Iodine Nutrition, Thyroid-stimulating Hormone, and Related Factors of Postpartum Women from three Different Areas in China: A Cross-sectional Survey.

Objective: Studies on the relationship between iodine, vitamin A (VA), and vitamin D (VD) and thyroid function are limited. This study aimed to analyze iodine and thyroid-stimulating hormone (TSH) status and their possible relationships with VA, VD, and other factors in postpartum women. Methods: A total of 1,311 mothers (896 lactating and 415 non-lactating) from Hebei, Zhejiang, and Guangxi provinces were included in this study. The urinary iodine concentration (UIC), TSH, VA, and VD were measured. Results: The median UIC of total and lactating participants were 142.00 µg/L and 139.95 µg/L, respectively. The median TSH, VA, and VD levels in all the participants were 1.89 mIU/L, 0.44 µg/mL, and 24.04 ng/mL, respectively. No differences in the UIC were found between lactating and non-lactating mothers. UIC and TSH levels were significantly different among the three provinces. The rural UIC was higher than the urban UIC. Obese mothers had a higher UIC and a higher prevalence of excessive TSH. Higher UICs and TSHs levels were observed in both the VD deficiency and insufficiency groups than in the VD-sufficient group. After adjustment, no linear correlation was observed between UIC and VA/VD. No interaction was found between vitamins A/D and UIC on TSH levels. Conclusion: The mothers in the present study had no iodine deficiency. Region, area type, BMI, and VD may be related to the iodine status or TSH levels.

Chronic Toxicity of Genetically Modified Maize with Cry1Ab-ma Gene and Its Effect on Serum Metabolites in Rats.

Genetic engineering has inserted the crystallin (Cry) gene of Bacillus thuringiensis into the genes of maize to cultivate a variety of transgenic insect-resistant maizes. At present, genetically modified maize with Cry1Ab-ma gene (maize CM8101) was in the stage of safety verification. In this study, a 1-year chronic toxicity test was carried out to evaluate the safety of maize CM8101. Wistar rats were selected for the experiment. Rats were randomly divided into three groups and fed the corresponding diets: genetically modified maize group (CM8101 group), parental maize group (Zheng58 group), and AIN group. Rat serum and urine were collected at the third, sixth, and twelfth months of the experiment, and viscera were collected at the end of the experiment for detection. Metabolomics was used to analyze the metabolites in the serum of rats at the 12th month. While the CM8101 group rats' diets were supplemented with 60% maize CM8101, no obvious poisoning symptoms were found in rats, and no poisoning death occurred. There were no negative effects on body weight, food intake, blood and urine indices, or organ histopathological examination results. Furthermore, metabolomics results revealed that, when compared to group differences, the gender of rats had a more obvious effect on metabolites. The CM8101 group primarily changed linoleic acid metabolism in female rats, while glyceropholipid metabolism was altered in male rats. In rats, consumption of maize CM8101 did not result in significant metabolic dysfunction.

Evaluation of Serum Zinc Status of Pregnant Women in the China Adult Chronic Disease and Nutrition Surveillance (CACDNS) 2015.

Objective: The purpose of this study was to evaluate serum zinc status of pregnant women in the China Adult Chronic Disease and Nutrition Surveillance (CACDNS) in 2015-2016. Methods: A total of 7147 apparently healthy pregnant women were randomly selected in 302 national monitoring sites. Information on age, race, residence region, education, pregnancy, and family income per annum was collected, and the concentration of serum zinc was determined. The evaluation of serum zinc status was further performed according to the recommendations by the International Zinc Nutrition Consultative Group (IZiNCG). Results: The median concentration of serum zinc was 858.9 µg/L with an interquartile range (IQR) of 712.9 µg/L and 1048.9 µg/L, while the overall prevalence of zinc deficiency was 3.5% with a 95% confidence interval (CI) of 3.0% and 3.9%. Serum zinc status of pregnant women changed greatly in the different categories, particular in pregnancy and family income per annum (p < 0.05), but no significant difference was observed in the prevalence of zinc deficiency (p > 0.05). Conclusions: The lower prevalence of zinc deficiency generally indicated a better zinc status for pregnant women in the CACDNS in 2015-2016. However, a well-designed evaluation system of zinc status for pregnant women should be continually optimized and improved by inducing more parameters such as biochemical, dietary, or functional indicators.

Basal Energy Expenditure of Chinese Healthy Adults: Comparison of Measured and Predicted Values.

OBJECTIVE: This study aimed to measure the basal energy expenditure (BEE) of Chinese healthy adults and establish an accurate predictive equation for this population. METHODS: In total, 470 Chinese healthy adults had their BEE measured using the Cosmed K4b 2 portable metabolic system. Multiple linear regression analysis was applied to develop new optimal equations for predicting BEE. The bias, accuracy rate, concordance correlation coefficient (CCC), and root mean square error (RMSE) were used to evaluate the accuracy of the predictive equations. RESULTS: There was a significant difference in BEE between males and females, with 5,954 kJ/d and 5,089 kJ/d, respectively. People living in rural areas expended significantly higher BEE (5,885 kJ/d) than those in urban areas (5,279 kJ/d). Previous equations developed by Henry, Schofield, Harris-Benedict (H-B), and Liu overestimated the BEE of Chinese healthy adults. The new equations derived from the present study displayed the smallest average bias and RMSE from the measured basal energy expenditure (mBEE). The CCC of the new equations was higher than other predictive equations, but it was lower than 0.8. There was no significant difference in the accuracy rate among all predictive equations. CONCLUSIONS: Sex and regional differences in BEE were observed in Chinese healthy adults. Neither the widely used previous predictive equations nor the one derived in the present study were accurate enough for estimating the BEE of Chinese healthy adults. Further study is required to develop more accurate equations for predicting the BEE of Chinese healthy adults aged between 20-45 years.