Age-related modification effect on the association between body mass index and the risk of hypertension: A Cohort Study on Chinese people living in the rural areas / 中华流行病学杂志

Objective: To study the modification effect of age on the association between body mass index and the risk of hypertension. Methods: People age ≥18 years old were selected by clusters, from a rural area of Henan province. In total, 20 194 people were recruited at baseline during 2007 and 2008, and the follow-up study was completed from 2013 to 2014. Logistic regression model was used to assess the risk of incident hypertension by baseline BMI and age-specific BMI. Results: During the 6-year follow-up period, 1 950 hypertensive persons were detected, including 784 men and 1 166 women, with cumulative incidence rates as 19.96%, 20.51%, and 19.61%, respectively. Compared with those whose BMI<22 kg/m(2), the RRs of hypertension were 1.09 (0.93-1.27), 1.17 (1.01-1.37), 1.34 (1.14-1.58) and 1.31 (1.09-1.56) for participants with BMI as 22-, 24-, 26- and ≥28 kg/m(2), respectively. In young and middle-aged populations, the risk of hypertension gradually increased with the rise of BMI (trend P<0.05). However, in the elderly, the increasing trend on the risk of hypertension risk was not as significantly obvious (trend P>0.05). Conclusion: The effect of BMI on the incidence of hypertension seemed to depend on age. Our findings suggested that a weight reduction program would be more effective on young or middle-aged populations, to prevent the development of hypertension.

Association between pregnancy-related anxiety of pregnant women and autism-like behavior in their offspring at 18 months of age / 中华流行病学杂志

Objective: To investigate the relationship of pregnancy-related anxiety of pregnant women in second/third trimesters and autism-like behaviors in their offspring at 18 months of age. Methods: Based on a prospective cohort study design, we evaluated the situation of pregnancy-related anxiety of women during second and third trimesters through a Pregnancy-Related Anxiety Questionnaire. Subjects under study were classified into three groups, 1) those with pregnancy- related anxiety during both trimesters, 2) those with pregnancy-related anxiety at one trimester and 3) those without pregnancy-related anxiety in either trimester. When their children were 18 months, autism-like behaviors (ALB) were evaluated, using the part A of Checklist for Autism in Toddlers-23, and then classified into three groups as non-ALB group, minor ALB group and major ALB group. Multi-nominal logistic Regression was used to analyze the relationship of pregnancy-related anxiety with autism-like behaviors. Results: Compared with non-ALB group, children whose mother with pregnancy-related anxiety during both trimesters presented significant higher risk on ALB than children whose mother without pregnancy-related anxiety in these two periods (relative risk, RR=2.43, 95% CI: 1.21-4.86, P=0.012), major factors as pregnant women's IQ and gestational diabetes mellitus, premature delivery and education levels of fosterers on these pregnant women were under control. Our results from the stratified analysis showed: when in the subgroup that mother was the main fosterer of the child, there was an significant increase of risk in children whose mothers with pregnancy-related anxiety during both trimesters (RR=4.22, 95%CI: 1.73-10.32, P=0.002). Conclusion: The association between pregnancy-related anxiety and autism-like behavior was not strong but influenced by the fosterer of the child.

Pregnancy-related anxiety associated with small-for-gestational-age infants / 中华流行病学杂志

Objective: To investigate the second or third trimester pregnancy-related anxiety on small-for-gestational-age infants. Methods: This study was based on Ma'anshan Birth Cohort Study (MABC), with 3 040 maternal-singleton pairs finally selected for data analysis, from May 2013 to September 2014. The psychological state of pregnancy was evaluated according to a self-developed 'anxiety scale for gestation'. Small-for-gestational-age was defined as 'having birth weight below the 10(th) percentile at a particular gestational week', while large-for-gestational-age infants was defined as 'having birth weight above the 90(th) percentile'. Birth weight between the 10(th) and 90(th) percentile was classified as appropriate-for-gestational age infants. χ(2) test was used to compare the distribution of characteristics in pregnancy among three groups with different birth weights. Multivariate logistic regression models were conducted to evaluate the associations between third trimester pregnancy- related anxiety and birth weight. Results: The incidence rates of small- and large-gestational-age infants were 9.6% and 16.6%, respectively. Difference between women with only one of the second or third trimester pregnancy-related anxiety syndromes and small-for-gestational-age infants showed no statistical significance. Women with both second and third trimester pregnancy-related anxieties might increase the risk of small-for-gestational-age infants (OR=1.39, 95%CI: 1.04-1.87). However, there was no significant difference between pregnancy-related anxiety and large-for- gestational-age infants (OR=1.05, 95%CI: 0.81-1.35) noticed. Conclusion: Women with second and third trimester pregnancy-related anxiety appeared a risk factor for small-for-gestational-age infants.