Timing of peak blood glucose after breakfast meals of different glycemic index in women with gestational diabetes

Impact of carbohydrate quantity and quality on maternal and pregnancy outcomes in gestational diabetes mellitus: A systematic review and meta-analysis

OBJECTIVE

To evaluate the impact of carbohydrate quantity and quality on maternal and pregnancy outcomes in gestational diabetes mellitus.

METHODS

Using a pre-defined search strategy, two researchers systematically searched MEDLINE, CINAHL Plus, and PubMed for randomized controlled trials comparing low-carbohydrate, low-glycaemic index, or low-glycaemic load diets with usual care in gestational diabetes mellitus. Mean differences and risk ratios were extracted.

RESULTS

Thirteen studies with 877 participants were included. Low-carbohydrate diet did not significantly differ from usual care for fasting blood glucose (3 studies; mean difference: 1.60 mmol/L; 95 % confidence interval: -1.95, 5.15), insulin requirement (2 studies; risk ratio: 1.01; 95 % confidence interval: 0.31, 3.05), birthweight (4 studies; mean difference: -0.23 kg; 95 % confidence interval: -1.90, 1.45), caesarean delivery (5 studies; risk ratio: 1.11; 95 % confidence interval: 0.66, 1.85), macrosomia (3 studies; risk ratio: 0.35; 95 % confidence interval: 0.00, 2130.64), large-for-gestational-age (2 studies; risk ratio: 0.46; 95 % confidence interval: 0.03, 7.20), and small-for-gestational-age infants (2 studies; risk ratio: 0.94; 95 % confidence interval: 0.00, 231.18). Low-glycaemic index diet did not significantly differ from usual care for the above outcomes either. However, low-glycaemic load diet reduced macrosomia risk (2 studies; risk ratio: 0.51; 95 % confidence interval: 0.43, 0.59).

CONCLUSIONS

Low-carbohydrate and low-glycaemic index diets do not differ from usual care for most maternal and foetal outcomes in gestational diabetes mellitus. But low-glycaemic load diet may reduce macrosomia risk.

Effect of Carbohydrate-Restricted Dietary Pattern on Insulin Treatment Rate, Lipid Metabolism and Nutritional Status in Pregnant Women with Gestational Diabetes in Beijing, China

Carbohydrates play an important role in blood glucose control in pregnant women with GDM. Carbohydrate-restricted dietary (CRD) pattern for gestational diabetes mellitus (GDM) has been widely used in clinics, but the change in insulin utilization rate beyond CRD intervention in GDM remains unclear. The aim of the present study was to explore the application of insulin in pregnancy with GDM, as well as the influence of CRD pattern on lipid metabolism and nutritional state. A retrospective study of 265 women with GDM who delivered in Peking University People's Hospital from July 2018 to January 2020 was conducted using a questionnaire survey. Women were divided into a CRD group or a control group according to whether they had received CRD intervention during pregnancy. There was no statistically significant difference in the rate of insulin therapy between the two groups (p > 0.05), the initial gestational week of the CRD group combined with insulin treatment was significantly higher than that of the control group (p < 0.05), and the risk of insulin therapy was positively correlated with fasting plasma glucose (FPG) in early pregnancy (p < 0.05). The incidence of abnormal low-density lipoprotein cholesterol levels in the CRD group was significantly lower than that in the control group (p < 0.05). There were no significant differences in nutritional indexes between the two groups. The results indicate that CRD intervention may be effective in delaying the use of insulin and improving the blood lipids metabolism during GDM pregnancy, while nutritional status may not be significantly affected under CRD intervention, and a high FPG in early pregnancy with GDM may be a risk factor for combined insulin therapy with CRD intervention.

Comparison of one hour versus 90 minute postprandial glucose measurement in women with gestational diabetes; which one is more effective?

In the present study, we aimed to compare postprandial 90 minute measurements and postprandial 1 hour (PP1-HR) measurements for prediction of foetal growth disturbances and pregnancy complications. This was a prospective study conducted in Acıbadem Mehmet Ali Aydınlar University Altunizade Hospital in Department of Perinatology. The study group consisted of patients diagnosed with gestational diabetes. In each antepartum visit, the patients fasting plasma glucose as well as PP1-HR and 90 minute measurements were made. Perinatal and neonatal data were obtained from each patient. The rate of large for gestational age infants was increased in patients when either PP1-HR measurement above 140 mg/dl or postprandial 90 minute measurement above 165 mg/dl compared to patients with normal PP1-HR or postprandial 90 minute measurement. Preterm delivery rate was increased in patients with postprandial 90 minute measurement above 165 mg/dl but not in patients with PP1-HR measurement above 140 mg/dl. The optimal cut-off for postprandial 90 minute measurement was 165 mg/dl based on receiver operating characteristics curve. Our preliminary data show that postprandial 90 minute measurements are superior to PP1-HR measurements in predicting large for gestational age infants.Impact StatementWhat is already known on this subject? Gestational diabetes (GDM) is defined as any degree of glucose intolerance with onset or first recognition in pregnancy. Maternal hyperglycaemia has been linked to metabolic alterations in the foetus and thus brings about foetal macrosomia as well as other pregnancy complications such as preterm delivery and preeclampsia.What the results of this study add? The findings of the present study suggest that postprandial 90 minute predicted more cases of LGA infants than postprandial 1-hour (PP1-HR) measurements. In addition, the rate of preterm deliveries was found to be increased in patients with mean postprandial 90 minute measurements above 165 mg/dl compared to patients with postprandial 90 minute measurements below 165 mg/dl. However, the rate of preterm deliveries was similar in patients with elevated PP1-HR measurements and patients with normal PP1-HR measurements.What the implications are of these findings for clinical practice and/or further research? Our study is the first to investigate the usefulness of postprandial 90 minute in a prospective design. Our preliminary data show that postprandial 90 minute measurements are superior to PP 1 measurements in predicting LGA babies. It also correlates better with preterm deliveries.

The Role of Dietary Carbohydrates in Gestational Diabetes

Gestational diabetes (GDM) is hyperglycemia that is recognized for the first time during pregnancy. GDM is associated with a wide range of short- and long-term adverse health consequences for both mother and offspring. It is a complex disease with a multifactorial etiology, with disturbances in glucose, lipid, inflammation and gut microbiota. Consequently, its management is complex, requiring patients to self-manage their diet, lifestyle and self-care behaviors in combination with use of insulin. In addition to nutritional recommendations for all pregnant women, special attention to dietary carbohydrate (CHO) amount and type on glucose levels is especially important in GDM. Dietary CHO are diverse, ranging from simple sugars to longer-chain oligo- and poly- saccharides which have diverse effects on blood glucose, microbial fermentation and bowel function. Studies have established that dietary CHO amount and type can impact maternal glucose and nutritional recommendations advise women with GDM to limit total intake or choose complex and low glycemic CHO. However, robust maternal and infant benefits are not consistently shown. Novel approaches which help women with GDM adhere to dietary recommendations such as diabetes-specific meal replacements (which provide a defined and complete nutritional composition with slowly-digested CHO) and continuous glucose monitors (which provide unlimited monitoring of maternal glycemic fluctuations) have shown benefits on both maternal and neonatal outcomes. Continued research is needed to understand and develop tools to facilitate patient adherence to treatment goals, individualize interventions and improve outcomes.

Relevance of the Glycemic Index and Glycemic Load for Body Weight, Diabetes, and Cardiovascular Disease

Despite initial enthusiasm, the relationship between glycemic index (GI) and glycemic response (GR) and disease prevention remains unclear. This review examines evidence from randomized, controlled trials and observational studies in humans for short-term (e.g., satiety) and long-term (e.g., weight, cardiovascular disease, and type 2 diabetes) health effects associated with different types of GI diets. A systematic PubMed search was conducted of studies published between 2006 and 2018 with key words glycemic index, glycemic load, diabetes, cardiovascular disease, body weight, satiety, and obesity. Criteria for inclusion for observational studies and randomized intervention studies were set. The search yielded 445 articles, of which 73 met inclusion criteria. Results suggest an equivocal relationship between GI/GR and disease outcome. The strongest intervention studies typically find little relationship among GI/GR and physiological measures of disease risk. Even for observational studies, the relationship between GI/GR and disease outcomes is limited. Thus, it is unlikely that the GI of a food or diet is linked to disease risk or health outcomes. Other measures of dietary quality, such as fiber or whole grains may be more likely to predict health outcomes. Interest in food patterns as predictors of health benefits may be more fruitful for research to inform dietary guidance.

GLYCEMIC INDEX OF PRE-EXERCISE MEAL IN DIABETES MELLITUS: A SYSTEMATIC REVIEW

ABSTRACT Physical exercise and diet quality are essential for glycemic control of diabetic patients, but consideration must be given to the risk of hypoglycemia in response to exercise. Therefore this study aims at 1) conducting a systematic review of the glycemic index (GI) of the pre-exercise meal and of glycemic behavior during and after aerobic exercise in diabetic subjects, and 2) discussing the safest and most appropriate pre-exercise nutritional guidance for this population. In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), two researchers independently undertook a systematic search. A third researcher participated in the selection of articles due to the presence of discrepancies. We selected two studies which both suggest that a low glycemic index (GI) meal is the best pre-exercise option, one of which suggests that the optimal time for food intake is 30 minutes before exercise. However, these results are not sufficient to define a clinical conduct, and other studies are needed to elucidate whether GI is a relevant parameter for pre- and post-exercise clinical monitoring of patients with diabetes mellitus (DM), particularly as regards to the different guidelines for type 1 and type 2 DM. Level of Evidence II; Prognostic Study.

Macronutrient Composition and Food Form Affect Glucose and Insulin Responses in Humans

Glycaemic index (GI) is used as an indicator to guide consumers in making healthier food choices. We compared the GI, insulin index (II), and the area under the curve for blood glucose and insulin as glucose (GR) and insulin responses (IR) of a newly developed liquid nutritional formula with one commercially available liquid product with different types of carbohydrates. We then evaluated the glucose and insulin responses of two test foods with comparable energy density and protein percentage but presented in different food forms (liquid vs. solid). Fourteen healthy women participated in the study. GI, II, GR, and IR were assessed after (independent) consumption of two liquid products and a solid breakfast meal. The two liquid foods showed comparable GI, whilst the liquid form appeared to produce lower median GI (25 vs. 54), and II (52 vs. 98) values compared to the solid breakfast (p < 0.02). The median GR and IR for solid breakfast were respectively 44% and 45% higher compared to the liquid product (p < 0.02). Liquid formulas with different carbohydrate qualities produced comparable glucose responses, while foods with comparable energy density and protein percentage but different food form elicited differential effects on GI, II, GR, and IR. Nutrient quality and food form need to be taken into consideration when developing low GI products to manage glycaemic responses.

Different types of dietary advice for women with gestational diabetes mellitus

BACKGROUND

Dietary advice is the main strategy for managing gestational diabetes mellitus (GDM). It remains unclear what type of advice is best.

OBJECTIVES

To assess the effects of different types of dietary advice for women with GDM for improving health outcomes for women and babies.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register (8 March 2016), PSANZ's Trials Registry (22 March 2016) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials comparing the effects of different types of dietary advice for women with GDM.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study eligibility, risk of bias, and extracted data. Evidence quality for two comparisons was assessed using GRADE, for primary outcomes for the mother: hypertensive disorders of pregnancy; caesarean section; type 2 diabetes mellitus; and child: large-for-gestational age; perinatal mortality; neonatal mortality or morbidity composite; neurosensory disability; secondary outcomes for the mother: induction of labour; perineal trauma; postnatal depression; postnatal weight retention or return to pre-pregnancy weight; and child: hypoglycaemia; childhood/adulthood adiposity; childhood/adulthood type 2 diabetes mellitus.

MAIN RESULTS

In this update, we included 19 trials randomising 1398 women with GDM, at an overall unclear to moderate risk of bias (10 comparisons). For outcomes assessed using GRADE, downgrading was based on study limitations, imprecision and inconsistency. Where no findings are reported below for primary outcomes or pre-specified GRADE outcomes, no data were provided by included trials. Primary outcomes Low-moderate glycaemic index (GI) versus moderate-high GI diet (four trials): no clear differences observed for: large-for-gestational age (risk ratio (RR) 0.71, 95% confidence interval (CI) 0.22 to 2.34; two trials, 89 infants; low-quality evidence); severe hypertension or pre-eclampsia (RR 1.02, 95% CI 0.07 to 15.86; one trial, 95 women; very low-quality evidence); eclampsia (RR 0.34, 95% CI 0.01 to 8.14; one trial, 83 women; very low-quality evidence) or caesarean section (RR 0.66, 95% CI 0.29 to 1.47; one trial, 63 women; low-quality evidence). Energy-restricted versus no energy-restricted diet (three trials): no clear differences seen for: large-for-gestational age (RR 1.17, 95% CI 0.65 to 2.12; one trial, 123 infants; low-quality evidence); perinatal mortality (no events; two trials, 423 infants; low-quality evidence); pre-eclampsia (RR 1.00, 95% CI 0.51 to 1.97; one trial, 117 women; low-quality evidence); or caesarean section (RR 1.12, 95% CI 0.80 to 1.56; two trials, 420 women; low-quality evidence). DASH (Dietary Approaches to Stop Hypertension) diet versus control diet (three trials): no clear differences observed for: pre-eclampsia (RR 1.00, 95% CI 0.31 to 3.26; three trials, 136 women); however there were fewer caesarean sections in the DASH diet group (RR 0.53, 95% CI 0.37 to 0.76; two trials, 86 women). Low-carbohydrate versus high-carbohydrate diet (two trials): no clear differences seen for: large-for-gestational age (RR 0.51, 95% CI 0.13 to 1.95; one trial, 149 infants); perinatal mortality (RR 3.00, 95% CI 0.12 to 72.49; one trial, 150 infants); maternal hypertension (RR 0.40, 95% CI 0.13 to 1.22; one trial, 150 women); or caesarean section (RR 1.29, 95% CI 0.84 to 1.99; two trials, 179 women). High unsaturated fat versus low unsaturated fat diet (two trials): no clear differences observed for: large-for-gestational age (RR 0.54, 95% CI 0.21 to 1.37; one trial, 27 infants); pre-eclampsia (no cases; one trial, 27 women); hypertension in pregnancy (RR 0.54, 95% CI 0.06 to 5.26; one trial, 27 women); caesarean section (RR 1.08, 95% CI 0.07 to 15.50; one trial, 27 women); diabetes at one to two weeks (RR 2.00, 95% CI 0.45 to 8.94; one trial, 24 women) or four to 13 months postpartum (RR 1.00, 95% CI 0.10 to 9.61; one trial, six women). Low-GI versus high-fibre moderate-GI diet (one trial): no clear differences seen for: large-for-gestational age (RR 2.87, 95% CI 0.61 to 13.50; 92 infants); caesarean section (RR 1.91, 95% CI 0.91 to 4.03; 92 women); or type 2 diabetes at three months postpartum (RR 0.76, 95% CI 0.11 to 5.01; 58 women). Diet recommendation plus diet-related behavioural advice versus diet recommendation only (one trial): no clear differences observed for: large-for-gestational age (RR 0.73, 95% CI 0.25 to 2.14; 99 infants); or caesarean section (RR 0.78, 95% CI 0.38 to 1.62; 99 women). Soy protein-enriched versus no soy protein diet (one trial): no clear differences seen for: pre-eclampsia (RR 2.00, 95% CI 0.19 to 21.03; 68 women); or caesarean section (RR 1.00, 95% CI 0.57 to 1.77; 68 women). High-fibre versus standard-fibre diet (one trial): no primary outcomes reported. Ethnic-specific versus standard healthy diet (one trial): no clear differences observed for: large-for-gestational age (RR 0.14, 95% CI 0.01 to 2.45; 20 infants); neonatal composite adverse outcome (no events; 20 infants); gestational hypertension (RR 0.33, 95% CI 0.02 to 7.32; 20 women); or caesarean birth (RR 1.20, 95% CI 0.54 to 2.67; 20 women). Secondary outcomes For secondary outcomes assessed using GRADE no differences were observed: between a low-moderate and moderate-high GI diet for induction of labour (RR 0.88, 95% CI 0.33 to 2.34; one trial, 63 women; low-quality evidence); or an energy-restricted and no energy-restricted diet for induction of labour (RR 1.02, 95% CI 0.68 to 1.53; one trial, 114 women, low-quality evidence) and neonatal hypoglycaemia (average RR 1.06, 95% CI 0.48 to 2.32; two trials, 408 infants; very low-quality evidence).Few other clear differences were observed for reported outcomes. Longer-term health outcomes and health services use and costs were largely not reported.

AUTHORS' CONCLUSIONS

Evidence from 19 trials assessing different types of dietary advice for women with GDM suggests no clear differences for primary outcomes and secondary outcomes assessed using GRADE, except for a possible reduction in caesarean section for women receiving a DASH diet compared with a control diet. Few differences were observed for secondary outcomes.Current evidence is limited by the small number of trials in each comparison, small sample sizes, and variable methodological quality. More evidence is needed to assess the effects of different types of dietary advice for women with GDM. Future trials should be adequately powered to evaluate short- and long-term outcomes.

Seventy two-hour glucose monitoring profiles in mild gestational diabetes mellitus: differences from healthy pregnancies and influence of diet counseling

OBJECTIVE

To study glucose profiles of gestational diabetes (GDM) patients with 72 h of continuous glucose monitoring (CGM) either before (GDM1) or after (GDM2) dietary counseling, comparing them with nondiabetic (NDM) controls.

DESIGN AND METHODS

We performed CGM on 22 GDM patients; 11 before and 11 after dietary counseling and compared them to 11 healthy controls. Several physiological and clinical characteristics of the glucose profiles were compared across the groups, including comparisons for pooled 24-h measures and hourly median values, summary measures representing glucose exposure (area under the median curves) and variability (amplitude, standard deviation, interquartile range), and time points related to meals.

RESULTS

Most women (81.8%) in the GDM groups had fasting glucose <95mg/dL, suggesting mild GDM. Variability, glucose levels 1 and 2h after breakfast and dinner, peak values after dinner and glucose levels between breakfast and lunch, were all significantly higher in GDM1 than NDM (P<0.05 for all comparisons). The GDM2 results were similar to NDM in all aforementioned comparisons (P>0.05). Both GDM groups spent more time with glucose levels above 140mg/dL when compared with the NDM group. No differences among the groups were found for: pooled measurements and hourly comparisons, exposure, nocturnal, fasting, between lunch and dinner and before meals, as well as after lunch (P>0.05 for all).

CONCLUSION

The main differences between the mild GDM1 group and healthy controls were related to glucose variability and excursions above 140mg/dL, while glucose exposure was similar. Glucose levels after breakfast and dinner also discerned the GDM1 group. Dietary counseling was able to keep glucose levels to those of healthy patients.