ABSTRACT
Background Exercise during pregnancy is closely related to maternal and infant health. Previous studies in developed countries have linked maternal exercise during pregnancy with newborn body weight as well as subcutaneous fat thickness. However, the relevant studies in China are limited, and the conclusions remain inconsistent. Objective To investigate the effects of maternal exercise during pregnancy on neonatal weight and subcutaneous fat thickness. Methods Based on the Shanghai Birth Cohort, 959 maternal-infant pairs were included in this study. The International Physical Activity Questionnaire was used to collect average weekly frequency and daily minutes of walking in the first and second trimesters, and entropy weight method was used to calculate the cumulative exercise index in the two trimesters. Birth weight was measured using a calibrated weigh scale. Subcutaneous fat thickness was measured at abdomen, scapula, and triceps with a Harpenden skinfold caliper for all newborns and the sum of the thickness for the three sites was then calculated. A multiple linear regression model was employed to estimate the relationships of cumulative exercise index during pregnancy with neonatal body weight and subcutaneous fat thickness. Subgroup analyses stratified by pre-pregnancy body mass index (BMI) and sex of newborns were also performed. Results The mean age of pregnant women was (28.5±3.8) years, and the pre-pregnancy BMI was (21.4±3.0) kg·m−2. Newborn boys were slightly more than newborn girls (54.3% vs 45.7%), and the neonatal weight was (3374.0±427.5) g. The means of newborns' abdominal, scapular, and triceps subcutaneous fat thickness were (4.4±1.3), (5.4±1.4), and (6.0±1.5) mm, respectively, and the sum of subcutaneous fat thickness was (15.8±3.9) mm. In the first and second trimesters, 77.3% and 88.7% of pregnant women walked 4 d per week and more, respectively; the daily minutes of walking was (36.9±27.2) min and (43.3±26.3) min, respectively; the cumulative exercise index was 25.6±17.7 and 35.9±21.1, respectively. The results of multiple linear regression analysis showed that the cumulative exercise index in the second trimester was negatively associated with newborns' abdominal (b=−0.006, 95%CI: −0.010-−0.003), scapular (b=−0.005, 95%CI: −0.009-−0.002), triceps (b=−0.006, 95%CI: −0.010-−0.002), and their sum of (b=−0.018, 95%CI: −0.028-−0.007) subcutaneous fat thickness (P<0.05); in the first and second trimesters, however, the relationship between maternal cumulative exercise and newborns' body weight was not significant. The results of stratified analyses showed that the negative associations between maternal cumulative exercise index and newborns' subcutaneous fat thickness for the second trimester remained significant in the subgroups of boys and neonates whose mothers had normal pre-pregnancy BMI (P<0.05). Conclusion Cumulative exercise index in the second trimester is negatively correlated with the neonatal thickness of subcutaneous fat, and the association may be altered by neonatal sexes and maternal pre-pregnancy BMI levels.
ABSTRACT
Background Heavy metals are widely present in the environment, difficult to degrade, and bioaccumulative. Children's physical development are not mature, and exposure to heavy metals which may cause irreversible harm to them. However, the current research conclusions are still inconsistent. Therefore, it is very important to pay attention to the impact of heavy metal pollutants on physical development. Objective To detect the level of heavy metal exposure of school-age children in Laizhou Wan, Shandong Province, and to explore the relationship between heavy metal exposure level and physical development indexes of school-age children. Methods The subjects of this study were 318 children born to pregnant women recruited from Laizhou Wan Birth Cohort in Shandong Province from September 2010 to December 2013. The school-age children at age 7 were followed up from July to September 2019. Their urine samples were collected and the levels of arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg) in urine were detected by inductively coupled plasma mass spectrometry (ICP-MS). At the same time, the height, weight, body mass index (BMI), waist circumference, and body fat percentage of the children were evaluate to analyze the relationship between the four heavy metals in children's urine and the indicators related to children's physical development. Results Among the 318 school-age children with an age (\begin{document}$\bar x \pm s $\end{document}) of (7.77±0.67) years, the median (P25, P75) levels of As, Cd, Pb, and Hg in urine were 73.98 (44.81, 124.61), 0.40 (0.27, 0.58), 1.20 (0.71, 1.72), and 2.38 (1.32, 4.80) µg·g−1 (of creatinine), respectively. The children’s urinary Cd level was positively correlated with their weight, BMI, and waist circumference (P<0.05), and corresponding regression coefficients (b) and its 95% confidence intervals (CI) were 0.99 (0.14-1.83), 0.43 (0.06-0.81), and 1.35 (0.27-2.42), respectively; while the other heavy metals were not related to the above physical development indicators (P>0.05). After sex stratification, it was found that boys’ urinary Cd level was positively correlated with their height, weight, BMI, and waist circumference (P <0.05) with associated b (95%CI) of 1.73 (0.53-2.93), 2.03 (0.60-3.47), 0.75 (0.11-1.38), and 2.66 (0.85-4.47), respectively; such associations were not found in girls. After further stratification of boys’ BMI according to normal, overweight, and obesity, it was found that a higher urinary Cd level was correlated with an increased risk of obesity in boys (P<0.05), and the associated b (95%CI) was 2.34 (1.02-5.36). Conclusion The level of urinary Cd exposure of boys in Laizhou Wan, Shandong Province is positively correlated with their height, weight, BMI, and waist circumference, and may be related to obesity in boys.
ABSTRACT
Objective To investigate the prevalence of allergic and infectious diseases in children， and to assess the influence of indoor and outdoor environmental factors on these two common diseases in children. Methods A questionnaire was used to investigate the prevalence of allergic and infectious diseases in 140 children of 7 years old in Laizhou Bay， Shandong Province. Logistic regression was used to analyze the associations between indoor and outdoor environmental factors and children’s allergic and infectious diseases， respectively. Results The prevalence of previous eczema and other allergic diseases for the past year in children was 37.9% and 15.0%， respectively， and the prevalence of infectious diseases for the past year was 35.7%. As for allergic diseases， eye irritation due to outdoor air （ OR =2.977； 95% CI ： 1.407‒6.296） and nose irritation due to outdoor air （ OR =5.147； 95% CI ： 1.272‒20.827） were the risk factors for previous eczema in children. Indoor musty taste increased the risks of urticaria （ OR =4.306； 95% CI ： 1.062‒17.454） and previous eczema （ OR =3.853； 95% CI ： 1.080‒13.743）. The use of cockroach killers indoors increased the risk of rhinitis （ OR =6.102； 95% CI ：1.297‒28.697）. As for infectious diseases， having outdoor pollution sources increased the risk of gastrointestinal infection （ OR =4.937； 95% CI ： 1.050‒23.216）， and the use of mosquito coils and clothing mothproofing agents increased the risks of respiratory （ OR =6.333； 95% CI ： 1.397‒28.714） and gastrointestinal infections （ OR =3.218； 95% CI ： 1.074‒9.644）， respectively. However， we did not find associations between indoor passive smoking and allergic or infectious diseases. Conclusion Except outdoor passive smoking， all the other indoor and outdoor environmental factors increase the risks of children’s allergies and infectious diseases.
ABSTRACT
Objective To investigate the prevalence of allergic and infectious diseases in children， and to assess the influence of indoor and outdoor environmental factors on these two common diseases in children. Methods A questionnaire was used to investigate the prevalence of allergic and infectious diseases in 140 children of 7 years old in Laizhou Bay， Shandong Province. Logistic regression was used to analyze the associations between indoor and outdoor environmental factors and children’s allergic and infectious diseases， respectively. Results The prevalence of previous eczema and other allergic diseases for the past year in children was 37.9% and 15.0%， respectively， and the prevalence of infectious diseases for the past year was 35.7%. As for allergic diseases， eye irritation due to outdoor air （ OR =2.977； 95% CI ： 1.407‒6.296） and nose irritation due to outdoor air （ OR =5.147； 95% CI ： 1.272‒20.827） were the risk factors for previous eczema in children. Indoor musty taste increased the risks of urticaria （ OR =4.306； 95% CI ： 1.062‒17.454） and previous eczema （ OR =3.853； 95% CI ： 1.080‒13.743）. The use of cockroach killers indoors increased the risk of rhinitis （ OR =6.102； 95% CI ：1.297‒28.697）. As for infectious diseases， having outdoor pollution sources increased the risk of gastrointestinal infection （ OR =4.937； 95% CI ： 1.050‒23.216）， and the use of mosquito coils and clothing mothproofing agents increased the risks of respiratory （ OR =6.333； 95% CI ： 1.397‒28.714） and gastrointestinal infections （ OR =3.218； 95% CI ： 1.074‒9.644）， respectively. However， we did not find associations between indoor passive smoking and allergic or infectious diseases. Conclusion Except outdoor passive smoking， all the other indoor and outdoor environmental factors increase the risks of children’s allergies and infectious diseases.