title: The l-arginine/nitric oxide pathway is impaired in overweight/obese pregnant women.
abstract: OBJECTIVE
  To evaluate the l-arginine/NO system and its role in insulin signaling and endothelial function during the pregnancy of women of different BMI categories.
  
  
  METHODS
  Twelve women with BMI⩾25 were compared with 10 normal-weight women in a fasting condition after the infusion of l-arginine (20g in 3h) and after the evaluation of the flow-mediated vasodilation (FMD) of the brachial artery between the 9th-12th and 24th-27th weeks. Blood samples for insulin and nitrite/nitrate (NOx) were collected at baseline and after 1, 2 and 3h after initiating the infusion.
  
  
  RESULTS
  In both trimesters, the baseline NOx levels were similar among groups. In the 1st trimester of the lean women, there was a NOx increase in response to l-Arg (AUC: 1328; 3, 3173), which had increased by the 2nd trimester (AUC: 3884; 1905, 7686); in overweight/obese women, no responses to l-Arg were found in the 1st or 2nd trimesters. In the 1st trimester, the insulin levels were significantly reduced in both groups after l-Arg infusion. Although the insulin levels in all BMI categories were higher in the 2nd trimester, such levels during weeks 24-27 were suppressed only in normal-weight women after l-Arg infusion. The FMD was higher during both trimesters in the lean controls and was impaired in the overweight/obese subjects.
  
  
  CONCLUSIONS
  NO availability is impaired in overweight/obese women during pregnancy, which affects endothelial functioning and interferes with insulin regulation. These mechanisms could be involved in the development of hypertensive disorders and glucose intolerance in this population.
authors.affiliation: Mother-Infant Department, University of Modena and Reggio Emilia, Modena, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Petrella
authors.affiliation: Mother-Infant Department, University of Modena and Reggio Emilia, Modena, Italy.
authors.forename: Lucrezia
authors.initials: L
authors.lastname: Pignatti
authors.affiliation: Mother-Infant Department, University of Modena and Reggio Emilia, Modena, Italy.
authors.forename: Isabella
authors.initials: I
authors.lastname: Neri
authors.affiliation: Mother-Infant Department, University of Modena and Reggio Emilia, Modena, Italy. Electronic address: fabio.facchinetti@unimore.it.
authors.forename: Fabio
authors.initials: F
authors.lastname: Facchinetti
keywords: Endothelial function; Insulin; Pregnancy; l-arginine