ABSTRACT
Objective@#To investigate the longitudinal association of plasma Irisin concentrations with changes in blood pressure (BP) levels among children,and to assess the moderating effect of physical activity (PA) or sedentary behavior (SB) on the relationship between Irisin levels and BP.@*Methods@#Based on a cohort study, a cluster sampling method was used to select 3 651 school aged children from five schools in Guangzhou in 2017 at the baseline survey and follow up in 2019. Both at baseline and during follow up, PA and SB were assessed by validated questionnaires, and BP levels were measured by an electronic sphygmomanometer. A final sample of 521 children were enrolled based on the PA and SB at baseline. Plasma Irisin concentrations were measured by ELISA at baseline. Logistic regression analysis was recruited for exploring the associations of plasma Irisin concentrations with changes in BP. Moderating effects of PA and SB on the relationship between Irisin concentrations and BP were estimated using stratified analysis.@*Results@#Logistic regression analysis indicated that there was no significant association between Irisin concentrations and changes in BP levels among children ( OR =0.98, P >0.05). After stratification for SB, Irisin levels in the low SB subgroup were inversely associated with changes in diastolic blood pressure ( OR=0.87, 95%CI=0.77-0.98, P =0.02). In addition, SB level had a moderating effect on the relationship between Irisin levels and the DBP changes ( P =0.01).@*Conclusion@#Increased Irisin concentration is associated with the decrease of DBP level among low SB children. Furthermore, SB level shows moderating role in the relationship between Irisin concentrations and changes in DBP levels.
ABSTRACT
Objective To continuously draw blood from caudal vein of SD rats which controlled by the homemade holder with an im-proved method, and the effects of this method was evaluated according to the relevant indicators. Methods The 24 SD rats should be drew the blood from the caudal vein by the improved disposable infusion needle and supplied physiological saline at the condition of ether inhala-tion anesthesia and once a day until to the thirteenth day,and then the times of draw blood and the number of survival rats only to calculate the success rate and survival rate of rats were record. Results In the 12 days,the tail vein blood of 24 SD rats were successfully collected. But a rat died of excessive ether inhalation anesthesia on the thirteenth day. The success rate was 99. 68% and the rat survival rate was 95. 83%. Conclusion The method that applying an improved disposable infusion needle and supplying physiological saline is safe and ef-fective,flexible and convenient,which is suitable for experimental study that needs to draw blood from caudal vein of the SD rat at the contin-uous time.