A mixed methods study of interventions and experiences to prevent type 2 diabetes mellitus following gestational diabetes mellitus

Abstract

Background: The prevalence of Gestational Diabetes Mellitus (GDM) is increasing globally and the link between GDM, obesity and the development of Type 2 Diabetes Mellitus (T2DM) in later life is increasingly recognised by international health authorities. Previous research suggests that strategies aimed at postpartum women and designed to promote weight loss through increased physical activity and dietary modifications may be feasible. However, recruitment and engagement of this cohort has met with differing success. Development of an evidence-based program that encourages behaviour modification resulting in weight loss may delay or prevent T2DM in this cohort.Aim: To develop, implement and evaluate a behaviour modification program to support lifestyle changes for women with a Body Mass Index (BMI) >25kg/m2, and who have experienced GDM, to delay or prevent development of T2DM.Method: Following a review of the literature, a mixed method approach was employed. A randomised controlled trial (RCT) of a behaviour modification intervention (which combined a pedometer web-based program with nutrition coaching) was conducted over a three month period. The primary outcome for the RCT was weight loss, and secondary outcomes included; improved insulin sensitivity, increased physical activity, improved diet quality and self-efficacy, decreased waist and hip measurements, and a decreased Free Fat Mass (FFM). Qualitative data collected through semi structured interviews conducted after the intervention, were thematically analysed to examine the women’s experiences of the intervention, barriers and enablers to participation, and to identify T2DM risk perceptions.Sample: Women with a BMI >25kg/m2, previously diagnosed with GDM were invited to participate six months (up to two years) postpartum. Results: Thirty-one women were randomised, with recruitment lower than originally projected. The intervention group had a median weight loss of 2.5 kg (IQR 1.4) (p=0.002), increased activity by 135 minutes/week, improved self-efficacy eating behaviour (p= 0.036), decreased median waist measurement of 3 cm (IQR 4.0) (p=0.037), and decreased median hip measurement of 3 cm (IQR5.0) (p=0.006). There was no difference in insulin sensitivity or FFM. Qualitative results revealed the pedometer and nutrition coaching were well received, and educating women in the immediate postpartum period outlining the risks of T2DM and an evidence-based behaviour modification program with follow up within the first year was considered optimum.Implications: These findings have important clinical implications for future programs designed to engage women previously diagnosed with GDM, with the aim of an eventual reduction in the risk of T2DM. A web-based pedometer intervention program combined with nutrition coaching has the potential to be translated into other settings. Education of women with GDM regarding self care in the immediate postpartum period could be incorporated into routine care, with health care professionals contacting women following discharge from hospital to support behaviour modifications designed to decrease the risk of T2DM.