Secondhand smoke is associated with more frequent hospitalizations in children with sickle cell disease

Abstract

Tobacco smoke exposure has been associated with more frequent hospitalizations in children with sickle cell disease (SCD), but previous studies have not quantified the exposure by objective methods. We enrolled 50 children and young adults with SCD in a retrospective and prospective cohort study and quantified tobacco smoke exposure by objective (salivary cotinine) and survey measures. We used a multivariable negative binomial regression model to evaluate the association between salivary cotinine and hospital admissions. Forty-five percent (22/49) of participants had significant elevation of salivary cotinine ( 0.5 ng/ ml). The incidence risk ratio (IRR) for hospital admission for those with elevated cotinine was 3.7 (95% CI 1.8-8). Those exposed to secondhand smoke but not primary smokers (cotinine between 0.5 and 10 ng/ml) had a similarly increased risk of hospitalization [IRR 4.3 (95% CI 1.8-10)]. We show that an objective measure of tobacco smoke exposure, salivary cotinine, is strongly associated with the rate of hospital admissions in children and young adults with SCD. This association underscores the importance of screening for tobacco smoke exposure in people with SCD. Further investigation is warranted to determine the mechanisms of and to evaluate interventions to decrease tobacco smoke exposure.

Sickle Cell Disease

“…79 In addition, high altitude has been linked to various complications in sickle cell disease, presumably because of lower oxygen levels. However, the evidence for this association comes primarily from small studies performed before hydroxyurea was widely used, and the true effects of altitude are unclear.…”

Secondhand Smoke Is an Important Modifiable Risk Factor in Sickle Cell Disease: A Review of the Current Literature and Areas for Future Research

“…Most pediatric studies have focused on secondhand exposures [9,10,11,13], and only one study has described the prevalence and ill effects of secondhand smoke in adults with SCD [8]. Three adult studies in SCD have focused on the prevalence and/or health consequences of smoking tobacco [8,12,18], and the remainder of the studies of adult SCD patients that we identified included tobacco use as a predictor/variable.…”

“…These include prophylaxis against influenza (vaccination) and pneumococcal infection (vaccination, penicillin in early childhood) [5], avoidance of exposure to cold water and weather [6], and malaria prophylaxis with bed nets and/or medications in parts of the world where it is endemic [7]. Evidence is mounting that tobacco smoke exposure (TSE), whether first-hand through primary smoking, or secondhand, is a common and important modifiable risk factor for pain [8,9,10], ACS [8,9,10,11,12], and lower airway obstruction [13,14] in children and adults with SCD. …”

“…TSE is associated with significant morbidity in children and adults with SCD, whether through secondhand exposure or through primary smoking [8,9,10,11,12,13]. TSE appears to have negative effects on pulmonary function and pulmonary exacerbations of SCD (i.e., more frequent ACS episodes) [8,9,10,11,13].…”

“…TSE appears to have negative effects on pulmonary function and pulmonary exacerbations of SCD (i.e., more frequent ACS episodes) [8,9,10,11,13]. It also has a negative impact on other acute complications of SCD, including more frequent painful vaso-occlusive crises [8,9,10]. TSE may exert direct, toxic effects on the airways of people with SCD, may enhance or exacerbate underlying systemic inflammatory processes, may influence pulmonary inflammation, or all of these.…”