Effectiveness of individualized counseling on the duration of exclusive breastfeeding: study protocol for a multicenter, randomized, parallel, and open clinical trial.

BACKGROUND: Despite the benefits of breastfeeding, early weaning is a reality, so less than 50% of children worldwide and in Brazil are on exclusive breastfeeding in the sixth month of life. A strategy to counteract this scenario is breastfeeding counseling. This study aims to verify the effectiveness of individualized counseling by nurses trained in breastfeeding counseling, on the duration of exclusive breastfeeding, compared to standard care. METHODS: Multicenter, randomized, parallel, and open clinical trial, with primiparous women aged over 18 years, hospitalized in rooming-in wards at participating centers and hemodynamically stable, aware, and oriented, who had a single-fetus pregnancy and gave birth, regardless of the type of delivery, with live child, gestational age of 37 to 42 weeks and birth weight greater than 2500 g. The women will be initially approached in rooming-in wards and, upon consent to participate in the study, will be allocated through randomization by blocks composed of eight participants in two groups: intervention and control. The randomization lists will be organized by a central without involvement with the study, which will manage the allocation groups and be prepared in the Randon® program. Women allocated to the intervention group will receive breastfeeding counseling by trained nurses, and those in the control group will receive standard care at the center participating in the study. DISCUSSION: The results can contribute to breastfeeding by evidencing possible exclusivity and duration of the counseling trained nurses provide. TRIAL REGISTRATION: REBEC RBR-4w9v5rq (UTN: U1111-1284-3559) ( https://ensaiosclinicos.gov.br/rg/RBR-4w9v5rq ). Posted on March 20, 2023.

Glucocorticoids decrease thermogenic capacity and increase triacylglycerol synthesis by glycerokinase activation in the brown adipose tissue of rats.

Although it is well established that glucocorticoids inactivate thermogenesis and promote lipid accumulation in interscapular brown adipose tissue (IBAT), the underlying mechanisms remain unknown. We found that dexamethasone treatment (1 mg/kg) for 7 days in rats decreased the IBAT thermogenic activity, evidenced by its lower responsiveness to noradrenaline injection associated with reduced content of mitochondrial proteins, respiratory chain protein complexes, noradrenaline, and the ß3 -adrenergic receptor. In parallel, to understand better how dexamethasone increases IBAT lipid content, we also investigated the activity of the ATP citrate lyase (ACL), a key enzyme of de novo fatty acid synthesis, glucose-6-phosphate dehydrogenase (G6PD), a rate-limiting enzyme of the pentose phosphate pathway, and the three glycerol-3-P generating pathways: (1) glycolysis, estimated by 2-deoxyglucose uptake, (2) glyceroneogenesis, evaluated by phosphoenolpyruvate carboxykinase activity and pyruvate incorporation into triacylglycerol-glycerol, and (3) direct phosphorylation of glycerol, investigated by the content and activity of glycerokinase. Dexamethasone increased the mass and the lipid content of IBAT as well as plasma levels of glucose, insulin, non-esterified fatty acid, and glycerol. Furthermore, dexamethasone increased ACL and G6PD activities (79% and 48%, respectively). Despite promoting a decrease in the incorporation of U-[14 C]-glycerol into triacylglycerol (~54%), dexamethasone increased the content (~55%) and activity (~41%) of glycerokinase without affecting glucose uptake or glyceroneogenesis. Our data suggest that glucocorticoid administration reduces IBAT thermogenesis through sympathetic inactivation and stimulates glycerokinase activity and content, contributing to increased generation of glycerol-3-P, which is mostly used to esterify fatty acid and increase triacylglycerol content promoting IBAT whitening.