Relationship between Urinary Cotinine Level and Diagnosis in Children Admitted to Hospital

Abstract

The reported association between passive smoking and respiratory illness in children has been based on the parents' assessment of their own level of smoking. To more critically evaluate a causal relationship between passive smoking and childhood ill health, we used urinary cotinine, which is the major metabolite of nicotine and has a long half-life, to objectively quantitate the level of passive smoking in children. Urine was collected from 609 children (median age 3.8 yr, range 1 month to 17 yr) on admission to hospital; cotinine levels were obtained in 491 of these samples, and a comprehensive respiratory questionnaire was completed for 468 children. Statistical analysis was carried out on transformed data using both parametric and nonparametric statistics. Cotinine levels in the children correlated with the parents' current smoking (p less than 0.001). Elevated levels were found in the 41 children admitted with bronchiolitis compared with a group of a similarly aged children with nonrespiratory illnesses (p less than 0.02). Elevated levels were not found for any other diagnosis. We conclude that the urinary cotinine approach has provided objective evidence linking passive smoking to hospital admission for bronchiolitis in infants.

Cotinine in Children Admitted for Asthma and Readmission

“…22 Another study linked urine cotinine levels to hospitalizations for bronchiolitis in infants. 23 The current study lends additional support to an emerging role for cotinine measurements as a biomarker and potential clinical measure for predicting future hospitalizations in children, especially those with respiratory conditions.…”

Passive smoking and the health of children.

“…37 Surprisingly, parental smoking does not increase the risk of hospital admission for acute asthma.263238 Reese et al found no association between urinary cotinine levels and asthma admissions, but they reported a positive correlation with admissions for bronchiolitis. 26 Ehrlich et al showed a correlation between recent passive smoking (as assessed by questionnaire and urinary levels of cotinine) and a diagnosis of asthma, but no association with acute exacerbations.38 They suggested that passive smoking increases hyperreactivity rather than producing bronchospasm.…”

Cigarette Smoke Alters Respiratory Syncytial Virus–Induced Apoptosis and Replication

“…Female smokers in the Israeli army had a 60% risk of influenza, compared with a 41.6% risk in nonsmokers (7). In addition, neonates and children exposed to cigarette smoke have a higher incidence and severity of viral infection (8)(9)(10)(11). These epidemiologic studies suggest that smoking is a risk factor for severe viral infection; however, the mechanism(s) for this are not known.…”