Rationale for insulin management in gestational diabetes mellitus

Incidence of Gestational Diabetes Diagnosed on the 100-G Glucose Tolerance Test in Pregnancies with a 50-G Glucose Challenge Test Result of 200 mg/dL or Greater

OBJECTIVE

This study aimed to assess the positive predictive value (PPV) of a 1-hour, 50-g glucose challenge test (GCT) result ≥200 mg/dL for the diagnosis of gestational diabetes mellitus (GDM) on a 3-hour, 100-g glucose tolerance test (GTT).

STUDY DESIGN

Pregnancies between 2008 and 2016 with a GCT result ≥200 mg/dL were identified retrospectively. GCT and GTT dates and results, demographics, and working due date (EDD) were extracted. Gestational age at testing was calculated from test date and EDD. As some clinicians presumptively diagnose GDM in such cases, if a GTT result was not available, clinic notes were reviewed to determine whether a GTT was ordered. Positive predictive values (PPV) were calculated at GCT cut-offs at and beyond 200 mg/dL. Subgroups were compared including early GCT (<16 weeks) versus routine GCT (24-28 weeks), GTT result normal versus GTT diagnostic of GDM, and GTT ordered versus GTT not ordered. Rates of use of medication for glycemic control were assessed among these groups.

RESULTS

Of 236 pregnant women with a GCT result ≥200 mg/dL, 115 (48%) GTT was ordered for 115 (49%), whereas 123 (52%) were managed as presumed GDM. Of 100 (87%) who completed the test, 81 (81%) were diagnosed with GDM with a median intertest interval of 14 days. No statistically significant differences were found between groups stratified by GTT result. Use of rates of metformin, glyburide, and insulin were similar between those diagnosed with GDM by GTT and those diagnosed with GDM by GCT alone.

CONCLUSION

A GCT result of ≥200 mg/dL has a PPV of 81% for diagnosis of GDM by GTT in a contemporary U.S. population, with a median intertest interval of 14 days between GCT and GTT. However, those diagnosed by GCT alone were as likely as those diagnosed by GTT to require medication for glycemic control, including insulin, suggesting that requiring a GTT may result in underdiagnosis and delayed treatment of GDM.

KEY POINTS

· A 50-g GCT result of 200 mg/dL or greater has a PPV of 81% for GDM on the 100 g GTT.. · Patients diagnosed with GDM by GCT alone were as likely to require insulin as those diagnosed by GTT.. · 81% of patients diagnosed with GDM on the GTT completed their GTT at least 1 week after the GCT, thus requiring GTT in this population may lead to unnecessary delays in care..

The Role of Lifestyle Intervention in the Prevention and Treatment of Gestational Diabetes

Obesity during pregnancy is associated with the development of adverse outcomes, including gestational diabetes mellitus (GDM). GDM is highly associated with obesity and independently increases the risk of both complications during pregnancy and future impaired glycemic control and risk factors for cardiovascular disease for both the mother and child. Despite extensive research evaluating the effectiveness of lifestyle interventions incorporating diet and/or exercise, there remains a lack of definitive consensus on their overall efficacy alone or in combination for both the prevention and treatment of GDM. Combination of diet and physical activity/exercise interventions for GDM prevention demonstrates limited success, whereas exercise-only interventions report of risk reductions ranging from 3 to 49%. Similarly, combination therapy of diet and exercise is the first-line treatment of GDM, with positive effects on maternal weight gain and the prevalence of infants born large-for-gestational age. Yet, there is inconclusive evidence on the effects of diet or exercise as standalone therapies for GDM treatment. In clinical care, women with GDM should be treated with a multidisciplinary approach, starting with lifestyle modification and escalating to pharmacotherapy if needed. Several key knowledge gaps remain, including how lifestyle interventions can be optimized during pregnancy, and whether intervention during preconception is effective for preventing the rising prevalence of GDM.

Beyond self-monitored plasma glucose and HbA1c: the role of non-traditional glycaemic markers in gestational diabetes mellitus

Strict glycaemic management is the cornerstone of metabolic control in gestational diabetes mellitus (GDM). Current monitoring standards involve self-monitoring plasma glucose (SMBG) and haemoglobin A1c (HbA1c). However, both have important limitations. SMBG only reflects instantaneous blood glucose and the inconvenience of self-collecting blood frequently results in poor compliance. HbA1c provides information on blood glucose levels from the previous 2 to 3 months and it is influenced by iron-deficient states, common during pregnancy. There is an urgent need for new shorter-term glycaemic markers, as glycated albumin, fructosamine or 1,5-anhydroglucitol. Glycated albumin seems especially interesting as it provides information on blood glucose levels over the foregoing 2-3 weeks and it is not influenced by iron deficiency or the dilutional anaemia of pregnancy. Fructosamine has a precise and inexpensive measurement and it is not affected by haemoglobin characteristics. This review further discusses the potential value of these non-traditional indicators of glycaemic control in patients with GDM, outlining their possible future applications.

Exercise improves glycaemic control in women diagnosed with gestational diabetes mellitus: a systematic review

QUESTION

Does exercise improve postprandial glycaemic control in women diagnosed with gestational diabetes mellitus?

DESIGN

A systematic review of randomised trials.

PARTICIPANTS

Pregnant women diagnosed with gestational diabetes mellitus.

INTERVENTION

Exercise, performed more than once a week, sufficient to achieve an aerobic effect or changes in muscle metabolism.

OUTCOME MEASURES

Postprandial blood glucose, fasting blood glucose, glycated haemoglobin, requirement for insulin, adverse events and adherence.

RESULTS

This systematic review identified eight randomised, controlled trials involving 588 participants; seven trials (544 participants) had data that were suitable for meta-analysis. Five trials scored ≥ 6 on the PEDro scale, indicating a relatively low risk of bias. Meta-analysis showed that exercise, as an adjunct to standard care, significantly improved postprandial glycaemic control (MD -0.33mmol/L, 95% CI -0.49 to -0.17) and lowered fasting blood glucose (MD -0.31 mmol/L, 95% CI -0.56 to -0.05) when compared with standard care alone, with no increase in adverse events. Effects of similar magnitude were found for aerobic and resistance exercise programs, if performed at a moderate intensity or greater, for 20 to 30minutes, three to four times per week. Meta-analysis did not show that exercise significantly reduced the requirement for insulin. All studies reported that complications or other adverse events were either similar or reduced with exercise.

CONCLUSION

Aerobic or resistance exercise, performed at a moderate intensity at least three times per week, safely helps to control postprandial blood glucose levels and other measures of glycaemic control in women diagnosed with gestational diabetes mellitus.

REGISTRATION

PROSPERO CRD42015019106. [Harrison AL, Shields N, Taylor NF, Frawley HC (2016) Exercise improves glycaemic control in women diagnosed with gestational diabetes mellitus: a systematic review.Journal of Physiotherapy62: 188-196].

Fetal and maternal metabolic responses to exercise during pregnancy

Pregnancy is characterized by physiological, endocrine and metabolic adaptations creating a pseudo-diabetogenic state of progressive insulin resistance. These adaptations occur to sustain continuous fetal requirements for nutrients and oxygen. Insulin resistance develops at the level of the skeletal muscle, and maternal exercise, especially activity involving large muscle groups improve glucose tolerance and insulin sensitivity. We discuss the maternal hormonal and metabolic changes associated with a normal pregnancy, the metabolic dysregulation that may occur leading to gestational diabetes mellitus (GDM), and the consequences to mother and fetus. We will then examine the acute and chronic (training) responses to exercise in the non-pregnant state and relate these alterations to maternal exercise in a low-risk pregnancy, how exercise can be used to regulate glucose tolerance in women at risk for or diagnosed with GDM. Lastly, we present key exercise guidelines to help maintain maternal glucose regulation and suggest future research directions.

Indicators of glycemic control in patients with gestational diabetes mellitus and pregnant women with diabetes mellitus

Recently, it has become clear that mild abnormal glucose tolerance increases the incidence of perinatal maternal-infant complications, and so the definition and diagnostic criteria of gestational diabetes mellitus (GDM) have been changed. Therefore, in patients with GDM and pregnant women with diabetes mellitus, even stricter glycemic control than before is required to reduce the incidence of perinatal maternal-infant complications. Strict glycemic control cannot be attained without an indicator of glycemic control; this review proposes a reliable indicator. The gold standard indicator of glycemic control in patients with diabetes mellitus is hemoglobin A1c (HbA1c); however, we have demonstrated that HbA1c does not reflect glycemic control accurately during pregnancy because of iron deficiency. It has also become clear that glycated albumin, another indicator of glycemic control, is not influenced by iron deficiency and therefore might be a better indicator of glycemic control in patients with GDM and pregnant women with diabetes mellitus. However, large-population epidemiological studies are necessary in order to confirm our proposal. Here, we outline the most recent findings about the indicators of glycemic control during pregnancy including fructosamine and 1,5-anhydroglucitol.

Predictors of large and small for gestational age birthweight in offspring of women with gestational diabetes mellitus

AIM

To identify predictors of large and small for gestational age in women with gestational diabetes mellitus.

METHODS

A retrospective audit of clinical data analysed for singleton births in women diagnosed with gestational diabetes by Australasian Diabetes in Pregnancy Society guidelines from 1994 to 2009. Exclusions were: incomplete data, delivered at < 36 weeks gestation and/or last recorded weight > 4 weeks pre-delivery. We assessed: pre-pregnancy BMI, ethnicity, total maternal weight gain, weight gain before and after treatment initiation for gestational diabetes, HbA(1c) at gestational diabetes presentation and treatment modality (diet or insulin) and smoking. Birthweight was assessed using customized percentile charts (large for gestational age > 90th; small for gestational age < 10th percentile). Multiple regression analyses were undertaken; statistical significance was p < 0.05.

RESULTS

There were 1695 women first seen at (mean ± sd) 28.1 ± 5.3 weeks gestation (range 6-39). Ethnic mix was South-East Asian 36.7%, Middle Eastern 27.6%, European 22.4%, Indian/Pakistani 8.6%, Samoan 1.9%, African 1.5% and Maori 1.1%. Therapy was diet 69.1% and insulin 30.9%. Mean total weight gain was 12.3 ± 6.1 kg, the majority (10.6 ± 6.0 kg), gained before dietary intervention. There were 7.9% small for gestational age and 15.2% large for gestational age births. Significant independent large for gestational age predictors were: weight gain before intervention, pre-pregnancy BMI, weight gain after intervention and treatment type, but not HbA1c or smoking. Significant small for gestational age predictors were: weight gain before intervention, weight gain after intervention, but not pre-pregnancy BMI, HbA(1c) or smoking.

CONCLUSION

Conventional treatment for gestational diabetes mellitus concentrates on management of blood glucose levels. The trends identified here emphasize the need to also address pregnancy weight gain stratified by pre-pregnancy BMI.

Gestational diabetes: risks, management, and treatment options

Gestational diabetes mellitus (GDM) is commonly defined as glucose intolerance first recognized during pregnancy. Diagnostic criteria for GDM have changed over the decades, and several definitions are currently used; recent recommendations may increase the prevalence of GDM to as high as one of five pregnancies. Perinatal complications associated with GDM include hypertensive disorders, preterm delivery, shoulder dystocia, stillbirths, clinical neonatal hypoglycemia, hyperbilirubinemia, and cesarean deliveries. Postpartum complications include obesity and impaired glucose tolerance in the offspring and diabetes and cardiovascular disease in the mothers. Management strategies increasingly emphasize optimal management of fetal growth and weight. Monitoring of glucose, fetal stress, and fetal weight through ultrasound combined with maternal weight management, medical nutritional therapy, physical activity, and pharmacotherapy can decrease comorbidities associated with GDM. Consensus is lacking on ideal glucose targets, degree of caloric restriction and content, algorithms for pharmacotherapy, and in particular, the use of oral medications and insulin analogs in lieu of human insulin. Postpartum glucose screening and initiation of healthy lifestyle behaviors, including exercise, adequate fruit and vegetable intake, breastfeeding, and contraception, are encouraged to decrease rates of future glucose intolerance in mothers and offspring.

Antenatal oral glucose-tolerance test values and pregnancy outcomes

Objective

The aim of the present study was to explore the impact of individual blood glucose values (n = 4; i.e. fasting and 1, 2 and 3 h following oral glucose administration) obtained during antenatal oral glucose-tolerance testing, together with two different sets of criteria used for diagnosis of gestational diabetes mellitus (GDM) — Carpenter and Coustan Criteria (CCC) and National Diabetes Data Group (NDDG) criteria — in predicting pregnancy outcomes and maternal insulin need.

Setting

Al Ain Hospital, United Arab Emirates.

Method

This observational uncontrolled cohort study gained its study subjects from a randomised, controlled, longitudinal, prospective clinical trial performed at Al Ain Hospital, Al Ain, United Arab Emirates. The eligible population was made up of all women (n = 720) who participated in an early screening programme for GDM. Those who had a positive oral glucose-tolerance test (OGTT) based on CCC were included in the study (n = 165). All recruited women with GDM were followed from time of recruitment to 6months postpartum. The sources of information used were maternal and neonatal medical records and laboratory findings for women both antenatally and postnatally.

Results

The maternal and neonatal outcomes indicated that the number of abnormally elevated antenatal OGTT values obtained during the diagnosis of GDM was significantly correlated with development of a number of pregnancy complications. Data analysis also indicated that the number of abnormal diagnostic antenatal OGTT values using CCC was significantly correlated with development of postpartum diabetes mellitus (P = 0.044) within 6months of delivery. The number of abnormal OGTT values significantly contributed to insulin need during the index pregnancy (P &lt; 0.05). The CCC approach was more sensitive than the NDDG methodology for predicting the onset of GDM and a number of the associated complications.

Conclusions

The study highlighted the importance of abnormal values for antenatal OGTT in identifying the need for insulin management in women with GDM.

Gestational Diabetes Mellitus: Physical Exercise and Health Outcomes

Purpose: Gestational diabetes mellitus (GDM) is a serious complication of pregnancy associated with increased risk of adverse outcomes for both mother and infant. This study assesses the association of maternal exercise during GDM pregnancy and selected maternal and infant adverse GDM-related outcomes. The analysis uses information derived from the 1988 National Maternal Infant Health Survey (NMIHS) data. Methods: Women in the 1988 NMIHS database were identified and grouped as to having experienced a non-GDM (n = 2,952,482) or GDM (n = 105,600) pregnancy. Non-GDM and GDM groups were compared as to demographic and personal-attribute variables. The second part of this study focused on the women with GDM pregnancy, specifically a subset (n = 75,160) who met inclusion/exclusion criteria for the study of exercise during pregnancy. Each was categorized to either the exercise group or the nonexercise group. Results: The non-GDM and GDM groups of pregnant women were not different as to the variables studied, except that older age and increased body mass index (BMI) were associated with GDM pregnancy. For the study of exercise during GDM pregnancy, the only variable that was associated with the exercise group was size of the infant. Participants in the exercise group were less likely than those in the nonexercise group to have delivered a large for gestational age (LGA) infant (F [1, 4314] = 9.82, p = .0017). Implications: The results of this study suggest that moderate maternal leisure time physical exercise during GDM pregnancy may reduce the risk of delivery of an LGA infant.

Pregnancy outcome in infertile patients with polycystic ovary syndrome who were treated with metformin

OBJECTIVE

To analyze pregnancy complications and outcome in patients with polycystic ovary syndrome (PCOS) treated with metformin.

DESIGN

Single center retrospective case analysis.

SETTING

Private regional nonurban referral subspecialty practice.

PATIENT(S)

After 7 months of average metformin use, 188 patients with PCOS (average infertility: 27 months) achieved 237 pregnancies.

INTERVENTION(S)

Of pregnancies established, metformin alone was used before conception in 124/237 (52%), oral fertility agents (CC or letrozole) in 81 (34%), gonadotropin therapy in 7 (3.0%), assisted reproduction in 17 (7.2%), and other fertility-promoting regimens in 8 (3.4%).

MAIN OUTCOME MEASURE(S)

Analysis of prepregnancy health parameters (weight, blood pressure, glucose tolerance, fasting and stimulated insulin levels) and pregnancy outcomes (miscarriage, pregnancy length, hypertension, gestational diabetes, weight gain, birth weight, sex ratio, congenital malformations, and breastfeeding success).

RESULT(S)

Metformin appears to decrease the rate of spontaneous abortion. The co-morbidities of PCOS including obesity, insulin resistance, and glucose sensitivity served as indicators of increased risk for pregnancy complications, especially gestational diabetes. No increase in pregnancy-induced hypertension was evident. Prematurity was increased. Neither PCOS nor metformin use appears to increase the rate of congenital anomaly. PCOS did not affect lactation.

CONCLUSION(S)

PCOS or its co-morbidities are associated with poorer pregnancy outcome. Implications and interventions are discussed.

Overweight and obese in gestational diabetes: the impact on pregnancy outcome

OBJECTIVE

We sought to investigate the relationship between prepregnancy weight, treatment modality (diet or insulin), level of glycemic control, and pregnancy outcome.

STUDY DESIGN

We recruited women with gestational diabetes (GDM) from inner city prenatal clinics. All women were instructed in the use of an intensified management protocol using memory reflectance meters. Outcomes were analyzed according to maternal prepregnancy body mass index (BMI, kg/m 2 ) categories: normal weight (BMI 18.5-24.9), overweight (BMI 25-29.9), and obese (BMI > or =30), and by diet or insulin therapy and glycemic control (mean blood glucose <100 mg/dL = good control). Pregnancy outcome variables included a composite outcome (at least 1 of the following: neonatal metabolic complications, large-for-gestational age or macrosomic infants, NICU admission for >24 hours, and the need for respiratory support) (not including oxygen therapy). In addition to composite outcome, a bivariate analysis was performed for each single variable, including preeclampsia and cesarean section delivery.

RESULTS

Four thousand and one women were enrolled. Obese women who achieved targeted levels of glycemic control had comparable pregnancy outcomes to normal weight and overweight women only when they were treated with insulin. Normal weight women treated with diet therapy who achieved targeted levels of glycemic control had good outcomes, but obese women treated with diet therapy who achieved targeted levels of glycemic control, nevertheless, had a 2- to 3-fold higher risk for adverse pregnancy outcome when compared with overweight and normal weight patients with well-controlled GDM. Women with GDM who failed to achieve established levels of glycemic control had significantly higher adverse pregnancy outcomes in all 3 maternal weight groups.

CONCLUSION

In obese women with BMI > or =30 with GDM, achievement of targeted levels of glycemic control was associated with enhanced outcome only in women treated with insulin.

Gestational diabetes: the consequences of not treating

OBJECTIVE

Untreated gestational diabetes mellitus carries significant risks of perinatal morbidity at all severity levels; treatment will enhance outcome.

STUDY DESIGN

A matched control of 555 gravidas, gestational diabetes mellitus diagnosed after 37 weeks, were compared with 1110 subjects treated for gestational diabetes mellitus and 1110 nondiabetic subjects matched from the same delivery year for obesity, parity, ethnicity, and gestational age at delivery. The nondiabetic subjects and those not treated for gestational diabetes mellitus were matched for prenatal visits.

RESULTS

A composite adverse outcome was 59% for untreated, 18% for treated, and 11% for nondiabetic subjects. A 2- to 4-fold increase in metabolic complications and macrosomia/large for gestational age was found in the untreated group with no difference between nondiabetic and treated subjects. Comparison of maternal size, parity, and disease severity revealed a 2- to 3-fold higher morbidity rate for the untreated groups, compared with the other groups.

CONCLUSION

Untreated gestational diabetes mellitus carries significant risks for perinatal morbidity in all disease severity levels. Timely and effective treatment may substantially improve outcome.

Fasting blood glucose levels and initiation of insulin therapy in gestational diabetes

OBJECTIVE

To determine whether an initial fasting blood glucose determination will predict which pregnant women will need insulin in addition to dietary measures to maintain fasting glucose levels during gestation.

METHODS

All women referred for management of gestational diabetes received dietary counseling and instructions for self-monitoring of blood glucose levels during fasting and at 2 hours after each meal. Insulin therapy was initiated if the fasting blood glucose value exceeded 5.8 mmol/L (105 mg/dL) on more than one occasion, the 2-hour postprandial glucose exceeded 8.3 mmol/L (150 mg/dL), or the 2-hour postprandial glucose exceeded 6.7 mmol/L (120 mg/dL) three times in a week. The use of diet alone or diet plus insulin therapy was determined by review of medical records.

RESULTS

Fifty-two pregnant women with fasting blood glucose levels of less than 5.8 mmol/L (105 mg/dL) and with two or more elevated blood glucose values on a 3-hour glucose tolerance test underwent follow-up at least through the 36th week of gestation. In 21 patients, insulin therapy was initiated in addition to diet. Two of five women with an initial fasting glucose level of less than 4.4 mmol/L (80 mg/dL) required insulin, and 8 of 24 women with fasting levels of 5.3 to 5.8 mmol/L (96 to 105 mg/dL) eventually needed insulin.

CONCLUSION

The height of the fasting blood glucose level in women with gestational diabetes does not separate those who will maintain blood glucose levels in the targeted therapeutic range on diet alone from those who will need insulin. Therefore, all women with gestational diabetes need to participate in self-monitoring of blood glucose levels.

Insulin and glyburide therapy: dosage, severity level of gestational diabetes, and pregnancy outcome

OBJECTIVE

We sought to investigate the association between glyburide dose, degree of severity in gestational diabetes mellitus (GDM), level of glycemic control, and pregnancy outcome in insulin- and glyburide-treated patients.

STUDY DESIGN

In a secondary analysis of our previous randomized study, 404 women were analyzed. The association among glyburide dose, severity of GDM, and selected maternal and neonatal factors was evaluated. Severity levels of GDM were stratified by fasting plasma glucose (FPG) from the oral glucose tolerance test (OGTT). Infants with birth weight at or above the 90th percentile were considered large-for-gestational age (LGA). Macrosomia was defined as birth weight > or =4000 g. Well-controlled was defined as mean blood glucose < or =95 mg/dL. The association between glyburide- and insulin-treated patients by severity of GDM and neonatal outcome was evaluated.

RESULTS

The dose received for the glyburide-treated patients was 2.5 mg-32%; 5 mg-23%; 10 mg-17%; 15 mg-8%; and 20 mg-20%. Patients were grouped into low (< or =10 mg) and high (>10 mg) daily dose of glyburide. A comparison between severity of the disease (fasting plasma glucose categories) and highest dose of glyburide revealed a significant difference between the low-95 FPG and the other severity categories (P = .02). Of patients in the well-controlled glycemic group, only 6% required the high dose of glyburide (>10 mg). In patients with poor glycemic control (mean blood glucose >95 mg/dL), 38% received the high dose of glyburide (P = .0001). Comparison between the high glyburide (>10 mg) and the low glyburide dosages (< or =10 mg) revealed that the rate of macrosomia was 16% vs 5% and LGA 22% vs 8%, (P = .01), respectively. No significant difference was found in composite outcome, metabolic complications, and Ponderal Index between the 2 dose groups. Stratification by disease severity revealed a significantly lower rate of LGA for both the glyburide- and insulin-treated subjects. No significant difference was found between metabolic, respiratory, and neonatal intensive care unit (NICU) for patients within each fasting plasma glucose severity category.

CONCLUSION

Glyburide and insulin are equally efficient for treatment of GDM in all levels of disease severity. Achieving the established level of glycemic control, not the mode of pharmacologic therapy, is the key to improving the outcome in GDM.

Diurnal glycemic profile in obese and normal weight nondiabetic pregnant women

OBJECTIVE

A paucity of data exists concerning the normal glycemic profile in nondiabetic pregnancies. Using a novel approach that provides continuous measurement of blood glucose, we sought to evaluate the ambulatory daily glycemic profile in the second half of pregnancy in nondiabetic women.

STUDY DESIGN

Fifty-seven obese and normal weight nondiabetic subjects were evaluated for 72 consecutive hours with continuous glucose monitoring by measurement interstitial glucose levels in subcutaneous tissue every 5 minutes. Subjects were instructed not to modify their lifestyle or to follow any dietary restriction. For each woman, mean and fasting blood glucose values were determined; for each meal during the study period, the first 180 minutes were analyzed.

RESULTS

For the study group, the fasting blood glucose level was 75 +/- 12 mg/dL; the mean blood glucose level was 83.7 +/- 18 mg/dL; the postprandial peak glucose value level was 110 +/- 16 mg/dL, and the time interval that was needed to reach peak postprandial glucose level was 70 +/- 13 minutes. A similar postprandial glycemic profile was obtained for breakfast, lunch, and dinner. Obese women were characterized by a significantly higher postprandial glucose peak value, increased 1- and 2-hour postprandial glucose levels, increased time interval for glucose peak, and significantly lower mean blood glucose during the night. No difference was found in fasting and mean blood glucose between obese and nonobese subjects.

CONCLUSION

Glycemic profile characterization in both obese and normal weight nondiabetic subjects provide a measure for the desired level of glycemic control in pregnancy that is complicated with diabetes mellitus.

Flexible treatment of Gestational Diabetes modulated on ultrasound evaluation of intrauterine growth: a controlled randomized clinical trial

OBJECTIVES

In order to prevent abnormalities of fetal growth still characterizing pregnancies complicated by Gestational Diabetes (GDM), in the present study we evaluated a therapeutic strategy for GDM based on ultrasound (US) measurement of fetal insulin-sensitive tissues.

METHODS

All GDM women diagnosed before 28th week immediately started diet and self-monitoring of blood glucose; after 2 weeks they were randomized to conventional (C) or modified (M) management. In C the glycemic target (GT) was fixed at 90 fasting/120 post-prandial mg/dl; in M GT varied, according to US measurement of the Abdominal Circumference (AC) centile performed every 2 weeks: 80/100 if AC > or =75th, 100/140 if AC<75th. Therapy was tailored to mean fasting (FG) and postprandial glycemia (PPG).

RESULTS

Globally, 229 women completed the study, 78 in C, 151 in M. Use of insulin was 16.7% in C, 30.4% in M (total groups), significantly more frequent in M than in C (59.7% vs 15.4%) when considering only women with AC > or =75th c. Mean metabolic data were similar in the 2 groups, but in M a tightly-optimized subgroup, resulting from the lowering of GT due to AC > or =75th, coexisted with a less-controlled one, whose higher GT was justified by AC<75th. Pregnancy outcome was better in M, with lower (p<0.05*) rate of LGA* (7.9% vs 17.9%), SGA (6.0% vs 9.0%) and Macrosomia* (3.3% vs 11.5%).

CONCLUSIONS

Our data show the value of a flexible US-based approach to the treatment of GDM. This model does not necessarily involve a generalized aggressive treatment, allowing to concentrate therapeutical efforts on a small subgroup of women showing indirect US evidence of fetal hyperinsulinization. Such a selective approach allowed to obtain a near-normalization of fetal growth, with clear advantages on global pregnancy outcome.

Oral hypoglycemic agents and the pregnant diabetic: "from bench to bedside"

Today, the criteria for diagnosis and treatment have evolved into an evidence-based medicine approach. The need for evidence-based information is especially critical in the management of gestational diabetes, in general, and especially in the use of oral hypoglycemic agents. These agents have been categorically contraindicated for decades in the United States based on anecdotal and/or weak evidence for these recommendations. In this article, the similarities between gestational and type 2 diabetes are described and the rationale for the use of oral hypoglycemic agents for the treatment of both are discussed. The author will show how research from basic sciences (placental transfers) to clinical studies (perinatal outcome) can lead to significant evidence on which to base management recommendations.

The impact of self-monitoring of blood glucose on self-efficacy and pregnancy outcomes in women with diet-controlled gestational diabetes

PURPOSE

The purpose of this study was to examine the effects of self-monitoring of blood glucose (SMBG) on feelings of self-efficacy, dietary compliance, and pregnancy outcomes in women with diet-controlled gestational diabetes mellitus (GDM).

METHODS

Fifty-eight women with GDM and a fasting blood glucose level < 95 mg/dL were randomly assigned to 2 groups. The experimental group measured their blood glucose levels 4 times daily using a reflectance meter with memory. Metabolic status was assessed in the control group by periodic monitoring at prenatal visits. Otherwise the management protocol was identical for both groups. The Diabetes Empowerment Scale was completed at study entry and at 37 weeks gestation to assess feelings of self-efficacy. Dietary compliance was assessed at each visit.

RESULTS

Both groups of women achieved excellent glucose control; only 1 woman in each group required insulin therapy. There were no significant differences with regard to feelings of self-efficacy, dietary compliance, birth weight, gestational age at delivery, Apgar scores, and neonatal complications. Rates of macrosomia, delivery by cesarean section, and occurrence of birth trauma were similar.

CONCLUSIONS

SMBG appears to have little effect on maternal feelings of self-efficacy, dietary compliance, or pregnancy outcomes in women with diet-controlled GDM.

A randomised controlled trial of dietary energy restriction in the management of obese women with gestational diabetes

A randomised controlled trial was designed to determine the effect of moderate 30% maternal dietary energy restriction on the requirement for maternal insulin therapy and the incidence of macrosomia in gestational diabetes. Although the control group restricted their intake to a level similar to that of the intervention group (6,845 kiloJoules (kJ) versus 6,579 kJ), the resulting cohort could not identify any adverse effect of energy restriction in pregnancy. Energy restriction did not alter the frequency of insulin therapy (17.5% in the intervention group and 16.9% in the control group). Mean birthweight (3,461 g in the intervention group and 3,267 g in the control group) was not affected. There was a trend in the intervention group towards later gestational age at commencement of insulin therapy (33 weeks versus 31 weeks) and lower maximum daily insulin dose (23 units versus 60 units) which did not reach statistical significance. Energy restriction did not cause an increase in ketonemia.

A comparison of glyburide and insulin in women with gestational diabetes mellitus

BACKGROUND

Women with gestational diabetes mellitus are rarely treated with a sulfonylurea drug, because of concern about teratogenicity and neonatal hypoglycemia. There is little information about the efficacy of these drugs in this group of women.

METHODS

We studied 404 women with singleton pregnancies and gestational diabetes that required treatment. The women were randomly assigned between 11 and 33 weeks of gestation to receive glyburide or insulin according to an intensified treatment protocol. The primary end point was achievement of the desired level of glycemic control. Secondary end points included maternal and neonatal complications.

RESULTS

The mean (+/-SD) pretreatment blood glucose concentration as measured at home for one week was 114+/-19 mg per deciliter (6.4+/-1.1 mmol per liter) in the glyburide group and 116+/-22 mg per deciliter (6.5+/-1.2 mmol per liter) in the insulin group (P=0.33). The mean concentrations during treatment were 105+/-16 mg per deciliter (5.9+/-0.9 mmol per liter) in the glyburide group and 105+/-18 mg per deciliter (5.9+/-1.0 mmol per liter) in the insulin group (P=0.99). Eight women in the glyburide group (4 percent) required insulin therapy. There were no significant differences between the glyburide and insulin groups in the percentage of infants who were large for gestational age (12 percent and 13 percent, respectively); who had macrosomia, defined as a birth weight of 4000 g or more (7 percent and 4 percent); who had lung complications (8 percent and 6 percent); who had hypoglycemia (9 percent and 6 percent); who were admitted to a neonatal intensive care unit (6 percent and 7 percent); or who had fetal anomalies (2 percent and 2 percent). The cord-serum insulin concentrations were similar in the two groups, and glyburide was not detected in the cord serum of any infant in the glyburide group.

CONCLUSIONS

In women with gestational diabetes, glyburide is a clinically effective alternative to insulin therapy.

Management of gestational diabetes with a conservative insulin protocol

OBJECTIVE

To investigate whether 2-hour postprandial blood glucose levels up to 8.0 mmol/L affect maternal or neonatal outcomes in pregnancies complicated by gestational diabetes mellitus (GDM).

DESIGN

Retrospective analysis of data collated by the Victorian Perinatal Data Collection Unit.

PATIENTS

394 GDM women and 394 control women matched for age and country of birth who gave birth at a university teaching hospital, 1991-1997.

MAIN OUTCOME MEASURES

Maternal--hypertension/pre-eclampsia, obstetric intervention, gestation at delivery, length of hospital stay; neonatal--Apgar scores, time to establish respiration, birthweight, macrosomia, large or small for gestational age (LGA or SGA), fetopelvic disproportion, jaundice, hypoglycaemia.

RESULTS

For most outcome measures there were no statistically significant differences between the GDM and control groups. However, in the GDM group, gestation was shorter, hospital stays longer and delivery interventions more common.

CONCLUSION

Our study suggests that maternal and neonatal outcomes in GDM women are comparable with those of women without GDM when 2-hour postprandial glucose levels of up to 8mmol/L are maintained. This is 1.0 mmol/L higher than the current Australian Diabetes in Pregnancy Society recommendation.

Pregnancy in diabetes

For patients with preconception diabetes, the most important aspect is the need for good glycemic control pre conception to lessen the risk of congenital malformations. Careful assessment of diabetes complications is essential prepregnancy. In the absence of major complications, good glycemic control gives the pregnant diabetic patient the same chance for a healthy baby as the rest of the population. Pregnancy alters carbohydrate tolerance, and thus gestational diabetes should be screened for and, when found, treated aggressively with dietary intervention, glucose monitoring, and insulin if good glycemic control has not been attained. These patients are at greatly increased risk for diabetes in the long term.

Anthropometric characteristics of full-term infants: effects of varying degrees of "normal" glucose metabolism

Aim of this study was to examine the maternal-neonatal outcome and the neonatal anthropometric characteristics of a full-term mother-infant pairs group with a positive oral glucose challenge test (GCT) without gestational diabetes mellitus (GDM). Our study involved 1615 white women with singleton pregnancies who underwent universal screening for GDM in two periods of pregnancy. This population was divided into three groups according to GCT results: 1) 172 patients with abnormal GCT in both periods; 2) 391 patient with normal GCT in the early period and abnormal GCT in the late period; 3) 1052 patients with normal GCT in both periods (control group). The incidence of LGA (large for gestational age) infants was higher in Group (40.7%) and Group 2 (22.0%) respect to control group (8.3%) (p < 0.00001 and p < 0.0001 respectively) and was significantly different in the two groups (p < 0.0008). Comparison among the three groups of LGA infants showed the following results: male and female newborns of Group I were heavier than those of Group 2 and of the control group, while males and females of the control group had significantly greater length and cranial circumference means. A significant decrease in ponderal index, choracic circumference, weight/length ratio means could be seen as well as a significative increase in cranial/thoracic circumference ratio means from Group I to the control group. These data confirm the involvement of fetal development in terms of weight and anthropometric characteristics in the presence of alterations in maternal glucose metabolism which are not currently classified as gestational diabetes.

Management of gestational diabetes mellitus

This article addresses management of gestational diabetes in a two part fashion. It discusses the pathophysiology and pathogenesis of diabetes and outlines the contemporary management approach for gestational diabetes in the 1990s.

Intensified versus conventional management of gestational diabetes

OBJECTIVE

We tested the hypothesis that intensified management of gestational diabetes mellitus on the basis of stringent glycemic control, verified glucose data, and adherence to an established criterion for insulin initiation results in near normoglycemia control and reduction of adverse outcomes.

STUDY DESIGN

A prospective, population-based study compared the effect on perinatal outcome of conventional (n = 1316) and intensified (n = 1145) management. Group assignment was based on availability of memory-based reflectance meters at entry to the program. A contemporaneous randomized control group (nondiabetic, n = 4922) was selected.

RESULTS

The diabetic groups were comparable in demographic characteristics and in factors associated with higher risk for adverse pregnancy outcome, such as previous macrosomia, previous gestational diabetes mellitus, and family history of diabetes. The control group was younger, less obese, and had a lower rate of previous macrosomia. The intensified management group had rates of macrosomia, cesarean section, metabolic complications, shoulder dystocia, stillbirth, neonatal intensive care unit days, and respiratory complications lower than those in the conventional management group and comparable to those of the nondiabetic controls. Other maternal complication rates, such as for preeclampsia, chronic hypertension, and infection, were similar for the three groups. Mean blood glucose levels were a good predictor of perinatal outcome. Gestational age at delivery, previous history of macrosomia, and overall mean blood glucose levels were the only significant predictors of birth weight percentile in both diabetic groups (logistic regression).

CONCLUSION

The intensified management approach is significantly associated with enhanced perinatal outcome. This management strategy clarifies the relationship between glycemic control and neonatal outcome.

A rationale for omitting two-hour postprandial glucose determinations in gestational diabetes

OBJECTIVE

In making decisions regarding initiation of insulin therapy in gestational diabetes, most maternal-fetal obstetricians rely more on elevated fasting glucose values than on elevated 2-hour postprandial levels. We sought to determine whether the latter test is necessary.

STUDY DESIGN

From the patients with gestational diabetes mellitus managed over a 17-month period at Grady Memorial Hospital, we retrospectively analyzed data to determine whether normal (< 105 mg/dl) fasting plasma glucose values predict elevated 2-hour postprandial values and whether the latter predict adverse outcome.

RESULTS

From 194 patients with gestational diabetes mellitus, 546 paired fasting and 2-hour postprandial glucose values were recorded. Fasting levels were normal in 467 (85%); in those, 2-hour levels were < 120 mg/dl in 83% and < 140 in fully 96%. In 131 women with all fasting plasma glucose values normal, the birth weights and the rates of cesarean delivery, shoulder dystocia, and macrosomia were similar, regardless of whether 2-hour postprandial glucose values were > or = 120. The actual cost of the 546 2-hour postprandial glucose tests was nearly $10,000.

CONCLUSION

For metabolic surveillance in gestational diabetes mellitus, the 2-hour postprandial glucose test seems unnecessary, provided fasting plasma glucose values remain normal.

Changes in the insulin-sensitive glycosyl-phosphatidyl-inositol signalling system with aging in rat hepatocytes

An inositol-phosphate glycan (InsP glycan), which is the polar head group of an insulin-sensitive glycosyl-phosphatidylinositol (glycosyl-PtdIns), has been reported to mimic some insulin actions when added to different types of cells. In connection with this, a specific, time-dependent and energy-dependent transport system for this InsP glycan has been identified in isolated rat hepatocytes [Alvarez, J. F., Sánchez-Arias, J. A., Guadaño, A., Estevez, F., Varela, I., Felíu, J. E. & Mato, J.M. (1991) Biochem. J. 274, 369-374]. Here we have investigated the glycosyl-PtdIns-dependent insulin-signalling system in hepatocytes isolated from either 3-month-old or 24-month-old rats. Aging reduced the stimulatory effect of insulin on [U-14C]glucose incorporation into glycogen, caused a significant decrease in basal glycosyl-PtdIns levels and blocked the insulin-mediated hydrolysis of this lipid. In 24-month-old rats, we also observed a diminution in the rate of hepatocyte InsP-glycan uptake and a marked reduction of the stimulatory effect of this compound on glycogen synthesis. These results support the hypothesis that insulin resistance associated with aging is accompanied by an impairment of the glycosyl-PtdIns-dependent cellular signalling system.