Reduced cardiorespiratory fitness, low physical activity and an urban environment are independently associated with increased cardiovascular risk in children

Aims/hypothesis: To assist in the development of preventive strategies, we studied whether the neighbourhood environment or modifiable behavioural parameters, including cardiorespiratory fitness (CRF) and physical activity (PA), are independently associated with obesity and metabolic risk markers in children. Methods: We carried out a cross-sectional analysis of 502 randomly selected first and fifth grade urban and rural Swiss schoolchildren with regard to CRF, PA and the neighbourhood (rural vs urban) environment. Outcome measures included BMI, sum of four skinfold thicknesses, homeostasis model assessment of insulin resistance (HOMA-IR) and a standardised clustered metabolic risk score. Results: CRF and PA (especially total PA, but also the time spent engaged in light and in moderate and vigorous intensity PA) were inversely associated with measures of obesity, HOMA-IR and the metabolic risk score, independently of each other, and of sociodemographic and nutritional parameters, media use, sleep duration, BMI and the neighbourhood environment (all p < 0.05). Children living in a rural environment were more physically active and had higher CRF values and reduced HOMA-IR and metabolic risk scores compared with children living in an urban environment (all p < 0.05). These differences in cardiovascular risk factors persisted after adjustment for CRF, total PA and BMI. Conclusions/interpretation: Reduced CRF, low PA and an urban environment are independently associated with an increase in metabolic risk markers in children. Trial registration: isrctn.org 15360785 Funding: The study was funded by the Federal office of Sports (Magglingen, Switzerland), the Swiss National Science Foundation (grant nos 3234-069271 and PMPDB-114401) and the Diabetes Foundation of the Region of Base

Cohort study on the effects of everyday life radio frequency electromagnetic field exposure on non-specific symptoms and tinnitus

BACKGROUND: There is public concern regarding potential health effects of radio frequency electromagnetic fields (RF-EMF) exposure, as produced by mobile phones or broadcast transmitters. The objective of this study was to investigate the association between RF-EMF exposure and non-specific symptoms and tinnitus in a prospective cohort study. METHODS: In 2008, 1375 randomly selected participants from Basel, Switzerland, were enrolled in a questionnaire survey with follow-up after one year (participation rate 82%). A score for somatic complaints (von Zerssen list) and headache (HIT-6) was assessed. Far-field environmental RF-EMF exposure was predicted using a validated prediction model. Regarding near-field exposure, self-reported mobile and cordless phone use as well as mobile phone operator data were collected. In multivariate regression models, we investigated whether exposure at baseline (cohort analysis) or changes in exposure between baseline and follow-up (change analysis) were related to changes in health scores. RESULTS: For participants in the top decile of environmental far-field RF-EMF exposure at baseline, in comparison to participants exposed below the median value, the change in the von Zerssen- and HIT-6-scores between baseline and follow-up was -0.12 (95%-CI: -1.79 to 1.56) and -0.37 (95%-CI: -1.80 to 1.07) units, respectively. Exposure to near-field sources and a change in exposure between baseline and follow-up were not related to non-specific symptoms. Similarly, no association between RF-EMF exposure and tinnitus was observed. CONCLUSIONS: In this first cohort study using objective and well-validated RF-EMF exposure measures, we did not observe an association between RF-EMF exposure and non-specific symptoms or tinnitu

Classification of personal exposure to radio frequency electromagnetic fields (RF-EMF) for epidemiological research : evaluation of different exposure assessment methods

The use of personal exposure meters (exposimeters) has been recommended for measuring personal exposure to radio frequency electromagnetic fields (RF-EMF) from environmental far-field sources in everyday life. However, it is unclear to what extent exposimeter readings are affected by measurements taken when personal mobile and cordless phones are used. In addition, the use of exposimeters in large epidemiological studies is limited due to high costs and large effort for study participants. In the current analysis we aimed to investigate the impact of personal phone use on exposimeter readings and to evaluate different exposure assessment methods potentially useful in epidemiological studies. We collected personal exposimeter measurements during one week and diary data from 166 study participants. Moreover, we collected spot measurements in the participants' bedrooms and data on self-estimated exposure, assessed residential exposure to fixed site transmitters by calculating the geo-coded distance and mean RF-EMF from a geospatial propagation model, and developed an exposure prediction model based on the propagation model and exposure relevant behavior. The mean personal exposure was 0.13mW/m(2), when measurements during personal phone calls were excluded and 0.15mW/m(2), when such measurements were included. The Spearman correlation with personal exposure (without personal phone calls) was 0.42 (95%-CI: 0.29 to 0.55) for the spot measurements, -0.03 (95%-CI: -0.18 to 0.12) for the geo-coded distance, 0.28 (95%-CI: 0.14 to 0.42) for the geospatial propagation model, 0.50 (95%-CI: 0.37 to 0.61) for the full exposure prediction model and 0.06 (95%-CI: -0.10 to 0.21) for self-estimated exposure. In conclusion, personal exposure measured with exposimeters correlated best with the full exposure prediction model and spot measurements. Self-estimated exposure and geo-coded distance turned out to be poor surrogates for personal exposure

Evaluation of a physical activity promotion program in primary care

Background. Physical inactivity increases the risk of many chronic disorders. It is not clear which strategies are the most appropriate to enable people to adopt a more active lifestyle. Randomized controlled trials have found that brief advice from GPs supported by written material had a significant positive effect on patient's physical activity. The pilot project ‘Move for Health and the Environment' translated this evidence into a program suitable for the real-life situation of busy practices. The aim of this study was to evaluate the change in physical activity level of the participating patients 1 year after the intervention. Methods. Patients aged 16-65 years completed a screening questionnaire before consultation with their physician. Insufficiently active patients were offered an information leaflet and a voucher for a physical activity counselling session. One year later, all inactive patients and a random selection of the active were re-contacted and invited to answer identical questions. Results. A total of 1239 (73.9%) returned the follow-up questionnaire. In all, 37.3% of the formerly inactive patients met the threshold of sufficient activity at follow-up, whereas 20.3% of the previously active no longer did. Formerly inactive patients reported an increase of 58.8 minutes/week of moderate and 34.6 minutes/week of vigorous activity and spending more time walking and cycling. Formerly active patients reported less time spent in moderate activities. Conclusions. Systematic counselling in primary care encouraged insufficiently active patients to adopt a more active lifestyle. Yet it became evident that active patients also need counselling to maintain their activity level

Survey on the occurrence of Brachyspira species and Lawsonia intracellularis in children living on pig farms

The occurrence of Brachyspira species and Lawsonia intracellularis was investigated by PCR analyses of faeces from 60 children living on European pig farms. In addition, 60 other children were included as controls. Two samples were positive for B. aalborgi but B. pilosicoli and L. intracellularis were not demonstrate

Weight-bearing bones are more sensitive to physical exercise in boys than in girls during pre- and early puberty: a cross-sectional study

Summary: We carried out a cross-section study of the sex-specific relationship between bone mineral content and physical activity at sites with different loading in pre- and early pubertal girls and boys. There was significant sensitivity of bone mineral content of the hip to physical exercise in boys, but not in girls. Background: Since little is known whether there are sex differences in sensitivity of bone to loading, we investigated sex differences in the cross-sectional association between measures of physical activity (PA) and bone mass and size in pre- and early pubertal children of both sexes. Methods: We measured bone mineral content/density (BMC/BMD) and fat-free mass (FFM) in 269 6- to 13-year-old children from randomly selected schools by dual-energy X-ray absorptiometry. Physical activity (PA) was measured by accelerometers and lower extremity strength by a jump-and-reach test. Results: Boys (n = 128) had higher hip and total body BMC and BMD, higher FFM, higher muscle strength and were more physically active than girls (n = 141). Total hip BMC was positively associated with time spent in total and vigorous PA in boys (r = 0.20-0.33, p < 0.01), but not in girls (r = 0.02-0.04, p=ns), even after adjusting for FFM and strength. While boys and girls in the lowest tertile of vigorous PA (22min/day) did not differ in hip BMC (15.62 vs 15.52g), boys in the highest tertile (72min/day) had significantly higher values than the corresponding girls (16.84 vs 15.71g, p < 0.05). Conclusions: Sex differences in BMC during pre- and early puberty may be related to a different sensitivity of bone to physical loading, irrespective of muscle mas

Personal and environmental factors associated with active commuting to school in Switzerland

Objective. To assess whether prevalence of active commuting and regular car trips to school varies across communities and language regions in Switzerland and to determine personal and environmental correlates. Methods. During the school year 2004/2005, 1345 parental questionnaires (response rate 65%) of children attending 1st, 4th and 8th grades were completed, 1031 could be linked to a GIS environmental database. A German-speaking, a French-speaking and a bilingual study area were included. Usual mode of transportation and frequency of regular car trips to school were assessed. Associations with personal and environmental factors were evaluated with multivariate regression models. Results. Seventy-eight percent of the children actively traveled to school. Twelve percent were regularly driven at least once a week by car. Major road crossings and distance were significantly related to usual mode of transportation, but not to regular car trips. Age, daycare attendance, parental safety concerns, number of cars in the household and belonging to French-speaking population were significantly associated with increased regular car trips. Conclusion. Objective predictors are main deciding factors for active commuting to school as main mode of transport whereas personal and lifestyle factors are important factors associated with frequency of car use. Not only objective but also differing cultural attitudes should be considered when promoting non-motorized travel