Protein intake in infancy and kidney size and function at the age of 6 years: The Generation R Study

Background: High protein intake has been linked to kidney growth and function. Whether protein intake is related to kidney outcomes in healthy children is unclear. Methods: We examined the associations between protein intake in infancy and kidney outcomes at age 6 years in 2968 children participating in a population-based cohort study. Protein intake at 1 year was assessed using a food-frequency questionnaire and was adjusted for energy intake. At age 6 years we measured the kidney volume and urinary albumin/creatinine ratio (ACR) of all participating children, and we estimated glomerular filtration rate (eGFR) using serum creatinine and cystatin C levels. Results: In models adjusted for age, sex, body surface area, and sociodemographic factors, a higher protein intake was associated with a lower ACR and a higher eGFR but was not consistently associated with kidney volume. However, after further adjustment for additional dietary and lifestyle factors, such as sodium intake, diet quality, and television watching, higher protein intake was no longer associated with kidney function. No differences in associations were observed between animal and vegetable protein intake. Conclusions: Our findings show that protein intake in early childhood is not independently associated with kidney size or function at the age of 6 years. Further study is needed on other early life predictors of kidney size and function in later life

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

On the Automatic Guidance System with Crab-Steering

Among the steering modes of farm tractor, the crab-steering has hardly been taken up in production and also in research. That mode of steering may be unapplicable to manual operating that has made familiar with normal mode of steering for long time, but because the vehicle with that mode can always hold its body in a certine direction, that type has a profitable property for the automatic guidance in field operation, and positional relation of sensor and implement is one-dimensional problem and attaching point of sensor to body is unrestricted. This type vehicle can not turn, but travelling of field operation necessitates no turning in many kinds of operations except at head land. At head land, it may be solved to change steering mode. The authors aspect to the property of crab-steering and aimed to develop the automatic guidance system with this steering mode. In this paper, the stability of relay-control system of automatic guidance was considered with describing-function method, and the results of tracking tests with trial vehicle were discussed and considered by means of time varying Fourier coefficients of tracking pass

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

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

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

Vitamin D deficiency in school-age children is associated with sociodemographic and lifestyle factors

There is concern about a reemergence of vitamin D deficiency in children in developed countries. The aims of this study were to describe vitamin D status in the Generation R study, a large multiethnic cohort of 6-y-old children in The Netherlands, and to examine sociodemographic, lifestyle, and dietary determinants of vitamin D deficiency. We measured serum 25-hydroxyvitamin D [25(OH)D] concentrations in 4167 children aged 6 y and defined deficiency following recommended cutoffs. We examined the associations between subject characteristics and vitamin D deficiency with the use of multivariable logistic regression analyses. Serum 25(OH)D concentrations ranged from 4 to 211 nmol/L (median: 64 nmol/L), with 6.2% of the children having severely deficient ( <25 nmol/L), 23.6% deficient (25 to <50 nmol/L), 36.5% sufficient (50 to <75 nmol/L), and 33.7% optimal (≥75 nmol/L) 25(OH)D concentrations. The prevalence of vitamin D deficiency [25(OH)D <50 nmol/L] was higher in winter (51.3%) than in summer (10.3%); and higher in African, Asian, Turkish, and Moroccan children (54.5%) than in those with a Dutch or other Western ethnic background (17.6%). In multivariable models, several factors were associated with vitamin D deficiency, including household income (OR: 1.74; 95% CI: 1.34, 2.27 for low vs. high income), child age (OR: 1.39; 95% CI: 1.20, 1.62 per year), child television watching (OR: 1.32; 95% CI: 1.06, 1.64 for ≥2 vs. <2 h/d), and playing outside (OR: 0.71; 95% CI: 0.57, 0.89 for ≥1 vs. <1 h/d). In a subgroup with dietary data (n = 1915), vitamin D deficiency was associated with a lower diet quality, but not with vitamin D intake or supplement use in early childhood. Suboptimal vitamin D status is common among 6-y-old children in The Netherlands, especially among non-Western children and in winter and spring. Important modifiable factors associated with vitamin D deficiency were overall diet quality, sedentary behavior, and playing outsid

Socioeconomic status is positively associated with measures of adiposity and insulin resistance, but inversely associated with dyslipidaemia in Colombian children

Q1Q1Artículo de investigación580-587Niños colombianosBackground - Low socioeconomic status (SES) has been associated with higher risk of cardiometabolic diseases in developed societies, but investigation of SES and cardiometabolic risk in children in less economically developed populations is sparse. We aimed to examine associations among SES and cardiometabolic risk factors in Colombian children. Methods - We used data from a population-based study of 1282 children aged 6–10 years from Bucaramanga, Colombia. SES was classified according to household wealth, living conditions and access to public utilities. Anthropometric and biochemical parameters were measured at a clinic visit. Cardiometabolic risk factors were analysed continuously using linear regression and as binary outcomes—according to established paediatric cut points—using logistic regression to calculate OR and 95% CIs. Results - Mean age of the children was 8.4 (SD 1.4) and 51.1% of the sample were boys. Odds of overweight/obesity, abdominal obesity and insulin resistance were greater among higher SES. Compared with the lowest SES stratum, children in the highest SES had higher odds of overweight/obesity (OR=3.25, 95% CI 1.89 to 5.57), abdominal obesity (OR=2.74, 95% CI 1.41 to 5.31) and insulin resistance (OR=2.60, 95% CI 1.81 to 3.71). In contrast, children in the highest SES had lower odds of hypertriglyceridaemia (triglycerides ≥90th centile; OR=0.28, 95% CI 0.14 to 0.54) and low (≤10th centile) high-density lipoprotein (HDL) cholesterol (OR=0.35, 95% CI 0.15 to 0.78). Conclusions - In Colombian children, SES is directly associated with obesity and insulin resistance, but inversely associated with dyslipidaemia (hypertriglyceridaemia and low HDL cholesterol). Our findings highlight the need to analyse cardiometabolic risk factors separately in children and to carefully consider a population's level of economic development when studying their social determinants of cardiometabolic disease