Maternal circulating adipokine profile and insulin resistance in women at high risk of developing gestational diabetes mellitus.

BACKGROUND: Cytokines produced by adipose and placental tissues (adipokines) have been implicated in the development of gestational diabetes mellitus (GDM). There is, however, limited research regarding the relationship between advancing pregnancy, maternal adipokine profile, insulin resistance and the development of GDM. Furthermore, no studies have investigated these parameters in women with a history of GDM who are at the highest risk of recurrence. This study examined the circulating concentrations of a number of adipokines associated with insulin resistance at two points in pregnancy, and determined whether they were altered in women who developed GDM. METHODS: Non-diabetic women with a history of GDM in a previous pregnancy (n=123) had blood drawn at 14 and 28weeks of pregnancy for GDM diagnosis, together with assessment of a range of adipokine concentrations by multiplex assay (fatty acid-binding protein 4 [FABP4], leptin, chemerin, adiponectin and resistin). RESULTS: With advancing pregnancy, maternal adiponectin concentrations decreased, while leptin and resistin levels increased (p<0.05). In women who developed GDM at 28weeks of pregnancy (42%), fasting and postprandial glucose levels were already significantly elevated by 14weeks (p<0.05), while adiponectin concentrations were lower (p<0.05). Adiponectin remained lower at the time of GDM diagnosis (p<0.05), while the other adipokines were similar between groups at each timepoint. CONCLUSION: Maternal glucose and adipokine profile is altered early in pregnancy in women with a history of GDM who subsequently develop recurrent disease.

Regular Exercise to Prevent the Recurrence of Gestational Diabetes Mellitus: A Randomized Controlled Trial.

OBJECTIVE: To investigate the effect of a supervised home-based exercise program on the recurrence and severity of gestational diabetes mellitus (GDM) together with other aspects of maternal health and obstetric and neonatal outcomes. METHODS: This randomized controlled trial allocated women with a history of GDM to an exercise intervention (14-week supervised home-based stationary cycling program) or to a control group (standard care) at 13±1 weeks of gestation. The primary outcome was a diagnosis of GDM. Secondary outcomes included maternal fitness, psychological well-being, and obstetric and neonatal outcomes. A sample size of 180 (90 in each group) was required to attain 80% power to detect a 40% reduction in the incidence of GDM. RESULTS: Between June 2011 and July 2014, 205 women provided written consent and completed baseline assessments. Of these, 33 (16%) were subsequently excluded as a result of an elevated baseline oral glucose tolerance test (OGTT), leaving 172 randomized to exercise (n=85) or control (n=87). Three women miscarried before the assessment of outcome measures (control=2; exercise=1). All remaining women completed the postintervention OGTT. The recurrence rate of GDM was similar between groups (control 40% [n=34]; exercise 40.5% [n=34]; P=.95) and the severity of GDM at diagnosis was unaffected by the exercise program with similar glucose and insulin responses to the OGTT (glucose 2 hours post-OGTT 7.7±1.5 compared with 7.6±1.6 mmol/L; P>.05). Maternal fitness was improved by the exercise program (P<.01) and psychological distress was reduced (P=.02). There were no differences in obstetric and neonatal outcomes between groups (P>.05). CONCLUSION: Supervised home-based exercise started at 14 weeks of gestation did not prevent the recurrence of GDM; however, it was associated with important benefits for maternal fitness and psychological well-being. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, https://clinicaltrials.gov, NCT01283854.

Enhancing energy expenditure and enjoyment of exercise during pregnancy through the addition of brief higher intensity intervals to traditional continuous moderate intensity cycling.

BACKGROUND: Current guidelines recommend that pregnant women without contraindications should engage in 30 min or more of moderate intensity exercise on most days of the week, however, many women fail to achieve this goal. This study examined the effect of adding brief higher intensity intervals to traditional continuous moderate intensity exercise on energy expenditure and the enjoyment of exercise in late pregnancy. This is important to determine given that any additional energy expenditure resulting from higher intensity intervals may be meaningless if enjoyment is compromised, since long-term adherence will likely be low. METHODS: In this study, 12 healthy pregnant women at 30 ± 1 weeks gestation, aged 35 ± 6 years with a BMI of 27.1 ± 4.3 kg/m(2) performed either 30 min of continuous cycling exercise (CONT) at a steady power output equivalent to 65 % age-predicted heart rate maximum or an equivalent period of interval cycling (INTV) consisting of continuous cycling at the same power output as CONT, but with the addition of six 15-s self-paced higher intensity efforts throughout, performed at regular intervals, on separate occasions in a counterbalanced order. RESULTS: Mean cycling power output, heart rate, oxygen consumption and energy expenditure were higher during INTV compared with CONT (P < 0.05). However, there was no difference in mean rate of perceived exertion between conditions. Enjoyment of exercise was higher with INTV (P = 0.01). CONCLUSIONS: The addition of six 15-s higher intensity intervals to continuous moderate intensity exercise effectively increased energy expenditure by 28 %, at the same time as enhancing the enjoyment of exercise in late pregnancy. While these findings may be specific to recreationally active women, this study provides a rationale for future studies to examine the physiological and psychological responses to regular interval training during pregnancy to optimise exercise prescription. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12616000680460 . 25 May 2016 (Registered retrospectively).