Browsing by keyword "PAPP-A"
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Adaptations of Adipose Tissue Expandability in Gestation are Associated with Maternal Glucose MetabolismPregnancy induces maternal metabolic adaptations including mild glucose intolerance and weight gain in order to support fetal development and lactation. Adipose tissue (AT) function in gestation is featured by reduced insulin sensitivity and fat mass accrual which partly accounts for the weight gain in pregnant women and adaptation of glucose metabolism. A common metabolic pregnancy complication is gestational diabetes mellitus (GDM), a disease characterized by impaired glucose tolerance with onset in gestation. However, the relationship between AT expandability and glucose metabolism in gestation is not well understood. The goal of this thesis was to investigate the adaptations of human AT expansion induced by pregnancy, how these changes are reflected in pregnancies complicated with GDM and characterize a mouse model to study the mechanisms underlying this disease. This dissertation illustrates that pregnancy promotes AT expandability by a signaling mechanism between placental pregnancy-associated plasma protein-A (PAPP-A) and AT- insulin-like growth factor binding protein-5 (IGFBP5). In addition, gravidas with GDM showed impaired AT expansion. Studies investigating the relationship between PAPP-A and glycemic state demonstrated that low levels of PAPP-A in the 1sttrimester are highly associated with the development of GDM. Moreover, PAPP-A knockout mice exhibit reduced insulin sensitivity and impaired AT growth exclusively in gestation. These results expand the knowledge of AT biology in gestation and have the potential to improve maternal care by proposing PAPP-A as an early biomarker and possible therapeutic for GDM. It also introduces a new mouse model to study the etiology of gestational diabetes.
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Association between First Trimester Pregnancy Associated Plasma Protein–A (PAPP-A) and Gestational Diabetes Mellitus DevelopmentBackground: Gestational diabetes (GDM) is a common pregnancy complication with significant cardiometabolic consequences for mothers and offspring. Previous research from our group suggests that adipose tissue IGFBP-5 and its unique metalloprotease PAPP-A (Pregnancy Associated Plasma Protein-A) may play mechanistic roles in GDM development by regulating functional IGF-1 levels and lipid storage and metabolism. Aim: To examine the relationship between circulating PAPP-A levels and GDM development. We hypothesized that high first trimester PAPP-A levels would be associated with decreased GDM risk. Methods: A retrospective cohort of women delivering singleton gestations at UMass Memorial Healthcare (2009, 2010, 2014, 2015) was assembled by abstracting electronic medical records. PAPP-A was measured in first trimester (11-14 weeks), and reported as quartiles of multiples of the mean (MoM) based on gestational age and adjusted for maternal weight and race/ethnicity. GDM diagnosis based on standard 2-step protocol (~24-28 weeks; failed 50g 1hr glucola screen then ≥2 abnormal values per Carpenter-Coustan criteria on 100g 3hr glucose tolerance test). Crude and multivariable-adjusted logistic regression models estimated the association between PAPP-A MoM quartiles and GDM. Results: Women (N=1,251) were 29.7 (SD:5.7) years old and 12.5 (SD:0.6) weeks gestation at PAPP-A measurement. 7.6% (n=95) developed GDM. Median PAPP-A MoM were 0.7 (inter-quartile range [IQR]=0.5-1.0) among women with GDM and 0.9 (IQR=0.6-1.3) among controls; 39% versus 23% were in the 1st quartile, respectively. After adjusting for pre-pregnancy body mass index, nuchal translucency, crown rump length, smoking status, and parity, women with PAPP-A MoM in 2nd, 3rd, and 4th quartiles had 52% (OR=0.48, 95%CI=0.26-0.88), 45% (OR=0.55, 95%CI=0.30-0.99) and 73% (OR=0.27, 95%CI=0.13-0.53) lower odds of GDM compared to women in the 1st quartile. Conclusion: Higher PAPP-A MoM levels were associated with lower GDM risk. Future studies will assess whether higher PAPP-A levels are associated with enhanced IGF-1 signaling and improved pregnancy metabolic homeostasis.

