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The American Journal of Clinical... Oct 2018Whole grains are often referred to collectively, despite differences in their composition, physical structure, processing, and potential health benefits. (Comparative Study)
Comparative Study Meta-Analysis
The effects of whole-grain compared with refined wheat, rice, and rye on the postprandial blood glucose response: a systematic review and meta-analysis of randomized controlled trials.
BACKGROUND
Whole grains are often referred to collectively, despite differences in their composition, physical structure, processing, and potential health benefits.
OBJECTIVE
The aim of this study was to compare the postprandial blood glucose response of whole-grain with refined wheat, rice, or rye, while controlling for the food delivery matrix and the processing of the grain (e.g., grinding, germination).
DESIGN
Eleven electronic databases were systematically searched to identify studies published up to and including November 2017. Randomized controlled trials comparing the effects of whole-grain wheat, rice, or rye with those of each grain's refined counterpart on postprandial blood glucose area under the curve (AUC) were included. Pooled effect sizes were computed by using the difference in the blood glucose AUC after the consumption of the whole compared with the refined grain.
RESULTS
Twenty publications were included, with 10, 14, and 5 strata (or active-control comparisons) on whole-grain wheat, rice, and rye, respectively. The consumption of ground (wholemeal) wheat, compared with white wheat, was not associated with a significant reduction in blood glucose AUC (-6.7 mmol/L ⋅ min; 95% CI: -25.1, 11.7 mmol/L ⋅ min; P = 0.477). The consumption of wholemeal rye, compared with endosperm rye, was not associated with a significant reduction in blood glucose AUC (-5.5 mmol/L ⋅ min; 95% CI: -24.8, 13.8 mmol/L ⋅ min; P = 0.576). The consumption of intact (whole-grain) rice, compared with white rice, was associated with a significant reduction in blood glucose AUC (-40.5 mmol/L ⋅ min; 95% CI: -59.6, -21.3 mmol/L ⋅ min; P < 0.001).
CONCLUSIONS
Compared with white rice, whole-grain rice significantly attenuates the postprandial blood glucose response. In most of the studies on wheat and rye, the postprandial blood glucose responses to foods formulated with wholemeal compared with refined flours were compared. Whether reductions in the blood glucose AUC can be achieved with whole-grain (as opposed to wholemeal) wheat and rye requires further investigation.
Topics: Adult; Aged; Blood Glucose; Bread; Dietary Fiber; Female; Flour; Humans; Male; Middle Aged; Oryza; Postprandial Period; Secale; Triticum; Whole Grains; Young Adult
PubMed: 30321274
DOI: 10.1093/ajcn/nqy112 -
Journal of Diabetes Research 2018Several clinical studies have reported the application of dipeptidyl peptidase-4 (DPP-4) inhibitors as treatments for type 1 diabetes mellitus (T1DM). This study aims to... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
Several clinical studies have reported the application of dipeptidyl peptidase-4 (DPP-4) inhibitors as treatments for type 1 diabetes mellitus (T1DM). This study aims to review the outcomes of these existing studies and to discuss the therapeutic effects of DPP-4 inhibitors on T1DM.
METHODS
We thoroughly searched the Medline, Embase, PubMed, and Cochrane Library databases and ClinicalTrials.gov for studies concerning the use of DPP-4 inhibitors in patients with T1DM.
RESULTS
In preclinical trials, DPP-4 inhibitors improved the pathogenesis of T1DM. However, only a portion of the studies showed potential efficacy regarding clinical glycemic control and other clinical parameters. From this meta-analysis, pooled data from 5 randomized controlled trials revealed that the additional use of DPP-4 inhibitors resulted in a greater decrease in glycated hemoglobin A1c (HbA1c) levels (0.07%, 95% CI (-0.37%-0.23%)) than insulin monotherapy, although the decrease was not significant. A small decrease in postprandial glucose or insulin consumption was confirmed.
CONCLUSION
Although DPP-4 inhibitors may be beneficial for T1DM, existing studies do not strongly support these positive effects in clinical practice. Further optimized clinical trials are needed.
Topics: Blood Glucose; Clinical Trials as Topic; Diabetes Mellitus, Type 1; Dipeptidyl-Peptidase IV Inhibitors; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Postprandial Period
PubMed: 29507862
DOI: 10.1155/2018/5308582 -
Appetite Jun 2018Exposure to hypoxia appears to depress appetite and energy intake, however the mechanisms are not fully understood. The aim of this review was to determine the magnitude... (Meta-Analysis)
Meta-Analysis
Exposure to hypoxia appears to depress appetite and energy intake, however the mechanisms are not fully understood. The aim of this review was to determine the magnitude of changes in hunger and energy intake in hypoxic compared with normoxic environments, and establish any alterations in appetite-related hormone concentrations. PubMed and The Cochrane Library as well as MEDLINE, SPORTDiscus, PsycINFO and CINAHL, via EBSCOhost, were searched through 1st April 2017 for studies that evaluated hunger, energy intake and/or appetite-related hormones in normoxia and during hypoxic exposure in a within-measures design. A total of 28 studies (comprising 54 fasted and 22 postprandial comparisons) were included. A random-effects meta-analysis was performed to establish standardised mean difference (SMD) with 95% confidence intervals. Hypoxic exposure resulted in a trivial but significant decrease in postprandial hunger scores (SMD: -0.15, 95% CI: -0.29 to -0.01; n = 14; p = 0.043) and a moderate decrease in energy intake (SMD: -0.50, 95% CI: -0.85 to -0.15; n = 8; p = 0.006). Hypoxic exposure resulted in a decrease (albeit trivial) in postprandial acylated ghrelin concentrations (SMD: -0.16, 95% CI: -0.25 to -0.08; n = 7; p < 0.0005), and a moderate increase in fasted insulin concentrations (SMD: 0.41, 95% CI: 0.17 to 0.65; n = 34; p = 0.001). Meta-regression revealed a decrease in postprandial acylated ghrelin concentrations (p = 0.010) and an increase in fasted insulin concentrations (p = 0.020) as hypoxic severity increased. Hypoxic exposure reduces hunger and energy intake, which may be mediated by decreased circulating concentrations of acylated ghrelin and elevated insulin concentrations. PROSPERO registration number: CRD42015017231.
Topics: Acylation; Adolescent; Adult; Aged; Appetite; Energy Intake; Fasting; Female; Ghrelin; Humans; Hunger; Hypoxia; Insulin; Male; Middle Aged; Postprandial Period; Young Adult
PubMed: 29374575
DOI: 10.1016/j.appet.2018.01.015 -
Trials Dec 2017Outcomes measured in clinical trials should be meaningful to patients, healthcare professionals and researchers, yet there is heterogeneity in the outcomes used across... (Review)
Review
BACKGROUND
Outcomes measured in clinical trials should be meaningful to patients, healthcare professionals and researchers, yet there is heterogeneity in the outcomes used across trials. This inconsistency impacts on the ability to compare findings and may mean that the results have little importance to healthcare professionals and the patients that they care for. The aim of the present study is to review the outcomes used in registered trials of therapies for type 2 diabetes mellitus as the first step in the development of a core outcome set for effectiveness trials in type 2 diabetes.
METHODS
A systematic review of clinicaltrials.gov entries was completed for randomised, open (actively recruiting or in follow-up period), phase 3 and 4 trials of type 2 diabetes mellitus in adults. Trials of the treatment of diabetes complications, co-morbidities, prevention and surgery were excluded. Each trial was screened for eligibility and outcomes extracted from the primary and secondary outcomes data fields and free text study information. The outcomes were recorded verbatim and classified into core outcome domains according to the COMET taxonomy.
RESULTS
A total of 354 trial registrations were reviewed for eligibility and 138 trials included. In total, 1444 outcomes were extracted with a median of eight outcomes per trial (range = 1-60). Outcomes were categorised into 30 different outcome domains according to the COMET taxonomy, but no single domain or outcome was measured in 100% of trials. The majority of trials (88%) included outcomes in the 'metabolism and nutrition' domain, such as lipids and lipoproteins (21%), HbA1c (18%), hypoglycaemia (14%), fasting plasma/blood glucose (11%), glycaemic variability (8%), postprandial response (8%) and insulin sensitivity (5%). Only 10% of trials included one or more patient reported outcomes; of these, 29% included the Diabetes Treatment Satisfaction Questionnaire.
CONCLUSIONS
There is marked heterogeneity in the outcomes measured in registered therapeutic intervention trials for type 2 diabetes. The use of an agreed set of core outcomes will improve the consistency of reporting in clinical trials for type 2 diabetes.
TRIAL REGISTRATION
The core outcome set study, of which this is a part, is registered in the COMET database, http://www.comet-initiative.org/studies/details/956 . Registered on 24 January 2017.
Topics: Biomarkers; Blood Glucose; Clinical Trials, Phase III as Topic; Clinical Trials, Phase IV as Topic; Diabetes Mellitus, Type 2; Endpoint Determination; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Lipids; Patient Reported Outcome Measures; Patient Satisfaction; Randomized Controlled Trials as Topic; Registries; Research Design; Treatment Outcome
PubMed: 29246177
DOI: 10.1186/s13063-017-2317-5 -
Diabetic Medicine : a Journal of the... Mar 2018The inability to achieve optimal diabetes glucose control in people with diabetes is multifactorial, but one contributor may be inadequate control of postprandial...
The inability to achieve optimal diabetes glucose control in people with diabetes is multifactorial, but one contributor may be inadequate control of postprandial glucose. In patients treated with multiple daily injections of insulin, both the dose and timing of meal-related rapid-acting insulin are key factors in this. There are conflicting opinions and evidence on the optimal time to administer mealtime insulin. We performed a comprehensive literature search to review the published data, focusing on the use of rapid-acting insulin analogues in patients with Type 1 diabetes. Pharmacokinetic and pharmacodynamic studies of rapid-acting insulin analogues, together with postprandial glucose excursion data, suggest that administering these 15-20 min before food would provide optimal postprandial glucose control. Data from clinical studies involving people with Type 1 diabetes receiving structured meals and rapid-acting insulin analogues support this, showing a reduction in post-meal glucose levels of ~30% and less hypoglycaemia when meal insulin was taken 15-20 min before a meal compared with immediately before the meal. Importantly, there was also a greater risk of postprandial hypoglycaemia when patients took rapid-acting analogues after eating compared with before eating.
Topics: Blood Glucose; Clinical Studies as Topic; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Humans; Hypoglycemic Agents; Insulin Aspart; Insulin Glargine; Insulin Lispro; Insulins; Postprandial Period
PubMed: 29044708
DOI: 10.1111/dme.13525 -
Advances in Nutrition (Bethesda, Md.) Sep 2017Numerous clinical trials have examined the role of anthocyanins on cardiometabolic health, but their effects have not been quantitatively synthesized and systematically... (Meta-Analysis)
Meta-Analysis Review
Numerous clinical trials have examined the role of anthocyanins on cardiometabolic health, but their effects have not been quantitatively synthesized and systematically evaluated. The aim of our study was to conduct a systematic review and meta-analysis of randomized controlled trials (RCTs) assessing the effects of anthocyanins on glycemic regulation and lipid profiles in both healthy populations and those with cardiometabolic diseases. The MEDLINE, EMBASE, Cochrane database, OVID EBM Reviews, and clinicaltrials.gov databases were searched until February 2017. RCTs with a duration of ≥2 wk that evaluated the effects of anthocyanins on glycemic control, insulin sensitivity, and lipids as either primary or secondary outcomes were included. The Cochrane Risk of Bias tool was used to assess the study quality. Standardized mean differences (SMDs) were determined by random-effects models. Meta-regression, sensitivity, and subgroup analyses were performed to explore the influence of covariates on the overall effects. Thirty-two RCTs (1491 participants) were eligible for meta-analysis. Anthocyanins significantly reduced fasting glucose (SMD: -0.31; 95% CI: -0.59, -0.04; = 80.7%), 2-h postprandial glucose (SMD: -0.82; 95% CI: -1.49, -0.15; = 77.7), glycated hemoglobin (SMD: -0.65; 95% CI: -1.00, -0.29; = 72.7%), total cholesterol (SMD: -0.33; 95% CI: -0.62, -0.03; = 86.9%), and LDL (SMD: -0.35; 95% CI: -0.66, -0.05; = 85.2%). Sensitivity analyses showed that the overall effects remained similar by excluding the trials with a high or unclear risk of bias. The significant improvements in glycemic control and lipids support the benefits of anthocyanins in the prevention and management of cardiometabolic disease. Further well-designed RCTs are needed to evaluate the long-term effects of anthocyanins on metabolic profiles and to explore the optimal formula and dosage. The protocol for this review was registered at https://www.crd.york.ac.uk/PROSPERO/#index.php as CRD42016033210.
Topics: Anthocyanins; Blood Glucose; Cardiovascular Diseases; Cholesterol; Humans; Insulin Resistance; Metabolic Syndrome; Postprandial Period; Randomized Controlled Trials as Topic; Sensitivity and Specificity; Triglycerides
PubMed: 28916569
DOI: 10.3945/an.116.014852 -
Nutrients Jul 2017There is growing evidence from both observational and intervention studies that Whole Grain (WG) cereals exert beneficial effects on human health, especially on the... (Meta-Analysis)
Meta-Analysis Review
BACKGROUNDS
There is growing evidence from both observational and intervention studies that Whole Grain (WG) cereals exert beneficial effects on human health, especially on the metabolic profile. The aim of this study was to perform a meta-analysis of randomised controlled trials (RCT) to assess the acute and medium/long-term effect of WG foods on glycaemic control and insulin sensitivity in healthy individuals.
METHODS
A search for all the published RCT on the effect of WG food intake on glycaemic and insulin response was performed up to December 2016. Effect size consisted of mean difference (MD) and 95% CI between the outcomes of intervention and the control groups using the generic inverse-variance random effects model.
RESULTS
The meta-analysis of the 14 studies testing the acute effects of WG foods showed significant reductions of the post-prandial values of the glucose iAUC (0-120 min) by -29.71 mmol min/L (95% CI: -43.57, -15.85 mmol min/L), the insulin iAUC (0-120 min) by -2.01 nmol min/L (95% CI: -2.88, -1.14 nmol min/L), and the maximal glucose and insulin response. In 16 medium- and long-term RCTs, effects of WG foods on fasting glucose and insulin and homeostatic model assessment-insulin resistance values were not significant.
CONCLUSIONS
The consumption of WG foods is able to improve acutely the postprandial glucose and insulin homeostasis compared to similar refined foods in healthy subjects. Further research is needed to better understand the long-term effects and the biological mechanisms.
Topics: Blood Glucose; Diet; Humans; Insulin; Insulin Resistance; Postprandial Period; Randomized Controlled Trials as Topic; Whole Grains
PubMed: 28753929
DOI: 10.3390/nu9070769 -
The Cochrane Database of Systematic... Jun 2017Self-monitoring of blood glucose (SMBG) is recommended as a key component of the management plan for diabetes therapy during pregnancy. No existing systematic reviews... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Self-monitoring of blood glucose (SMBG) is recommended as a key component of the management plan for diabetes therapy during pregnancy. No existing systematic reviews consider the benefits/effectiveness of various techniques of blood glucose monitoring on maternal and infant outcomes among pregnant women with pre-existing diabetes. The effectiveness of the various monitoring techniques is unclear.
OBJECTIVES
To compare techniques of blood glucose monitoring and their impact on maternal and infant outcomes among pregnant women with pre-existing diabetes.
SEARCH METHODS
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 November 2016), searched reference lists of retrieved studies and contacted trial authors.
SELECTION CRITERIA
Randomised controlled trials (RCTs) and quasi-RCTs comparing techniques of blood glucose monitoring including SMBG, continuous glucose monitoring (CGM) or clinic monitoring among pregnant women with pre-existing diabetes mellitus (type 1 or type 2). Trials investigating timing and frequency of monitoring were also included. RCTs using a cluster-randomised design were eligible for inclusion but none were identified.
DATA COLLECTION AND ANALYSIS
Two review authors independently assessed study eligibility, extracted data and assessed the risk of bias of included studies. Data were checked for accuracy. The quality of the evidence was assessed using the GRADE approach.
MAIN RESULTS
This review update includes at total of 10 trials (538) women (468 women with type 1 diabetes and 70 women with type 2 diabetes). The trials took place in Europe and the USA. Five of the 10 included studies were at moderate risk of bias, four studies were at low to moderate risk of bias, and one study was at high risk of bias. The trials are too small to show differences in important outcomes such as macrosomia, preterm birth, miscarriage or death of baby. Almost all the reported GRADE outcomes were assessed as being very low-quality evidence. This was due to design limitations in the studies, wide confidence intervals, small sample sizes, and few events. In addition, there was high heterogeneity for some outcomes.Various methods of glucose monitoring were compared in the trials. Neither pooled analyses nor individual trial analyses showed any clear advantages of one monitoring technique over another for primary and secondary outcomes. Many important outcomes were not reported.1. Self-monitoring versus standard care (two studies, 43 women): there was no clear difference for caesarean section (risk ratio (RR) 0.78, 95% confidence interval (CI) 0.40 to 1.49; one study, 28 women) or glycaemic control (both very low-quality), and not enough evidence to assess perinatal mortality and neonatal mortality and morbidity composite. Hypertensive disorders of pregnancy, large-for-gestational age, neurosensory disability, and preterm birth were not reported in either study.2. Self-monitoring versus hospitalisation (one study, 100 women): there was no clear difference for hypertensive disorders of pregnancy (pre-eclampsia and hypertension) (RR 4.26, 95% CI 0.52 to 35.16; very low-quality: RR 0.43, 95% CI 0.08 to 2.22; very low-quality). There was no clear difference in caesarean section or preterm birth less than 37 weeks' gestation (both very low quality), and the sample size was too small to assess perinatal mortality (very low-quality). Large-for-gestational age, mortality or morbidity composite, neurosensory disability and preterm birth less than 34 weeks were not reported.3. Pre-prandial versus post-prandial glucose monitoring (one study, 61 women): there was no clear difference between groups for caesarean section (RR 1.45, 95% CI 0.92 to 2.28; very low-quality), large-for-gestational age (RR 1.16, 95% CI 0.73 to 1.85; very low-quality) or glycaemic control (very low-quality). The results for hypertensive disorders of pregnancy: pre-eclampsia and perinatal mortality are not meaningful because these outcomes were too rare to show differences in a small sample (all very low-quality). The study did not report the outcomes mortality or morbidity composite, neurosensory disability or preterm birth.4. Automated telemedicine monitoring versus conventional system (three studies, 84 women): there was no clear difference for caesarean section (RR 0.96, 95% CI 0.62 to 1.48; one study, 32 women; very low-quality), and mortality or morbidity composite in the one study that reported these outcomes. There were no clear differences for glycaemic control (very low-quality). No studies reported hypertensive disorders of pregnancy, large-for-gestational age, perinatal mortality (stillbirth and neonatal mortality), neurosensory disability or preterm birth.5.CGM versus intermittent monitoring (two studies, 225 women): there was no clear difference for pre-eclampsia (RR 1.37, 95% CI 0.52 to 3.59; low-quality), caesarean section (average RR 1.00, 95% CI 0.65 to 1.54; I² = 62%; very low-quality) and large-for-gestational age (average RR 0.89, 95% CI 0.41 to 1.92; I² = 82%; very low-quality). Glycaemic control indicated by mean maternal HbA1c was lower for women in the continuous monitoring group (mean difference (MD) -0.60 %, 95% CI -0.91 to -0.29; one study, 71 women; moderate-quality). There was not enough evidence to assess perinatal mortality and there were no clear differences for preterm birth less than 37 weeks' gestation (low-quality). Mortality or morbidity composite, neurosensory disability and preterm birth less than 34 weeks were not reported.6. Constant CGM versus intermittent CGM (one study, 25 women): there was no clear difference between groups for caesarean section (RR 0.77, 95% CI 0.33 to 1.79; very low-quality), glycaemic control (mean blood glucose in the 3rd trimester) (MD -0.14 mmol/L, 95% CI -2.00 to 1.72; very low-quality) or preterm birth less than 37 weeks' gestation (RR 1.08, 95% CI 0.08 to 15.46; very low-quality). Other primary (hypertensive disorders of pregnancy, large-for-gestational age, perinatal mortality (stillbirth and neonatal mortality), mortality or morbidity composite, and neurosensory disability) or GRADE outcomes (preterm birth less than 34 weeks' gestation) were not reported.
AUTHORS' CONCLUSIONS
This review found no evidence that any glucose monitoring technique is superior to any other technique among pregnant women with pre-existing type 1 or type 2 diabetes. The evidence base for the effectiveness of monitoring techniques is weak and additional evidence from large well-designed randomised trials is required to inform choices of glucose monitoring techniques.
Topics: Blood Glucose Self-Monitoring; Cesarean Section; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Fasting; Female; Glycated Hemoglobin; Hospitalization; Humans; Infant, Newborn; Perinatal Mortality; Postprandial Period; Pregnancy; Pregnancy Complications, Cardiovascular; Pregnancy Outcome; Pregnancy in Diabetics; Premature Birth; Randomized Controlled Trials as Topic; Telemedicine
PubMed: 28602020
DOI: 10.1002/14651858.CD009613.pub3 -
Advances in Nutrition (Bethesda, Md.) Mar 2017Research findings over the past several decades have shown that inflammation is a prominent feature of many chronic diseases, with poor diet being one likely... (Review)
Review
Research findings over the past several decades have shown that inflammation is a prominent feature of many chronic diseases, with poor diet being one likely inflammatory stimulus. Specifically, a single high-fat meal (HFM) has been suggested to increase inflammation, although there is currently no consensus with regard to the specific changes in many of the proinflammatory markers that are frequently assessed after an HFM. The aim of this systematic review was to objectively describe the postprandial timing and magnitude of changes in 5 common inflammatory markers: interleukin (IL) 6, C-reactive protein (CRP), tumor necrosis factor (TNF) α, IL-1β, and IL-8. Ten relevant databases were searched, yielding 494 results, of which 47 articles met the pre-established inclusion criteria: ) healthy men and women aged 18-60 y, ) consuming a single HFM (≥30% fat, ≥500 kcal), and ) assessing relevant inflammatory markers postmeal for ≥2 h. The only marker found to consistently change in the postprandial period was IL-6: on average, from a baseline of ∼1.4 pg/mL, it peaked at ∼2.9 pg/mL ∼6 h post-HFM (an average relative change of ∼100%). CRP, TNF-α, IL-1β, and IL-8 did not change significantly in 79% (23 of 29), 68% (19 of 28), 67% (2 of 3), and 75% (3 of 4) of included studies, respectively. We conclude that there is strong evidence that CRP and TNF-α are not responsive at the usual time scale observed in postprandial studies in healthy humans younger than age 60 y. However, future research should further investigate the role of IL-6 in the postprandial period, because it routinely increases even in healthy participants. We assert that the findings of this systematic review on markers of inflammation in the postprandial period will considerably aid in informing future research and advancing clinical knowledge.
Topics: Adolescent; Adult; Biomarkers; C-Reactive Protein; Cytokines; Databases, Factual; Diet, High-Fat; Dietary Fats; Female; Humans; Inflammation; Male; Meals; Middle Aged; Postprandial Period; Young Adult
PubMed: 28298267
DOI: 10.3945/an.116.014431 -
The Cochrane Database of Systematic... Apr 2016Gestational diabetes mellitus (GDM) has major short- and long-term implications for both the mother and her baby. GDM is defined as a carbohydrate intolerance resulting... (Review)
Review
BACKGROUND
Gestational diabetes mellitus (GDM) has major short- and long-term implications for both the mother and her baby. GDM is defined as a carbohydrate intolerance resulting in hyperglycaemia or any degree of glucose intolerance with onset or first recognition during pregnancy from 24 weeks' gestation onwards and which resolves following the birth of the baby. Rates for GDM can be as high as 25% depending on the population and diagnostic criteria used and rates are increasing globally. Risk factors associated with GDM include advanced maternal age, obesity, ethnicity, family history of diabetes, and a previous history of GDM, macrosomia or unexplained stillbirth. There is wide variation internationally in glycaemic treatment target recommendations for women with GDM that are based on consensus rather than high-quality trials.
OBJECTIVES
To assess the effect of different intensities of glycaemic control in pregnant women with GDM on maternal and infant health outcomes.
SEARCH METHODS
We searched the Cochrane Pregancy and Childbirth Group's Trials Register (31 January 2016), ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (1 February 2016) and reference lists of the retrieved studies.
SELECTION CRITERIA
We included one randomised controlled trial. Cluster-randomised and quasi-randomised controlled trials were eligible for inclusion.
DATA COLLECTION AND ANALYSIS
We used the methods described in the Cochrane Handbook for Systematic Reviews of Interventions for carrying out data collection, assessing study quality and analysing results. Two review authors independently assessed trial eligibility for inclusion, evaluated methodological quality and extracted data for the one included study. We sought additional information from one trial author but had no response. We assessed the quality of evidence for selected outcomes using the GRADE approach.
MAIN RESULTS
We included one Canadian trial of 180 women, recruited between 20 to 32 weeks' gestation, who had been diagnosed with GDM. Data from 171 of the 180 women were published as a conference abstract and no full report has been identified. The overall risk of bias of the single included study was judged to be unclear.The included trial did not report on any of this review's primary outcomes. For the mother, these were hypertension disorders of pregnancy or subsequent development of type 2 diabetes. For the infant, our primary outcomes were (perinatal (fetal and neonatal) mortality; large-for-gestational age; composite of death or severe morbidity or later childhood neurosensory disability).The trial did report data relating to some of this review's secondary outcomes. There was no clear difference in caesarean section rates for women assigned to using strict glycaemic targets (pre-prandial 5.0 mmol/L (90 mg/L) and at one-hour postprandial 6.7 mmol/L (120 mg/dL)) (28/85, 33%) when compared with women assigned to using liberal glycaemic targets (pre-prandial 5.8 mmol/L (103 mg/dL) and at one-hour postprandial 7.8 mmol/L (140 mg/dL)) (21/86, 24%) (risk ratio (RR) 1.35, 95% confidence interval (CI) 0.83 to 2.18, one trial, 171 women; very low quality). Using the GRADE approach, we found the quality of the evidence to bevery low for caesarean section due to poor reporting of risk of bias, imprecision and publication bias. Strict glycaemic targets were associated with an increase in the use of pharmacological therapy (identified as the use of insulin in this study) (33/85; 39%) compared with liberal glycaemic targets (18/86; 21%) (RR 1.85, 95% CI 1.14 to 3.03; one trial, 171 women). CIs are wide suggesting imprecision and caution is required when interpreting the data. No other secondary maternal outcome data relevant to this review were reported. For the infant, there were no clear differences between the groups of women receiving strict and liberal glycaemic targets for macrosomia (birthweight greater than 4000 g) (RR 1.35, 95% CI 0.31 to 5.85, one trial, 171 babies); small-for-gestational age (RR 1.12, 95% CI 0.48 to 2.63, one trial, 171 babies); birthweight (mean difference (MD) -92.00 g, 95% CI -241.97 to 57.97, one trial, 171 babies) or gestational age (MD -0.30 weeks, 95% CI -0.73 to 0.13, one trial, 171 babies). Adverse effects data were not reported. No other secondary neonatal outcomes relevant to this review were reported.
AUTHORS' CONCLUSIONS
This review is based on a single study (involving 180 women) with an unclear risk of bias. The trial (which was only reported in a conference abstract) did not provide data for any of this review's primary outcomes but did provide data for a limited number of our secondary outcomes. There is insufficient evidence to guide clinical practice for targets for glycaemic control for women with GDM to minimise adverse effects on maternal and fetal health. Glycaemic target recommendations from international professional organisations for maternal glycaemic control vary widely and are reliant on consensus given the lack of high-quality evidence.Further high-quality trials are needed, and these should compare different glycaemic targets for guiding treatment of women with GDM, assess both short-term and long-term health outcomes for women and their babies, include women's experiences and assess health services costs. Four studies are ongoing.
Topics: Cesarean Section; Diabetes, Gestational; Female; Fetal Macrosomia; Humans; Hyperglycemia; Infant, Newborn; Postprandial Period; Pregnancy; Randomized Controlled Trials as Topic
PubMed: 27055233
DOI: 10.1002/14651858.CD011624.pub2