseline, current smokers were 561 (51.6%). Standard intervention was performed in 4 of 10 centers and included 343 smokers; soft intervention was performed in 6 centers (218 smokers). At last visit, 35 patients in standard (10.8%) and 6 in soft intervention (2.8%) achieved self-reported tobacco abstinence ≥6 months (P = 0.0009). Overall, the 5As intervention led to 7.3% 6-month interruptions. In the multivariable analysis, significant predictors for 6-month smoking cessation were: lower Fagerström score, stage of change (preparation/contemplation vs. precontemplation), and standard intervention.

CONCLUSION

Adherence to the 5As brief intervention emerged as a critical factor for success. In fact, compared with soft intervention, the standard intervention significantly increased abstinence, highlighting that clinicians need more time and supporting tools to encourage PLWH to quit smoking.

An update on drug-drug interactions between antiretroviral therapies and drugs of abuse in HIV systems

INTRODUCTION

While considerable progress has been made in the fight against HIV/AIDS, to date there has not been a cure, and millions of people around the world are currently living with HIV/AIDS. People living with HIV/AIDS have substance abuse disorders at higher rates than non-infected individuals, which puts them at an increased risk of drug-drug interactions.

AREAS COVERED

Potential drug-drug interactions are reviewed for a variety of potential drugs of abuse, both licit and illicit. These drugs include alcohol, cigarettes or other nicotine delivery systems, methamphetamine, cocaine, opioids, and marijuana. Potential interactions include decreased adherence, modulation of drug transporters, or modulation of metabolic enzymes. We also review the relative incidence of the use of these drugs of abuse in People living with HIV/AIDS.

EXPERT OPINION

Despite considerable improvements in outcomes, disparities in outcomes between PLWHA who use drugs of abuse, vs those who do not still exist. It is of critical necessity to improve outcomes in these patients and to work with them to stop abusing drugs of abuse.

Contribution of Behavioral Health Factors to Non-AIDS-Related Comorbidities: an Updated Review

PURPOSE OF REVIEW

We summarize recent literature on the contribution of substance use and depression to non-AIDS-related comorbidities. Discussion of recent randomized clinical trials and implementation research to curtail risk attributed to each behavioral health issue is provided.

RECENT FINDINGS

Smoking, unhealthy alcohol use, opioid use, and depression are common among PWH and individually contribute to increased risk for non-AIDS-related comorbidities. The concurrence of these conditions is notable, yet understudied, and provides opportunity for linked-screening and potential treatment of more than one behavioral health factor. Current results from randomized clinical trials are inconsistent. Investigating interventions to reduce the impact of these behavioral health conditions with a focus on implementation into clinical care is important. Non-AIDS-defining cancers, cardiovascular disease, liver disease, and diabetes are leading causes of morbidity in people with HIV. Behavioral health factors including substance use and mental health issues, often co-occurring, likely contribute to the excess risk of non-AIDS-related comorbidities.

Smoking habits in HIV-infected people compared with the general population in Italy: a cross-sectional study

Background

Tobacco use is a leading cause of preventable diseases and death for all individuals, even more so for people living with HIV (PLWH), due to their status of chronic inflammation. To date, in Italy no study was performed to compare smoking habits in PLWH and the general population. We aimed to investigate smoking habits in PLWH, as compared to the general population.

Methods

Multi-center cross-sectional study. Smoking habits were compared between PLWH and the general population. PLWH were enrolled in the STOPSHIV Study. The comparison group from the general population was derived from a survey performed by the National Statistics Institute (ISTAT), with a stratified random sampling procedure matching 2:1 general population subjects with PLWH by age class, sex, and macro-area of residence.

Results

The total sample consisted of 1087 PLWH (age 47.9 ± 10.8 years, male 73.5%) and 2218 comparable subjects from the general population. Prevalence of current smokers was 51.6% vs 25.9% (p < 0.001); quitting smoking rate was 27.1% vs. 50.1% (p < 0.001) and the mean number of cigarettes smoked per day was 15.8 vs. 11.9 (p < 0.001), respectively for PLWH and the general population. Smoking and heavy smoking rates amongst PLWH were significantly higher even in subjects who reported diabetes, hypertension and extreme obesity (p < 0.001). Logistic regressions showed that PLWH were more likely current smokers (adjusted Odds Ratio, aOR = 3.11; 95% Confidence Interval (CI) =2.62–3.71; p < 0.001) and heavy smokers (> 20 cigarettes per day) (aOR = 4.84; 95% CI = 3.74–6.27; p < 0.001). PLWH were less likely to have quitted smoking (aOR = 0.36; 95% CI = 0.29–0.46; p < 0.001).

Conclusion

HIV-infected patients showed a higher rate of current smokers, a larger number of cigarettes smoked and a lower quitting rate than the general population. Our findings emphasize the need for smoking cessation strategies targeting HIV persons.

Bidirectional Associations among Nicotine and Tobacco Smoke, NeuroHIV, and Antiretroviral Therapy

People living with HIV (PLWH) in the antiretroviral therapy (ART) era may lose more life-years to tobacco use than to HIV. Yet, smoking rates are more than twice as high among PLWH than the general population, contributing not just to mortality but to other adverse health outcomes, including neurocognitive deficits (neuroHIV). There is growing evidence that synergy with chronic inflammation and immune dysregulation that persists despite ART may be one mechanism by which tobacco smoking contributes to neuroHIV. This review will summarize the differential effects of nicotine vs tobacco smoking on inflammation in addition to the effects of tobacco smoke components on HIV disease progression. We will also discuss biomarkers of inflammation via neuroimaging as well as biomarkers of nicotine dependence (e.g., nicotine metabolite ratio). Tobacco smoking and nicotine may impact ART drug metabolism and conversely, certain ARTs may impact nicotine metabolism. Thus, we will review these bidirectional relationships and how they may contribute to neuroHIV and other adverse outcomes. We will also discuss the effects of tobacco use on the interaction between peripheral organs (lungs, heart, kidney) and subsequent CNS function in the context of HIV. Lastly, given the dramatic rise in the use of electronic nicotine delivery systems, we will discuss the implications of vaping on these processes. Despite the growing recognition of the importance of addressing tobacco use among PLWH, more research is necessary at both the preclinical and clinical level to disentangle the potentially synergistic effects of tobacco use, nicotine, HIV, cognition and immune dysregulation, as well as identify optimal approaches to reduce tobacco use. Graphical Abstract Proposed model of the relationships among HIV, ART, smoking, inflammation, and neurocognition. Solid lines represent relationships supported by evidence. Dashed lines represent relationships for which there is not enough evidence to make a conclusion. (a) HIV infection produces elevated levels of inflammation even among virally suppressed individuals. (b) HIV is associated with deficits in cognition function. (c) Smoking rates are higher among PLWH, compared to the general population. (d) The nicotine metabolite ratio (NMR) is associated with smoking behavior. (e) HIV and tobacco use are both associated with higher rates of psychiatric comorbidities, such as depression, and elevated levels of chronic stress. These factors may represent other mechanisms linking HIV and tobacco use. (f) The relationship between nicotine, tobacco smoking, and inflammation is complex, but it is well-established that smoking induces inflammation; the evidence for nicotine as anti-inflammatory is supported in some studies, but not others. (g) The relationship between tobacco use and neurocognition may differ for the effects of nicotine (acute nicotine use may have beneficial effects) vs. tobacco smoking (chronic use may impair cognition). (h) Elevated levels of inflammation may be associated with deficits in cognition. (i) PLWH may metabolize nicotine faster than those without HIV; the mechanism is not yet known and the finding needs validation in larger samples. We also hypothesize that if HIV-infection increases nicotine metabolism, then we should observe an attenuation effect once ART is initiated. (j) It is possible that the increase in NMR is due to ART effects on CYP2A6. (k) We hypothesize that faster nicotine metabolism may result in higher levels of inflammation since nicotine has anti-inflammatory properties.

Placebo-controlled randomized clinical trial testing the efficacy and safety of varenicline for smokers with HIV

BACKGROUND

People living with HIV/AIDS (PLWH) smoke tobacco at higher rates and have more difficulty quitting than the general population, which contributes to significant life-years lost. The effectiveness of varenicline, one of the most effective tobacco dependence treatments, is understudied in HIV. We evaluated the safety and efficacy of varenicline for smoking cessation among PLWH.

METHODS

This was a single-site randomized, double-blind, placebo-controlled, phase 3 clinical trial (NCT01710137). PLWH on antiretroviral therapy (ART) who were treatment-seeking daily smokers were randomized (1:1) to 12 weeks of varenicline (n = 89) or placebo (n = 90). All participants were offered six smoking cessation behavioral counseling sessions. The primary outcome was 7-day point prevalence abstinence, confirmed with breath carbon monoxide, at Weeks 12 and 24. Continuous abstinence and time to relapse were secondary outcomes. Safety measures were treatment-related side effects, adverse events, blood pressure, viral load, and ART adherence.

RESULTS

Of the 179 smokers, 81% were African American, and 68% were male. Varenicline increased cessation at Week 12 (28.1% vs. 12.1%; OR = 4.54, 95% CI:1.83-11.25, P = .001). Continuous abstinence from Week 9 to 12 was higher for varenicline vs. placebo (23.6% vs. 10%; OR = 4.65, 95% CI:1.71-12.67, P = .003); at Week 24, there was no effect of varenicline for point prevalence (14.6% vs. 10%), continuous abstinence (10.1% vs. 6.7%), or time to relapse (Ps > .05). There were no differences between varenicline and placebo on safety measures (Ps > .05).

CONCLUSIONS

Varenicline is safe and efficacious for short-term smoking cessation among PLWH and should be used to reduce tobacco-related life-years lost in this population.

Racial/ethnic differences in perceived risks and benefits of quitting smoking in a sample of African American and Hispanic adults living with HIV/AIDS: A preliminary study

Persons living with HIV/AIDS (PLWH) report very high prevalences of cigarette smoking, and there are racial/ethnic disparities in smoking consequences and quit outcomes. In this exploratory pilot study, we examined racial/ethnic differences in perceived risks and benefits of quitting cigarette smoking among 97 adult PLWH in the Bronx, New York (Hispanic, 53.6%; African American, 46.4%). Compared to African American PLWH, Hispanic PLWH reported greater endorsement of overall risks and benefits and risks of negative affect, difficulty concentrating, social ostracism, loss of enjoyment, and cravings. It may be useful to incorporate risks and benefits of quitting into smoking treatment for African American and Hispanic PLWH.