Tobacco smoking and associated factors in human immunodeficiency virus-infected adults attending human immunodeficiency virus clinics in the Western Cape province, South Africa

Exploring the associations of tobacco smoking and serum cotinine levels with selected inflammatory markers in adults with HIV in South Africa

This study examined the associations between tobacco smoking and serum cotinine levels, an objective biochemical measure of tobacco smoke exposure, with markers of inflammation, i.e., interferon-gamma (IFN-γ), interleukin 10 (IL-10), interleukin 2 (IL-2) and tumour necrosis factor-alpha (TNF-α) in people living with HIV (PLWH).These specific markers were selected because of their hypothesised associations with smoking, PLWH and their outcomes. In a random sample of ≥ 18-year-old PLWH receiving care at 17 public healthcare facilities across the Western Cape Province in South Africa, data collection included self-reported smoking history, and serum levels of cotinine and selected inflammatory markers. The inflammatory marker data were log transformed because of the skewedness of their distribution. Linear regression models (1) adjusted for age and gender, and (2) fully adjusted for age, gender, current alcohol use, body mass index and CD4 counts were used to examine the associations between smoking tobacco or serum cotinine and inflammatory markers. Level of significance was p < 0.05. Among 749 PLWH who were mainly women (79%), the mean age was 38.5 (8.9) years and similar when stratified by smoking status. Serum cotinine levels exhibited a striking discrepancy, with a median of 154 ng/mL among current smokers, in stark contrast to the consistent median values of 10 ng/mL observed among past and never smokers. In regression models adjusted for age and gender, current smoking and frequent smoking were associated with lower IL-2 but higher TNF-α. Log-cotinine exhibited associations with IFN-γ, IL-10, and TNF-α, while cotinine levels ≥ 10 ng/mL compared to < 10 ng/mL were associated with higher IFN-γ and TNF-α. In fully adjusted models, log-cotinine and cotinine levels ≥ 10 ng/mL displayed significant associations with higher IFN-γ and lower IL-2. This study underscores the importance of investigating the interplay between smoking tobacco or serum cotinine levels with pro-inflammatory cytokines in PLWH. It signals the need for comprehensive research to unravel the potential synergistic impacts of smoking tobacco and HIV infection on chronic inflammation and immune dysregulation, shedding light on critical avenues for intervention and management strategies.

Tobacco smoking, smoking cessation and life expectancy among people with HIV on antiretroviral therapy in South Africa: a simulation modelling study

INTRODUCTION

As access to effective antiretroviral therapy (ART) has improved globally, tobacco-related illnesses, including cardiovascular disease, cancer and chronic respiratory conditions, account for a growing proportion of deaths among people with HIV (PWH). We estimated the impact of tobacco smoking and smoking cessation on life expectancy among PWH in South Africa.

METHODS

In a microsimulation model, we simulated 18 cohorts of PWH with virologic suppression, each homogenous by sex, initial age (35y/45y/55y) and smoking status (current/former/never). Input parameters were from data sources published between 2008 and 2022. We used South African data to estimate age-stratified mortality hazard ratios: 1.2-2.3 (females)/1.1-1.9 (males) for people with current versus never smoking status; and 1.0-1.3 (females)/1.0-1.5 (males) for people with former versus never smoking status, depending on age at cessation. We assumed smoking status remains unchanged during the simulation; people who formerly smoked quit at model start. Simulated PWH face a monthly probability of disengagement from care and virologic non-suppression. In sensitivity analysis, we varied smoking-associated and HIV-associated mortality risks. Additionally, we estimated the total life-years gained if a proportion of all virologically suppressed PWH stopped smoking.

RESULTS

Forty-five-year-old females/males with HIV with virologic suppression who smoke lose 5.3/3.7 life-years compared to PWH who never smoke. Smoking cessation at age 45y adds 3.4/2.4 life-years. Simulated PWH who continue smoking lose more life-years from smoking than from HIV (females, 5.3 vs. 3.0 life-years; males, 3.7 vs. 2.6 life-years). The impact of smoking and smoking cessation increase as smoking-associated mortality risks increase and HIV-associated mortality risks, including disengagement from care, decrease. Model results are most sensitive to the smoking-associated mortality hazard ratio; varying this parameter results in 1.0-5.1 life-years gained from cessation at age 45y. If 10-25% of virologically suppressed PWH aged 30-59y in South Africa stopped smoking now, 190,000-460,000 life-years would be gained.

CONCLUSIONS

Among virologically suppressed PWH in South Africa, tobacco smoking decreases life expectancy more than HIV. Integrating tobacco cessation interventions into HIV care, as endorsed by the World Health Organization, could substantially improve life expectancy.

Factors Influencing Tobacco Smoking and Cessation Among People Living with HIV: A Systematic Review and Meta-analysis

Tobacco smoking is highly prevalent among people living with HIV (PLWH), yet there is a lack of data on smoking behaviours and effective treatments in this population. Understanding factors influencing tobacco smoking and cessation is crucial to guide the design of effective interventions. This systematic review and meta-analysis of studies conducted in both high-income (HICs) and low- and middle-income countries (LMICs) synthesised existing evidence on associated factors of smoking and cessation behaviour among PLWH. Male gender, substance use, and loneliness were positively associated with current smoking and negatively associated with smoking abstinence. The association of depression with current smoking and lower abstinence rates were observed only in HICs. The review did not identify randomised controlled trials conducted in LMICs. Findings indicate the need to integrate smoking cessation interventions with mental health and substance use services, provide greater social support, and address other comorbid conditions as part of a comprehensive approach to treating tobacco use in this population. Consistent support from health providers trained to provide advice and treatment options is also an important component of treatment for PLWH engaged in care, especially in LMICs.

The influence of smoking and HIV infection on pulmonary function

Background

Prevalence of HIV, smoking, and pulmonary infections in South Africa are high.

Objectives

We investigated the role of smoking and HIV status on lung function.

Methods

This is a secondary analysis of a cross-sectional study conducted in South Africa. Data included demographics, pulmonary risk factors and a spirometry test to obtain the forced expiratory volume in one second (FEV1) and the ratio of FEV1/forced vital capacity (FVC). In the initial multivariable regression analysis, the effect of smoking on pulmonary function in HIV-positive adults was assessed. The analysis was repeated, assessing the influence of HIV status on lung function in both HIV-negative and HIV-positive smokers. The models were adjusted for age, sex, body mass index (BMI), time since HIV diagnosis, antiretroviral treatment (ART) use, occupational hazards, history of tuberculosis or pneumonia, indoor smoking and the presence of an indoor fireplace during childhood.

Results

This study included 524 people living with HIV (PLWH, 66.7% female, mean age 40.9 years [s.d.; 9.4]) and 79 HIV-negative smokers (77.2% male, mean age 34.4 years [s.d.: 12.1]). Of the PLWH, 118 (22.5%) were past or current smokers and 406 (77.5%) were non-smokers. Smoking was not associated with changes in the FEV1 or FEV1/FVC ratio in multivariable regression analysis. In the second analysis, HIV status was also not associated with reduced pulmonary function following adjustment for confounders.

Conclusion

Neither smoking nor being HIV-positive was associated with decreased pulmonary function in this relatively young population. These findings should be confirmed in a longitudinal study, including an older population.

Using a Syndemics Framework to Understand How Substance Use Contributes to Morbidity and Mortality among People Living with HIV in Africa: A Call to Action

Substance use is increasing throughout Africa, with the prevalence of alcohol, tobacco, cannabis, and other substance use varying regionally. Concurrently, sub-Saharan Africa bears the world's largest HIV burden, with 71% of people living with HIV (PWH) living in Africa. Problematic alcohol, tobacco, and other substance use among PWH is associated with multiple vulnerabilities comprising complex behavioral, physiological, and psychological pathways that include high-risk behaviors (e.g., sexual risk-taking), HIV disease progression, and mental health problems, all of which contribute to nonadherence to antiretroviral therapy. Physiologically, severe substance use disorders are associated with increased levels of biological markers of inflammation; these, in turn, are linked to increased mortality among PWH. The biological mechanisms that underlie the increased risk of substance use among PWH remain unclear. Moreover, the biobehavioral mechanisms by which substance use contributes to adverse health outcomes are understudied in low- and middle-income countries (LMIC). Syndemic approaches to understanding the co-occurrence of substance use and HIV have largely been limited to high-income countries. We propose a syndemic coupling conceptual model to disentangle substance use from vulnerabilities to elucidate underlying disease risk for PWH. This interventionist perspective enables assessment of biobehavioral mechanisms and identifies malleable targets of intervention.

Tobacco Smoking and Associated Factors Among People Living With HIV in Uganda

INTRODUCTION

The prevalence of smoking among people living with HIV (PLWH) in Uganda is high.

AIMS AND METHODS

We assessed the smoking patterns, behaviors, and associated factors among PLWH in Uganda through a cross-sectional survey. Descriptive statistics were used to describe smoking patterns and behaviors. Logistic regression was used to identify factors associated with current smoking status.

RESULTS

We recruited 777 participants between October and November 2019: 387 (49.8%) current smokers and 390 (50.2%) nonsmokers. 60.9% were males, and the mean age was 40.5 (SD 10.7) years. In multivariate logistic regression, the following increased the odds of being a current smoker: being male (odds ratio [OR] 6.60 [95% confidence interval, CI = 4.34-10.04]), having at least two smokers among five closest friends (OR 3.97 [95% CI = 2.08-7.59]), living in smoking-permitted households (OR 5.83 [95% CI = 3.32-10.23]), alcohol use (OR 3.96 [95% CI = 2.34-6.71]), a higher perceived stress score (OR 2.23 [95% CI = 1.50-3.34]), and higher health-related quality of life (OR 5.25 [95% CI = 1.18-23.35]). Among smokers, the mean Fagerström Test for Nicotine Dependence score was 3.0 (SD 1.9), and 52.5% were making plans to quit. Self-efficacy to resist smoking and knowledge of the impact of smoking on PLWH's health were low.

CONCLUSIONS

Being male, having at least two smokers among five closest friends, living in smoking-permitted households, alcohol use, higher perceived stress scores, and higher health-related quality of life were associated with being a current smoker. Smokers had low to moderate nicotine dependence, high willingness to quit, and low self-efficacy.

IMPLICATIONS

Future behavioral smoking cessation interventions for PLWH should address co-consumption with alcohol and comorbid mental health conditions that are common among PLWH such as stress. In addition, they should take into account the lack of knowledge among this population of the impact of smoking on their health, and low self-efficacy. Given the relatively low levels of nicotine dependency and high levels of willingness to quit in our sample, smoking cessation interventions, if offered, are likely to support this population in achieving long-term smoking abstinence.