Effect of a low glycaemic index diet on blood glucose in women with gestational hyperglycaemia

Diet and carbohydrate food knowledge of multi-ethnic women: a comparative analysis of pregnant women with and without Gestational Diabetes Mellitus

Background

Diet therapy is the cornerstone for the management of gestational diabetes mellitus (GDM). Carbohydrate is the primary nutrient affecting postprandial blood glucose levels. Hence, knowledge of food containing carbohydrates can assist women with GDM optimize glycemic control. Despite that, there is a paucity of research on carbohydrate-related knowledge of women with GDM. The United Arab Emirates (UAE) has one of the highest prevalence of diabetes (19.2%) in the world. This study compared diet and knowledge of carbohydrate-containing foods among pregnant women with and without GDM in the UAE.

Methods

The sample consisted of multi-ethnic women with GDM (n = 94) and a control group of healthy pregnant women (n = 90) attending prenatal clinics in three hospitals in Al Ain, UAE. Data were collected using a questionnaire and a 24-hour recall. Knowledge of food sources of carbohydrate, dietary patterns, and nutrient intakes of the two groups were compared.

Results

There were no significant differences in the mean knowledge score of food sources of carbohydrate between women with GDM and that of pregnant women without GDM. Similarly, there were no significant differences in energy and nutrient intakes between the two groups with the exception of percent energy from protein. Women with GDM reported significantly lower intake of fruits and fruit juices (P = 0.012) and higher consumption of milk and yogurt (P = 0.004) compared to that of women without GDM. Twenty-two percent of women with GDM indicated they never visited a dietitian for counseling while 65% reported they visited a dietitian only once or twice during the pregnancy. Predictors of carbohydrate knowledge score were perceived knowledge of diet and GDM and parity among women with GDM and parity and educational level among those without GDM.

Conclusion

The results of the study highlight the urgent need to provide nutrition education for women with GDM in the UAE.

Low-carbohydrate diet for the treatment of gestational diabetes mellitus: a randomized controlled trial

OBJECTIVE

Medical nutrition therapy based on the control of the amount and distribution of carbohydrates (CHO) is the initial treatment for gestational diabetes mellitus (GDM), but there is a need for randomized controlled trials comparing different dietary strategies. The purpose of this study was to test the hypothesis that a low-CHO diet for the treatment of GDM would lead to a lower rate of insulin treatment with similar pregnancy outcomes compared with a control diet.

RESEARCH DESIGN AND METHODS

A total of 152 women with GDM were included in this open, randomized controlled trial and assigned to follow either a diet with low-CHO content (40% of the total diet energy content as CHO) or a control diet (55% of the total diet energy content as CHO). CHO intake was assessed by 3-day food records. The main pregnancy outcomes were also assessed.

RESULTS

The rate of women requiring insulin was not significantly different between the treatment groups (low CHO 54.7% vs. control 54.7%; P = 1). Daily food records confirmed a difference in the amount of CHO consumed between the groups (P = 0.0001). No differences were found in the obstetric and perinatal outcomes between the treatment groups.

CONCLUSIONS

Treatment of women with GDM using a low-CHO diet did not reduce the number of women needing insulin and produced similar pregnancy outcomes. In GDM, CHO amount (40 vs. 55% of calories) did not influence insulin need or pregnancy outcomes.

Dietary carbohydrates for diabetics

The literature on the impact of dietary carbohydrates in the regulation of blood glucose levels and other metabolic abnormalities in diabetic patients over the last 3 years is reviewed. We try to differentiate the metabolic effects due to the amount of carbohydrates from those due to their different types. The review comprises a part dealing with the effects of diets having low or high carbohydrate content on body weight reduction, and a part in which the amount and the quality of carbohydrates are discussed in relation to isoenergetic diets. Overall, the data accumulated in the period considered seem to confirm that the decrease in energy intake is more important than the qualitative composition of the diet to reduce body weight, but that both the amount and the quality of carbohydrates are important in modulating blood glucose levels and other cardiovascular risk factors in both the fasting and the postprandial phases in diabetic individuals.

Different types of dietary advice for women with gestational diabetes mellitus

BACKGROUND

Gestational diabetes mellitus (GDM) affects a significant number of women each year and is associated with a wide range of adverse outcomes for women and their babies. Dietary counselling is the main strategy in managing GDM, but it remains unclear which dietary therapy is best.

OBJECTIVES

To assess the effects of different types of dietary advice for women with GDM on pregnancy outcomes.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (17 May 2012) and the WOMBAT Perinatal Trials Registry (17 April 2012).

SELECTION CRITERIA

Randomised controlled trials (RCTs) and cluster-RCTs assessing the effects of different types of dietary advice for women with GDM on pregnancy outcomes.We intended to compare two or more forms of the same type of dietary advice against each other, i.e. standard dietary advice compared with individualised dietary advice, individual dietary education sessions compared with group dietary education sessions. We intended to compare different intensities of dietary intervention with each other, i.e. single dietary counselling session compared with multiple dietary counselling sessions.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, extracted data and assessed risk of bias of included studies. Data were checked for accuracy.

MAIN RESULTS

We included nine trials; 429 women (436 babies) provided outcome data. All nine included trials had small sample sizes with variation in levels of risk of bias. A total of 11 different types of dietary advice were assessed under six different comparisons, including:low-moderate glycaemic index (GI) food versus high-moderate GI food, low-GI diet versus high-fibre moderate-GI diet, energy-restricted diet versus no energy restriction diet, low-carbohydrate diet (≤ 45% daily total energy intake from carbohydrate) versus high-carbohydrate diet (≥ 50% daily total energy intake from carbohydrate), high-monounsaturated fat diet (at least 20% total energy from monounsaturated fat) versus high-carbohydrate diet (at least 50% total energy from carbohydrate), standard-fibre diet (American Diabetes Association (ADA) diet) (20 grams fibre/day) versus fibre-enriched diet (80 grams fibre/day).In the low-moderate GI food versus moderate-high GI food comparison, no significant differences were seen for macrosomia or large-for-gestational age (LGA), (two trials, 89 babies) (risk ratio (RR) 0.45, 95% confidence interval (CI) 0.10 to 2.08), (RR 0.95, 95% CI 0.27 to 3.36), respectively; or caesarean section (RR 0.66, 95% CI 0.29 to 1.47, one trial, 63 women).In the low-GI diet versus high-fibre moderate-GI diet comparison, no significant differences were seen for macrosomia or LGA (one trial, 92 babies) (RR 0.32, 95% CI 0.03 to 2.96), (RR 2.87, 95% CI 0.61 to 13.50), respectively; or caesarean section (RR 1.80, 95% CI 0.66 to 4.94, one trial, 88 women).In the energy-restricted versus unrestricted diet comparison, no significant differences were seen for macrosomia (RR 1.56, 95% CI 0.61 to 3.94, one trial, 122 babies); LGA (RR 1.17, 95% CI 0.65 to 2.12, one trial, 123 babies); or caesarean section (RR 1.18, 95% CI 0.74 to 1.89, one trial, 121 women).In the low- versus high-carbohydrate diet comparison, none of the 30 babies in a single trial were macrosomic; and no significant differences in caesarean section rates were seen (RR 1.40, 95% CI 0.57 to 3.43, one trial, 30 women).In the high-monounsaturated fat versus high-carbohydrate diet comparison, neither macrosomia or LGA (one trial 27 babies) (RR 0.65, 95% CI 0.91 to 2.18), (RR 0.54 95% CI 0.21 to 1.37), respectively showed significant differences. Women having a high-monounsaturated fat diet had a significantly higher body mass index (BMI) at birth (mean difference (MD) 3.90 kg/m², 95% CI 2.41 to 5.39, one trial, 27 women) and at six to nine months postpartum (MD 4.10 kg/m², 95% CI 2.34 to 5.86, one trial, 27 women) when compared with those having a high-carbohydrate diet. However, these findings were based on a single, small RCT with baseline imbalance in maternal BMI.Perinatal mortality was reported in only trial which recorded no fetal deaths in either the energy- restricted or unrestricted diet group.A single trial comparing ADA diet (20 grams gram fibre/day) with fibre-enriched fibre enriched diet (80 grams gram fibre/day) did not report any of our prespecified primary outcomes.Very limited data were reported on the prespecified outcomes for each of the six comparisons. Only one trial reported on early postnatal outcomes. No trial reported long-term health outcomes for women and their babies. No data were reported on health service cost or women's quality of life.

AUTHORS' CONCLUSIONS

Data for most comparisons were only available from single studies and they are too small for reliable conclusions about which types of dietary advice are the most suitable for women with GDM. Based on the current available evidence, we did not find any significant benefits of the diets investigated.Further larger trials with sufficient power to assess the effects of different diets for women with GDM on maternal and infant health outcomes are needed. Outcomes such as longer-term health outcomes for women and their babies, women's quality of life and health service cost should be included.

Carbohydrates, glycemic index, and pregnancy outcomes in gestational diabetes

This review critically evaluates the current evidence regarding the effect of the dietary glycemic index (GI) on pregnancy outcomes in gestational diabetes mellitus (GDM). Current evidence, although limited, consistently supports the advantages of, and has demonstrated no disadvantages of, a low-GI diet. We conclude that pregnant women with GDM are likely to benefit from following a low-GI meal pattern, with no significant side effects, and consideration of the GI should be given when formulating a diet for GDM. However, until larger scale intervention trials are completed, an exclusive low-GI diet should not replace the current recommended diets for GDM from relevant government and health agencies. Further studies that intervene at an earlier stage of pregnancy are required.

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

This study aims to determine the peak timing of postprandial blood glucose level (PBGL) of two breakfasts with different glycemic index (GI) in gestational diabetes mellitus (GDM). Ten women with diet-controlled GDM who were between 30 and 32 weeks of gestation were enrolled in the study. They consumed two carbohydrate controlled, macronutrient matched bread-based breakfasts with different GI (low vs. high) on two separate occasions in a random order after an overnight fast. PBGLs were assessed using a portable blood analyser. Subjects were asked to indicate their satiety rating at each blood sample collection. Overall the consumption of a high GI breakfast resulted in a greater rise in PBGL (mean ± SEM peak PBGL: low GI 6.7 ± 0.3 mmol/L vs. high GI 8.6 ± 0.3 mmol/L; p < 0.001) and an earlier peak PBGL time (16.9 ± 4.9 min earlier; p = 0.015), with high variability in PBGL time between subjects. There was no significant difference in subjective satiety throughout the test period. In conclusion, the low GI breakfast produced lower postprandial glycemia, and the peak PBGL occurred closer to the time recommended for PBGL monitoring (i.e., 1 h postprandial) in GDM than a macronutrient matched high GI breakfast.

The IDEAL study: investigation of dietary advice and lifestyle for women with borderline gestational diabetes: a randomised controlled trial - study protocol

BACKGROUND

The Australian Carbohydrate Intolerance Study in Pregnant Women (ACHOIS) showed that treatment of pregnant women with mild gestational diabetes mellitus is beneficial for both women and their infants. It is still uncertain whether there are benefits of similar treatment for women with borderline gestational diabetes.This trial aims to assess whether dietary and lifestyle advice and treatment given to pregnant women who screen for borderline gestational diabetes reduces neonatal complications and maternal morbidities.

METHODS/DESIGN

DESIGN

Multicentre, randomised controlled trial.

INCLUSION CRITERIA

Women between 240 and 346 weeks gestation with a singleton pregnancy, a positive oral glucose challenge test (venous plasma glucose ≥7.8 mmol/L) and a normal oral 75 gram glucose tolerance test (fasting venous plasma glucose <5.5 mmol/L and a 2 hour glucose <7.8 mmol/L) with written, informed consent.Trial entry and randomisation: Women with an abnormal oral glucose tolerance test (fasting venous plasma glucose ≥5.5 mmol/L or 2 hour glucose ≥7.8 mmol/L) will not be eligible and will be offered treatment for gestational diabetes, consistent with recommendations based on results of the ACHOIS trial. Eligible women will be randomised into either the 'Routine Care Group' or the 'Intervention Group'.Study groups: Women in the 'Routine Care Group' will receive routine obstetric care reflecting current clinical practice in Australian hospitals. Women in the 'Intervention Group' will receive obstetric care, which will include dietary and lifestyle advice, monitoring of blood glucose and further medical treatment for hyperglycaemia as appropriate.Primary study outcome: Incidence of large for gestational age infants.

SAMPLE SIZE

A sample size of 682 women will be sufficient to show a 50% reduction in the risk of large for gestational age infants (alpha 0.05 two-tailed, 80% power, 4% loss to follow up) from 14% to 7% with dietary and lifestyle advice and treatment.

DISCUSSION

A conclusive trial outcome will provide reliable evidence of relevance for the care of women with borderline glucose intolerance in pregnancy and their infants.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry - ACTRN12607000174482.

Determinants of the intention of preconception care use: lessons from a multi-ethnic urban population in the Netherlands

OBJECTIVES

To investigate the determinants of the intention of preconception care use of women in a multi-ethnic urban population.

METHODS

The ASE-model-a health behaviour model-was used as an explanatory framework. A representative sample was taken from the municipal population registers of two districts in Rotterdam, the Netherlands, 2009-2010. 3,225 women (aged 15-60 years) received a questionnaire, which was returned by 631: 133 Dutch, 157 Turkish and Moroccan, and 341 Surinamese and Antillean. Descriptive, univariate and multivariate analyses were performed.

RESULTS

The multiple logistic analyses showed that intention to attend preconception care was significantly higher in women with a Turkish and Moroccan background (β 1.02, P = 0.006), a higher maternal age (β 0.04, P = 0.008) and a positive attitude (β 0.50, P < 0.001). Having no relationship (β -1.16, P = 0.004), multiparity with previous adverse perinatal outcome (β -1.32, P = 0.001), a high educational level (β -1.23, P = 0.03), having paid work (β -0.72, P = 0.01) and experienced barriers level (β -0.15, P = 0.003) were associated with less intention to use preconception care.

CONCLUSIONS

Modifiable determinants as attitude and barriers can be addressed to enhance preconception care attendance.

Gestational diabetes mellitus: a positive predictor of type 2 diabetes?

The aim of this paper is to consider the relative benefits of screening for type two diabetes mellitus in women with a previous pregnancy complicated by gestational diabetes mellitus. Recent studies suggest that women who experience GDM are at a greater risk of developing type 2 diabetes within 10-20 years of their index pregnancy. If considered as a stand-alone indicator of the risk of developing type 2 diabetes, GDM is a poor diagnostic test. Most women do not develop GDM during pregnancy and of those that do most do not develop type 2 diabetes. There is, however, a clear need for better early detection of predisposition to disease and/or disease onset to significantly impact on this global pandemic. The putative benefits of multivariate approaches and first trimester and preconception screening to increase the sensitivity of risk assignment modalities for type 2 diabetes are proposed.

Interventions for pregnant women with hyperglycaemia not meeting gestational diabetes and type 2 diabetes diagnostic criteria

BACKGROUND

Pregnancy hyperglycaemia without meeting gestational diabetes mellitus (GDM) diagnostic criteria affects a significant proportion of pregnant women each year. It is associated with a range of adverse pregnancy outcomes. Although intensive management for women with GDM has been proven beneficial for women and their babies, there is little known about the effects of treating women with hyperglycaemia who do not meet diagnostic criteria for GDM and type 2 diabetes (T2DM).

OBJECTIVES

To assess the effects of different types of management strategies for pregnant women with hyperglycaemia not meeting diagnostic criteria for GDM and T2DM (referred as borderline GDM in this review).

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 September 2011).

SELECTION CRITERIA

Randomised and cluster-randomised trials comparing alternative management strategies for women with borderline GDM.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, extracted data and assessed risk of bias of included studies. Data were checked for accuracy.

MAIN RESULTS

We included four trials involving 543 women and their babies (but only data from 521 women and their babies is included in our analyses). Three of the four included studies had moderate to high risk of bias and one study was at low to moderate risk of bias. Babies born to women receiving management for borderline GDM (generally dietary counselling and metabolic monitoring) were less likely to be macrosomic (birthweight greater than 4000 g) (three trials, 438 infants, risk ratio (RR) 0.38, 95% confidence interval (CI) 0.19 to 0.74) or large-for-gestational (LGA) age (three trials, 438 infants, RR 0.37, 95% CI 0.20 to 0.66) when compared with those born to women in the routine care group. There were no significant differences in rates of caesarean section (three trials, 509 women, RR 0.93, 95% CI 0.68 to 1.27) and operative vaginal birth (one trial, 83 women, RR 1.37, 95% CI 0.20 to 9.27) between the two groups.

AUTHORS' CONCLUSIONS

This review found interventions including providing dietary advice and blood glucose level monitoring for women with pregnancy hyperglycaemia not meeting GDM and T2DM diagnostic criteria helped reduce the number of macrosomic and LGA babies without increasing caesarean section and operative vaginal birth rates. It is important to notice that the results of this review were based on four small randomised trials with moderate to high risk of bias without follow-up outcomes for both women and their babies.

Contemporary management of gestational diabetes

PURPOSE OF REVIEW

To understand all of the current options available to treat glucose intolerance in pregnancy.

RECENT FINDINGS

Recent attention to the use of oral agents in the treatment of gestational diabetes remains controversial. This review will outline the advantages and disadvantages, as well as safety profiles of two classes of oral mediations.

SUMMARY

There are many effective treatments for gestational diabetes. Oral medications appear to be well tolerated and effective for treatment of gestational diabetes, and may offer a greater patient compliance. The literature supports use of oral medications as first-line treatment for patients with gestational diabetes that cannot achieve glycemic goals with diet and exercise.

A randomized controlled trial investigating the effects of a low-glycemic index diet on pregnancy outcomes in gestational diabetes mellitus

OBJECTIVE

The prevalence of gestational diabetes mellitus (GDM) is rising. There is little evidence to demonstrate the effectiveness of one dietary therapy over another. We aimed to investigate the effect of a low-glycemic index (LGI) versus a conventional high-fiber diet on pregnancy outcomes, neonatal anthropometry, and maternal metabolic profile in GDM.

RESEARCH DESIGN AND METHODS

Ninety-nine women (age 26-42 years; mean ± SD prepregnancy BMI 24 ± 5 kg/m²) diagnosed with GDM at 20-32 weeks' gestation were randomized to follow either an LGI (n = 50; target glycemic index [GI] ~50) or a high-fiber moderate-GI diet (HF) (n = 49; target GI ~60). Dietary intake was assessed by 3-day food records. Pregnancy outcomes were collected from medical records.

RESULTS

The LGI group achieved a modestly lower GI than the HF group (mean ± SEM 47 ± 1 vs. 53 ± 1; P < 0.001). At birth, there was no significant difference in birth weight (LGI 3.3 ± 0.1 kg vs. HF 3.3 ± 0.1 kg; P = 0.619), birth weight centile (LGI 52.5 ± 4.3 vs. HF 52.2 ± 4.0; P = 0.969), prevalence of macrosomia (LGI 2.1% vs. HF 6.7%; P = 0.157), insulin treatment (LGI 53% vs. HF 65%; P = 0.251), or adverse pregnancy outcomes.

CONCLUSIONS

In intensively monitored women with GDM, an LGI diet and a conventional HF diet produce similar pregnancy outcomes.

Intergenerational cycle of obesity and diabetes: how can we reduce the burdens of these conditions on the health of future generations?

Prepregnancy overweight or obesity and excessive gestational weight gain have been associated with increased risk of maternal and neonatal complications. Moreover, offspring from obese women are more likely to develop obesity, diabetes mellitus, and cardiovascular diseases in their lifetime. Gestational diabetes mellitus (GDM) is one of the most common complications associated with obesity and appears to have a direct impact on the future metabolic health of the child. Fetal programming of metabolic function induced by obesity and GDM may have intergenerational effect and thus perpetuate the epidemic of cardiometabolic conditions. The present paper thus aims at discussing the impact of maternal obesity and GDM on the developmental programming of obesity and metabolic disorders in the offspring. The main interventions designed to reduce maternal obesity and GDM and their ability to break the vicious circle that perpetuates the transmission of obesity and metabolic conditions to the next generations are also addressed.

Perceived barriers to application of glycaemic index: valid concerns or lost in translation?

The term glycaemic-index (GI) originally appeared in the literature in the early 1980s. GI categorizes carbohydrate according to glycaemic effect postprandially. Since its inception, GI has obtained and maintained interest of academics and clinicians globally. Upon review of GI literature, it becomes clear that the clinical utility of GI is a source of controversy. Can and should GI be applied clinically? There are academics and clinicians on both sides of the argument. Certainly, this controversy has been a stimulus for the evolution of GI methodology and application research, but may also negatively impact clinicians' perception of GI if misunderstood. This article reviews two assessments of GI that are often listed as barriers to application; the GI concept is (1) too complex and (2) too difficult for clients to apply. The literature reviewed does not support the majority of purported barriers, but does indicate that there is a call from clinicians for more and improved GI education tools and clinician GI education. The literature indicates that the Registered Dietitian (RD) can play a key role in GI knowledge translation; from research to application. Research is warranted to assess GI education tool and knowledge needs of clinicians and the clients they serve.

Treatments for gestational diabetes

BACKGROUND

Gestational diabetes (GDM) affects 3% to 6% of all pregnancies. Women are often intensively managed with increased obstetric monitoring, dietary regulation, and insulin. However, there has been no sound evidence base to support intensive treatment. The key issue for clinicians and consumers is whether treatment of GDM improves perinatal outcome.

OBJECTIVES

To compare the effect of alternative treatment policies for GDM on both maternal and infant outcomes.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (January 2009) and bibliographies of relevant papers.

SELECTION CRITERIA

Randomised controlled trials comparing alternative management strategies for women with GDM and impaired glucose tolerance in pregnancy.

DATA COLLECTION AND ANALYSIS

Two authors and a member of the Cochrane Pregnancy and Childbirth Group's editorial team extracted and checked data independently. Disagreements were resolved through discussion with the third author.

MAIN RESULTS

Eight randomised controlled trials (1418 women) were included.Caesarean section rate was not significantly different when comparing any specific treatment with routine antenatal care (ANC) including data from five trials with 1255 participants (risk ratio (RR) 0.94, 95% confidence interval (CI) 0.80 to 1.12). However, when comparing oral hypoglycaemics with insulin as treatment for GDM, there was a significant reduction (RR 0.46, 95% CI 0.27 to 0.77, two trials, 90 participants). There was a reduction in the risk of pre-eclampsia with intensive treatment (including dietary advice and insulin) compared to routine ANC (RR 0.65, 95% CI 0.48 to 0.88, one trial, 1000 participants). More women had their labours induced when given specific treatment compared to routine ANC (RR 1.33, 95% CI 1.13 to 1.57, two trials, 1068 participants). The composite outcome of perinatal morbidity (death, shoulder dystocia, bone fracture and nerve palsy) was significantly reduced for those receiving intensive treatment for mild GDM compared to routine ANC (RR 0.32, 95% CI 0.14 to 0.73, one trial, 1030 infants).There was a reduction in the proportion of infants weighing more than 4000 grams (RR 0.46, 95% CI 0.34 to 0.63, one trial, 1030 infants) and the proportion of infants weighing greater than the 90th birth centile (RR 0.55, 95% CI 0.30 to 0.99, three trials, 223 infants) of mothers receiving specific treatment for GDM compared to routine ANC. However, there was no statistically significant difference in this proportion between infants of mothers receiving oral drugs compared to insulin as treatment for GDM.

AUTHORS' CONCLUSIONS

Specific treatment including dietary advice and insulin for mild GDM reduces the risk of maternal and perinatal morbidity. However, it is associated with higher risk of labour induction. More research is needed to assess the impact of different types of intensive treatment, including oral drugs and insulin, on individual short- and long-term infant outcomes.