Eoin Noctor

Type 2 diabetes after gestational diabetes: The influence of changing diagnostic criteria

A previous diagnosis of gestational diabetes (GDM) carries a lifetime risk of progression to type 2 diabetes of up to 60%. Identification of those women at higher risk of progression to diabetes allows the timely introduction of measures to delay or prevent diabetes onset. However, there is a large degree of variability in the literature with regard to the proportion of women with a history of GDM who go on to develop diabetes. Heterogeneity between cohorts with regard to diagnostic criteria used, duration of follow-up, and the characteristics of the study population limit the ability to make meaningful comparisons across studies. As the new International Association for Diabetes in Pregnancy Study Group criteria are increasingly adopted worldwide, the prevalence of GDM is set to increase by two-to three-fold. Here, we review the literature to examine the evolution of diagnostic criteria for GDM, the implications of changing criteria on the proportion of women with previous GDM progressing to diabetes, and how the use of different diagnostic criteria may influence the development of appropriate follow-up strategies.

An evaluation of Croí MyAction community lifestyle modification programme compared to standard care to reduce progression to diabetes/pre-diabetes in women with prior gestational diabetes mellitus (GDM): study protocol for a randomised controlled trial

BackgroundUniversal screening using the International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria has identified a prevalence of gestational diabetes mellitus (GDM) of 12.4% in women living in Ireland. Women with prior GDM are at increased risk of developing type 2 diabetes later in life. A number of risk factors linked to the development of type 2 diabetes are potentially modifiable through lifestyle and behaviour changes, and medical management. No previous Irish studies have adequately investigated the efficacy of lifestyle intervention programmes in reducing these risk factors in women with prior GDM. Through a two-group, parallel randomised controlled trial (RCT), this study aims to assess the clinical impact, cost-effectiveness and psychological experience of the Croí MyAction intensive lifestyle modification programme for women with prior GDM.Methods/DesignA total of 54 women with a history of GDM and persistent post-partum glucose dysfunction (impaired glucose tolerance (IGT) or impaired fasting glucose (IFG)), are randomly assigned to a control arm (n = 27) or to the Croí MyAction intervention group (n = 27). The control arm receives usual health care advice - written information on diet and lifestyle changes for reducing diabetes risks and visits with general practitioners as required. The intervention group receives usual health care as per the control group in addition to attending a 12-week intensive lifestyle modification programme known as Croí MyAction. Croí MyAction involves 2.5 hour sessions once per week (for 12 weeks) comprising a group exercise programme, group health promotion or education seminars, and one-to-one meetings with a multidisciplinary health care team to personalise risk factor reductions. Randomisation and allocation to the intervention arms is carried out by an independent researcher, ensuring that the allocation sequence is concealed from study researchers until the interventions are assigned. The primary analysis is based on glucose dysfunction, comparing a mean reduction in fasting plasma glucose (FPG) levels on a 75 gram oral glucose tolerance test (OGTT) in the two groups at a one-year, post-intervention follow-up. The trial is funded by the Irish Health Research Board (HRB). Ethics approval was obtained on 27 March 2012 from the Clinical Research Ethics Committee, Galway University Hospitals, Health Service Executive of Ireland (Ref: C.A.691).Trial registrationCurrent Controlled Trials ISRCTN41202110.

Abnormal glucose tolerance post-gestational diabetes mellitus as defined by the International Association of Diabetes and Pregnancy Study Groups criteria

OBJECTIVE An increase in gestational diabetes mellitus (GDM) prevalence has been demonstrated across many countries with adoption of the International Association of the Diabetes and Pregnancy Study Groups (IADPSG) diagnostic criteria. Here, we determine the cumulative incidence of abnormal glucose tolerance among women with previous GDM, and identify clinical risk factors predicting this. DESIGN Two hundred and seventy women with previous IADPSG-defined GDM were prospectively followed up for 5years (mean 2.6) post-index pregnancy, and compared with 388 women with normal glucose tolerance (NGT) in pregnancy. METHODS Cumulative incidence of abnormal glucose tolerance (using American Diabetes Association criteria for impaired fasting glucose, impaired glucose tolerance and diabetes) was determined using the Kaplan-Meier method of survival analysis. Cox regression models were constructed to test for factors predicting abnormal glucose tolerance. RESULTS Twenty-six percent of women with previous GDM had abnormal glucose tolerance vs 4% with NGT, with the log-rank test demonstrating significantly different survival curves (P<0.001). Women meeting IADPSG, but not the World Health Organization (WHO) 1999 criteria, had a lower cumulative incidence than women meeting both sets of criteria, both in the early post-partum period (4.2% vs 21.7%, P<0.001) and at longer-term follow-up (13.7% vs 32.6%, P<0.001). Predictive factors were glucose levels on the pregnancy oral glucose tolerance test, family history of diabetes, gestational week at testing, and BMI at follow-up. CONCLUSIONS The proportion of women developing abnormal glucose tolerance remains high among those with IADPSG-defined GDM. This demonstrates the need for continued close follow-up, although the optimal frequency and method needs further study.

Can the Onset of Type 2 Diabetes Be Delayed by a Group-Based Lifestyle Intervention in Women with Prediabetes following Gestational Diabetes Mellitus (GDM)? Findings from a Randomized Control Mixed Methods Trial

Objective. To evaluate a 12-week group-based lifestyle intervention programme for women with prediabetes following gestational diabetes (GDM). Design. A two-group, mixed methods randomized controlled trial in which 50 women with a history of GDM and abnormal glucose tolerance postpartum were randomly assigned to intervention (n = 24) or wait control (n = 26) and postintervention qualitative interviews with participants. Main Outcome Measures. Modifiable biochemical, anthropometric, behavioural, and psychosocial risk factors associated with the development of type 2 diabetes. The primary outcome variable was the change in fasting plasma glucose (FPG) from study entry to one-year follow-up. Results. At one-year follow-up, the intervention group showed significant improvements over the wait control group on stress, diet self-efficacy, and quality of life. There was no evidence of an effect of the intervention on measures of biochemistry or anthropometry; the effect on one health behaviour, diet adherence, was close to significance. Conclusions. Prevention programmes must tackle the barriers to participation faced by this population; home-based interventions should be investigated. Strategies for promoting long-term health self-management need to be developed and tested.

Factors influencing lifestyle behaviours during and after a gestational diabetes mellitus pregnancy

Objective: This qualitative study examined the healthy lifestyle behaviours undertaken during and after a pregnancy complicated by gestational diabetes mellitus (GDM) and the factors that influenced the likelihood of undertaking of such behaviours. Methods: Semi-structured telephone interviews were conducted with women who had a pregnancy complicated by GDM in the previous 3–7 years. Interviews were analysed using a theoretical thematic analysis approach. Results: Thirteen women provided interviews as part of this study. Women typically engaged in healthy behaviours in terms of diet, physical activity and glucose monitoring during their GDM pregnancy, but generally these behaviours were not maintained postpartum. Women appear not to be intrinsically motivated to engage in healthy lifestyle behaviours, but rather require the support of an extrinsic motivator such as their unborn child or the support of healthcare professionals. A gap exists between womens knowledge of their increased long-term diabetes risk and the behaviours which they undertake to reduce this risk in the postpartum period. Conclusion: Women with previous GDM need increased support in the postpartum period to assist them to develop self-management and prioritisation skills to take control of their increased type 2 diabetes mellitus risk.

The prevalence of metabolic syndrome up to 5 years post-partum in patients with a history of gestational diabetes mellitus

Metabolic syndrome (MetS) is associated with cardiovascular mortality and increased risk of type 2 diabetes.

ATLANTIC DIP: The prevalence of pre-diabetes/type 2 diabetes in an Irish population with gestational diabetes mellitus 1-5 years post index pregnancy

The ATLANTIC-DIP (diabetes in pregnancy) programme showed 18% of women with gestational diabetes mellitus (GDM) screened with a 75g oral glucose tolerance test (OGTT) 12 weeks post-partum demonstrated glucose intolerance. However, long-term data on progression to type 2 diabetes (T2DM) post gestational diabetes (GDM) in an Irish population is lacking.

Validation of a diabetes risk score in identifying patients at risk of progression to abnormal glucose tolerance post partum

FINDRISC (Finnish Diabetes Risk Score) is a risk assessment tool widely used for the prediction of the development of type 2 diabetes (T2DM), combining a questionnaire with simple anthropometric measurements to identify patients at risk of developing diabetes, with increasing score (0-26) signifying increased risk. A cut off score of 9 has previously been proposed (with drug-treated DM as the endpoint) with a positive predictive value (PPV) of 0.12 and negative predictive value (NPV) of 0.99, area under receiver operating characteristic curve (AuROC)=0.80. It has been well validated in the general population.