Intrapartum serum prolactin may predict risk of postpartum diabetes

1. In a prospective trial of over 360 pregnant women, high intrapartum serum prolactin was associated with a decreased risk of postpartum prediabetes and diabetes.

Evidence Rating Level: 2 (Good)

Study Rundown: Gestational diabetes (GDM) is a common complication in pregnancy that has been associated with an increased risk of developing type 2 diabetes (T2DM). Previous preclinical studies have demonstrated several circulating hormones, such as prolactin and human placental lactogen (HPL) may have important regulatory effects on beta islet cell function within the pancreas, and thus may be involved in the pathophysiology of GDM and subsequent post-partum T2DM. The purpose of this trial is to evaluation longitudinal associations between serum prolactin and HPL and future diabetes risk.

The study prospectively analyzed the glucose and hormone results of over 360 pregnant women intrapartum and 3 months postpartum. At the conclusion of the trial, intrapartum serum prolactin levels were significantly higher in women with normal postpartum glucose tolerance compared to women with postpartum prediabetes or T2DM. Additionally, there was no significant association between other hormones and metabolites and abnormal glucose tolerance. The results of this study support the use of serum prolactin as a predictive factor for future diabetes risk in pregnancy. The study is limited by a small sample size of patients who were with abnormal glucose tolerance postpartum as well as the lack of prolactin measurements postpartum or prior to pregnancy, which can further establish this association. Additional large prospective trials are required to confirm this association.

Click to read the study in Diabetes Care

Relevant Reading: Evaluation of Circulating Determinants of Beta-cell Function in Women with and without Gestational Diabetes

In-Depth [prospective cohort]: This was a prospective trial of 367 patients with singleton pregnancies in a single tertiary care center in Toronto, Canada. Patients included in the study underwent routine oral glucose tolerance tests (OGTT) as well as a hormone and metabolic panel including fasting serum HPL and prolactin. An additional OGTT was performed at 3-months postpartum to assess glucose tolerance. At the conclusion of the study, 66 (17.9%) patients were found to be pre-diabetic or diabetic according to OGTT. Overall, serum prolactin was significantly higher in patients with normal postpartum glucose tolerance compared to patients with abnormal postpartum OGTT results (mean: 98.2 vs. 80.2 ng/mL; p = 0.0003). There were no differences between the two groups in any other metabolic or hormone markers. In linear regression analysis, higher levels of serum prolactin was significantly associated with decreased risk of postpartum prediabetes or diabetes (OR: 0.50; 95% CI: 0.35 to 0.72; p = 0.0002).

Image: PD

©2015 2 Minute Medicine, Inc. All rights reserved. No works may be reproduced without expressed written consent from 2 Minute Medicine, Inc. Inquire about licensing here. No article should be construed as medical advice and is not intended as such by the authors or by 2 Minute Medicine, Inc.