Using high-resolution residential greenspace measures in an urban environment to assess risks of allergy outcomes in children.

Despite reported health benefits of urban greenspace (gs), the epidemiological evidence is less clear for allergic disease. To address a limitation of previous research, we examined the associations of medium- and high-resolution residential gs measures and tree and/or grass canopies with allergic outcomes for children enrolled in the longitudinal cincinnati childhood allergy and air pollution study (ccaaps). We estimated residential gs based on 400 m radial buffers around participant addresses (n = 478) using the normalized differential vegetation index (ndvi) and land cover-derived urban greenspace (ugs) (tree and grass coverage, combined and separate) at 30 m and 1.5-2.5 m resolution, respectively. Associations between outdoor aeroallergen sensitization and allergic rhinitis at age 7 and residential gs measures at different exposure windows were examined using multivariable logistic regression models. A 10% increase in ugs-derived grass coverage was associated with an increased risk of sensitization to grass pollens (adjusted odds ratio [aor]: 1.27; 95% confidence interval = 1.02-1.58). For each 10% increase in ugs-derived tree canopy coverage, nonstatistically significant decreased odds were found for grass pollen sensitization, tree pollen sensitization, and sensitization to either (aor range = 0.87-0.94). Results similar in magnitude to ugs-tree canopy coverage were detected for ndvi and allergic sensitizations. High-resolution (down to 1.5 m) gs measures of grass- and tree-covered areas showed associations in opposite directions for different allergy outcomes. These data suggest that measures strongly correlated with tree canopy (e.g., ndvi) may be insufficient to detect health effects associated with proximity to different types of vegetation or help elucidate mechanisms related to specific gs exposure pathways.

Estimating sampling frequency in pollen exposure assessment over time.

A time series model was fitted to the pollen concentration data collected in the Greater Cincinnati area for the Cincinnati Childhood Allergy and Air Pollution Study (CCAAPS). A traditional time series analysis and temporal variogram approach were applied to the regularly spaced databases (collected in 2003) and irregularly spaced ones (collected in 2002), respectively. The aim was to evaluate the effect of the sampling frequency on the sampling precision in terms of inverse of standard error of the overall level of mean value across time. The presence of high autocorrelation in the data was confirmed and indicated some degree of temporal redundancy in the pollen concentration data. Therefore, it was suggested that sampling frequency could be reduced from once a day to once every several days without a major loss of sampling precision of the overall mean over time. Considering the trade-offs between sampling frequency and the possibility of sampling bias increasing with larger sampling interval, we recommend that the sampling interval should take values from 3 to 5 days for the pollen monitoring program, if the goal is to track the long-term average.

Changes in caffeine consumption as a signal of pregnancy.

OBJECTIVES: The purpose of this prospective study was to examine caffeine consumption and other signals of early pregnancy. STUDY DESIGN: One hundred and five pregnant, nonsmoking, coffee drinkers ages 18-40 were enrolled by the ninth week after their last menstrual period (LMP). Participants kept daily diaries of beverage and caffeine consumption and symptoms. Urine samples were collected to assess hormone metabolites. Descriptive statistics were generated. RESULTS: During the first trimester, 96% of subjects decreased or quit drinking coffee, 65% of whom reported a unique aversion to coffee. The mean daily caffeine consumption at LMP from coffee alone was 119 mg (S.D., 105), with a range 1-574 mg. There was a 59% decrease of mean daily consumption of caffeine from coffee between weeks 4 and 6, from 96 to 39 mg. The vast majority of subjects experienced nausea (98%) and appetite loss (93%); vomiting was less prevalent (54%). The most common dietary aversions included meat, coffee, spicy foods, and dairy products. Hormone metabolite patterns are reported. CONCLUSION: Signals of early pregnancy included an aversion to coffee in addition to nausea and vomiting, which resulted in decreased caffeine consumption. These symptoms often interfered with daily life and lasted beyond the first trimester for many. Consideration should be given that a decrease in caffeine consumption may be a signal for a healthy pregnancy and acting as a confounder.

Pregnancy hormone metabolite patterns, pregnancy symptoms, and coffee consumption.

Because of contradictory reports of pregnancy outcomes and coffee intake, this study was designed to determine how hormone metabolite levels, symptoms, and coffee consumption patterns are related. Eligible subjects were recruited in Cincinnati, Ohio, from 1996 to 1998, aged 18-40 years, and nonsmokers; drank at least 18 ounces (1 ounce = 29.6 ml) of coffee per week (including decaffeinated) at the last menstrual period; and were enrolled by 9 weeks from the last menstrual period. Beverage consumption and pregnancy symptoms were recorded daily. Weekly, first-morning urine samples were collected to assess human chorionic gonadotropin, estrone-3-glucuronide, and pregnanediol-3-glucuronide. A time-dependent, repeated measures analysis was performed to test several associations. Data from 92 subjects were analyzed with the following results. 1) Coffee consumption was significantly, inversely associated with weekly levels of estrone-3-glucuronide and human chorionic gonadotropin. 2) Weekly hours of nausea were significantly, directly associated with human chorionic gonadotropin and inversely with estrone-3-glucuronide and pregnanediol-3-glucuronide. 3) Weekly coffee consumption was significantly associated with vomiting but not with nausea or appetite loss. 4) Weekly levels of pregnanediol-3-glucuronide were 32.2% lower in subjects who drank at least 8 ounces of coffee/day at the last menstrual period, though above what was necessary to maintain those pregnancies. This study shows the significance of these important variables to be considered in future research.