Continuous glucose monitoring during pregnancy complicated by gestational diabetes mellitus

Glycemic variability in diagnosis of gestational diabetes as predictor of pharmacological treatment

INTRODUCTION

To establish whether glycemic variability (GV) parameters used when gestational diabetes mellitus (GDM) has been diagnosed could help predict the probability that a patient will need pharmacological treatment, and to analyze the link of these parameters to the development of maternal-fetal complications.

MATERIALS AND METHODS

A prospective study of 87 women with GDM who underwent retrospective continuous glucose monitoring (CGM) for six days between weeks 26 and 32 of gestation, following diagnosis. The mean glycemia levels and GV variables were analyzed together with their link to maternal-fetal complications, and the need for pharmacological treatment. ROC (receiver operating characteristic) curves were developed to determine validity to detect the need for pharmacological treatment.

RESULTS

Patients with higher mean glycemia (p < 0.001) and continuous overlapping of net glycemic action in a period of n-hours (CONGAn) (p = 0.001) required pharmacological treatment. The ROC curves showed cut-off points of 98.81 mg/dL for mean glycemia, and 86.70 mg/dL for CONGAn, with 83.3% sensitivity and 67.8% specificity for both parameters. No relation between the GV parameters and development of maternal-fetal complications was observed.

CONCLUSIONS

The use of CGM, once GDM is diagnosed, enables us to identify those patients who would benefit from closer monitoring during gestation, and facilitate a speedier take-up of pharmacological treatment. However, prospective studies involving a higher number of patients are needed, as well as a cost assessment for recommending the use of CGM following GDM diagnosis.

Assessing Glycemic Control Using CGM for Women with Diabetes in Pregnancy

PURPOSE OF REVIEW

Diabetes during pregnancy increases the risk of maternal and fetal complications. This article reviews the types of CGM currently available, the glucose metrics which correlate with pregnancy outcomes, endocrine organization recommendations, clinical considerations for CGM implementation, and anticipated directions for future research.

RECENT FINDINGS

CGM use during pregnancy is increasing, and recommendations for use have been incorporated into many organizations' consensus guidelines. Increased time spent within a target range of 63-140 mg/dL and lower mean glucose are associated with lower risk of neonatal complications including large for gestational age infants. Use of CGM during pregnancy can detect postprandial and nocturnal hyperglycemia missed by self-monitoring of blood glucose (SMBG) which can be used for prognosis and to guide pharmacologic interventions. The use of continuous glucose monitoring (CGM) during pregnancies complicated by type 1, type 2, and gestational diabetes has been shown to improve outcomes.

Cycling reduces blood glucose excursions after an oral glucose tolerance test in pregnant women: a randomized crossover trial

The aim of this study was to evaluate the effect of an acute bout of cycling immediately after oral glucose intake on glucose metabolism in pregnant women at risk for gestational diabetes mellitus (GDM). Fifteen pregnant women with BMI ≥ 27 kg/m² were enrolled in a randomized crossover controlled study and underwent two oral glucose tolerance tests (OGTTs) ingesting 75 g of glucose followed by either 20 min of stationary cycling at moderate intensity (65%-75% maximal heart rate) or rest. Using continuous glucose monitors, glucose was measured up to 48 h after the OGTT. Glucose, insulin, and C-peptide were determined at baseline and after 1 and 2 h. One hour after glucose intake, mean blood glucose was significantly lower after cycling compared with rest (p = 0.002). Similarly, mean glucose peak level was significantly lower after cycling compared with after rest (p = 0.039). Lower levels of insulin and C-peptide were observed after 1 h (p < 0.01). Differences in glucose measurements after 2 h and up to 48 h were not statistically different. We found that 20 min of cycling at moderate intensity after glucose intake reduced blood glucose excursions in pregnant women at risk for GDM. ClinicalTrials.gov Identifier: NCT03644238. Novelty Bullets In pregnant women, we found that cycling after glucose intake resulted in significantly lower glucose levels compared with rest. The exercise intervention studied is feasible for pregnant women and could be readily used to reduce glucose excursions.

Continuous Glucose Monitoring and Glycemic Patterns in Pregnant Women with Gestational Diabetes Mellitus

Background: Continuous glucose monitoring (CGM) could detect certain patterns of hyperglycemia at different times of the day that may help predict the development of maternal-fetal complications and the probability of needing pharmacological treatment. Methods: This study prospectively examined 77 women with gestational diabetes mellitus (GDM) who were placed on a CGM system for 6 days after diagnosis between 26 and 32 weeks of gestation. Patterns of hyperglycemia before meals (period of time of an hour just before meal) (>95 mg/dL), after meals (time interval of 2 h and half just after meal) (>140 mg/dL), and overnight (0-7 am) (>120 mg/dL) and their association with maternal-fetal complications and pharmacological treatment were analyzed. Receiver operating characteristic curves were developed to estimate the validity of the various patterns in detecting the need for pharmacological treatment. Results: A statistically significant relationship was observed between time in hyperglycemia after lunch and macrosomia (P = 0.035) and large for gestational age infants (P = 0.010). Pharmacological treatment was required for patients with time above range (TAR; P = 0.006) and those with hyperglycemia patterns before breakfast (P < 0.001), after breakfast (P = 0.006), before dinner (P = 0.012), and overnight (P = 0.001). Every additional percentage point of TAR was associated with a 24% increase in the probability of pharmacological treatment. Conclusions: The use of CGM for the diagnosis of GDM allows the identification of those patients who would benefit from closer monitoring during pregnancy, including self-monitoring of both pre- and postprandial blood glucose levels, facilitating the initiation of early pharmacological treatment.

The value of Continuous Glucose Monitoring and Self-Monitoring of Blood Glucose in patients with Gestational Diabetes Mellitus during Ramadan fasting

INTRODUCTION

In order to achieve the recommended glycemic control, women with Gestational Diabetes Mellitus (GDM) are instructed to self-monitor blood glucose (SMBG) regularly. The purpose of this study was to evaluate glucose readings provided by Continuous Glucose Monitoring (CGM) and SMBG in GDM patients during Ramadan fasting.

METHODS

This is a prospective observational study that recruited GDM patients treated with diet ± metformin were enrolled. They agreed to wear the iPro®2 ProfessionalCGM device and to do SMBG by glucose reading meters, during fasting and after meals. We evaluated the rates of hypoglycemia and hyperglycemia in each approach. The frequency and timing of SMBG was investigated.

RESULTS

Twenty-five patients were recruited. A total of 36,628 readings by CGM device and 408 readings using glucose meters and were captured. Average glucose level was 103 ± 8 mg/dl (5.7 ± 0.4 mmol/l) and 113 ± 14 mg/d (6.28 ± 0.8 mmol/L) on CGM and glucose meters respectively. The rate of hyperglycemia was 5.65% and 14.2% and hypoglycemia was 4.35% and 1.5% using CGM and glucose meters respectively. While all hypoglycemic episodes occurred between 16:00-19:00 in both approaches, only 38 readings (9%) of SMBG readings were done in that time frame.

CONCLUSION

Although the frequency of SMBG using glucose meters for women with GDM and fasting Ramadan was acceptable, the timing was not. CGM detected more hypoglycemia and less hyperglycemia than SMBG. Relying on Intermittent SMBG in the management of GDM patients during Ramadan fasting might be misleading.

Suboptimal Nocturnal Glucose Control Is Associated With Large for Gestational Age in Treated Gestational Diabetes Mellitus

OBJECTIVE

Continuous glucose monitoring (CGM) provides far greater detail about fetal exposure to maternal glucose across the 24-h day. Our aim was to examine the role of temporal glucose variation on the development of large for gestational age (LGA) infants in women with treated gestational diabetes mellitus (GDM).

RESEARCH DESIGN AND METHODS

We performed a prospective observational study of 162 pregnant women with GDM in specialist multidisciplinary antenatal diabetes clinics. Participants undertook 7-day masked CGM at 30-32 weeks' gestation. Standard summary indices and glycemic variability measures of CGM were calculated. Functional data analysis was applied to determine differences in temporal glucose profiles. LGA was defined as birth weight ≥90th percentile adjusted for infant sex, gestational age, maternal BMI, ethnicity, and parity.

RESULTS

Mean glucose was significantly higher in women who delivered an LGA infant (6.2 vs. 5.8 mmol/L, P = 0.025, or 111.6 mg/dL vs. 104.4 mg/dL). There were no significant differences in percentage time in, above, or below the target glucose range or in glucose variability measures (all P > 0.05). Functional data analysis revealed that the higher mean glucose was driven by a significantly higher glucose for 6 h overnight (0030-0630 h) in mothers of LGA infants (6.0 ± 1.0 mmol/L vs. 5.5 ± 0.8 mmol/L, P = 0.005, and 108.0 ± 18.0 mg/dL vs. 99.0 ± 14.4 mg/dL).

CONCLUSIONS

Mothers of LGA infants run significantly higher glucose overnight compared with mothers without LGA infants. Detecting and addressing nocturnal glucose control may help to further reduce rates of LGA in women with GDM.

Management of postprandial hyperglycaemia and weight gain in women with gestational diabetes mellitus using a novel telemonitoring system

OBJECTIVES

The purpose of this study was to investigate the effect of remotely delivered telemedicine dietary advice on monitoring of blood glucose levels and weight gain of women with gestational diabetes mellitus (GDM).

METHODS

Women with GDM were recruited and randomly allocated into two groups: a Tele-GDM group that received a telemonitoring device, and a control group that was followed-up traditionally. A telemonitoring service calculated the ratio of reaching or exceeding the pregnancy weight gain target (according to pre-pregnancy weight), following Institute of Medicine guidelines for healthy pregnancy weight gain.

RESULTS

The sample comprised 27 women in the Tele-GDM group and 30 in the control group. At the end of pregnancy, the Tele-GDM group showed significantly lower 2-hour postprandial glucose levels than the control group. Most women in the Tele-GDM group reached their recommended range of weight gain at the end of pregnancy. Additionally, the Tele-GDM group showed significantly lower weight gain than the control group.

CONCLUSIONS

Telemonitoring can facilitate close monitoring of women with GDM and motivate patients to adopt a healthy lifestyle.

Glucose Fluctuations during Gestation: An Additional Tool for Monitoring Pregnancy Complicated by Diabetes

Continuous glucose monitoring (CGM) gives a unique insight into magnitude and duration of daily glucose fluctuations. Limited data are available on glucose variability (GV) in pregnancy. We aimed to assess GV in healthy pregnant women and cases of type 1 diabetes mellitus or gestational diabetes (GDM) and its possible association with HbA1c. CGM was performed in 50 pregnant women (20 type 1, 20 GDM, and 10 healthy controls) in all three trimesters of pregnancy. We calculated mean amplitude of glycemic excursions (MAGE), standard deviation (SD), interquartile range (IQR), and continuous overlapping net glycemic action (CONGA), as parameters of GV. The high blood glycemic index (HBGI) and low blood glycemic index (LBGI) were also measured as indicators of hyperhypoglycemic risk. Women with type 1 diabetes showed higher GV, with a 2-fold higher risk of hyperglycemic spikes during the day, than healthy pregnant women or GDM ones. GDM women had only slightly higher GV parameters than healthy controls. HbA1c did not correlate with GV indicators in type 1 diabetes or GDM pregnancies. We provided new evidence of the importance of certain GV indicators in pregnant women with GDM or type 1 diabetes and recommended the use of CGM specifically in these populations.

Technology and pregnancy

In the USA, depending upon the diagnosis criteria used, 135,000-200,000 women annually develop gestational diabetes mellitus, adding to the number of pregnant women already suffering from either type 1 or type 2 diabetes. Maternal hyperglycaemia and the resultant fetal hyperinsulinaemia are central to the pathophysiology of diabetic complications of pregnancy. These complications include congenital malformations and an increase in neonatal intensive care unit admission and birth trauma. In addition, there is an increased rate of accelerated fetal growth, neonatal metabolic complications and risk for stillbirth. Importantly, during the last century there were two breakthroughs in diabetes management and monitoring that changed the course of treatment: the discovery of insulin and the progress in the understanding of glucose monitoring. As technology has evolved, both glucose monitoring and insulin administration can now be achieved in a continuous fashion. In this review of the literature we focus on the utility of new technologies in the management and monitoring of diabetes in pregnancy.

Pharmaceutical care of patients with gestational diabetes mellitus

RATIONALE, AIMS AND OBJECTIVE

To investigate whether the introduction of a programme of optimising drug treatment, intensive education and self-monitoring of patients diagnosed with gestational diabetes mellitus (GDM) at an early stage (<20 gestational weeks), will improve management outcomes as determined by objective measures of patient knowledge about diabetes, glycaemia control, maternal/neonatal complications, and health-related quality of life.

METHODS

The study was a randomized, controlled, longitudinal, prospective clinical trial performed at Al-Ain Hospital, Al-Ain, United Arab Emirates. Over an 18-month period, patients diagnosed with GDM were recruited and were randomly assigned to either an intervention or a control group, in a ratio of 3:2. Intervention patients received a structured pharmaceutical care service (including education and introduction of intensive self-monitoring) while control patients received traditional services. Patients were followed up from time of recruitment until 6 months postnatally at scheduled outpatient clinics. A range of clinical and humanistic outcome measures, including maternal and neonatal complications, were used to assess the impact of the intervention.

RESULTS

A total of 165 patients (99 intervention, 66 control) completed the study. The intervention patients exhibited a range of benefits from the provision of the programme when compared with control group patients. Statistically significant (P < 0.05) improvements were shown in the intervention group for knowledge of diabetes, health-related quality of life (as determined by the SF36), control of plasma glucose and HbA(1c), maternal complications [e.g. decreased incidence of pre-eclampsia (5.1% vs. 16.7%), eclampsia (1.0% vs. 7.6%), episodes of severe hyperglycaemia (3.0% vs. 19.7%) and need for Caesarean section (7.1% vs. 18.2%)], and neonatal complications [e.g. decreased incidence of neonatal hypoglycaemia (2.0% vs. 10.6%), respiratory distress at birth (4.0% vs. 15.2%), hyperbilirubinaemia (1.0% vs. 12.1%) and large for gestational age (9.0% vs. 22.7%)].

CONCLUSION

The research provides clear evidence that provision of pharmaceutical care adds value to the management of GDM as exemplified by improved maternal and neonatal outcomes.

A method for assessing quality of control from glucose profiles

AIM

As the practice of multiple assessments of glucose concentration throughout the day increases for people with diabetes, there is a need for an assessment of glycaemic control weighted for the clinical risks of both hypoglycaemia and hyperglycaemia.

METHODS

We have developed a methodology to report the degree of risk which a glycaemic profile represents. Fifty diabetes professionals assigned risk values to a range of 40 blood glucose concentrations. Their responses were summarised and a generic function of glycaemic risk was derived. This function was applied to patient glucose profiles to generate an integrated risk score termed the Glycaemic Risk Assessment Diabetes Equation (GRADE). The GRADE score was then reported by use of the mean value and the relative percent contribution to the weighted risk score from the hypoglycaemic, euglycaemic, hyperglycaemic range, respectively, e.g. GRADE (hypoglycaemia%, euglycaemia%, hyperglycaemia%).

RESULTS

The GRADE scores of indicative glucose profiles were as follows: continuous glucose monitoring profile non-diabetic subjects GRADE = 1.1, Type 1 diabetes continuous glucose monitoring GRADE = 8.09 (20%, 8%, 72%), Type 2 diabetes home blood glucose monitoring GRADE = 9.97 (2%, 7%, 91%).

CONCLUSIONS

The GRADE score of a glucose profile summarises the degree of risk associated with a glucose profile. Values < 5 correspond to euglycaemia. The GRADE score is simple to generate from any blood glucose profile and can be used as an adjunct to HbA1c to report the degree of risk associated with glycaemic variability.

Evaluation of Metabolic Control in Women with Gestational Diabetes Mellitus by the Continuous Glucose Monitoring System: A Pilot Study

OBJECTIVE

To evaluate the blood glucose concentrations in a group of women with gestational diabetes mellitus (GDM), by the use of a continuous glucose monitoring system (CGMS).

METHODS

Seven women with diet-controlled GDM (group G1), 5 with diet- and insulin-controlled GDM (group G2), and 7 healthy, pregnant women (group N) were included in the study. The treatment was adjusted on the basis of self-monitoring of blood glucose (SMBG). The self-monitoring was performed 4 times a day, with the goals of fasting blood glucose values of <90 mg/dL and postprandial (2 hours after each meal) values of <120 mg/dL. Then patients were submitted to a 72-hour period of use of the CGMS.

RESULTS

In the 3 study groups--N, G1, and G2, respectively--no significant differences were noted in individual study parameters, measured with the CGMS in regard to the following: mean 24-hour glycemia (85, 87, and 91 mg/dL), fasting blood glucose (79, 88, and 82 mg/dL), postprandial glucose (96, 97, and 105 mg/dL), mean glucose level during the night (77, 71, and 75 mg/dL), and area under the glycemia curve (281, 315, and 310). Moreover, no significant difference was found in the total duration of glycemia below 60 mg/dL (317, 300, and 370 minutes) or the duration of glycemia of more than 120 mg/dL (259, 225, and 394 minutes) in group N, G1, and G2, respectively. With use of the CGMS, however, in comparison with SMBG, a wider range of glycemic levels was observed in all 3 study groups: for the healthy, pregnant women, 41 to 194 mg/dL versus 61 to 151 mg/dL; for G1, 40 to 244 mg/dL versus 40 to 180 mg/dL; and for G2, 40 to 173 mg/dL versus 50 to 157 mg/dL.

CONCLUSION

The therapy, based on SMBG levels, when applied to the group of women with GDM, brought the glucose levels under effective control, with mean outcome values similar to those observed in the group of normal pregnant women. Nevertheless, using the CGMS, we detected long, asymptomatic periods of high and low blood glucose levels, both in the patients with GDM and in the unaffected pregnant women. The use of the CGMS for monitoring blood glucose profiles might be beneficial in this group of pregnant women.

Monitoring glycemic control: the importance of self-monitoring of blood glucose

Several methods, each with differing utility and limitations, exist for monitoring glycemic control. Hemoglobin A1c (HbA1c) is considered the standard measure of long-term glycemic control, and HbA1c levels are strongly associated with complications of diabetes. However, HbA1c does not provide "real-time" information about individual hyperglycemic or hypoglycemic excursions. Urine glucose testing is noninvasive and inexpensive, but it is dependent on the patient's individual renal threshold and can only detect glucose concentrations above this threshold. As such, urine testing cannot be recommended for diabetes management that aims for near-normoglycemia. Self-monitoring of blood glucose (SMBG) complements HbA1c by providing real-time blood glucose data. It is an educational tool for both patients and their healthcare providers to understand the effects of diet, exercise, and medications on day-to-day glycemic control. However, guidelines from various international diabetes organizations vary in their level of specificity regarding the frequency and timing of self-monitoring. SMBG should be implemented for all patients as part of an overall diabetes management plan that includes specific instruction on how, when, and why to test.

Nutrition and pregnancy: the link between dietary intake and diabetes

Pregnancy is a time when serial metabolic changes in the mother are carefully regulated to provide optimum substrate to both mother and fetus. Subtle perturbations in maternal metabolism can have implications not only for the index pregnancy, but also for future generations. The literature provides evidence that maternal nutrition plays a major role in the destiny of the offspring. Both maternal malnutrition and overnutrition are associated with subsequent diabetes in the offspring. Pregnancy represents a window of opportunity for health care providers to change dietary patterns toward habits that will be healthier for the individual now, as well as impacting on the future. The challenge for clinicians is to provide nutritional information based on scientific evidence that facilitates the normalization of fetal nutrition, and thus minimize the risk that the child will develop diabetes.