Search

Rachel A Tinius,1 Kristin Yoho,1 Maire M Blankenship,2 Jill M Maples3 1School of Kinesiology, Recreation, and Sport, Western Kentucky University, Bowling Green, KY, 42101, USA; 2School of Nursing and Allied Health, Western Kentucky University, Bowling Green, KY, 42101, USA; 3Department of Obstetrics and Gynecology, University of Tennessee Graduate School of Medicine, Knoxville, TN, 37920, USACorrespondence: Rachel A TiniusSchool of Kinesiology, Recreation, and Sport, Western Kentucky University, Bowling Green, KY, 42101, USATel +1 270-745-5026Email Rachel.tinius@wku.eduBackground: Metabolic dysfunction after pregnancy may have serious consequences for a new mother. The purpose of the study was to characterize basic changes that occur in metabolic profiles from late pregnancy through 4– 6 months postpartum. A secondary purpose was to determine metabolic factors that may be contributing to postpartum weight retention.Methods: Participants (n=25) came in for 2 visits: late pregnancy (∼ 34 weeks gestation) and postpartum (4-6 months). Resting metabolic rate (RMR), respiratory quotient (RQ), and substrate oxidation values were assessed for 15 minutes during fasted conditions. Blood was drawn and skinfold anthropometry was performed to assess additional outcomes (inflammation, insulin resistance, lipid profiles, body composition). The participants completed a number of surveys that examined other lifestyle and demographic data of interest. At the postpartum visit, additional assessments regarding sleep and breastfeeding habits were administered.Results: RMR was lower during postpartum (1517.2± 225.1 kcal/day) compared to pregnancy (1867.9± 302.6 kcal/day) (p< 0.001), and remained lower when expressing RMR per kg body weight (postpartum: 22.3± 2.7 vs pregnant: 23.7± 3.4 kcal/kg, (p=0.034). Relative RMR (RMR per kg body weight) was negatively correlated to insulin resistance (HOMA-IR) during postpartum (r=− .463, p=0.034). Maternal HOMA-IR, inflammation (CRP), triglycerides (TAG), and carbohydrate oxidation were all positively correlated to postpartum weight retention (HOMA-IR: r=0.617, p=0.004; CRP: r=0.477, p=0.039, TAG: r=0.463, p=0.040; Carbohydrate Oxidation: (r=0.469, p=0.018).Conclusion: Metabolic rate is lower during postpartum compared to pregnancy, and may be connected to insulin resistance. Maternal insulin resistance, inflammation, blood lipids, and substrate metabolism are all related to postpartum weight retention.Keywords: postnatal, metabolic rate, insulin resistance, inflammation

Plasma immunoreactive vasopressin (iAVP) was studied by RIA in a patient suffering from polyuria during chronic treatment with lithium. The combined use of two antisera specific for different regions of the AVP molecule allowed us to detect circulating forms which are modified in the acyclic tripeptide portion. In this lithium-treated patient, iAVP was abnormally low with respect to plasma osmolality. However, iAVP increased during hypertonic saline infusion, probably through an osmosensitive mechanism. A remarkable finding was that contrary to the observations made in healthy subjects and in another patient with diabetes insipidus, iAVP measured with the antiserum specific for the acyclic portion of the AVP molecule was below the values measured with the antiserum specific for the hexapeptide ring. This unusual immunoreactivity profile suggests that the plasma of this polyuric lithium-treated patient contains vasopressin-like peptides which differ from arginine vasopressin in the structure of the C-terminal tripeptide tail.