Using smartphones to collect time-activity data for long-term personal-level air pollution exposure assessment.

Because of the spatiotemporal variability of people and air pollutants within cities, it is important to account for a person's movements over time when estimating personal air pollution exposure. This study aimed to examine the feasibility of using smartphones to collect personal-level time-activity data. Using Skyhook Wireless's hybrid geolocation module, we developed "Apolux" (Air, Pollution, Exposure), an Android(TM) smartphone application designed to track participants' location in 5-min intervals for 3 months. From 42 participants, we compared Apolux data with contemporaneous data from two self-reported, 24-h time-activity diaries. About three-fourths of measurements were collected within 5 min of each other (mean=74.14%), and 79% of participants reporting constantly powered-on smartphones (n=38) had a daily average data collection frequency of <10 min. Apolux's degree of temporal resolution varied across manufacturers, mobile networks, and the time of day that data collection occurred. The discrepancy between diary points and corresponding Apolux data was 342.3 m (Euclidian distance) and varied across mobile networks. This study's high compliance and feasibility for data collection demonstrates the potential for integrating smartphone-based time-activity data into long-term and large-scale air pollution exposure studies.

A hospice-hospital partnership: reducing hospitalization costs and 30-day readmissions among seriously ill adults.

BACKGROUND: Inpatient palliative care (IPC) has been associated with numerous clinical benefits. Observational and randomized studies of cost savings associated with IPC provide conflicting results, and the association with readmission is not well understood. OBJECTIVE: We aimed to estimate the influence of IPC on hospitalization costs and readmission rates. METHODS: We measured hospitalization costs and 30-day readmission rates among 1004 patients who received IPC at two western New York hospitals in 2012. Using propensity score matching, we compared outcomes among patients receiving palliative care with those among 1004 similar adults who were hospitalized during the same period and did not receive palliative care. RESULTS: On average, cost per admission was $1,401 (13%) lower among patients receiving palliative care than comparison patients (p<0.05). Cost reductions were evident within intensive care and laboratory services. Readmission rates were significantly lower among palliative care patients discharged with hospice care (1.1%) than comparison patients (6.6%), but significantly higher among palliative care patients discharged to other locations (12.1%). CONCLUSIONS: Receipt of IPC appears to reduce hospitalization costs among adult western New Yorkers. Furthermore, care coordinated with postdischarge hospice services appears to substantially reduce the likelihood of readmission.

Clinical impact of a home-based palliative care program: a hospice-private payer partnership.

CONTEXT: Outpatient programs have been traditionally offered in the U.S. under programs such as the Medicare Hospice Benefit. Recommendations now emphasize a blended model in which palliative care is offered concurrently with curative approaches at the onset of serious or life-limiting disease. The efficacy of nonhospice outpatient palliative care programs is not well understood. OBJECTIVES: The aim of the study was to evaluate the clinical impact of a home-based palliative care program, Home Connections, implemented as a partnership between a not-for-profit hospice and two private insurers. METHODS: This was a prospective, observational, database study of 499 Home Connections participants enrolled between July 1, 2008, and May 31, 2013. Measured outcomes were advance directive completion, site of death, symptom severity over time, program satisfaction, and hospice referral and average length of stay. RESULTS: Seventy-one percent of participants completed actionable advance directives after enrollment, and the site of death was home for 47% of those who died during or after participation in the program. Six of eight symptom domains (anxiety, appetite, dyspnea, well-being, depression, and nausea) showed improvement. Patients, caregivers, and physicians gave high program satisfaction scores (93%-96%). Home Connections participants who subsequently enrolled in hospice care had a longer average length of stay of 77.9 days compared with all other hospice referrals (average length of stay 56.5 days). CONCLUSION: A home-based palliative care program was developed between two local commercial payers and a not-for-profit hospice. Not only did this program improve symptom management, advance directive completion, and satisfaction, but it also facilitated the transition of patients into hospice care, when appropriate.

Household air quality risk factors associated with childhood pneumonia in urban Dhaka, Bangladesh.

To inform interventions to reduce the high burden of pneumonia in urban settings such as Kamalapur, Bangladesh, we evaluated household air quality risk factors for radiographically confirmed pneumonia in children. In 2009-2010, we recruited children < 5 years of age with pneumonia and controls from a population-based surveillance for respiratory and febrile illnesses. Piped natural gas was used by 85% of 331 case and 91% of 663 control households. Crowding, a tin roof in the living space, low socioeconomic status, and male sex of the child were risk factors for pneumonia. The living space in case households was 28% less likely than in control households to be cross-ventilated. Particulate matter concentrations were not significantly associated with pneumonia. With increasing urbanization and supply of improved cooking fuels to urban areas, the high burden of respiratory illnesses in urban populations such as Kamalapur may be reduced by decreasing crowding and improving ventilation in living spaces.

Pregnancy-related characteristics and breast cancer risk.

Breast tissues undergo extensive physiologic changes during pregnancy, which may affect breast carcinogenesis. Gestational hypertension, preeclampsia/eclampsia, gestational diabetes, pregnancy weight gain, and nausea and vomiting (N&V) during pregnancy may be indicative of altered hormonal and metabolic profiles and could impact breast cancer risk. Here, we examined associations between these characteristics of a woman's pregnancy and her subsequent breast cancer risk. Participants were parous women that were recruited to a population-based case-control study (Western New York Exposures and Breast Cancer Study). Cases (n = 960), aged 35-79 years, had incident, primary, histologically confirmed breast cancer. Controls (n = 1,852) were randomly selected from motor vehicle records (< 65 years) or Medicare rolls (≥ 65 years). Women were queried on their lifetime pregnancy experiences. Multivariable-adjusted logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). N&V during pregnancy was inversely associated with breast cancer risk. Relative to those who never experienced N&V, ever experiencing N&V was associated with decreased risk (OR 0.69, 95% CI 0.56-0.84) as were increased N&V severity (p trend < 0.001), longer duration (p trend < 0.01), and larger proportion of affected pregnancies (p trend < 0.0001) among women with ≥ 3 pregnancies. Associations were stronger for more recent pregnancies (< 5 years). Findings did not differ by menopausal status or breast cancer subtype including estrogen receptor and HER2 expression status. Other pregnancy characteristics examined were not associated with risk. We observed strong inverse associations between pregnancy N&V and breast cancer risk. Replication of these findings and exploration of underlying mechanisms could provide important insight into breast cancer etiology and prevention.

Exposure to traffic emissions: associations with biomarkers of antioxidant status and oxidative damage.

BACKGROUND: Oxidative stress has been implicated as a possible mechanism for adverse health effects associated with traffic emissions. We examined the association of an estimate of traffic emissions with blood biomarkers of antioxidant capacity (glutathione, glutathione peroxidase, trolox-equivalent antioxidant capacity) and oxidative damage (thiobarbituric acid-reactive substances (TBARS)) among 1810 healthy women, randomly selected from Erie and Niagara Counties in Western New York. METHODS: A geographic traffic emission and meteorological dispersion model was used to estimate annual polycyclic aromatic hydrocarbon (PAH) exposure from traffic emissions for each woman based on her residence at the time of study. Associations of traffic-related PAH exposure with measures of oxidative stress and antioxidant capacity were examined in multiple regression analyses with adjustment for potential confounders. RESULTS: Higher traffic-related PAH exposure was associated with decreased glutathione and increased glutathione peroxidase. Stronger associations between traffic-related PAH exposure and levels of glutathione and glutathione peroxidase were suggested among nonsmoking women without secondhand smoke exposure, especially among premenopausal nonsmoking women. Associations were also stronger for measurements made in warmer months. CONCLUSIONS: These findings suggest that PAHs or other components of traffic emissions may impact anti-oxidative capacity among healthy women, particularly premenopausal non-smokers without secondhand smoke exposure.

Relation of blood cadmium, lead, and mercury levels to biomarkers of lipid peroxidation in premenopausal women.

Exposures to cadmium, lead, and mercury are associated with adverse health effects, including cardiovascular disease, which may be promoted by lipid peroxidation. The authors examined cadmium, lead, and mercury in relation to plasma levels of F(2)-8α isoprostanes (isoprostane), 9-hydroperoxy-10,12-octadecadienoic acid (9-HODE), 13-hydroxy-9,11-octadecadienoic acid (13-HODE), and thiobarbituric acid reactive substances (TBARS) in 252 women from western New York State (2005-2007). Healthy premenopausal women were followed for ≤2 menstrual cycles, with biomarkers of lipid peroxidation being assessed ≤8 times per cycle. Metals were measured at baseline in whole blood. Linear mixed models were used to estimate the association between cadmium, lead, and mercury and lipid peroxidation biomarkers. Median cadmium, lead, and mercury levels were 0.30 µg/L, 0.86 µg/dL, and 1.10 µg/L, respectively. Blood cadmium, lead, and mercury were not associated with increases in isoprostane, TBARS, 9-HODE, or 13-HODE levels. Isoprostane levels decreased 6.80% (95% confidence interval: -10.40, -3.20) per 1% increase in mercury. However, after adjustment for a simulated strong confounding factor, such as precisely measured fish consumption, the observed association was attenuated, suggesting that this unexpected association could be attributable to unmeasured confounding. In this population of healthy premenopausal women with low exposure levels, cadmium, lead, and mercury were not associated with elevated lipid peroxidation biomarkers.

Age at menarche, menstrual cycle characteristics and risk of gestational diabetes.

AIMS: We examined associations of age at menarche and menstrual cycle characteristics with gestational diabetes mellitus (GDM) risk. METHODS: Study participants (N=3490) recruited prior to 16 weeks of gestation were followed until delivery. Menstrual history data were collected using questionnaires. GDM was diagnosed using the American Diabetes Association 2003 guidelines. Logistic regression was used to estimate odds-ratios (OR) and 95% confidence intervals (CI). RESULTS: Age at menarche was not associated with GDM risk. Women who had long menstrual cycles (>36 days) had higher risk of GDM compared with women who had normal cycle length (25-30 days) (OR=1.6; 95%CI0.98-2.67). Women who had long menstrual cycles and were either overweight or gained >5kg in adulthood had 4-5-fold higher GDM risk compared with women who had normal cycle length and were non-obese or gained <5kg in adulthood, respectively (OR=4.03; 95%CI:2.08-7.81 and OR=4.62, 95%CI:2.65-8.07, respectively). CONCLUSION: Longer menstrual cycles are significantly associated with increased risk of GDM, particularly among women who were either overweight or obese pre-pregnancy, or had ≥5kg weight gain in adult hood. Menstrual history may help identify women with increased risk of GDM.

Ambient carbon monoxide and fine particulate matter in relation to preeclampsia and preterm delivery in western Washington State.

BACKGROUND: Preterm delivery and preeclampsia are common adverse pregnancy outcomes that have been inconsistently associated with ambient air pollutant exposures. OBJECTIVES: We aimed to prospectively examine relations between exposures to ambient carbon monoxide (CO) and fine particulate matter [≤ 2.5 µm in aerodynamic diameter (PM2.5)] and risks of preeclampsia and preterm delivery. METHODS: We used data from 3,509 western Washington women who delivered infants between 1996 and 2006. We predicted ambient CO and PM2.5 exposures using regression models based on regional air pollutant monitoring data. Models contained predictor terms for year, month, weather, and land use characteristics. We evaluated several exposure windows, including prepregnancy, early pregnancy, the first two trimesters, the last month, and the last 3 months of pregnancy. Outcomes were identified using abstracted maternal medical record data. Covariate information was obtained from maternal interviews. RESULTS: Predicted periconceptional CO exposure was significantly associated with preeclampsia after adjustment for maternal characteristics and season of conception [adjusted odds ratio (OR) per 0.1 ppm=1.07; 95% confidence interval (CI), 1.02-1.13]. However, further adjustment for year of conception essentially nullified the association (adjusted OR=0.98; 95% CI, 0.91-1.06). Associations between PM2.5 and preeclampsia were nonsignificant and weaker than associations estimated for CO, and neither air pollutant was strongly associated with preterm delivery. Patterns were similar across all exposure windows. CONCLUSIONS: Because both CO concentrations and preeclampsia incidence declined during the study period, secular changes in another preeclampsia risk factor may explain the association observed here. We saw little evidence of other associations with preeclampsia or preterm delivery in this setting.

A case-control investigation of adenomyosis: impact of control group selection on risk factor strength.

OBJECTIVE: Using a medical record abstraction-based case-control study with two control groups, we evaluated adenomyosis risk factors and investigated differences related to comparison group selection. MATERIALS AND METHODS: Medical records of all female 18- to 49-year-old Group Health (GH) enrollees with ICD-9 code 617.0 were abstracted using a standard data collection form. Cases were enrollees diagnosed with adenomyosis (n = 174) between April 1996 and September 2001. For comparison, medical records of two control groups were selected from the GH population: An age-matched sample of female enrollees (population-based controls; n = 149) and all female 18- to 49-year-old enrollees undergoing a hysterectomy (hysterectomy controls; n = 106) during the same time without adenomyosis. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using logistic regression, adjusted for identified covariates. RESULTS: Compared with normal and underweight women, overweight and obese women had increased adenomyosis risk using hysterectomy controls (OR, 2.2, 95% CI, 1.0-4.5; obese: OR, 2.2; 95% CI, 1.1-4.3) and population controls (overweight: OR, 2.1; 95% CI, 1.2-4.0; obese: OR, 3.8; 95% CI, 2.0-7.0). Using population controls, women with at least one live birth were more likely to have adenomyosis than nulliparous women (OR, 3.4; 95% CI, 1.9-6.2). CONCLUSION: Although some risk factors persisted in analyses using either control group, divergent results in relation to other risk factors for adenomyosis suggest that results of investigations of this disease may be affected by the choice of the comparison population.

Energy expenditure and plasma F2-isoprostanes across the menstrual cycle.

INTRODUCTION: Habitual energy expenditure seems to favorably alter oxidant/antioxidant balance. Sparse evidence suggests that hormones that fluctuate during the menstrual cycle, particularly estrogens, may influence concentrations of oxidative biomarkers and their relation to energy expenditure. METHODS: We investigated the relation between energy expenditure and plasma free F2-isoprostane concentrations in 259 healthy, regularly menstruating 18- to 44-yr-old participants of the BioCycle Study. Habitual energy expenditure was measured using a baseline International Physical Activity Questionnaire and categorized as low, moderate, or high. Women were followed for one or two subsequent menstrual cycles. Past-week and past-day physical activity were measured during follow-up using questionnaires and diaries, respectively. F2-isoprostane concentrations were measured in blood samples collected at both menses (approximate cycle day 2; low serum estradiol concentration) and the late follicular phase (approximate cycle day 12; peak estradiol concentration). Generalized estimating equations were used to model the energy expenditure/isoprostane association, adjusting for confounders. RESULTS: Habitual energy expenditure was positively associated with F2-isoprostane concentration (adjusted difference in median F2-isoprostane, high versus low energy expenditure: 17.4%; 95% confidence interval (CI)=3.3%-31.4%). This association was not modified by cycle phase (interaction, P=0.61) or differences in peak estradiol concentration across women (interaction, P=0.20). Past-week and past-day physical activity measures were not associated with F2-isoprostane concentration (category trend, P=0.50 and P=0.18, respectively). CONCLUSIONS: These results suggest that higher habitual energy expenditure may be associated with higher concentration of F2-isoprostanes in healthy, reproductive-aged women. Estradiol concentration changes during the menstrual cycle do not seem to influence this relationship.

The association between gestational diabetes mellitus and recreational physical activity.

We aimed to investigate the association of recreational physical activity before pregnancy with gestational diabetes mellitus (GDM). A cross-sectional study was performed using self-reported data from the Pregnancy Risk Assessment and Monitoring System. The study population included 1,052 self-reported GDM cases and 10,351 non-GDM controls. Recreational physical activity in the 3 months before pregnancy was recalled in postpartum structured interviews. Compared to women exercising less than 1 day per week, women who exercised >5 days per week in the 3 months before pregnancy had a 31% lower odds of GDM (adjusted odds ratio [aOR]: 0.69; 95% confidence interval [CI]: 0.46, 1.03). Women who exercised 1-4 days per week had a 7% lower odds of GDM (aOR: 0.93; 95%CI: 0.72, 1.19). We did not observe statistically significant associations between pre-pregnancy physical activity and GDM risk. However, the magnitude and direction of association are consistent with previous observational studies. These studies collectively suggest a role of physical activity in GDM prevention.

Age at menarche, menstrual characteristics, and risk of preeclampsia.

We examined associations of age at menarche and menstrual characteristics with the risk of preeclampsia among participants (n = 3,365) of a pregnancy cohort study. Data were collected using in-person interviews and medical record abstraction. Logistic regression was used to estimate adjusted odds ratio (OR) and 95% confidence interval (95% CI). There was a significant inverse association between age at menarche and risk of preeclampsia (P value for trend < 0.05). Association of long cycle length (>36 days) with higher risk of preeclampsia was present only among women who had prepregnancy body mass index <25 kg/m(2) (interaction P value = 0.04). Early menarche is associated with higher risk of preeclampsia. Prepregnancy weight may modify associations of long menstrual cycles with risk of preeclampsia.

Relation of whole blood carboxyhemoglobin concentration to ambient carbon monoxide exposure estimated using regression.

Exposure to carbon monoxide (CO) and other ambient air pollutants is associated with adverse pregnancy outcomes. While there are several methods of estimating CO exposure, few have been evaluated against exposure biomarkers. The authors examined the relation between estimated CO exposure and blood carboxyhemoglobin concentration in 708 pregnant western Washington State women (1996-2004). Carboxyhemoglobin was measured in whole blood drawn around 13 weeks' gestation. CO exposure during the month of blood draw was estimated using a regression model containing predictor terms for year, month, street and population densities, and distance to the nearest major road. Year and month were the strongest predictors. Carboxyhemoglobin level was correlated with estimated CO exposure (rho = 0.22, 95% confidence interval (CI): 0.15, 0.29). After adjustment for covariates, each 10% increase in estimated exposure was associated with a 1.12% increase in median carboxyhemoglobin level (95% CI: 0.54, 1.69). This association remained after exclusion of 286 women who reported smoking or being exposed to secondhand smoke (rho = 0.24). In this subgroup, the median carboxyhemoglobin concentration increased 1.29% (95% CI: 0.67, 1.91) for each 10% increase in CO exposure. Monthly estimated CO exposure was moderately correlated with an exposure biomarker. These results support the validity of this regression model for estimating ambient CO exposures in this population and geographic setting.

A prospective study of maternal carboxyhaemoglobin and pre-eclampsia risk.

We aimed to measure the relationship between early-pregnancy maternal carboxyhaemoglobin and subsequent pre-eclampsia risk. A nested case-control analysis was conducted using data from a western Washington State cohort study (1996-2004). We measured maternal whole blood carboxyhaemoglobin in 128 women who developed pre-eclampsia and 419 normotensive controls (mean gestational age at blood draw, 14.8 weeks). After adjustment for confounders, high (>/=1%) vs. low (<0.7%) carboxyhaemoglobin odds ratios [OR] and 95% confidence intervals [CI] were 4.09 [1.30, 12.9] in multiparous women, 0.53 [0.23, 1.26] in primiparae and 1.11 [0.55, 2.25] in the overall study population (parity interaction P = 0.01). The influence of parity on the association was unexpected. The association between high carboxyhaemoglobin and pre-eclampsia risk in multiparae implicates hypoxia at the fetal-maternal interface as a pathogenic mechanism. These results also suggest that the aetiology of the disease may differ according to parity.

Infant exposure to fine particulate matter and traffic and risk of hospitalization for RSV bronchiolitis in a region with lower ambient air pollution.

Few studies investigate the impact of air pollution on the leading cause of infant morbidity, acute bronchiolitis. We investigated the influence of PM(2.5) and other metrics of traffic-derived air pollution exposure using a matched case-control dataset derived from 1997 to 2003 birth and infant hospitalization records from the Puget Sound Region, Washington State. Mean daily PM(2.5) exposure for 7, 30, 60 and lifetime days before case bronchiolitis hospitalization date were derived from community monitors. A regional land use regression model of NO(2) was applied to characterize subject's exposure in the month prior to case hospitalization and lifetime average before hospitalization. Subject's residential proximity within 150 m of highways, major roadways, and truck routes was also assigned. We evaluated 2604 (83%) cases and 23,354 (85%) controls with information allowing adjustment for mother's education, mother's smoking during pregnancy, and infant race/ethnicity. Effect estimates derived from conditional logistic regression revealed very modest increased risk and were not statistically significant for any of the exposure metrics in fully adjusted models. Overall, risk estimates were stronger when restricted to bronchiolitis cases attributed to respiratory syncytial virus (RSV) versus unspecified and for longer exposure windows. The adjusted odds ratio (OR(adj)) and 95% confidence interval per 10 mcg/m(3) increase in lifetime PM(2.5) was 1.14, 0.88-1.46 for RSV bronchiolitis hospitalization. This risk was also elevated for infants who resided within 150 m of a highway (OR(adj) 1.17, 0.95-1.44). This study supports a developing hypothesis that there may be a modest increased risk of bronchiolitis attributable to chronic traffic-derived particulate matter exposure particularly for infants born just before or during peak RSV season. Future studies are needed that can investigate threshold effects and capture larger variability in spatial contrasts among populations of infants.

A prospective analysis of recreational physical activity and preeclampsia risk.

PURPOSE: Although literature suggests that physical activity may reduce preeclampsia risk, most prior studies have relied on retrospective exposure assessment. We aimed to assess prospectively the relation between recreational physical activity before and during pregnancy and risk of preeclampsia. METHODS: We used data from a 1996-2003 cohort study of 2241 pregnant western Washington State residents. During structured interviews conducted at 15 wk of gestation, on average, women reported recreational activities during the year before pregnancy and during the previous 7 d. Preeclampsia diagnosis was established for 111 women using medical record data and standard guidelines. RESULTS: Recreational activity in the year before pregnancy was nonstatistically significantly associated with reduced preeclampsia risk (adjusted odds ratio [OR] for any vs none 0.55, 95% confidence interval [CI] 0.30-1.02). Any activity during early pregnancy was not strongly associated with preeclampsia risk (adjusted OR = 1.07, 95% CI = 0.67-1.69). Compared with women who reported no recreational activity before or during early pregnancy, risk was nonsignificantly lower among those who were active only before pregnancy (OR = 0.73, 95% CI = 0.30-1.77) and during both periods (OR = 0.76, 95% CI = 0.34-1.73). Those who were active only in early pregnancy had nonsignificantly increased preeclampsia risk (OR = 2.03, 95% CI = 0.71-5.81). CONCLUSION: These results corroborate previous case-control studies suggesting that prepregnancy recreational activity reduces preeclampsia risk. The absence of an association with early-pregnancy recreational activity in this cohort may be due to misclassification of usual early-pregnancy activity.

Pre-pregnancy body mass index and weight gain during pregnancy in relation to preterm delivery subtypes.

BACKGROUND: Associations between preterm delivery (PTD) and pre-pregnancy body mass index (BMI) and pregnancy weight gain may differ across outcome subtypes. METHODS: The authors analyzed data from 2,468 cohort participants in western Washington State, USA (1996-2005) and examined pre-pregnancy BMI and weight gain rate from pre-pregnancy to 18-22 weeks' gestation in relation to spontaneous PTD after preterm labor, spontaneous PTD after preterm premature rupture of membranes (PPROM), and indicated PTD. RESULTS: Each 5 kg/m(2) BMI increase was associated with indicated PTD (adjusted odds ratio [OR] 1.71, 95% confidence interval [CI] 1.40-2.06). The association weakened somewhat after adjustment for hypertension and diabetes before and/or during pregnancy (5 kg/m(2) adjusted OR, 1.40; 95% CI, 1.12-1.75). Associations with spontaneous PTD and PPROM were weaker (5 kg/m(2) adjusted ORs, 0.90 and 1.14, respectively). Weight gain was associated with indicated delivery among women with normal BMI (0.1 kg/week adjusted OR, 1.22; 95% CI, 1.02-1.45) but not among overweight or obese women (adjusted OR, 1.02; 95% CI, 0.87-1.20). Weight gain was inversely associated with spontaneous PTD (0.1 kg/week adjusted OR, 0.87; 95% CI, 0.77-0.99) and not strongly associated with PPROM (adjusted OR, 1.03; 95% CI, 0.90-1.17). CONCLUSIONS: Pre-pregnancy overweight increases indicated PTD risk independently of hypertension and diabetes. High early pregnancy weight gain increases indicated PTD risk in women with a normal BMI.

First-trimester mean arterial pressure and risk of preeclampsia.

BACKGROUND: Maternal second-trimester mean arterial pressure (MAP) is associated with a risk of preeclampsia in some but not all published studies. We examined average first-trimester MAP in relation to preeclampsia risk among 1655 women. METHODS: Using blood-pressure measurements recorded during prenatal care, we calculated MAP, and averaged the values within the first trimester. We defined preeclampsia according to national criteria, using information abstracted from medical records. We classified participants by MAP quartiles: <79, 79-83, 84-88, and >or=89 mm Hg. We calculated risk ratios (RRs) and 95% confidence intervals (CIs) adjusted for prepregnancy body mass index, age, race/ethnicity, and parity. RESULTS: High-quartile MAP was associated with an increased risk of preeclampsia when using current diagnostic criteria (adjusted RR versus low-quartile, 3.0; 95% CI, 1.2-7.4) but not when using older criteria (RR, 1.2; 95% CI, 0.6-2.2). First-trimester MAP did not strongly predict future preeclampsia (area under the receiver operating curve, 0.71). A MAP >/=88 mm Hg predicted preeclampsia with a sensitivity of 0.78 and a specificity of 0.63. CONCLUSIONS: Although first-trimester MAP is strongly associated with risk of preeclampsia, it poorly discriminates between women who will and will not develop the disease.

Weight characteristics and height in relation to risk of gestational diabetes mellitus.

Increasing prevalence of overweight and obesity motivated this prospective examination of gestational diabetes mellitus in relation to self-reported adult height, weight, and weight fluctuation. Gestational diabetes was assessed by use of medical records in 1,644 women enrolled in Seattle and Tacoma, Washington, between 1996 and 2002. After adjustment, risk was inversely related to height and directly related to pregravid body mass index (p(trend) < 0.001). The relation with body mass index at age 18 years was J shaped, with higher risk among lean women (adjusted relative risk (RR) = 1.79, 95% confidence interval (CI): 1.01, 2.84) and obese women (RR = 4.53, 95% CI: 1.25, 16.43) versus normal-weight women. Weight gain between age 18 years and the study pregnancy was associated with increased risk independently of body mass index at 18 years and other confounders (>/=10-kg gain vs. <2.5-kg change: RR = 3.43, 95% CI: 1.60, 7.37). Weight cycling (loss and regain of >/=6.8 kg) was not associated after adjustment for body mass index at 18 years and adult weight change (>/=3 vs. zero cycles: RR = 1.23, 95% CI: 0.56, 2.73). Cycling was nonsignificantly related among women who gained 10 kg or more during adulthood (>/=3 vs. zero cycles: RR = 2.04, 95% CI: 0.83, 5.02). Efforts to prevent obesity and weight gain among young women may reduce gestational diabetes risk.