Nonpharmacological interventions to prevent type 2 diabetes in women diagnosed with gestational diabetes mellitus: a systematic overview

The effectiveness of pharmacological and lifestyle interventions to reduce the risk of diabetes and hyperglycaemia following gestational diabetes: A systematic review and meta-analysis

AIMS

To synthesize the available evidence to better understand the effectiveness of interventions to prevent or delay hyperglycaemia and Type 2 diabetes mellitus (T2DM) postnatally in women with current or previous gestational diabetes mellitus (GDM).

METHODS

We searched five databases up to December 2020 for primary peer-reviewed articles reporting postpartum glycaemic outcomes in women with (previous) GDM following pharmacological or lifestyle intervention. Outcomes were relative risk of T2DM or continuous measures of glycaemia, change or at follow-up. A minimum of two studies evaluating the same intervention-outcome combination were needed to conduct meta-analyses, otherwise studies were described narratively. Meta-regression was used to evaluate whether associations varied by additional variables. We assessed risk of bias using the Critical Appraisal Skills Programme checklist. PROSPERO record CRD42018102380.

RESULTS

We included 31 studies in the review with a total sample size of 8624 participants, and 26 studies in meta-analyses. Two-thirds of studies followed up participants at 1 year or less. Pharmacological interventions were associated with reduced risk of T2DM (0.80 [95% CI 0.64-1.00], n = 6 studies), as were lifestyle interventions albeit with a smaller effect size (0.88 [95% CI 0.76-1.01], n = 12 studies). Dietary and physical activity interventions were associated with a small reduction in fasting plasma glucose, particularly in longer interventions, but inconsistent effects were seen for other continuous outcomes.

CONCLUSIONS

Although possibly due to chance, interventions to reduce hyperglycaemia after GDM may be effective. Future research should improve understanding of how interventions affect glucose control and how to optimise interventions for this population.

Exercise, aerobic fitness, and muscle strength in relation to glucose tolerance 6 to 10 years after gestational diabetes

AIMS

We sought to identify self-reported exercise and objectively measured fitness variables associated with glucose tolerance and metabolic health 6-10 years after gestational diabetes (GDM) METHODS: Women (n = 84) underwent oral glucose tolerance testing (OGTT), body composition measurements, and lifestyle questionnaires 6 and 10 years after GDM. In a subset (n = 45), peak oxygen uptake (VO_2peak), peak fat oxidation, and maximal isometric strength of five muscle groups were tested.

RESULTS

At 10 years, 41 women (49%) had impaired glucose metabolism or type 2 diabetes (T2D). VO_2peak and muscle strength were lowest in the T2D group. In a regression analysis, VO_2peak and all strength measurements were associated negatively with HbA1c and waist-hip ratio and positively with high-density lipoprotein cholesterol. However, only muscle strength was associated with fasting and area-under-the-curve glucose. For changes between the 6- and 10-year follow-ups, only muscle strength was associated with HbA1c change, whereas both VO_2peak and strength were associated with high-density lipoprotein level and changes in waist-hip ratio. Peak fat oxidation and self-reported physical activity showed no or weak relationships with glycemic variables.

CONCLUSION

Objectively measured fitness variables, particularly muscle strength, were strongly associated with glycemic and other metabolic outcomes in a high-risk group after GDM.

A Protocol of Process Evaluations of Interventions for the Prevention of Type 2 Diabetes in Women With Gestational Diabetes Mellitus: A Systematic Review

Background

Process evaluations of randomised controlled trials (RCTs) can provide insight and inform us on the intervention implementation, the causal mechanisms and the contextual factors. This will inform about interventions’ success or failure due to their implementation or the interventions themselves. We aim to consolidate the methodology from previous process evaluations of complex interventions upon their findings on facilitators and barriers to address the prevention of type 2 diabetes mellitus among women with gestational diabetes mellitus (GDM).

Methods

Comprehensive search will be conducted on electronic databases and reference lists of recent reviews for RCTs of complex interventions which address process evaluations of diabetes prevention intervention (DPI) for women with GDM in healthcare settings. There is no restriction on the language of the papers and year of publication until December 2020. Data from each study will be extracted by two reviewers independently using standardised forms. Data extracted include descriptive items on the study design and the outcomes of process evaluations from the three dimensions: (1) implementation; (2) mechanism of impact and (3) context. The quality of the studies will be assessed using mixed methods appraisal tool which is designed for the appraisal of mixed studies in systematic reviews. A narrative and framework analysis of the findings will be presented to inform the contents of a new DPI for women with GDM.

Discussion

The findings from this process evaluation findings are valuable in determining whether a complex intervention should be scaled up or modified for other contexts in future plan. It will give deeper understanding of potential challenges and solutions to aid in the implementation of effective DPIs for GDM in Malaysia.

Diabetes prevention interventions for women after gestational diabetes mellitus: an overview of reviews

Aims

To present an overview of reviews of interventions for the prevention of diabetes in women after gestational diabetes mellitus (GDM) with the overall aim of gaining information in order to establish local interventions.

Methods

Six databases were searched for quantitative, qualitative or mixed‐methods systematic reviews. All types of interventions or screening programmes were eligible. The outcomes were effectiveness of reducing diabetes incidence, encouraging healthy behavioural changes and enhancing women's perceptions of their increased risks of developing type 2 diabetes following GDM.

Results

Eighteen reviews were included: three on screening programmes and seven on participation and risk perceptions. Interventions promoting physical activity, healthy diet, breastfeeding and antidiabetic medicine reported significantly decreased incidence of postpartum diabetes, up to 34% reduction after any breastfeeding compared to none. Effects were larger if the intervention began early after birth and lasted longer. Participation in screening rose up to 40% with face‐to‐face recruitment in a GDM healthcare setting. Interventions were mainly based in healthcare settings and involved up to nine health professions, councillors and peer educators, mostly dieticians. Women reported a lack of postpartum care and demonstrated a low knowledge of risk factors for developing type 2 diabetes. Typical barriers to participation were lack of awareness of increased risk and low levels of support from family.

Conclusions

Lifestyle interventions or pharmacological treatment postpartum was effective in decreasing diabetes incidence following GDM. Women's knowledge of the risk of diabetes and importance of physical activity was insufficient. Early face‐to‐face recruitment increased participation in screening. Programmes aimed at women following a diagnosis of GDM ought to provide professional and social support, promote screening, breastfeeding, knowledge of risk factors, be long‐lasting and offered early after birth, preferably by face‐to‐face recruitment.

Methods for depicting overlap in overviews of systematic reviews: An introduction to static tabular and graphical displays

BACKGROUND AND OBJECTIVE

To introduce potential static tabular and graphical techniques for visually presenting overlap between systematic reviews (SRs) included in overviews of systematic reviews (OoSRs).

METHODS

The graphical approaches described include Venn and Euler diagrams, as well as matrix-based, node-link, and aggregation-based techniques. We used fundamental concepts of mathematics from set and network theory to develop our novel graphical approaches. The graphical displays were created using R.

RESULTS

Overview authors have the flexibility to choose from a variety of visualizations, depending on the characteristics of their study. If the OoSRs include few SRs, a Venn or an Euler diagram can be used. In case of OoSRs with more SRs, Upset plots, heatmaps, and node-link graphs are more appropriate for visualizing overlapping SRs. Stacked bar plots constitute an aggregation-based technique of illustrating overlap. Strengths and limitations of each graphical approach are presented.

CONCLUSION

The degree of overlap should be explored for the entire study and for specific outcomes of interest. The proposed graphical techniques may assist methodologists and authors in identifying overlap, which in turn may improve validity and transparency in OoSRs. More research is needed to understand which technique would be most useful and easiest to understand.

Exploring the effectiveness of physical activity interventions in women with previous gestational diabetes: A systematic review of quantitative and qualitative studies

Women with previous Gestational Diabetes Mellitus (GDM) have seven times the risk of Type 2 diabetes later in life compared to women without GDM. Physical activity can reduce this risk and most women with previous GDM are not physically active.

Aims

To explore: (1) effectiveness of physical activity interventions for women with previous GDM; (2) factors that women with previous GDM perceive influence their physical activity; (3) how these factors are addressed by the interventions.

Methods

A systematic review of quantitative (aim 1) and qualitative (aim 2) studies with a mixed-methods synthesis (aim 3) was conducted in October 2017 following Cochrane methodology. Of 8101 articles identified, twenty-eight studies were included in total: 18 in Review 1 and 10 in Review 2.

Results

Four interventions significantly increased physical activity and 14 had either mixed effectiveness or no changes in physical activity. Reporting of intervention components and study quality varied greatly. Relevant qualitative factors included accounting for childcare issues, social support and cultural sensitivities. Interventions that incorporated these factors were associated with effectiveness. Education about how to reduce future risk of Type 2 diabetes and using pedometers in interventions were not associated with intervention effectiveness. Other factors that future interventions should address consist of ‘putting others before yourself’; ‘putting off lifestyle change’; ‘lack of support from healthcare professionals’ and ‘being a healthy role model for families’.

Conclusion

Combining the results of qualitative and quantitative studies can provide a nuanced understanding of the effectiveness of physical activity and lifestyle interventions.

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Women with previous gestational diabetes are at high risk for type 2 diabetes.

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Interventions to increase physical activity have not worked for this group.

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Mixed-methods reviews allow us to identify effective intervention components.

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Childcare, social support and cultural relevance are part of successful interventions.

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Interventions should incorporate this review's results to improve effectiveness.