Household Air Pollution Interventions to Improve Health in Low- and Middle-Income Countries: An Official American Thoracic Society Research Statement

Background: An estimated 3 billion people, largely in low- and middle-income countries, rely on unclean fuels for cooking, heating, and lighting to meet household energy needs. The resulting exposure to household air pollution (HAP) is a leading cause of pneumonia, chronic lung disease, and other adverse health effects. In the last decade, randomized controlled trials of clean cooking interventions to reduce HAP have been conducted. We aim to provide guidance on how to interpret the findings of these trials and how they should inform policy makers and practitioners.Methods: We assembled a multidisciplinary working group of international researchers, public health practitioners, and policymakers with expertise in household air pollution from within academia, the American Thoracic Society, funders, nongovernmental organizations, and global organizations, including the World Bank and the World Health Organization. We performed a literature search, convened four sessions via web conference, and developed consensus conclusions and recommendations via the Delphi method.Results: The committee reached consensus on 14 conclusions and recommendations. Although some trials using cleaner-burning biomass stoves or cleaner-cooking fuels have reduced HAP exposure, the committee was divided (with 55% saying no and 45% saying yes) on whether the studied interventions improved measured health outcomes.Conclusions: HAP is associated with adverse health effects in observational studies. However, it remains unclear which household energy interventions reduce exposure, improve health, can be scaled, and are sustainable. Researchers should engage with policy makers and practitioners working to scale cleaner energy solutions to understand and address their information needs.

Arsenic exposure associated T cell proliferation, smoking, and vitamin D in Bangladeshi men and women

There are limited data examining the consequences of environmental exposure to arsenic on the immune system in adults, particularly among smokers. Smoking has been shown to exacerbate or contribute to impaired immune function in men chronically exposed to arsenic. In contrast, vitamin D (VitD) is known to have a positive influence on innate and adaptive immune responses. The effect of circulating VitD on arsenic-associated immune dysfunction is not known. Here we examine the relationship of arsenic exposure and T cell proliferation (TCP), a measure of immune responsiveness, and circulating VitD among adult men and women in Bangladesh. Arsenic exposure was assessed using total urinary arsenic as well as urinary arsenic metabolites all adjusted for urinary creatinine. TCP was measured ex vivo in cryopreserved peripheral blood mononuclear cells from 614 adult participants enrolled in the Bangladesh Health Effects of Arsenic Longitudinal Study; serum VitD was also evaluated. The influence of cigarette smoking on arsenic-induced TCP modulation was assessed only in males as there was an inadequate number of female smokers. These studies show that arsenic suppressed TCP in males. The association was significantly strong in male smokers and to a lesser extent in male non-smokers. Interestingly, we found a strong protective effect of high/sufficient serum VitD levels on TCP among non-smoking males. Furthermore, among male smokers with low serum VitD (⊔20 ng/ml), we found a strong suppression of TCP by arsenic. On the other hand, high VitD (>20 ng/ml) was found to attenuate effects of arsenic on TCP among male-smokers. Overall, we found a strong protective effect of VitD, when serum levels were >20 ng/ml, on arsenic-induced inhibition of TCP in men, irrespective of smoking status. To our knowledge this is the first large study of immune function in healthy adult males and females with a history of chronic arsenic exposure.

Implementation of clean cookstove interventions and its effects on blood pressure in low-income and middle-income countries: systematic review

OBJECTIVE

A review of the implementation outcomes of clean cookstove use, and its effects on blood pressure (BP) in low-income and middle-income countries (LMICs).

DESIGN

Systematic review of studies that reported the effect of clean cookstove use on BP among women, and implementation science outcomes in LMICs.

DATA SOURCES

We searched PubMed, Embase, INSPEC, Scielo, Cochrane Library, Global Health and Web of Science PLUS. We conducted searches in November 2017 with a repeat in May 2018. We did not restrict article publication date.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

We included only studies conducted in LMICs, published in English, regardless of publication year and studies that examined the use of improved or clean cookstove intervention on BP. Two authors independently screened journal article titles, abstracts and full-text articles to identify those that included the following search terms: high BP, hypertension and or household air pollution, LMICs, cookstove and implementation outcomes.

RESULTS

Of the 461 non-duplicate articles identified, three randomised controlled trials (RCTs) (in Nigeria, Guatemala and Ghana) and two studies of pre-post design (in Bolivia and Nicaragua) met eligibility criteria. These articles evaluated the effect of cookstove use on BP in women. Two of the three RCTs reported a mean reduction in diastolic BP of -2.8 mm Hg (-5.0, -0.6; p=0.01) for the Nigerian study; -3.0 mm Hg; (-5.7, -0.4; p=0.02) for the Guatemalan study; while the study conducted in Ghana reported a non-significant change in BP. The pre-post studies reported a significant reduction in mean systolic BP of -5.5 mm Hg; (p=0.01) for the Bolivian study, and -5.9 mm Hg (-11.3, -0.4; p=0.05) for the Nicaraguan study. Implementation science outcomes were reported in all five studies (three reported feasibility, one reported adoption and one reported feasibility and adoption of cookstove interventions).

CONCLUSION

Although this review demonstrated that there is limited evidence on the implementation of clean cookstove use in LMICs, the effects of clean cookstove on BP were significant for both systolic and diastolic BP among women. Future studies should consider standardised reporting of implementation outcomes.

A continuum of admixture in the Western Hemisphere revealed by the African Diaspora genome

The African Diaspora in the Western Hemisphere represents one of the largest forced migrations in history and had a profound impact on genetic diversity in modern populations. To date, the fine-scale population structure of descendants of the African Diaspora remains largely uncharacterized. Here we present genetic variation from deeply sequenced genomes of 642 individuals from North and South American, Caribbean and West African populations, substantially increasing the lexicon of human genomic variation and suggesting much variation remains to be discovered in African-admixed populations in the Americas. We summarize genetic variation in these populations, quantifying the postcolonial sex-biased European gene flow across multiple regions. Moreover, we refine estimates on the burden of deleterious variants carried across populations and how this varies with African ancestry. Our data are an important resource for empowering disease mapping studies in African-admixed individuals and will facilitate gene discovery for diseases disproportionately affecting individuals of African ancestry.

Arsenic and lung disease mortality in Bangladeshi adults

BACKGROUND

Chronic arsenic exposure through drinking water is a public health problem affecting millions of people worldwide, including at least 30 million in Bangladesh. We prospectively investigated the associations of arsenic exposure and arsenical skin lesion status with lung disease mortality in Bangladeshi adults.

METHODS

Data were collected from a population-based sample of 26,043 adults, with an average of 8.5 years of follow-up (220,157 total person-years). There were 156 nonmalignant lung disease deaths and 90 lung cancer deaths ascertained through October 2013. We used Cox proportional hazards models to estimate adjusted hazard ratios and 95% confidence intervals (CIs) for lung disease mortality.

RESULTS

Creatinine-adjusted urinary total arsenic was associated with nonmalignant lung disease mortality, with persons in the highest tertile of exposure having a 75% increased risk for mortality (95% CI = 1.15-2.66) compared with those in the lowest tertile of exposure. Persons with arsenical skin lesions were at increased risk of lung cancer mortality (hazard ratio = 4.53 [95% CI = 2.82-7.29]) compared with those without skin lesions.

CONCLUSIONS

This prospective investigation of lung disease mortality, using individual-level arsenic measures and skin lesion status, confirms a deleterious effect of ingested arsenic on mortality from lung disease. Further investigations should evaluate effects on the incidence of specific lung diseases, more fully characterize dose-response, and evaluate screening and biomedical interventions to prevent premature death among arsenic-exposed populations, particularly among those who may be most susceptible to arsenic toxicity.

Arsenic exposure and impaired lung function. Findings from a large population-based prospective cohort study

RATIONALE

Exposure to arsenic through drinking water has been linked to respiratory symptoms, obstructive lung diseases, and mortality from respiratory diseases. Limited evidence for the deleterious effects on lung function exists among individuals exposed to a high dose of arsenic.

OBJECTIVES

To determine the deleterious effects on lung function that exist among individuals exposed to a high dose of arsenic.

METHODS

In 950 individuals who presented with any respiratory symptom among a population-based cohort of 20,033 adults, we evaluated the association between arsenic exposure, measured by well water and urinary arsenic concentrations measured at baseline, and post-bronchodilator-administered pulmonary function assessed during follow-up.

MEASUREMENTS AND MAIN RESULTS

For every one SD increase in baseline water arsenic exposure, we observed a lower level of FEV1 (-46.5 ml; P < 0.0005) and FVC (-53.1 ml; P < 0.01) in regression models adjusted for age, sex, body mass index, smoking, socioeconomic status, betel nut use, and arsenical skin lesions status. Similar inverse relationships were observed between baseline urinary arsenic and FEV1 (-48.3 ml; P < 0.005) and FVC (-55.2 ml; P < 0.01) in adjusted models. Our analyses also demonstrated a dose-related decrease in lung function with increasing levels of baseline water and urinary arsenic. This association remained significant in never-smokers and individuals without skin lesions, and was stronger in male smokers. Among male smokers and individuals with skin lesions, every one SD increase in water arsenic was related to a significant reduction of FEV1 (-74.4 ml, P < 0.01; and -116.1 ml, P < 0.05) and FVC (-72.8 ml, P = 0.02; and -146.9 ml, P = 0.004), respectively.

CONCLUSIONS

This large population-based study confirms that arsenic exposure is associated with impaired lung function and the deleterious effect is evident at low- to moderate-dose range.

The academic health center in complex humanitarian emergencies: lessons learned from the 2010 Haiti earthquake

On January 12, 2010, a 7.0-magnitude earthquake struck Haiti. The event disrupted infrastructure and was marked by extreme morbidity and mortality. The global response to the disaster was rapid and immense, comprising multiple actors-including academic health centers (AHCs)-that provided assistance in the field and from home. The authors retrospectively examine the multidisciplinary approach that the University of Chicago Medicine (UCM) applied to postearthquake Haiti, which included the application of institutional structure and strategy, systematic deployment of teams tailored to evolving needs, and the actual response and recovery. The university mobilized significant human and material resources for deployment within 48 hours and sustained the effort for over four months. In partnership with international and local nongovernmental organizations as well as other AHCs, the UCM operated one of the largest and more efficient acute field hospitals in the country. The UCM's efforts in postearthquake Haiti provide insight into the role AHCs can play, including their strengths and limitations, in complex disasters. AHCs can provide necessary intellectual and material resources as well as technical expertise, but the cost and speed required for responding to an emergency, and ongoing domestic responsibilities, may limit the response of a large university and hospital system. The authors describe the strong institutional backing, the detailed predeployment planning and logistical support UCM provided, the engagement of faculty and staff who had previous experience in complex humanitarian emergencies, and the help of volunteers fluent in the local language which, together, made UCM's mission in postearthquake Haiti successful.

Prospective trial of efficacy and safety of ondansetron and fluoxetine in patients with obstructive sleep apnea syndrome

STUDY OBJECTIVE

Incremental withdrawal of serotonin during wake to sleep transition is postulated as a key mechanism that renders the pharyngeal airway collapsible. While serotonin promotion with reuptake inhibitors have demonstrated modest beneficial effects during NREM sleep on obstructive sleep apnea (OSA), animal studies suggest a potential therapeutic role for selective serotonin receptor antagonists (5-HT3) in REM sleep. We aimed to test the hypothesis that a combination of ondansetron (Ond) and fluoxetine (Fl) may effectively reduce expression of disordered breathing during REM and NREM sleep in patients with OSA.

DESIGN AND SETTING

A prospective, parallel-groups, single-center trial in patients with OSA.

PARTICIPANTS

35 adults with apnea hypopnea index (AHI) > 10; range 10-98.

INTERVENTION

Subjects were randomized to placebo, n = 7; Ond (24 mg QD), n = 9; Fl (5 mg QD) + Ond (12 mg QD), n = 9; and Fl (10 mg QD) + Ond (24 mg QD), n = 10.

MEASUREMENTS AND RESULTS

AHI was measured by in-lab polysomnography after a 7-day no-treatment period (Baseline) and on days 14 and 28 of treatment. The primary endpoint was AHI reduction at days 14 and 28. OND+FL resulted in approximately 40% reduction of baseline AHI at days 14 and 28 (unadjusted P < 0.03 for each) and improved oximetry trends. This treatment-associated relative reduction in AHI was also observed in REM and supine sleep.

CONCLUSIONS

Combined treatment with OND+FL is well-tolerated and reduces AHI, yielding a potentially therapeutic response in some subjects with OSA.

Efficacy of Mirtazapine in Obstructive Sleep Apnea Syndrome

STUDY OBJECTIVES

Decreased serotonergic facilitation of upper-airway motor neurons during sleep has been postulated as an important mechanism rendering the upper airway vulnerable to obstruction in patients with obstructive sleep apnea syndrome (OSA). Although serotonin reuptake inhibitors have been shown to produce modest reductions in the apnea-hypopnea index (AHI) during non-rapid eye movement (NREM) sleep, they have not been proven to be generally effective as treatments for OSA. Conversely, antagonists of type 3 (5-HT3) serotonin receptors effectively have been shown to reduce the frequency of central apneas during rapid eye movement (REM) sleep in a rodent model of sleep-related breathing disorder. We sought to determine whether mirtazapine, a mixed 5-HT2/5-HT3 antagonist that also promotes serotonin release in the brain would effectively reduce AHI during both NREM and REM sleep in patients with OSA.

DESIGN

A randomized, double-blind, placebo-controlled, 3-way crossover study of mirtazapine in patients with OSA.

SETTING

Laboratory studies were conducted in the Center for Sleep and Ventilatory Disorders at the University of Illinois Medical Center.

PATIENTS

Seven adult men and 5 adult women with newly diagnosed (treatment-naïve) and medically uncomplicated OSA were randomized into the study.

INTERVENTIONS

Each subject self-administered oral medications 30 minutes before bedtime each night for 3 consecutive 7-day treatment periods. These treatments comprised (1) placebo, (2) 4.5 mg per day of mirtazapine, and (3) 15 mg per day of mirtazapine. The order of treatments was randomized for each subject, and orders were counterbalanced for the overall study.

MEASUREMENTS AND RESULTS

Each subject charted his or her sleep-wake schedule throughout the study and completed the Stanford Sleepiness Scale every 2 hours during the seventh day of each treatment period. Subjects were studied by laboratory polysomnography on the seventh night of each treatment period. With respect to placebo treatment, 4.5 mg of mirtazapine significantly reduced the AHI in all sleep stages to 52%, with 11 of 12 subjects showing improvement over placebo; 15 mg of mirtazapine reduced the AHI to 46%, with 12 of 12 subjects showing improvement over placebo. Sleep fragmentation was reduced only by the higher dose of mirtazapine. Gross changes in sleep architecture were unremarkable.

CONCLUSIONS

Daily administration of 4.5 to 15 mg of mirtazapine for 1 week reduces AHI by half in adult patients with OSA. This represents the largest and most consistent drug-treatment effect demonstrated to date in a controlled trial. These findings suggest the therapeutic potential of mixed-profile serotonergic drugs in OSA and provide support for future studies with related formulations. Mirtazapine also is associated with sedation and weight gain-2 negative side effects in patients with OSA. In view of the above, we do not recommend use of mirtazapine as a treatment for OSA.

Systemic sclerosis complicated by diffuse alveolar hemorrhage

A 38-year-old woman with limited cutaneous systemic sclerosis and pulmonary fibrosis developed diffuse alveolar hemorrhage during the course of her disease that responded well to steroids. We present the clinical history of the patient and discuss the different theories behind the association. The importance of steroid therapy for treatment of alveolar hemorrhage in this particular condition is emphasized.