Effect of docosahexenoic acid supplementation on infant's growth and body mass index during maternal pregnancy / 中华流行病学杂志

Objective: To investigate the effects of docosahexenoic acid (DHA) supplementation on infant's growth and BMI during pregnancy. Methods: A total of 1 516 healthy pregnant women delivered their babies in two maternal and child health care hospitals in Beijing and were chosen as the subjects in this cohort study from May to October 2015. Self-developed questionnaires were used to gather general information of the subjects, including age, height, weight, weight gain during pregnancy, delivery mode, DHA supplementation etc., before giving birth. Information on body length, weight, head circumference and BMI at birth and 6 months postnatal, of the infants were recorded. Breast milk was collected to test the fatty acid profiles by using the gas chromatography (GC) method at one to three months postnatally. Results: The overall rate of DHA supplementation was 47.76% among the pregnant women, in which introduction of DHA from the early and second stage of the pregnancy accounted for 49.31% and 39.64% respectively. When DHA supplementation began from the early pregnant stage, the DHA concentration showed an increase in the milk (P<0.05), whereas the supplementation began from the second and third stages did not affect the milk DHA concentration (P>0.05). Higher height and lower BMI were seen in the infants at birth and 6 months in the supplementation group when comparing to the non-supplementary group (P<0.05), with the greatest effects noticed in the earliest supplementation group. Specifically, the head circumference appeared larger from the early pregnant stage in the DHA supplementary group, than that in the non-supplement group (P=0.001). The increment of head circumference was larger than that in the other groups when the infants were 6-month old (P<0.01). Results from the partial regression analysis showed that during pregnancy, there were positive correlations between DHA supplementation and height (r=0.324, r=0.216), head circumference (r=0.221, r=0.302) as well as the increment of head circumference (r=0.276) at birth and 6 months (P<0.05). Whereas, a negative correlation was shown between DHA and the infants' BMI (r=-0.310, r=-0.371) (P<0.05) when supplementation was given during maternal pregnancy. Conclusions: When DHA supplementation program was carried out during maternal pregnancy, it could increase the height and head circumference and inhibit the rapid increase of BMI in the infants BMI. Our findings seemed helpful in promoting brain development and preventing the childhood obesity.

Prevalence of musculoskeletal disorders and related factors in female greenhouse workers in Shandong province / 中华流行病学杂志

Objective: To study the prevalence of musculoskeletal disorders (MSDs) and related factors in female greenhouse workers. Method: A questionnaire survey was conducted among 851 female greenhouse workers in Shandong province in 2015. Results: The incidence of MSDs among the female greenhouse workers was 82.79%. For the MSDs in female greenhouse workers, the top four affected body sites were low back (65.82%), knees (49.10%), neck (25.75%) and shoulder (23.47%). Multivariate logistic regression analysis showed that age ≥50 years (OR=2.098, 95%CI: 1.353-3.252), working years ≥20 (OR=1.703, 95%CI: 1.116-2.599), repetitive work (OR=1.903, 95%CI: 1.183-3.061), standing for prolonged time (OR=2.902, 95%CI: 1.183-7.120) and frequent slightly bending down (OR=2.979, 95%CI: 1.823-4.867) were the main risk factors for MSDs in female greenhouse workers. Aiding tools was the protective factor (OR=0.400, 95%CI:0.229-0.697). Conclusions: The findings showed a relatively higher prevalence of MSDs in female greenhouse workers. It is necessary to take appropriate measures to prevent and control the incidence of MSDs in female greenhouse workers.