House Dust Endotoxin and Wheeze in the First Year of Life

Abstract

We examined endotoxin exposure and wheezing episodes during the first year of life in a birth cohort of 499 infants with one or both parents having a history of asthma or allergy. We measured endotoxin in settled dust from the baby's bed, bedroom floor, family room, and kitchen floor within the first 3 mo after birth. The primary outcomes were any wheeze (versus no wheeze), and repeated wheeze (versus one or no report of wheeze). We found a significant univariate association of elevated endotoxin (> or = 100 EU/ mg) in family room dust with increased risk of any wheeze (Relative Risk = 1.29, 95% CI = 1.03-1.62). The association was not confounded by cockroach allergen, lower respiratory illness (croup, bronchitis, bronchiolitis, and pneumonia), smoking during pregnancy, lower birth weight, maternal asthma, presence of dog, and race/ethnicity in a multivariate model; the multivariate relative risk (RR = 1.33) was marginally significant (95% CI: 1.00-1.76, p < 0.05). In a multivariate model, controlling for the above covariates, elevated endotoxin in family room dust was significantly associated with increased risk (RR = 1.56, 95% CI = 1.03-2.38) of repeated wheeze. These results suggest that home endotoxin exposure may independently increase risk of any wheeze and repeated wheeze during the first year of life for children with a familial predisposition to asthma or allergy.

Endotoxin in inner-city homes: Associations with wheeze and eczema in early childhood

“…Similar to the Boston study, we found both a negative association between endotoxin exposure and eczema and positive association between endotoxin exposure and wheeze (25,32). The decreased risk for eczema and potential "protection" from early atopic disease is consistent with the "hygiene hypothesis."…”

“…Results from a relatively small study in metropolitan Denver found an inverse association with endotoxin concentration and atopy (3), while a positive association between endotoxin concentration and wheeze was found in a mixed urban and suburban birth cohort in Boston (32,33). This latter Boston study also found an inverse association between endotoxin and eczema (25).…”

“…Associations with allergic disease (both positive and negative) have been reported with endotoxin expressed both as a concentration and as a load (3,4,24,32,34), and we have analyzed our results throughout using both measures for comparison. The majority of the home characteristics and the only health effects significantly associated with endotoxin were observed with concentration of endotoxin.…”

Indoor airborne fungi and wheeze in the first year of life among a cohort of infants at risk for asthma

“…These findings were independent of season of home sampling, the baby's age at the time of the visit, gender, the mother's age, insurance type and several risk factors for infant wheeze including: day care attendance (Ball et al, 2000;Stark et al, 2003), endotoxin levels (Park et al, 2001), maternal smoking during pregnancy (Gold et al, 1999;Lannero et al, 2006) and exposure to environmental tobacco smoke (Strachan and Cook, 1997;Stein et al, 1999). Although ''high'' levels of Aspergillus, Cladosporium, and Acrodontium demonstrated positive associations with wheeze in unadjusted analyses (each P value was r0.05), the odds ratios decreased following the addition of season of visit and other covariables.…”

Expressing urine from a gel disposable diaper for biomonitoring using phthalates as an example

“…The mechanism for the protective effect of exposure to farm animals is thought to be via induction of Th1 immune responses (Gereda et al, 2000b). Interestingly, increased exposure to lipopolysaccharides in non-farming domestic environments has been associated with an increased risk of recurrent wheeze during the first year of life in children with a family history of allergy (Park et al, 2001); however, the levels of exposure are substantially less than those experienced by farmers' children. A recent study of rural Iowa children seems to contradict the "hygiene hypothesis" that early-life exposure to farm animals is protective against allergic diseases.…”