Lifestyle intervention can reduce the risk of gestational diabetes: a meta‐analysis of randomized controlled trials

This study aimed to examine the effect of lifestyle intervention on the risk of gestational diabetes mellitus (GDM). We searched PubMed, Springer and other databases to retrieve articles published in English and Chinese up to 30 September 2015. The inclusion criteria were randomized controlled trials evaluating the effects of lifestyle intervention on risk of GDM. Exclusion criteria were studies with prepregnancy diabetes mellitus or interventions with nutrient supplements. Random‐effect and fixed‐effect model analyses were used to obtain pooled relative risks and 95% confidence intervals (CIs) of diet and physical activity on the risk of GDM. Subgroup analyses were performed to check the consistency of effect sizes across groups where appropriate. We identified 29 randomized controlled trials with 11,487 pregnant women, addressing the effect of lifestyle intervention on the risk of GDM. In the pooled analysis, either diet or physical activity resulted in an 18% (95%CI 5–30%) reduction in the risk of GDM (P = 0.0091). Subgroup analysis showed that such intervention was effective among women with intervention before the 15th gestational week (relative risk: 0.80, 95%CI 0.66–0.97), but not among women receiving the intervention afterwards. We conclude that lifestyle modification during pregnancy, especially before the 15th gestational week, can reduce the risk of GDM. © 2016 World Obesity     

Metabolic effects of breastfeed in women with prior gestational diabetes mellitus: A systematic review and meta‐analysis

This study was undertaken to provide comprehensive analyses of current research developments in the field of breastfeed (BF) and metabolic‐related outcomes among women with prior gestational diabetes mellitus (GDM). Database PubMed, Embase, BIOSIS Previews, Web of Science, and Cochrane Library were searched through December 3, 2017. Odds ratio (OR) and weighted mean difference (WMD) with 95% confidence interval (CI) were pooled by random‐effects model using Stata version 12.0. Twenty‐three observational studies were included in quantitative synthesis. Reduced possibility of progression to type 2 diabetes mellitus (T2DM; OR = 0.79; 95% CI, 0.68‐0.92) and pre‐DM (OR = 0.66; 95% CI, 0.51‐0.86) were found among women with longer BF of any intensity after GDM pregnancy. The positive effect of longer BF on progression to T2DM gradually became prominent with the extension of follow‐up period. Compared with women with shorter BF, those with longer BF manifested more favourable metabolic parameters, including significant lower body mass index, fasting glucose, triglyceride, and higher insulin sensitivity index. The findings support that BF may play an important role in protection against the development of T2DM‐related outcomes in midlife of women with prior GDM. However, further studies are needed to reveal the etiological mechanism.     

Long‐term risk of diabetes in women at varying durations after gestational diabetes: a systematic review and meta‐analysis with more than 2 million women

This study aims to investigate the impact of gestational diabetes mellitus (GDM) on the long‐term risks of diabetes in women with prior GDM, including the effect at different time periods after GDM. We searched PubMed and other databases to retrieve articles which were published prior to February 28, 2017. Cohort studies which evaluated the risk and time of onset of diabetes postpartum in women with and without GDM were included. Meta‐analysis with random effects models was used to obtain pooled relative risks and 95% confidence intervals for the risk of diabetes. Subgroup analyses were performed to check for different effect sizes as well as consistency across groups. Multivariable logistic regression was used to adjust for confounders. Thirty cohort studies with 2,626,905 pregnant women were included. Women with prior GDM had 7.76‐fold (95% confidence intervals: 5.10–11.81) unadjusted pooled risk of diabetes as compared with women without GDM, whilst the adjusted risk was 17.92‐fold (16.96–18.94). The adjusted ORs of GDM for diabetes among women at <3, ≥3 – <6 and ≥6 – <10 years after GDM were 5.37 (3.51–9.34), 16.55 (16.08–17.04) and 8.20 (4.53–14.86), respectively. Women with prior GDM had substantially increased risk of diabetes, with the risk highest during the 3–6 years after GDM.     

Different intervention strategies for preventing type 2 diabetes mellitus in China: A systematic review and network meta‐analysis of randomized controlled trials

Different strategies are increasingly used for early intervention in prediabetes in China, but the effects of these strategies on incident diabetes have not yet been confirmed. The aim of the present study was to assess systematically the effects of different strategies for preventing diabetes, aimed at Chinese people with prediabetes. Seven electronic databases were searched to identify eligible trials published from inception to September 20, 2016. Randomized controlled trials with a minimum follow‐up duration of 6 months were included. Standard pairwise meta‐analysis with a random‐effects model and network meta‐analysis with a frequentist framework were performed. A total of 63 studies, including 11 intervention strategies, were included. Compared with placebo, all strategies, except for lipid‐affecting drugs and sitagliptin, reduced the rate of incident diabetes with different levels of effectiveness, ranging from 0.18 (95% confidence interval [CI] 0.12, 0.27) to 0.39 (95% CI 0.20, 0.75). Ranking probability analysis indicated that metformin and β‐cell‐stimulating drugs reduced the risk of diabetes most, with probabilities of 87.4% and 81%, respectively. Ethnicity and cultural factors should be considered for diabetes prevention. Most of the included trials were of poor methodological quality, however, and the results should be interpreted with caution.     

Potential protective effect of lactation against incidence of type 2 diabetes mellitus in women with previous gestational diabetes mellitus: A systematic review and meta‐analysis

Lactation may protect women with previous gestational diabetes mellitus (GDM) from developing type 2 diabetes mellitus, but the results of existing studies are inconsistent, ranging from null to beneficial. We aimed to conduct a systematic review to gather available evidence. Databases MEDLINE, CINAHL, PubMed, and EMBASE were searched on December 15, 2015, without restriction of language or publication year. A manual search was also conducted. We included observational studies (cross‐sectional, case‐control, and cohort study) with information on lactation and type 2 diabetes mellitus incidence among women with previous GDM. We excluded case studies without control data. Data synthesis was conducted by random‐effect meta‐analysis. Fourteen reports of 9 studies were included. Overall risk of bias using RoBANS ranged from low to unclear. Longer lactation for more than 4 to 12 weeks postpartum had risk reduction of type 2 diabetes mellitus compared with shorter lactation (OR 0.77, 95% CI 0.01‐55.86; OR 0.56, 95% CI 0.35‐0.89; OR 0.22, 95% CI 0.13‐0.36; type 2 diabetes mellitus evaluation time < 2 y, 2‐5 y, and >5 y, respectively). Exclusive lactation for more than 6 to 9 weeks postpartum also had lower risk of type 2 diabetes mellitus compared with exclusive formula (OR 0.42, 95% CI 0.22‐0.81). The findings support the evidence that longer and exclusive lactation may be beneficial for type 2 diabetes mellitus prevention in women with previous GDM. However, the evidence relies only on observational studies. Therefore, further studies are required to address the true causal effect.     

Coronary artery bypass grafting versus percutaneous coronary intervention in patients with noninsulin treated type 2 diabetes mellitus: A meta‐analysis of randomized controlled trials

Background

The outcomes and prognosis of revascularization by either coronary artery bypass grafting (CABG) surgery or percutaneous coronary intervention (PCI) in patients with noninsulin‐treated type 2 diabetes mellitus (NITDM) have not yet been well established.

Methods

Randomized controlled trials (RCTs) were identified by searching Pubmed, EMBASE, and Cochrane library from inception until May 2016. Heterogeneity was evaluated, and the pooled hazard ratio (HR) was calculated by using a fixed‐effect model. A random‐effect model was used when statistically significant heterogeneity was observed (I² ≥ 50%). All data analyses were carried out by using RevMan 5.3 and STATA software 12.0.

Results

A total of 4 RCTs involving 5 studies, consisting of 2270 patients with noninsulin‐treated type 2 diabetes mellitus, were identified. Compared with CABG‐treated patients, PCI‐treated patients had significantly higher all‐cause mortality (HR 1.39; 95% CI 1.01 to 1.91; P = .04), myocardial infarction (HR 2.14; 95% CI 1.40 to 3.27; P = .0004), repeated revascularization (HR 2.52; 95% CI 1.77 to 3.57; P < .00001), and major adverse cardiovascular and cerebrovascular events (HR 1.50; 95% CI 1.20‐1.87; P = .0004). However, PCI was associated with lower incidence of stoke (HR 0.47; 95% CI 0.24 to 0.90; P = .02).

Conclusions

In NITDM patients, our study suggests that CABG surgery is associated with reduced risk of mortality and morbidity, although with increased incidence of stroke compared with percutaneous coronary intervention. The decision if to have percutaneous coronary intervention or CABG surgery should factor the risk for stroke of the patients when considering CABG over percutaneous coronary intervention. Adequately powered RCTs are needed to confirm the results of this meta‐analysis.     

Maternal and neonatal outcomes after energy-restricted diet for women with gestational diabetes mellitus: A systematic review and meta-analysis of randomized controlled trials

Background:Gestational diabetes mellitus (GDM) affects 1% to 14% of pregnant women annually worldwide and is one of the most common pregnancy complications.Objective:We reviewed studies on maternal and neonatal outcomes after dietary managements for women with GDM comparing caloric-restricted (intervention group) and unrestricted diets (control group).Methods:We systematically searched online databases including Medline, Cochrane Controlled Register of Trials (CENTRAL), ScienceDirect, and Google Scholar from inception until September 2019. We performed a meta-analysis with random-effects model and reported pooled risk ratios (RRs) or pooled mean differences (MD) with 95% confidence intervals (CIs).Results:We analyzed data from 6 randomized controlled trials including 1300 participants, most of them with high bias risks. We found that the women in the intervention group achieved slightly better glycemic control (pooled MD, −0.72 mg/dL; 95% CI, −7.10 to 5.66 mg/dL) and overall pregnancy outcomes (except neonatal hypoglycemia) than the women in the control group.Conclusion:An energy-restricted diet does not seem superior to the usual/standard GDM diet based on maternal or neonatal outcomes. But, clinical recommendations cannot be made as the evidence is inconclusive.     

Gene‐lifestyle interaction on risk of type 2 diabetes: A systematic review

The pathophysiological influence of gene‐lifestyle interactions on the risk to develop type 2 diabetes (T2D) is currently under intensive research. This systematic review summarizes the evidence for gene‐lifestyle interactions regarding T2D incidence. MEDLINE, EMBASE, and Web of Science were systematically searched until 31 January 2019 to identify publication with (a) prospective study design; (b) T2D incidence; (c) gene‐diet, gene‐physical activity, and gene‐weight loss intervention interaction; and (d) population who are healthy or prediabetic. Of 66 eligible publications, 28 reported significant interactions. A variety of different genetic variants and dietary factors were studied. Variants at TCF7L2 were most frequently investigated and showed interactions with fiber and whole grain on T2D incidence. Further gene‐diet interactions were reported for, eg, a western dietary pattern with a T2D‐GRS, fat and carbohydrate with IRS1 rs2943641, and heme iron with variants of HFE. Physical activity showed interaction with HNF1B, IRS1, PPARγ, ADRA2B, SLC2A2, and ABCC8 variants and weight loss interventions with ENPP1, PPARγ, ADIPOR2, ADRA2B, TNFα, and LIPC variants. However, most findings represent single study findings obtained in European ethnicities. Although some interactions have been reported, their conclusiveness is still low, as most findings were not yet replicated across multiple study populations.     

Metformin in pregnancy to avert gestational diabetes in women at high risk: Meta‐analysis of randomized controlled trials

Previous randomized and observational studies on the efficacy of metformin in pregnancy to reduce incident gestational diabetes mellitus (GDM) in women at high risk (obesity, polycystic ovary syndrome [PCOS], or pregestational insulin resistance) have been conflicting and several groups are planning further randomized controlled trials (RCTs) to answer this question conclusively. This work assesses the efficacy of metformin in pregnancy to avert one outcome—incident GDM in women at high risk. We included RCTs comparing metformin with usual care or placebo controls in terms of incident GDM and recruiting women at high risk during early pregnancy. Eleven eligible trials enrolled 2370 adult women whose intervention arm consisted of metformin started at conception or before 20 weeks of gestation. Risk of GDM was similar in intervention compared with controls (risk ratio [RR] 1.03; 95% confidence interval [CI], 0.85‐1.24). The data were of sufficient quality meeting the criteria for consistency and directness. We conclude that metformin does not contribute to averting the GDM outcome in women at high risk when initiated in pregnancy. The evidence provided by this synthesis affirms that further broad clinical trials investigating this question are no longer needed.     

Bariatric surgery: a systematic review and network meta‐analysis of randomized trials

The clinical efficacy and safety of bariatric surgery trials were systematically reviewed. MEDLINE, EMBASE, CENTRAL were searched to February 2009. A basic PubCrawler alert was run until March 2010. Trial registries, HTA websites and systematic reviews were searched. Manufacturers were contacted. Randomized trials comparing bariatric surgeries and/or standard care were selected. Evidence‐based items potentially indicating risk of bias were assessed. Network meta‐analysis was performed using Bayesian techniques. Of 1838 citations, 31 RCTs involving 2619 patients (mean age 30–48 y; mean BMI levels 42–58 kg/m²) met eligibility criteria. As compared with standard care, differences in BMI levels from baseline at year 1 (15 trials; 1103 participants) were as follows: jejunoileal bypass [MD: ?11.4 kg/m²], mini‐gastric bypass [?11.3 kg/m²], biliopancreatic diversion [?11.2 kg/m²], sleeve gastrectomy [?10.1 kg/m²], Roux‐en‐Y gastric bypass [?9.0 kg/m²], horizontal gastroplasty [?5.0 kg/m²], vertical banded gastroplasty [?6.4 kg/m²], and adjustable gastric banding [?2.4 kg/m²]. Bariatric surgery appears efficacious compared to standard care in reducing BMI. Weight losses are greatest with diversionary procedures, intermediate with diversionary/restrictive procedures, and lowest with those that are purely restrictive. Compared with Roux‐en‐Y gastric bypass, adjustable gastric banding has lower weight loss efficacy, but also leads to fewer serious adverse effects.