Hour-by-hour physical activity patterns of adults aged 45-65 years: a cross-sectional study

Background

Limited information exists on hour-by-hour physical activity (PA) patterns among adults aged 45–65 years. Therefore, this study aimed to distinguish typical hour-by-hour PA patterns, and examined which individuals typically adopt certain PA patterns.

Methods

Accelerometers measured light and moderate-vigorous PA. GIS-data provided proportions of land use within an 800 and 1600 m buffer around participant’s homes. Latent class analyses were performed to distinguish PA patterns and groups of individuals with similar PA patterns.

Results

Four PA patterns were identified: a morning light PA pattern, a mid-day moderate-vigorous PA pattern, an overall inactive pattern and an overall active pattern. Groups of individuals with similar PA patterns differed in ethnicity, dog ownership, and the proportion of roads, sports terrain, larger green and blue space within their residential areas.

Conclusions

Four typical hour-by-hour PA patterns, and three groups of individuals with similar patterns were distinguished. It is this combination that can substantially contribute to the development of more tailored policies and interventions. PA patterns were only to a limited extent associated with personal and residential characteristics, suggesting that other factors such as work time regimes, family life and leisure may also have considerable impact on the distribution of PA throughout the day.

Neighborhood-based PA and its environmental correlates: a GIS- and GPS based cross-sectional study in the Netherlands

Background

To improve our understanding of the neighborhood environment – physical activity (PA) relationship, it is of importance to assess associations between neighborhood environmental characteristics and neighborhood-based PA.

Methods

Participants’ (N = 308; 45–65 years) light PA (LPA) and moderate-vigorous PA (MVPA) within a 400, 800, and 1600 m buffer around adults’ homes was measured using accelerometers and GPS-devices. Land use data in ArcGIS provided neighborhood characteristics for the same buffers. Multilevel linear regression models, adjusted for socio-demographic variables and attitude towards PA, were used to assess associations of objective neighborhood characteristics with neighborhood-based LPA and MVPA.

Results

LPA was positively associated with the proportions of roads (within a 400 m buffer), and negatively associated with the proportions of recreational areas (within an 800 m buffer), and the proportion of green space (within the 800 m and 1600 m buffers). Multiple characteristics of 400 m buffers were positively associated with MVPA, i.e. proportions of green space, blue space, residences, shops and foodservice industry, sports terrain, and public social-cultural facilities. Also, characteristics of larger buffers were positively associated with MVPA, i.e. the proportions of shops and foodservice industry, sports terrain, and blue space (within an 800 m buffer), and the proportion of public social-cultural facilities (within the 800 m and 1600 m buffers).

Conclusions

Objective neighborhood characteristics of smaller as well as larger sized buffers were associated with neighborhood-based LPA and MVPA. Green and blue spaces seem to be of particular importance for PA in the smallest buffer, i.e. in the direct surrounding of adults’ homes.

The role of high-intensity physical exercise in the prevention of disability among community-dwelling older people

Background

Moderate to vigorous physical activity (MVPA) is considered important to prevent disability among community-dwelling older people. To develop MVPA programs aimed at reducing or preventing disability more insight is needed in the contributions of exercise duration and intensity and the interplay between the two.

Methods

Longitudinal data of 276 Dutch community-dwelling persons aged 65 years and older participating in the Elderly And their Neighbourhood (ELANE) study were used. MVPA exercise (yes/no), duration (hours per two weeks), intensity (Metabolic Equivalent of Task; METs), and energy expenditure (MET-hours per two weeks), and disability in instrumental activities of daily living (range 0–8) were measured twice within 9 months to account for fluctuations over time. Associations between the four exercise measures and disability were tested with longitudinal tobit regression analyses.

Results

MVPA exercise was associated with fewer disabilities. While exercise duration was not associated with disability, whereas an increase of one MET in exercise intensity was associated with 0.14 fewer disabilities (95 % CI: -0.26 to -0.02). For exercise energy expenditure, an increase of one MET-hour exercise per two weeks was associated with 0.03 fewer disabilities (95 % CI: -0.05 to -0.01).

Conclusions

Higher-intensity exercise may help to prevent disability among community-dwelling older people. Further investigation is needed to explore the preventive effects in more detail.

Children's route choice during active transportation to school: difference between shortest and actual route

Background

The purpose of this study is to increase our understanding of environmental correlates that are associated with route choice during active transportation to school (ATS) by comparing characteristics of actual walking and cycling routes between home and school with the shortest possible route to school.

Methods

Children (n = 184; 86 boys, 98 girls; age range: 8–12 years) from seven schools in suburban municipalities in the Netherlands participated in the study. Actual walking and cycling routes to school were measured with a GPS-device that children wore during an entire school week. Measurements were conducted in the period April–June 2014. Route characteristics for both actual and shortest routes between home and school were determined for a buffer of 25 m from the routes and divided into four categories: Land use (residential, commercial, recreational, traffic areas), Aesthetics (presence of greenery/natural water ways along route), Traffic (safety measures such as traffic lights, zebra crossings, speed bumps) and Type of street (pedestrian, cycling, residential streets, arterial roads). Comparison of characteristics of shortest and actual routes was performed with conditional logistic regression models.

Results

Median distance of the actual walking routes was 390.1 m, whereas median distance of actual cycling routes was 673.9 m. Actual walking and cycling routes were not significantly longer than the shortest possible routes. Children mainly traveled through residential areas on their way to school (>80 % of the route). Traffic lights were found to be positively associated with route choice during ATS. Zebra crossings were less often present along the actual routes (walking: OR = 0.17, 95 % CI = 0.05–0.58; cycling: OR = 0.31, 95 % CI = 0.14–0.67), and streets with a high occurrence of accidents were less often used during cycling to school (OR = 0.57, 95 % CI = 0.43–0.76). Moreover, percentage of visible surface water along the actual route was higher compared to the shortest routes (walking: OR = 1.04, 95 % CI = 1.01–1.07; cycling: OR = 1.03, 95 % CI = 1.01–1.05).

Discussion

This study showed a novel approach to examine built environmental exposure during active transport to school. Most of the results of the study suggest that children avoid to walk or cycle along busy roads on their way to school.

Electronic supplementary material

The online version of this article (doi:10.1186/s12966-016-0373-y) contains supplementary material, which is available to authorized users.

Natural and built environmental exposures on children's active school travel: A Dutch global positioning system-based cross-sectional study

Physical inactivity among children is on the rise. Active transport to school (ATS), namely walking and cycling there, adds to children's activity level. Little is known about how exposures along actual routes influence children's transport behavior. This study examined how natural and built environments influence mode choice among Dutch children aged 6-11 years. 623 school trips were tracked with global positioning system. Natural and built environmental exposures were determined by means of a geographic information system and their associations with children's active/passive mode choice were analyzed using mixed models. The actual commuted distance is inversely associated with ATS when only personal, traffic safety, and weather features are considered. When the model is adjusted for urban environments, the results are reversed and distance is no longer significant, whereas well-connected streets and cycling lanes are positively associated with ATS. Neither green space nor weather is significant. As distance is not apparent as a constraining travel determinant when moving through urban landscapes, planning authorities should support children's ATS by providing well-designed cities.

Reliability of concentrations of organophosphate pesticide metabolites in serial urine specimens from pregnancy in the Generation R Study

The widespread use of organophosphate (OP) pesticides has resulted in ubiquitous exposure in humans, primarily through their diet. Exposure to OP pesticides may have adverse health effects, including neurobehavioral deficits in children. The optimal design of new studies requires data on the reliability of urinary measures of exposure. In the present study, urinary concentrations of six dialkyl phosphate (DAP) metabolites, the main urinary metabolites of OP pesticides, were determined in 120 pregnant women participating in the Generation R Study in Rotterdam. Intra-class correlation coefficients (ICCs) across serial urine specimens taken at <18, 18-25, and >25 weeks of pregnancy were determined to assess reliability. Geometric mean total DAP metabolite concentrations were 229 (GSD 2.2), 240 (GSD 2.1), and 224 (GSD 2.2) nmol/g creatinine across the three periods of gestation. Metabolite concentrations from the serial urine specimens in general correlated moderately. The ICCs for the six DAP metabolites ranged from 0.14 to 0.38 (0.30 for total DAPs), indicating weak to moderate reliability. Although the DAP metabolite levels observed in this study are slightly higher and slightly more correlated than in previous studies, the low to moderate reliability indicates a high degree of within-person variability, which presents challenges for designing well-powered epidemiological studies.

Physical activity in non-frail and frail older adults

Introduction

Physical activity (PA) is important for healthy ageing. Better insight into objectively measured PA levels in older adults is needed, since most previous studies employed self-report measures for PA assessment, which are associated with overestimation of PA.

Aim

This study aimed to provide insight in objectively measured indoor and outdoor PA of older adults, and in PA differences by frailty levels.

Methods

Data were collected among non-frail (N = 74) and frail (N = 10) subjects, aged 65 to 89 years. PA, measured for seven days with accelerometers and GPS-devices, was categorized into three levels of intensity (sedentary, light, and moderate-to-vigorous PA).

Results

Older adults spent most time in sedentary and light PA. Subjects spent 84.7%, 15.1% and 0.2% per day in sedentary, light and moderate-to-vigorous PA respectively. On average, older adults spent 9.8 (SD 23.7) minutes per week in moderate-to-vigorous activity, and 747.0 (SD 389.6) minutes per week in light activity. None of the subjects met the WHO recommendations of 150 weekly minutes of moderate-to-vigorous PA. Age-, sex- and health status-adjusted results revealed no differences in PA between non-frail and frail older adults. Subjects spent significantly more sedentary time at home, than not at home. Non-frail subjects spent significantly more time not at home during moderate-to-vigorous activities, than at home.

Conclusions

Objective assessment of PA in older adults revealed that most PA was of light intensity, and time spent in moderate-to-vigorous PA was very low. None of the older adults met the World Health Organization recommendations for PA. These levels of MVPA are much lower than generally reported based on self-reported PA. Future studies should employ objective methods, and age specific thresholds for healthy PA levels in older adults are needed. These results emphasize the need for effective strategies for healthy PA levels for the growing proportion of older adults.

Reproducibility of urinary bisphenol A concentrations measured during pregnancy in the Generation R Study

The potential human health effects of bisphenol A (BPA) exposure are a public health concern. In order to design adequately powered epidemiological studies to address potential health effects, data on the reproducibility of BPA concentration in serial urine specimens taken during pregnancy are needed. To provide additional data on the reproducibility of maternal urine specimens, 80 women in the Generation R Study (Rotterdam, The Netherlands) contributed a spot urine specimen at <18, 18-25, and >25 weeks of pregnancy. Reproducibility, estimated by the intraclass correlation coefficient (ICC), was 0.32 (95% confidence interval: 0.18-0.46), and, on a creatinine basis, 0.31 (95% confidence interval: 0.16-0.47). Although the ICC observed in the Generation R Study is slightly higher than previous reproducibility studies of BPA, it nevertheless indicates a high degree of within-person variability that presents challenges for designing well-powered epidemiologic studies.

Active transport between home and school assessed with GPS: a cross-sectional study among Dutch elementary school children

Background

Active transport to school is associated with higher levels of physical activity in children. Promotion of active transport has therefore gained attention as a potential target to increase children’s physical activity levels. Recent studies have recognized that the distance between home and school is an important predictor for active travel among children. These studies did not yet use the promising global positioning system (GPS) methods to objectively assess active transport. This study aims to explore active transport to school in relation to the distance between home and school among a sample of Dutch elementary school children, using GPS.

Methods

Seventy-nine children, aged 6-11 years, were recruited in six schools that were located in five cities in the Netherlands. All children were asked to wear a GPS receiver for one week. All measurements were conducted between December 2008 and April 2009. Based on GPS recordings, the distance of the trips between home and school were calculated. In addition, the mode of transport (i.e., walking, cycling, motorized transport) was determined using the average and maximum speed of the GPS tracks. Then, proportion of walking and cycling trips to school was determined in relation to the distance between home and school.

Results

Out of all school trips that were recorded (n = 812), 79.2% were classified as active transport. On average, active commuting trips were of a distance of 422 meters with an average speed of 5.2 km/hour. The proportion of walking trips declined significantly at increased school trip distance, whereas the proportion of cycling trips (β = 1.23, p < 0.01) and motorized transport (β = 3.61, p < 0.01) increased. Almost all GPS tracks less than 300 meters were actively commuted, while of the tracks above 900 meters, more than half was passively commuted.

Conclusions

In the current research setting, active transport between home and school was the most frequently used mode of travel. Increasing distance seems to be associated with higher levels of passive transport. These results are relevant for those involved in decisions on where to site schools and residences, as it may affect healthy behavior among children.

Characteristics of residential areas and transportational walking among frail and non-frail Dutch elderly: does the size of the area matter?

Background

A residential area supportive for walking may facilitate elderly to live longer independently. However, current evidence on area characteristics potentially important for walking among older persons is mixed. This study hypothesized that the importance of area characteristics for transportational walking depends on the size of the area characteristics measured, and older person’s frailty level.

Methods

The study population consisted of 408 Dutch community-dwelling persons aged 65 years and older participating in the Elderly And their Neighborhood (ELANE) study in 2011–2012. Characteristics (aesthetics, functional features, safety, and destinations) of areas surrounding participants’ residences ranging from a buffer of 400 meters up to 1600 meters (based on walking path networks) were linked with self-reported transportational walking using linear regression analyses. In addition, interaction effects between frailty level and area characteristics were tested.

Results

An increase in functional features (e.g. presence of sidewalks and benches) within a 400 meter buffer, in aesthetics (e.g. absence of litter and graffiti) within 800 and 1200 meter buffers, and an increase of one destination per buffer of 400 and 800 meters were associated with more transportational walking, up to 2.89 minutes per two weeks (CI 1.07-7.32; p < 0.05). No differences were found between frail and non-frail elderly.

Conclusions

Better functional and aesthetic features, and more destinations in the residential area of community-dwelling older persons were associated with more transportational walking. The importance of area characteristics for transportational walking differs by area size, but not by frailty level. Neighbourhood improvements may increase transportational walking among older persons, thereby contributing to living longer independently.

Schoolyard physical activity of 6-11 year old children assessed by GPS and accelerometry

BACKGROUND

Children's current physical activity levels are disturbingly low when compared to recommended levels. This may be changed by intervening in the school environment. However, at present, it is unclear to what extent schoolyard physical activity contributes towards reaching the daily physical activity guideline. The aim of this study was to examine how long and at what intensity children are physically active at the schoolyard during different time segments of the day. Moreover, the contribution of schoolyard physical activity towards achieving the recommended guideline for daily physical activity was investigated.

METHODS

Children (n=76) between the age of 6-11 years were recruited in six different schools in five cities (>70.000 residents) in the Netherlands. During the weekdays of a regular school week, childrens' physical activity and location were measured with ActiGraph accelerometers and Travelrecorder GPS receivers. Data was collected from December 2008 to April 2009. From the data, the amount of moderate to vigorous physical activity (MVPA) on and outside the schoolyard was established. Moreover, the percentage of MVPA on the schoolyard was compared between the following segments of the day: pre-school, school, school recess, lunch break and post-school. Differences between boys and girls were compared using linear and logistic mixed-effects models.

RESULTS

On average, children spent 40.1 minutes/day on the schoolyard. During this time, boys were more active on the schoolyard, with 27.3% of their time spent as MVPA compared to 16.7% among girls (OR=2.11 [95% CI 1.54 - 2.90]). The children were most active on the schoolyard during school recess, during which boys recorded 39.5% and girls recorded 23.4% of the time as MVPA (OR=2.55 [95% CI: 1.69 - 3.85]). Although children were only present at the schoolyard for 6.1% of the total reported time, this time contributed towards 17.5% and 16.8% of boys' and girls' minutes of MVPA.

CONCLUSIONS

On the schoolyard, children's physical activity levels are higher than on average over the whole day. Physical activity levels are particularly high during school recess. The school environment seems to be an important setting for improving children's physical activity levels. Further research on the facilitators of these high activity levels may provide targets for further promotion of physical activity among children.

Management of undescended testis: a decision analysis

BACKGROUND

Undescended testis (UDT) or cryptorchidism is the most common genital anomaly seen in boys and can be treated surgically by orchidopexy. The age at which orchidopexy should be performed is controversial for both congenital and acquired UDT.

METHODS

A decision analysis is performed in which all available knowledge is combined to assess the outcomes of orchidopexy at different ages.

RESULTS

Without surgery, unilateral congenital UDT and bilateral congenital UDT are associated with average losses in quality-adjusted life-years (QALYs) of 1.53 QALYs (3% discounting 0.66 QALYs) and 5.23 QALYs (1.91 QALYs), respectively. Surgery reduces this QALY loss to on average 0.84 QALYs (0.21 QALYs) for unilateral UDT and 1.66 QALYs (0.40 QALYs) for bilateral UDT. Surgery at detection will lead to the lowest QALY loss of 0.91 (0.34) and 1.73 (0.60) QALYs, respectively, for unilateral and bilateral acquired UDT compared with surgery during puberty and no surgery. No sensitivity analysis is able to change the preferences for these strategies.

CONCLUSIONS

Based on our decision analytic model using societal valuations of health outcomes, surgery for unilateral UDT (both congenital and acquired) yielded the lowest loss in QALYs. Given the modest differences in outcomes, there is room for patient (or parent) preference with respect to the performance and timing of surgery in case of unilateral UDT. For bilateral UDT (both congenital and acquired), orchidopexy at any age provides considerable benefit, in particular through improved fertility. As there is no strong effect of timing, the age at which orchidopexy is performed should be discussed with the parents and the patient. More clinical evidence on issues related to timing may in the future modify these results and hence this advice.

Fetal growth and prenatal exposure to bisphenol A: the generation R study

BACKGROUND

Prenatal exposure to bisphenol A (BPA) has been associated with adverse birth outcomes, but findings of previous studies have been inconsistent.

OBJECTIVE

We investigated the relation of prenatal BPA exposure with intrauterine growth and evaluated the effect of the number of measurements per subject on observed associations.

METHODS

This study was embedded in a Dutch population-based prospective cohort study, with urine samples collected during early, mid-, and late pregnancy. The study comprised 219 women, of whom 99 had one measurement, 40 had two measurements, and 80 had three measurements of urinary BPA. Fetal growth characteristics were repeatedly measured by ultrasound during pregnancy and combined with measurements at birth. Linear regression models for repeated measurements of both BPA and fetal growth were used to estimate associations between urinary concentrations of creatinine-based BPA (BPACB) and intrauterine growth.

RESULTS

The relationship between BPACB and fetal growth was sensitive to the number of BPA measurements per woman. Among 80 women with three BPA measurements, women with BPACB > 4.22 μg/g crea (creatinine) had lower growth rates for fetal weight and head circumference than did women with BPACB < 1.54 μg/g crea, with estimated differences in mean values at birth of -683 g (20.3% of mean) and -3.9 cm (11.5% of mean), respectively. When fewer measurements were available per woman, the exposure-response relationship became progressively attenuated and statistically nonsignificant.

CONCLUSION

Our findings suggest that maternal urinary BPA may impair fetal growth. Because previous studies have shown contradictory findings, further evidence is needed to corroborate these findings in the general population.

Maternal exposure to particulate air pollution and term birth weight: a multi-country evaluation of effect and heterogeneity

BACKGROUND

A growing body of evidence has associated maternal exposure to air pollution with adverse effects on fetal growth; however, the existing literature is inconsistent.

OBJECTIVES

We aimed to quantify the association between maternal exposure to particulate air pollution and term birth weight and low birth weight (LBW) across 14 centers from 9 countries, and to explore the influence of site characteristics and exposure assessment methods on between-center heterogeneity in this association.

METHODS

Using a common analytical protocol, International Collaboration on Air Pollution and Pregnancy Outcomes (ICAPPO) centers generated effect estimates for term LBW and continuous birth weight associated with PM(10) and PM(2.5) (particulate matter ≤ 10 and 2.5 µm). We used meta-analysis to combine the estimates of effect across centers (~ 3 million births) and used meta-regression to evaluate the influence of center characteristics and exposure assessment methods on between-center heterogeneity in reported effect estimates.

RESULTS

In random-effects meta-analyses, term LBW was positively associated with a 10-μg/m3 increase in PM10 [odds ratio (OR) = 1.03; 95% CI: 1.01, 1.05] and PM(2.5) (OR = 1.10; 95% CI: 1.03, 1.18) exposure during the entire pregnancy, adjusted for maternal socioeconomic status. A 10-μg/m3 increase in PM(10) exposure was also negatively associated with term birth weight as a continuous outcome in the fully adjusted random-effects meta-analyses (-8.9 g; 95% CI: -13.2, -4.6 g). Meta-regressions revealed that centers with higher median PM(2.5) levels and PM(2.5):PM(10) ratios, and centers that used a temporal exposure assessment (compared with spatiotemporal), tended to report stronger associations.

CONCLUSION

Maternal exposure to particulate pollution was associated with LBW at term across study populations. We detected three site characteristics and aspects of exposure assessment methodology that appeared to contribute to the variation in associations reported by centers.

Air pollution, fetal and infant tobacco smoke exposure, and wheezing in preschool children: a population-based prospective birth cohort

BACKGROUND

Air pollution is associated with asthma exacerbations. We examined the associations of exposure to ambient particulate matter (PM10) and nitrogen dioxide (NO2) with the risk of wheezing in preschool children, and assessed whether these associations were modified by tobacco smoke exposure.

METHODS

This study was embedded in the Generation R Study, a population-based prospective cohort study among 4,634 children. PM10 and NO2 levels were estimated for the home addresses using dispersion modeling. Annual parental reports of wheezing until the age of 3 years and fetal and infant tobacco smoke exposure was obtained by questionnaires.

RESULTS

Average annual PM10 or NO2 exposure levels per year were not associated with wheezing in the same year. Longitudinal analyses revealed non-significant tendencies towards positive associations of PM10 or NO2 exposure levels with wheezing during the first 3 years of life (overall odds ratios (95% confidence interval): 1.21 (0.79, 1.87) and 1.06 (0.92, 1.22)) per 10 μg/m3 increase PM10 and NO2, respectively). Stratified analyses showed that the associations were stronger and only significant among children who were exposed to both fetal and infant tobacco smoke (overall odds ratios 4.54 (1.17, 17.65) and 1.85 (1.15, 2.96)) per 10 μg/m3 increase PM10 and NO2, respectively (p-value for interactions <0.05).

CONCLUSIONS

Our results suggest that long term exposure to traffic-related air pollutants is associated with increased risks of wheezing in children exposed to tobacco smoke in fetal life and infancy. Smoke exposure in early life might lead to increased vulnerability of the lungs to air pollution.

Air pollution exposure and markers of placental growth and function: the generation R study

BACKGROUND

Air pollution exposure during pregnancy might affect placental growth and function, perhaps leading to pregnancy complications.

OBJECTIVE

We prospectively evaluated the associations of maternal air pollution exposure with markers of placental growth and function among 7,801 pregnant women in the Netherlands.

METHODS

We estimated levels of particulate matter ≤ 10 µm in aerodynamic diameter (PM10) and nitrogen dioxide (NO2) at the home address for different periods during pregnancy using dispersion modeling techniques. Pro- and anti-angiogenic factors [placental growth factor (PlGF) and soluble fms-like tyrosine kinase 1 (sFlt-1), respectively] were measured in first- and second-trimester maternal blood and in fetal cord blood samples at delivery. Pulsatility index of the uterine and umbilical arteries was measured by Doppler ultrasound in second and third trimester, and notching was assessed in third trimester. Placenta weight and birth weight were obtained from medical records.

RESULTS

Higher PM10 and NO2 exposure levels were associated with lower second-trimester maternal sFlt-1 and PlGF levels. PM10 and NO2 exposures averaged over total pregnancy were associated with higher sFlt-1 and lower PlGF levels in fetal cord blood, consistent with an anti-angiogenic state. PM10 and NO2 exposures were not consistently associated with second- or third-trimester placental resistance indices. NO2 exposure was associated with third-trimester notching (odds ratio 1.33; 95% CI: 0.99, 1.78 per 10-µg/m3 increase in the prior 2 months). PM10 and NO2 exposures were associated with lower placenta weight (-11.8 g; 95% CI: -20.9, -2.7, and -10.7 g; 95% CI: -19.0, -2.4, respectively, per 10-µg/m3 increase in the prior 2 months), but not with placenta to birth weight ratio.

CONCLUSIONS

Our results suggest that maternal air pollution exposure may influence markers of placental growth and function. Future studies are needed to confirm these findings and explore the maternal and fetal consequences.

Chronic air pollution exposure during pregnancy and maternal and fetal C-reactive protein levels: the Generation R Study

BACKGROUND

Exposure to air pollution has been associated with higher C-reactive protein (CRP) levels, suggesting an inflammatory response. Not much is known about this association in pregnancy.

OBJECTIVES

We investigated the associations of air pollution exposure during pregnancy with maternal and fetal CRP levels in a population-based cohort study in the Netherlands.

METHODS

Particulate matter (PM) with an aerodynamic diameter ≤ 10 μm (PM10) and nitrogen dioxide (NO2) levels were estimated at the home address using dispersion modeling for different averaging periods preceding the blood sampling (1 week, 2 weeks, 4 weeks, and total pregnancy). High-sensitivity CRP levels were measured in maternal blood samples in early pregnancy (n = 5,067) and in fetal cord blood samples at birth (n = 4,450).

RESULTS

Compared with the lowest quartile, higher PM10 exposure levels for the prior 1 and 2 weeks were associated with elevated maternal CRP levels (> 8 mg/L) in the first trimester [fourth PM10 quartile for the prior week: odds ratio (OR), 1.32; 95% confidence interval (CI): 1.08, 1.61; third PM10 quartile for the prior 2 weeks: OR, 1.28; 95% CI: 1.06, 1.56]; however, no clear dose-response relationships were observed. PM10 and NO2 exposure levels for 1, 2, and 4 weeks preceding delivery were not consistently associated with fetal CRP levels at delivery. Higher long-term PM10 and NO2 exposure levels (total pregnancy) were associated with elevated fetal CRP levels (> 1 mg/L) at delivery (fourth quartile PM10: OR, 2.18; 95% CI: 1.08, 4.38; fourth quartile NO2: OR, 3.42; 95% CI: 1.36, 8.58; p-values for trend < 0.05).

CONCLUSIONS

Our results suggest that exposure to air pollution during pregnancy may lead to maternal and fetal inflammatory responses.

Air pollution exposure estimation using dispersion modelling and continuous monitoring data in a prospective birth cohort study in The Netherlands

Previous studies suggest that pregnant women and children are particularly vulnerable to the adverse effects of air pollution. A prospective cohort study in pregnant women and their children enables identification of the specific effects and critical periods. This paper describes the design of air pollution exposure assessment for participants of the Generation R Study, a population-based prospective cohort study from early pregnancy onwards in 9778 women in The Netherlands. Individual exposures to PM10 and NO2 levels at the home address were estimated for mothers and children, using a combination of advanced dispersion modelling and continuous monitoring data, taking into account the spatial and temporal variation in air pollution concentrations. Full residential history was considered. We observed substantial spatial and temporal variation in air pollution exposure levels. The Generation R Study provides unique possibilities to examine effects of short- and long-term air pollution exposure on various maternal and childhood outcomes and to identify potential critical windows of exposure.

European birth cohorts for environmental health research

BACKGROUND

Many pregnancy and birth cohort studies investigate the health effects of early-life environmental contaminant exposure. An overview of existing studies and their data is needed to improve collaboration, harmonization, and future project planning.

OBJECTIVES

Our goal was to create a comprehensive overview of European birth cohorts with environmental exposure data.

METHODS

Birth cohort studies were included if they a) collected data on at least one environmental exposure, b) started enrollment during pregnancy or at birth, c) included at least one follow-up point after birth, d) included at least 200 mother-child pairs, and e) were based in a European country. A questionnaire collected information on basic protocol details and exposure and health outcome assessments, including specific contaminants, methods and samples, timing, and number of subjects. A full inventory can be searched on www.birthcohortsenrieco.net.

RESULTS

Questionnaires were completed by 37 cohort studies of > 350,000 mother-child pairs in 19 European countries. Only three cohorts did not participate. All cohorts collected biological specimens of children or parents. Many cohorts collected information on passive smoking (n = 36), maternal occupation (n = 33), outdoor air pollution (n = 27), and allergens/biological organisms (n = 27). Fewer cohorts (n = 12-19) collected information on water contamination, ionizing or nonionizing radiation exposures, noise, metals, persistent organic pollutants, or other pollutants. All cohorts have information on birth outcomes; nearly all on asthma, allergies, childhood growth and obesity; and 26 collected information on child neurodevelopment.

CONCLUSION

Combining forces in this field will yield more efficient and conclusive studies and ultimately improve causal inference. This impressive resource of existing birth cohort data could form the basis for longer-term and worldwide coordination of research on environment and child health.

Testicular microlithiasis in two boys with a chromosomal abnormality

A nine and 13-year-old boy, previously diagnosed with 18q syndrome and an 11q deletion, respectively were diagnosed with testicular microlithiasis (TM). Both cases demonstrate that TM occurs in patients with various chromosomal abnormalities

Air pollution exposure during pregnancy, ultrasound measures of fetal growth, and adverse birth outcomes: a prospective cohort study

BACKGROUND

Air pollution exposure during pregnancy might have trimester-specific effects on fetal growth.

OBJECTIVE

We prospectively evaluated the associations of maternal air pollution exposure with fetal growth characteristics and adverse birth outcomes in 7,772 subjects in the Netherlands.

METHODS

Particulate matter with an aerodynamic diameter < 10 μm (PM10) and nitrogen dioxide (NO2) levels were estimated using dispersion modeling at the home address. Fetal head circumference, length, and weight were estimated in each trimester by ultrasound. Information on birth outcomes was obtained from medical records.

RESULTS

In cross-sectional analyses, NO2 levels were inversely associated with fetal femur length in the second and third trimester, and PM10 and NO2 levels both were associated with smaller fetal head circumference in the third trimester [-0.18 mm, 95% confidence interval (CI): -0.24, -0.12 mm; and -0.12 mm, 95% CI: -0.17, -0.06 mm per 1-μg/m3 increase in PM10 and NO2, respectively]. Average PM10 and NO2 levels during pregnancy were not associated with head circumference and length at birth or neonatally, but were inversely associated with birth weight (-3.6 g, 95% CI: -6.7, -0.4 g; and -3.4 g, 95% CI: -6.2, -0.6 g, respectively). Longitudinal analyses showed similar patterns for head circumference and weight, but no associations with length. The third and fourth quartiles of PM10 exposure were associated with preterm birth [odds ratio (OR) = 1.40, 95% CI: 1.03, 1.89; and OR = 1.32; 95% CI: 0.96, 1.79, relative to the first quartile]. The third quartile of PM10 exposure, but not the fourth, was associated with small size for gestational age at birth (SGA) (OR = 1.38; 95% CI: 1.00, 1.90). No consistent associations were observed for NO2 levels and adverse birth outcomes.

CONCLUSIONS

Results suggest that maternal air pollution exposure is inversely associated with fetal growth during the second and third trimester and with weight at birth. PM10 exposure was positively associated with preterm birth and SGA.

The International Collaboration on Air Pollution and Pregnancy Outcomes: initial results

BACKGROUND

The findings of prior studies of air pollution effects on adverse birth outcomes are difficult to synthesize because of differences in study design.

OBJECTIVES

The International Collaboration on Air Pollution and Pregnancy Outcomes was formed to understand how differences in research methods contribute to variations in findings. We initiated a feasibility study to a) assess the ability of geographically diverse research groups to analyze their data sets using a common protocol and b) perform location-specific analyses of air pollution effects on birth weight using a standardized statistical approach.

METHODS

Fourteen research groups from nine countries participated. We developed a protocol to estimate odds ratios (ORs) for the association between particulate matter ≤ 10 μm in aerodynamic diameter (PM₁₀) and low birth weight (LBW) among term births, adjusted first for socioeconomic status (SES) and second for additional location-specific variables.

RESULTS

Among locations with data for the PM₁₀ analysis, ORs estimating the relative risk of term LBW associated with a 10-μg/m³ increase in average PM₁₀ concentration during pregnancy, adjusted for SES, ranged from 0.63 [95% confidence interval (CI), 0.30-1.35] for the Netherlands to 1.15 (95% CI, 0.61-2.18) for Vancouver, with six research groups reporting statistically significant adverse associations. We found evidence of statistically significant heterogeneity in estimated effects among locations.

CONCLUSIONS

Variability in PM₁₀-LBW relationships among study locations remained despite use of a common statistical approach. A more detailed meta-analysis and use of more complex protocols for future analysis may uncover reasons for heterogeneity across locations. However, our findings confirm the potential for a diverse group of researchers to analyze their data in a standardized way to improve understanding of air pollution effects on birth outcomes.

Air pollution, blood pressure, and the risk of hypertensive complications during pregnancy: the generation R study

Exposure to air pollution is associated with elevated blood pressure and cardiovascular disease. We assessed the associations of exposure to particulate matter (PM(10)) and nitrogen dioxide (NO(2)) levels with blood pressure measured in each trimester of pregnancy and the risks of pregnancy-induced hypertension and preeclampsia in 7006 women participating in a prospective cohort study in the Netherlands. Information on gestational hypertensive disorders was obtained from medical records. PM(10) exposure was not associated with first trimester systolic and diastolic blood pressure, but a 10-μg/m(3) increase in PM(10) levels was associated with a 1.11-mm Hg (95% confidence interval [CI] 0.43 to 1.79) and 2.11-mm Hg (95% CI 1.34 to 2.89) increase in systolic blood pressure in the second and third trimester, respectively. Longitudinal analyses showed that elevated PM(10) exposure levels were associated with a steeper increase in systolic blood pressure throughout pregnancy (P<0.01), but not with diastolic blood pressure patterns. Elevated NO(2) exposure was associated with higher systolic blood pressure levels in the first, second, and third trimester (P<0.05), and with a more gradual increase when analyzed longitudinally (P<0.01). PM(10) exposure, but not NO(2) exposure, was associated with an increased risk of pregnancy-induced hypertension (odds ratio 1.72 [95% CI 1.12 to 2.63] per 10-μg/m(3) increase). In conclusion, our results suggest that air pollution may affect maternal cardiovascular health during pregnancy. The effects might be small but relevant on a population level.

Maternal exposure to the Dutch famine before conception and during pregnancy: quality of life and depressive symptoms in adult offspring

BACKGROUND

Gestational exposure to famine has been associated with several chronic diseases in adulthood, but few studies in humans have related prenatal famine exposure to health-related quality of life. We used the circumstances of the Dutch Famine of 1944-1945 (during which official rations were <900 kcal/day for 24 weeks) to assess whether exposure to famine prior to conception or at specified stages of pregnancy was related to self-reported health-related quality of life and depressive symptoms in adulthood.

METHODS

We studied 923 individuals, including persons born in western Holland between January 1945 and March 1946, persons born in the same 3 institutions in 1943 and 1947 and same-sex siblings of persons in series 1 or 2. Between 2003 and 2005 (mean age: 59 years), we assessed self-reported quality of life with the Short Form 36 questionnaire and derived mental and physical component scores. Depressive symptoms were assessed with the Center for Epidemiologic Studies Depression scale.

RESULTS

Mean mental and physical component scores were 52.4 (SD = 9.4) and 48.9 (9.0), respectively. The mean depression score was 11.6 (7.4). Age-, sex-, and schooling-adjusted estimates for mutually adjusted exposures were -2.48 for the mental component score with exposure before conception (95% confidence interval = -4.46 to -0.50) and 0.07 with exposure during pregnancy (-1.15 to 1.29). Adjusted estimates for the physical component score were 1.26 with exposure before conception (-0.67 to 3.19) and -0.73 with exposure during pregnancy (-1.94 to 0.48). Adjusted estimates for the depression score were 2.07 with exposure before conception (0.60 to 3.54) and 0.96 with exposure during pregnancy (0.09 to 1.88). There was no evidence of heterogeneity of effects by specific periods of pregnancy exposed to famine.

CONCLUSIONS

A mother's exposure to famine prior to conception of her offspring was associated with lower self-reported measures of mental health and quality of life in her adult offspring.

Residential traffic exposure and pregnancy-related outcomes: a prospective birth cohort study

BACKGROUND

The effects of ambient air pollution on pregnancy outcomes are under debate. Previous studies have used different air pollution exposure assessment methods. The considerable traffic-related intra-urban spatial variation needs to be considered in exposure assessment. Residential proximity to traffic is a proxy for traffic-related exposures that takes into account within-city contrasts.

METHODS

We investigated the association between residential proximity to traffic and various birth and pregnancy outcomes in 7,339 pregnant women and their children participating in a population-based cohort study. Residential proximity to traffic was defined as 1) distance-weighted traffic density in a 150 meter radius, and 2) proximity to a major road. We estimated associations of these exposures with birth weight, and with the risks of preterm birth and small size for gestational age at birth. Additionally, we examined associations with pregnancy-induced hypertension, (pre)eclampsia, and gestational diabetes.

RESULTS

There was considerable variation in distance-weighted traffic density. Almost fifteen percent of the participants lived within 50 m of a major road. Residential proximity to traffic was not associated with birth and pregnancy outcomes in the main analysis and in various sensitivity analyses.

CONCLUSIONS

Mothers exposed to residential traffic had no higher risk of adverse birth outcomes or pregnancy complications in this study. Future studies may be refined by taking both temporal and spatial variation in air pollution exposure into account.

Prevalence of testicular microlithiasis in asymptomatic males 0 to 19 years old

PURPOSE

We assessed the prevalence of testicular microlithiasis via ultrasound in asymptomatic males 0 to 19 years old.

MATERIALS AND METHODS

We studied only patients with 2 scrotal testes at birth and at examination. We excluded boys with a history of undescended testis, hydrocele, varicocele and syndromes associated with testicular microlithiasis. To assess for testicular microlithiasis, we scanned the scrotum ultrasonographically by recording transverse and longitudinal images of each testis. Classic testicular microlithiasis was defined as 5 or more echogenic foci in either or both testes. Boys with fewer than 5 microliths (but with at least 1) were deemed to have limited testicular microlithiasis.

RESULTS

We examined 694 asymptomatic boys between October 2007 and July 2008, of whom 670 participated in the study. Classic testicular microlithiasis was present in 16 boys (2.4%) and limited testicular microlithiasis in 12 (1.8%), yielding a total prevalence of 4.2%. Classic testicular microlithiasis was found in 1 patient younger than 6 years, 8 boys 6 to 12 years old and 7 boys older than 12 years. There was a significant difference in prevalence among the 3 age groups (p = 0.032). Testicular malignancies were not found in any patient. Of the 24 boys excluded from the study testicular microlithiasis was seen in 4.

CONCLUSIONS

The prevalence of classic testicular microlithiasis in asymptomatic boys is 2.4% and increases with age.

Levels of metabolites of organophosphate pesticides, phthalates, and bisphenol A in pooled urine specimens from pregnant women participating in the Norwegian Mother and Child Cohort Study (MoBa)

Concerns about reproductive and developmental health risks of exposure to organophosphate (OP) pesticides, phthalates, and bisphenol A (BPA) among the general population are increasing. Six dialkyl phosphate (DAP) metabolites, 3,5,6-trichloro-2-pyridinol (TCPy), BPA, and fourteen phthalate metabolites were measured in 10 pooled urine samples representing 110 pregnant women who participated in the Norwegian Mother and Child Birth Cohort (MoBa) study in 2004. Daily intakes were estimated from urinary data and compared with reference doses (RfDs) and daily tolerable intakes (TDIs). The MoBa women had a higher mean BPA concentration (4.50 microg/L) than the pregnant women in the Generation R Study (Generation R) in the Netherlands and the National Health and Nutrition Examination Survey (NHANES) in the United States. The mean concentration of total DAP metabolites (24.20 microg/L) in MoBa women was higher than that in NHANES women but lower than that in Generation R women. The diethyl phthalate metabolite mono-ethyl phthalate (MEP) was the dominant phthalate metabolite in all three studies, with the mean concentrations of greater than 300 microg/L. The MoBa and Generation R women had higher mean concentrations of mono-n-butyl phthalate (MnBP) and mono-isobutyl phthalate (MiBP) than the NHANES women. The estimated average daily intakes of BPA, chlorpyrifos/chlorpyrifos-methyl and phthalates in MoBa (and the other two studies) were below the RfDs and TDIs. The higher levels of metabolites in the MoBa participants may have been from intake via pesticide residues in food (organophosphates), consumption of canned food, especially fish/seafood (BPA), and use of personal care products (selected phthalates).

Urinary metabolite concentrations of organophosphorous pesticides, bisphenol A, and phthalates among pregnant women in Rotterdam, the Netherlands: the Generation R study

Concern about potential health impacts of low-level exposures to organophosphorus (OP) pesticides, bisphenol A (BPA), and phthalates among the general population is increasing. We measured levels of six dialkyl phosphate (DAP) metabolites of OP pesticides, a chlorpyrifos-specific metabolite (3,5,6-trichloro-2-pyridinol, TCPy), BPA, and 14 phthalate metabolites in urine samples of 100 pregnant women from the Generation R study, the Netherlands. The unadjusted and creatinine-adjusted concentrations were reported, and compared to National Health and Nutrition Examination Survey and other studies. In general, these metabolites were detectable in the urine of the women from the Generation R study and compared with other groups, they had relatively high-level exposures to OP pesticides and several phthalates but similar exposure to BPA. The median concentrations of total dimethyl (DM) metabolites was 264.0 n mol/g creatinine (Cr) and of total DAP was 316.0 n mol/g Cr. The median concentration of mono-ethyl phthalate (MEP) was 222.0 microg/g Cr; the median concentrations of mono-isobutyl phthalate (MiBP) and mono-n-butyl phthalate (MnBP) were above 50 microg/g Cr. The median concentrations of the three secondary metabolites of di-2-ethylhexyl phthalate (DEHP) were greater than 20 microg/g Cr. The data indicate that the Generation R study population provides a wide distribution of selected environmental exposures. Reasons for the relatively high levels and possible health effects need investigation.

[Undescended testis: current views and advice for treatment]

--Undescended testis (UDT) is one of the most common urogenital abnormalities in boys. --UDT is defined as a testis which cannot be brought into a stable scrotal position. --At present, congenital and acquired forms of UDT are recognised. Congenital UDT is defined as a UDT which has never descended from birth. Acquired UDT is defined as a UDT which has been fully descended in the past. --Congenital UDT should be treated surgically between 6 to 12 months of age. --The treatment of acquired UDT is still disputed. As yet, awaiting spontaneous descent at early puberty seems to be the most rational treatment. --In the Netherlands, the high number of late orchidopexies is due to surgery for acquired UDT. To reduce this high number, the guidelines of the first development conference on 'non-scrotal testis' dating back to 1986 should be revised on several points.

Maternal pregnancy serum level of heptachlor epoxide, hexachlorobenzene, and beta-hexachlorocyclohexane and risk of cryptorchidism in offspring

Prenatal exposure to environmental endocrine disrupters has been postulated to cause adverse effects on male reproductive health. Exposure to organochlorine pesticides with anti-androgenic and estrogenic potency has been shown to interfere with the sex-hormone-dependent process of testicular descent in animal models. We examined the relation between serum levels of the pesticides heptachlor epoxide (HCE), hexachlorobenzene (HCB), and beta-hexachlorocyclohexane (beta-HCCH) in pregnant women, and the occurrence of cryptorchidism in their sons. These three pesticides were previously suggested as risk factors for cryptorchidism. In a nested case-control design, we compared serum levels between mothers of cases (n = 219) and controls (n = 564), selected from the Collaborative Perinatal Project, a US birth cohort study of pregnancies in 1959-1966. The offspring of mothers with HCE levels above the 90th percentile compared to those below the 10th percentile had an adjusted odds ratio of cryptorchidism of 1.2 (95% confidence interval 0.6-2.6); for beta-HCCH the odds ratio was 1.6 (0.7-3.6). For HCB the adjusted odds ratio was near one. These results provide little support for an association of cryptorchidism with exposure to low levels of HCE or HCB. For beta-HCCH the findings were somewhat suggestive of an association but were inconclusive.

Reduction in the number of orchidopexies for cryptorchidism after recognition of acquired undescended testis and implementation of expectative policy

BACKGROUND

Since the mid-1990s, acquired undescended testis has gradually been recognised as a separate entity for which the efficacy of prepubertal surgery has not been univocally been demonstrated. Therefore, in our hospital, orchidopexy was no longer routinely performed for acquired undescended testis.

AIM

To investigate the effect of expectative policy in our hospital on the number of orchidopexies.

METHODS

Two 5-year periods were compared. Period A (1991-1995), in which undescended testis was treated surgically, and period B (2000-2004), in which prepubertal orchidopexy in our hospital was no longer performed for acquired undescended testis. In addition, a comparison was made between the percentage reduction in hospital and national figures.

RESULTS

In period B, the number of orchidopexies in our hospital was reduced by 61.8% (from 387 to 148), mainly in the age group >6 years. Nationally, during the same period, the number of orchidopexies decreased only by 2.4% (from 18 024 to 17 591).

CONCLUSION

The results of this study confirm that recognition of acquired undescended testis is crucial for reducing the high number of (late) orchidopexies.

Does folic acid and zinc sulphate intervention affect endocrine parameters and sperm characteristics in men?

We evaluated pre- and post-intervention endocrine and semen parameters in a double-blind, placebo-controlled intervention study to investigate the underlying mechanism of increased sperm concentration after folic acid and zinc sulphate intervention. A total of 47 fertile and 40 subfertile males participated in a 26-week intervention study consisting of a daily treatment with folic acid (5 mg/day) and zinc sulphate (66 mg/day), or placebo. Pre- and post-intervention semen parameters, serum folate, zinc, follicle-stimulating hormone (FSH), testosterone and inhibin B concentrations were measured. The results indicated that intervention treatment significantly increased sperm concentration in subfertile males. Other semen and endocrine parameters were not affected by intervention treatment. At baseline, positive correlations were found between serum zinc and sperm concentration, motility and inhibin B. Serum zinc and FSH were inversely correlated. As (already) well known from previous research, inhibin B positively correlated with sperm concentration, motility and morphology, and was inversely correlated with FSH. The latter was positively correlated with testosterone. In addition, testosterone and inhibin B were inversely correlated. After intervention, the correlations with zinc disappeared. We conclude that the increase in sperm concentration after folic acid and zinc sulphate intervention is not the result of alterations in FSH, testosterone or inhibin B concentrations. Although zinc and folate have several effects on spermatogenesis, the underlying mechanisms involved are not clear.

The cryptorchidism prevalence among infants in the general population of Rotterdam, the Netherlands

Published trends and geographical differences in cryptorchidism rates are almost exclusively derived from hospital-based birth defect registers, which are sensitive to selection bias and incomplete reporting. This study aimed to accurately assess the cryptorchidism prevalence in the general population of Rotterdam. Of 7652 consecutive male live births, 7292 (95%) were examined for cryptorchidism at Child Healthcare Centres around the age of 1 month. In a subgroup of cases, the persistence of cryptorchidism was re-assessed during a follow-up examination by expert specialists. The cryptorchidism rate at the median age of 35 days was 1.2% (89/7292). In the re-examined subgroup (median age 95 days) 69% of the boys (24/35) had persistent cryptorchidism, of which 20 were unilateral and four bilateral. The population rate of 1.2% falls within the range of 0.9-9% reported by others. Differences in case ascertainment and population characteristics probably explain part of the differences between studies. Our cross-sectional design does not allow for analysis of a temporal trend, but provides a baseline for future trend studies. To study cryptorchidism rates, trends, and risk factors, a systematic case ascertainment is warranted.

Serum levels of sex hormone-binding globulin (SHBG) are not associated with lower levels of non-SHBG-bound testosterone in male newborns and healthy adult men

OBJECTIVE

It is generally accepted that SHBG decreases the bioavailability and activity of testosterone (T). In in vitro experiments increased levels of SHBG will be associated with decreased levels of non-SHBG bound testosterone (non-SHBG-T). However, in vivo SHBG can alter both production and clearance rates and thus plasma levels of T.

DESIGN AND PATIENTS

In order to study the effect of SHBG on the levels of non-SHBG-T in vivo in the presence of an active hypothalamo-pituitary-gonadal (HPG) axis we conducted a cross sectional study in 400 healthy adult men with an age range of 40-80 years and in 106 newborn boys.

MEASUREMENTS

In both groups, regression coefficients (beta) and partial correlation coefficients (r) were calculated for the relationship between SHBG and T or non-SHBG-T. Adult men were divided into age groups per decade (40-50 years, 51-60 years, 61-70 years and 71-80 years) to study possible differences in the impact of SHBG on the level of non-SHBG-T throughout ageing.

RESULTS

Higher levels of SHBG were associated with higher levels of total testosterone in neonates (beta = 0.02 +/- 0.004, r = 0.44, P < 0.001) but not with non-SHBG-T (beta = -0.001 +/- 0.001, r = 0.05, P = 0.52). In adult men there was a significant age related increase in levels of SHBG and an age-related decrease of both total and non-SHBG-T. Higher SHBG was strongly associated with higher total testosterone in all age groups (beta = 0.26, 0.26, 0.26 and 0.23 for 40-50 years, 51-60 years, 61-70 years and 71-80 years, respectively, P < 0.001 for all age groups). Higher SHBG was not or only slightly associated with higher non-SHBG-T beta = 0.02 (P = 0.32), beta = 0.04 (P = 0.03), beta = 0.04 (P = 0.02) and beta = 0.02 (P = 0.16) for 40-50 years, 51-60 years, 61-70 years and 71-80 years, respectively.

CONCLUSIONS

In contrast to general belief, SHBG levels barely influence levels of non-SHBG-bound testosterone both in male newborns and healthy adult men: the influence, if any, is positive. Consequently the age related increase of SHBG does not account for the age related decline in non-SHBG-T in healthy adult men.

Maternal and paternal risk factors for cryptorchidism and hypospadias: a case-control study in newborn boys

Little is known on environmental risk factors for cryptorchidism and hypospadias, which are among the most frequent congenital abnormalities. The aim of our study was to identify risk factors for cryptorchidism and hypospadias, with a focus on potential endocrine disruptors in parental diet and occupation. In a case-control study nested within a cohort of 8,698 male births, we compared 78 cryptorchidism cases and 56 hypospadias cases with 313 controls. The participation rate was 85% for cases and 68% for controls. Through interviews, information was collected on pregnancy aspects and personal characteristics, lifestyle, occupation, and dietary phytoestrogen intake of both parents. Occupational exposure to potential endocrine disruptors was classified based on self-reported exposure and ratings of occupational hygienists based on job descriptions. Our findings indicate that paternal pesticide exposure was associated with cryptorchidism [odds ratio (OR) = 3.8; 95% confidence interval (95% CI), 1.1-13.4]. Smoking of the father was associated with hypospadias (OR = 3.8; 95% CI, 1.8-8.2). Maternal occupational, dietary, and lifestyle exposures were not associated with either abnormality. Both abnormalities were associated with suboptimal maternal health, a lower maternal education, and a Turkish origin of the parents. Being small for gestational age was a risk factor for hypospadias, and preterm birth was a risk factor for cryptorchidism. Because paternal pesticide exposure was significantly associated with cryptorchidism and paternal smoking was associated with hypospadias in male offspring, paternal exposure should be included in further studies on cryptorchidism and hypospadias risk factors.

Bilateral Testicular Microlithiasis Predicts the Presence of the Precursor of Testicular Germ Cell Tumors in Subfertile Men

PURPOSE

A high prevalence of testicular microlithiasis has been described in adolescent and adult clinical cases of invasive testicular germ cell tumor (TGCT), that is seminomas and nonseminomas. However, to our knowledge it remains to be established whether testicular microlithiasis also indicates the presence of the pre-invasive lesion of this cancer, known as carcinoma in situ (CIS). We determined the predictive value of unilateral and bilateral testicular microlithiasis for CIS in subfertile men, a known risk population for TGCTs (approximately 1%).

MATERIALS AND METHODS

In a retrospective cross-sectional study the association between testicular microlithiasis and CIS was studied in a group of 263 men referred for subfertility. Testicular microlithiasis and CIS were diagnosed in all men by scrotal ultrasound and in testicular histology specimens as part of the routine evaluation of all patients.

RESULTS

Of the 263 subfertile men 53 (20%) had testicular microlithiasis. No CIS or TGCT was identified in the 23 men with unilateral testicular microlithiasis. In contrast, 6 of the 30 men (20%) with bilateral testicular microlithiasis were diagnosed with CIS. Therefore, the prevalence of CIS in subfertile men with bilateral testicular microlithiasis is significantly higher than in patients without testicular microlithiasis (1 of 210, 0.5%) and with unilateral testicular microlithiasis (0 of 23, 0%) (p <0.0001).

CONCLUSIONS

Bilateral testicular microlithiasis is indicative for CIS in subfertile men. Since these men are at particular risk for invasive TGCT, an assessment of testicular microlithiasis is a valuable tool for the early diagnosis of this disease.

The effect of cryptorchidism on inhibin B in a subfertile population

OBJECTIVE

Prepubertal cryptorchidism may cause fertility problems in adulthood, due to impaired spermatogenesis. Serum inhibin B has emerged as an accurate marker of spermatogenesis. The aim of this study was to evaluate the impact of a history of cryptorchidism on serum inhibin B levels and other markers of spermatogenesis in subfertile men.

PATIENTS AND MEASUREMENTS

In a retrospective study, the effect of cryptorchidism on inhibin B, FSH, LH, free testosterone, testicular volume and semen parameters was assessed in a case-control study within a population of 2613 subfertile men. Of these, 161 and 102 subjects had a history of, respectively, unilateral and bilateral cryptorchidism that was treated by orchiopexy in childhood. Hormone data were complete for 64 cryptorchid patients (32 unilateral and 32 bilateral). A group of 128 patients was randomly selected out of the remaining group of 2350 men with idiopathic subfertility. An additional control group consisted of 32 fertile men from the general population.

RESULTS

In cryptorchid subfertile men, inhibin B concentrations were significantly lower than in noncryptorchid subfertile men and fertile men (103 ng/l, 143 ng/l and 148 ng/l, respectively; P < 0.01). The FSH concentration was significantly higher in cryptorchid men vs. noncryptorchid men and controls (6.1 IU/l vs. 3.3 and 2.9 IU/l, respectively; P < 0.01). Testicular volumes and sperm concentration of cryptorchid men were significantly lower than in noncryptorchid subfertile men (12 vs. 15 ml, P < 0.01 and 3.8 x 10(6) sperm/ml vs. 17.4 x 10(6) sperm/ml; P < 0.05). A significantly higher inhibin B level and sperm concentration was observed in men undergoing orchiopexy at an early age (1-4 years) compared with men treated between 5 and 9 years or later (P < 0.05).

CONCLUSION

Spermatogenesis is more impaired in cryptorchid subfertile men compared to men with idiopathic subfertility, as reflected by a lower inhibin B concentration.

Subtotal obstruction of the male reproductive tract

Bilateral obstruction of the male reproductive tract is suspected in men with azoospermia, normal testicular volume and normal FSH. A testicular biopsy is required to differentiate between an obstruction and a testicular insufficiency. Unilateral or subtotal bilateral obstructions and epididymal dysfunction may cause severe oligozoospermia in men with a normal spermatogenesis. However, information on spermatogenesis in oligozoospermic men is lacking, since testicular biopsy is not routinely performed. Men with a sperm concentration of <1 x 10(6) spermatozoa/ml were investigated for possible partial obstruction by performing a testicular biopsy under local anaesthesia. Spermatogenesis was determined by the Johnsen scoring method. A testicular biopsy was performed in 78 men with severe oligozoospermia. The medical history showed male accessory gland infection in 12.8%, previous hernia repair in 14.1% and a history of cryptorchidism in 12.8%. A normal or slightly disturbed spermatogenesis (Johnsen score >8) was present in 39/78 (50%) of the men. Hernia repair occurred more often in men with normal spermatogenesis. A varicocele was predominantly seen in men with a disturbed spermatogenesis. FSH was significantly lower ( P<0.0001) in men with normal spermatogenesis. Subtotal obstruction of the male reproductive tract is a frequent cause of severe oligozoospermia in men with a normal testicular volume and a normal FSH. In other cases, an epididymal dysfunction might explain the oligozoospermia in men with a normal testicular biopsy score.

Inhibin B: a novel marker of spermatogenesis

Subfertility affects about 15% of all couples. Assessment of spermatogenesis has a central role in the evaluation of the subfertile couple. Classical markers of spermatogenesis, such as semen analysis, testicular biopsy and endocrine evaluation all have their diagnostic limitations. There is a clear need for accurate additional markers of spermatogenesis. Recently, the serum inhibin B level has emerged as a sensitive endocrine marker of spermatogenesis. This paper summarises the pros and cons of different markers of spermatogenesis, with specific focus on serum inhibin B. The serum inhibin B level has been shown to be associated with classical markers of spermatogenesis, particularly testicular histology, and to be the most accurate endocrine marker of spermatogenesis. A subnormal serum inhibin B level clearly reflects disturbed spermatogenesis. Before puberty, when no spermatogenesis takes place, inhibin B is a marker of testicular integrity. Clinical applications of serum inhibin B in childhood and adulthood are given, and a view on future directions and research is presented. The serum inhibin B level has proven to be valuable in the evaluation of spermatogenesis, and holds a promise for further research.

A high hypospadias rate in The Netherlands

BACKGROUND

Reports on increasing hypospadias trends are based on birth defect registries, which are prone to inaccuracy. We assessed the prevalence of hypospadias precisely, by prospective examination of all newborns in Rotterdam over a 2-year period.

METHODS

A total of 7292 consecutive male births were examined for the presence of hypospadias, classified by severity.

RESULTS

The frequency of hypospadias in newborn boys was 0.73% (53/7292). The rate among live births was 38 per 10 000, which is 6 times the previously reported rate for the Southwestern Netherlands (6.2) (P < 0.0001). This registry excludes glandular hypospadias. Without glandular cases, our rate is 26 per 10 000, which is still 4-fold higher (P < 0.0001). The ratio of minor to major hypospadias was 0.3. In 79% of cases, surgery was indicated.

CONCLUSIONS

We found a 4-fold higher than expected hypospadias rate, which may be explained by case ascertainment differences. The proportion of major cases was higher than generally assumed. This study provides evidence for substantial geographical differences. Explanations for temporal and geographical differences need to be explored. To monitor hypospadias rates and trends accurately, complete case ascertainment, including standardized classification of severity, is warranted.

Increased serum inhibin B levels after varicocele treatment

OBJECTIVE

Inhibin B is secreted by Sertoli cells in response to FSH and is the major feedback regulator of FSH secretion in man. The serum inhibin B level has emerged as a good marker of spermatogenesis and Sertoli cell function. Varicocele has been associated with infertility and disturbed spermatogenesis. We have studied the effect of varicocele treatment on serum inhibin B levels, with the aim of investigating the effect on spermatogenesis and the involvement of the Sertoli cell in varicocele pathophysiology.

DESIGN AND PATIENTS

In a pre-post test design, the effect of varicocele surgery on inhibin B levels was studied in 30 infertile men.

MEASUREMENTS

Endocrinology (inhibin B, FSH, LH, SHBG and testosterone) and semen analysis (sperm concentration, motility and morphology).

RESULTS

In men receiving varicocele treatment, a significant increase in serum inhibin B levels was observed from 133.9 +/- 13.4 pretreatment to 167.8 +/- 16.1 ng/l after treatment (mean +/- SEM, P < 0.0001). No significant changes were observed in serum levels of FSH, LH and testosterone. The serum SHBG level decreased from 32.9 +/- 3.5 to 28.6 +/- 3.4 nmol/l (mean +/- SEM, P = 0.04) and the free androgen index was significantly increased from 66 +/- 5.9 pretreatment to 85 +/- 6.8 after treatment (P = 0.02, mean +/- SEM). Semen analysis showed a significant improvement in sperm concentration, from 6.5 +/- 1.9 pretreatment to 19.3 +/- 4.9 x 106/ml after treatment (P = 0.003, mean +/- SEM), and in sperm motility from the baseline level of 17 +/- 3 to 32 +/- 4% after treatment (P = 0.001, mean +/- SEM).

CONCLUSIONS

Varicocele treatment can increase serum inhibin B levels, indicating improvement of spermatogenesis and Sertoli cell function. This finding suggests that the pathophysiology of varicocele involves impairment of Sertoli cell function or a different distribution of germ cell stages.

The advantages of standardized evaluation of male infertility

Healthcare can be improved by standardization and by evaluation of diagnostic methods and treatments. In the field of andrology, in which large patient numbers are required for the evaluation of diagnostic procedures and treatments, structured data collection and multicentre studies are especially warranted. Concomitant with routine clinical practice, a large amount of clinical data are collected that may be used to evaluate andrological care. Structuring and electronic storage of data holds promise in terms of clarity and accessibility of the data and its use for validation studies. The aim of the present work was to study the merits of routine collection of a common dataset in a computer-based patient record (CPR) for standardization, quality of data and clinical research. It was studied whether the data were of sufficient quality and accessibility for much needed studies on aetiology, interventions and diagnostics in andrology. Data collection in a structured CPR promoted complete and comprehensive data. We describe the advantages, pitfalls and solutions with this approach. Data on the uniform examination of 1549 infertile men became readily accessible. Population characteristics, basal associations and original studies were enabled and provided insight into the efficiency of clinical practice. In 66% of men, a cause for their infertility was identified, which provides a better rationale for treatment than semen parameters alone. For more than 30% of the patients, a rational andrological treatment was available, which could be deployed before assisted reproductive technologies were resorted to. However, most treatments have not been properly validated. The thorough diagnostic evaluation identifies subgroups that require an evidence base for treatment and further study on aetiology and diagnosis. Structured collection of uniform patient data through a CPR was feasible and facilitated the evaluation of diagnostic and therapeutic modalities. The reported advantages, pitfalls and solutions with this approach may help other centres to decide on how to implement a CPR. Conscientious collection of a standard data set in infertility centres facilitates pooling of data and evidence-based multicentre research.

Is routine scrotal ultrasound advantageous in infertile men?

PURPOSE

We determine the value of routine scrotal ultrasonography in the evaluation of male infertility.

MATERIALS AND METHODS

Scrotal color Doppler ultrasonography reports of 1,372 infertile men were reviewed to assess the prevalence of scrotal abnormalities and compared to clinical findings.

RESULTS

The prevalence of scrotal abnormalities was 38%. Testicular tumor was found in 0.5%, varicocele in 29.7%, testicular cyst in 0.7%, testicular microlithiasis in 0.9%, epididymal cyst in 7.6% and hydrocele in 3.2% of the cases. Overall, 67% of sonography findings were not evident on palpation, and only 1 of 7 testicular tumors was suspected. Of the varicoceles 60% were not found on physical examination. The rate of testicular tumors (1/200) was higher than that reported for the general European population (1/20,000).

CONCLUSIONS

Routine scrotal ultrasound provides valuable information in the diagnostic evaluation of infertile men and substantially more pathological conditions are detected compared to clinical palpation. The high prevalence of testicular malignancies underlines the clinical relevance of routine scrotal ultrasonography in infertile men.

Improvement of sperm count and motility after ligation of varicoceles detected with colour Doppler ultrasonography

The debate regarding the efficacy of varicocele ligation for improvement of semen parameters and pregnancy rates is ongoing. In addition, no consensus exists as to the benefit of treatment of subclinical varicoceles. The aim of this study was to investigate, retrospectively, the effect of high ligation of both subclinical and clinical varicoceles on sperm count and motility. The value of several factors from history-taking and physical examination for the prediction of successful varicocelectomy was analysed. A total of 139 patients, operated on for a unilateral varicocele on the left side, were studied. Varicoceles were subclinical in 73 patients, based on colour Doppler ultrasonography, and 66 varicoceles were clinical, based on palpation in addition to ultrasonography. Comparison of semen parameters before and after surgery revealed a significant improvement. The median sperm count increased from 10.0 to 14.7, and from 18.2 to 28.6 million/ejaculate, in patients with subclinical and clinical varicoceles, respectively (p < 0.001). The percentage improvement in median sperm count in subclinical varicoceles was not statistically different from the improvement in clinical varicoceles. Mean progressive motility improved significantly after ligation (p < 0.001). The improvement in motility in subclinical varicoceles, from 16 to 23%, was significantly larger than the 24 to 27% improvement in clinical varicoceles. The increase in sperm count was related positively to testicular volume before surgery (p < 0.05). The increase in sperm motility was significantly lower in patients with a history of cryptorchidism (n = 22, p < 0.05). The present data show that ligation of varicoceles detected using Doppler ultrasonography, whether palpable or not, results in an increase in sperm concentration and motility.