Prenatal traffic-related air pollution exposures, cord blood adipokines and infant weight.

OBJECTIVE: Studies suggest that prenatal exposure to traffic-related air pollution (TRAP) may contribute to childhood obesity. While exact mechanisms for this association are unknown, circulating adipokines are hypothesized to contribute to early-life weight gain. METHODS: The Maternal and Child Health Study birth cohort included 136 women from the Los Angeles County + University of Southern California Medical Center. This study estimated prenatal residential TRAP exposure and used linear regression analysis to examine associations between adipokines with TRAP exposure and infant weight change (birth to 6 months). RESULTS: A one standard deviation (1-SD: 2 ppb) increase in prenatal non-freeway nitrogen oxides was associated with 33% (P = 0.01) higher leptin and 9% higher high molecular weight adiponectin levels (P = 0.07) in cord blood. Leptin levels were 71% higher in mothers who lived <75 m than those living >300 m from major roadways (P = 0.03). A 1-SD (10 ng mL-1 ) increase in leptin was associated with a significant increase in infant weight change in female infants (0.62 kg, P = 0.02) but not male infants (0.11 kg, P = 0.48). CONCLUSIONS: Higher TRAP exposures were associated with higher cord blood levels of leptin and high molecular weight adiponectin. These adipokines were associated with increased infant weight change in female infants, which may have implications for future obesity risk.

Characteristics of work related asthma: results from a population based survey.

OBJECTIVES: Many risk factors for asthma have been investigated, one of which is the workplace. Work related asthma is a frequently reported occupational respiratory disease yet the characteristics which distinguish it from non-work related asthma are not well understood. The purpose of this study was to examine differences between work related and non-work related asthma with respect to healthcare use and asthma control characteristics. METHODS: Data from the Massachusetts Behavioral Risk Factor Surveillance System for 2001 and 2002 were used for this analysis. Work related status of asthma was determined by self-report of ever having been told by a physician that asthma was work related. Healthcare measures evaluated were emergency room visits and physician visits for worsening asthma and for routine care. Characteristics of asthma control evaluated were frequency of asthma symptoms, asthma attacks, difficulty sleeping, and asthma medication usage in the last 30 days and limited activity in the past 12 months. RESULTS: The prevalence of lifetime and current asthma in Massachusetts were 13.0% and 9.2%, respectively. Approximately 6.0% (95% CI 4.8 to 7.3) of lifetime and 6.2% (95% CI 4.7 to 7.8) of current asthma cases were work related. In the past 12 months, individuals with work related current asthma were 4.8 times (95% CI 2.0 to 11.6) as likely to report having an asthma attack, 4.8 times (95% CI 1.8 to 13.1) as likely to visit the emergency room at least once, and 2.5 times (95% CI 1.1 to 6.0) as likely to visit the doctor at least once for worsening asthma compared to individuals with non-work related asthma. CONCLUSIONS: Work related asthma is associated with increased frequency of asthma attacks and use of healthcare services. A better understanding of factors that contribute to differences in healthcare use and asthma control is needed to improve prevention and control strategies for individuals suffering from the disease.