Lactation after normal pregnancy is not associated with blood glucose fluctuations

Breastfeeding is associated with a delayed decrease in postprandial maternal glucose concentration

BACKGROUND

Breastfeeding has long-term benefits in reducing the risk of diabetes; however, information about the acute influence on maternal glucose profile is scarce. Thus, the aim of the study was to assess maternal glucose fluctuations associated with breastfeeding episodes in women with normal glucose status.

METHODS

We performed an observational study of glucose fluctuations with breastfeeding episodes in 26 women with normal glucose status in fasting and postprandial state. Continuous glucose monitoring was performed using CGMS MiniMed Gold®/iPro2® (Medtronic, Dublin, Ireland) three months after delivery under real-life conditions. We compared fasting and postprandial periods of 150 minutes affected or not by a breastfeeding episode.

RESULTS

Mean glucose concentration of postprandial periods affected by breastfeeding was lower than not affected (-6.31 mg/dL [95% CI: -11.17, -1.62] P<0.01). Glucose concentration was significantly lower between 50 and 105 minutes after meal initiation (maximum difference -9.19 mg/dL [95% CI: -16.03, -2.16] at 91-95 min). Mean glucose concentrations of fasting periods affected by breastfeeding were similar to those not affected (-0.18 mg/dL [95% CI: -2.7, 0] P=0.831).

CONCLUSIONS

In women with normal glucose status, breastfeeding episodes are associated with a lower glucose concentration in the postprandial but not in the fasting state.

Dietary Advice to Support Glycaemic Control and Weight Management in Women with Type 1 Diabetes during Pregnancy and Breastfeeding

In women with type 1 diabetes, the risk of adverse pregnancy outcomes, including congenital anomalies, preeclampsia, preterm delivery, foetal overgrowth and perinatal death is 2-4-fold increased compared to the background population. This review provides the present evidence supporting recommendations for the diet during pregnancy and breastfeeding in women with type 1 diabetes. The amount of carbohydrate consumed in a meal is the main dietary factor affecting the postprandial glucose response. Excessive gestational weight gain is emerging as another important risk factor for foetal overgrowth. Dietary advice to promote optimized glycaemic control and appropriate gestational weight gain is therefore important for normal foetal growth and pregnancy outcome. Dietary management should include advice to secure sufficient intake of micro- and macronutrients with a focus on limiting postprandial glucose excursions, preventing hypoglycaemia and promoting appropriate gestational weight gain and weight loss after delivery. Irrespective of pre-pregnancy BMI, a total daily intake of a minimum of 175 g of carbohydrate, mainly from low-glycaemic-index sources such as bread, whole grain, fruits, rice, potatoes, dairy products and pasta, is recommended during pregnancy. These food items are often available at a lower cost than ultra-processed foods, so this dietary advice is likely to be feasible also in women with low socioeconomic status. Individual counselling aiming at consistent timing of three main meals and 2-4 snacks daily, with focus on carbohydrate amount with pragmatic carbohydrate counting, is probably of value to prevent both hypoglycaemia and hyperglycaemia. The recommended gestational weight gain is dependent on maternal pre-pregnancy BMI and is lower when BMI is above 25 kg/m². Daily folic acid supplementation should be initiated before conception and taken during the first 12 gestational weeks to minimize the risk of foetal malformations. Women with type 1 diabetes are encouraged to breastfeed. A total daily intake of a minimum of 210 g of carbohydrate is recommended in the breastfeeding period for all women irrespective of pre-pregnancy BMI to maintain acceptable glycaemic control while avoiding ketoacidosis and hypoglycaemia. During breastfeeding insulin requirements are reported approximately 20% lower than before pregnancy. Women should be encouraged to avoid weight retention after pregnancy in order to reduce the risk of overweight and obesity later in life. In conclusion, pregnant women with type 1 diabetes are recommended to follow the general dietary recommendations for pregnant and breastfeeding women with special emphasis on using carbohydrate counting to secure sufficient intake of carbohydrates and to avoid excessive gestational weight gain and weight retention after pregnancy.

Breastfeeding effect on glucose tolerance assessment in women with previous gestational diabetes mellitus: A randomized controlled trial

AIMS

To test whether breastfeeding during the oral glucose tolerance test (OGTT) affects glucose and insulin outcomes (main outcome: 120 min plasma glucose).

METHODS

A randomized crossover trial was conducted in 20 women with prior gestational diabetes mellitus. Each woman undertook two OGTTs in the first 3 months after delivery, breastfeeding the infant in one and avoiding breastfeeding in the other. Glucose and insulin were measured at 0, 30, 60 and 120 min. Statistics included: T-test for paired data, general linear model (GLM) for repeated measures. Analysis of covariance (ANCOVA) was used to adjust for glucose and insulin values at 0 min. Statistical dispersion for GLM and ANCOVA outcomes is expressed as standard error.

RESULTS

In the OGTTs with breastfeeding, higher values were observed for overall glucose and insulin concentrations, glucose and insulin peaks and individual time points of glucose (at 0, 30 and 60 min) and insulin (at 0 and 60 min) but without differences at 120 min (glucose 6.7 ± 0.3 vs. 6.9 ± 0.3 mmol/L, p = 0.506). The rate of abnormal tests was not different. ANCOVA confirmed higher postchallenge glucose values in the OGTT with breastfeeding and similar glucose values at 120 min.

CONCLUSIONS

According to the results of this randomized trial, we conclude that breastfeeding during the OGTT resulted in similar 120 min glucose concentration and glycaemic status categorization. However, breastfeeding during the OGTT led to clear differences in glucose and insulin values in the first hour, that warrant further studies.

Artificial Sweeteners in Breast Milk: A Clinical Investigation with a Kinetic Perspective

Artificial sweeteners (ASs) are calorie-free chemical substances used instead of sugar to sweeten foods and drinks. Pregnant women with obesity or diabetes are often recommended to substitute sugary products with ASs to prevent an increase in body weight. However, some recent controversy surrounding ASs relates to concerns about the risk of obesity caused by a variety of metabolic changes, both in the mother and the offspring. This study addressed these concerns and investigated the biodistribution of ASs in plasma and breast milk of lactating women to clarify whether ASs can transfer from mother to offspring through breast milk. We recruited 49 lactating women who were provided with a beverage containing four different ASs (acesulfame-potassium, saccharin, cyclamate, and sucralose). Blood and breast milk samples were collected before and up to six hours after consumption. The women were categorized: BMI < 25 (n = 20), BMI > 27 (n = 21) and type 1 diabetes (n = 8). We found that all four ASs were present in maternal plasma and breast milk. The time-to-peak was 30−120 min in plasma and 240−300 min in breast milk. Area under the curve (AUC) ratios in breast milk were 88.9% for acesulfame-potassium, 38.9% for saccharin, and 1.9% for cyclamate. We observed no differences in ASs distributions between the groups.

Cytosolic phosphoenolpyruvate carboxykinase deficiency: Expanding the clinical phenotype and novel laboratory findings

Cytosolic phosphoenolpyruvate carboxykinase (PEPCK-C) deficiency due to the homozygous PCK1 variant has recently been associated with childhood-onset hypoglycemia with a recognizable pattern of abnormal urine organic acids. In this study, 21 children and 3 adult patients with genetically confirmed PEPCK-C deficiency were diagnosed during the years 2016 to 2019 and the available biochemical and clinical data were collected. All patients were ethnic Finns. Most patients (22 out of 24) had a previously published homozygous PCK1 variant c.925G>A. Two patients had a novel compound heterozygous PCK1 variant c.925G>A and c.716C>T. The laboratory results showed abnormal urine organic acid profile with increased tricarboxylic acid cycle intermediates and inadequate ketone body production during hypoglycemia. The hypoglycemic episodes manifested predominantly in the morning. Infections, fasting or poor food intake, heavy exercise, alcohol consumption, and breastfeeding were identified as triggering factors. Five patients presented with neonatal hypoglycemia. Hypoglycemic seizures occurred in half of the patients (12 out of 24). The first hypoglycemic episode often occurred at the age of 1-2 years, but it sometimes presented at a later age, and could re-occur during school age or adulthood. This study adds to the laboratory data on PEPCK-C deficiency, confirming the recognizable urine organic acid pattern and identifying deficient ketogenesis as a novel laboratory finding. The phenotype is expanded suggesting that the risk of hypoglycemia may continue into adulthood if predisposing factors are present.

CopenFast trial: Faster-acting insulin Fiasp versus insulin NovoRapid in the treatment of women with type 1 or type 2 diabetes during pregnancy and lactation - a randomised controlled trial

INTRODUCTION

Faster-acting insulin aspart (Fiasp) is approved for use in pregnancy and lactation, but no clinical study has evaluated its effects during this life stage in women with pre-existing diabetes. The aim of the CopenFast trial is to evaluate the effect of Fiasp compared with insulin aspart (NovoRapid) on maternal glycaemic control during pregnancy, delivery and lactation and on fetal growth and infant health.

METHODS AND ANALYSIS

An open-label randomised controlled trial of pregnant women with type 1 or type 2 diabetes including women on multiple daily injection (MDI) therapy or insulin pump therapy. During a 2-year inclusion period, approximately 220 women will be randomised 1:1 to Fiasp or NovoRapid in early pregnancy and followed until 3 months after delivery. At 9, 21 and 33 gestational weeks and during planned induction of labour or caesarean section, women are offered blinded continuous glucose monitoring (CGM) for 7 days. Randomisation will stratify for type of diabetes and insulin treatment modality (MDI or insulin pump therapy, respectively). Health status of the infants will be followed until 3 months of age. The primary outcome is birth weight SD score adjusted for gestational age and gender. Secondary outcomes include maternal glycaemic control including glycated haemoglobin, preprandial and postprandial self-monitored plasma glucose levels, episodes of mild and severe hypoglycaemia, maternal gestational weight gain and weight retention, CGM time spent in, above and below target ranges as well as pregnancy outcomes including pre-eclampsia, preterm delivery, perinatal mortality and neonatal morbidity. Data analysis will be performed according to the intention-to-treat principle.

ETHICS AND DISSEMINATION

The trial has been approved by the Regional Ethics Committee (H-19029966) on 7 August 2019. Results will be sought disseminated in peer-reviewed journals and at scientific meetings.

TRIAL REGISTRATION NUMBER

NCT03770767.

Mucosal Immunity and Liver Metabolism in the Complex Condition of Lactation Insufficiency

Lactation insufficiency is variously defined and includes the inability to produce milk, not producing enough milk to exclusively meet infant growth requirements, and pathological interruption of lactation (e.g., mastitis). Of women with intent-to-breastfeed, lactation insufficiency has been estimated to affect 38%-44% of newly postpartum women, likely contributing to the nearly 60% of infants that are not breastfed according to the World Health Organization's guidelines. To date, research and clinical practice aimed at improving feeding outcomes have focused on hospital lactation support and education, with laudable results. However, researchers' reports of recent rodent studies concerning fundamental lactation biology have suggested that the underlying pathologies of lactation insufficiency may be more nuanced than is currently appreciated. In this article, we identify mucosal biology of the breast and lactation-specific liver biology as two under-researched aspects of lactation physiology. Specifically, we argue that further scientific inquiry into reproductive state-dependent regulation of immunity in the human breast will reveal insights into novel immune based requirements for healthy lactation. Additionally, our synthesis of the literature supports the hypothesis that the liver is an essential player in lactation-highlighting the potential that pathologies of the liver may also be associated with lactation insufficiency. More research into these biologic underpinnings of lactation is anticipated to provide new avenues to understand and treat lactation insufficiency.

Diabetes Management During Breastfeeding in Women with Type 1 Diabetes

PURPOSE OF REVIEW

To provide an update on glycemic management of type 1 diabetes during breastfeeding with focus on diet and insulin treatment to prevent hypoglycemia, ketoacidosis, and weight retention. Recommendations for insulin pump settings are given.

RECENT FINDINGS

Women with type 1 diabetes are encouraged to breastfeed. Hypoglycemia is a concern in the breastfeeding period among women with type 1 diabetes, and ketoacidosis may also occur. The usual goals for glucose values for persons with diabetes also apply during breastfeeding. The recommended minimum daily carbohydrate intake is 210 g during breastfeeding, and this may contribute to prevention of hypoglycemia and ketoacidosis while aiming for gradual weight loss. Insulin requirements are 21% lower during breastfeeding than before pregnancy. Diabetes management in breastfeeding women with type 1 diabetes includes the same goals for glucose values as in other persons with diabetes, sufficient carbohydrate intake, and adequate reduction in insulin dose.

Breastfeeding at night is rarely followed by hypoglycaemia in women with type 1 diabetes using carbohydrate counting and flexible insulin therapy

AIMS/HYPOTHESIS

Hypoglycaemia in association with breastfeeding is a feared condition in mothers with type 1 diabetes. Thus, routine carbohydrate intake at each breastfeed, particularly at night, is often recommended despite lack of evidence. We aimed to evaluate glucose levels during breastfeeding, focusing on whether night-time breastfeeding induced hypoglycaemia in mothers with type 1 diabetes.

METHODS

Of 43 consecutive mothers with type 1 diabetes, 33 (77%) were included prospectively 1 month after a singleton delivery. Twenty-six mothers (mean [SD] age 30.7 [5.8] years, mean [SD] duration of diabetes 18.6 [10.3] years) were breastfeeding and seven mothers (mean [SD] age 31.7 [5.6] years, mean [SD] duration of diabetes 20.4 [6.2] years) were bottle-feeding their infants with formula. All were experienced in carbohydrate counting using individually tailored insulin therapy with insulin analogues (45% on insulin pump, 55% on multiple daily injections). Thirty-two women with type 1 diabetes, matched for age ±1 year and BMI ±1 kg/m², who had not given birth or breastfed in the previous year, served as a control group. Blinded continuous glucose monitoring (CGM) for 6 days was applied at 1, 2 and 6 months postpartum in the breastfeeding mothers who recorded breastfeeds and carbohydrate intake at each CGM period. CGM was applied at 1 month postpartum in the formula-feeding mothers and once in the control women. The insulin dose was individually tailored after each CGM period.

RESULTS

The percentage of night-time spent with CGM <4.0 mmol/l was low (4.6%, 3.1% and 2.7% at each CGM period in the breastfeeding mothers vs 1.6% in the control women, p = 0.77), and the breastfeeding mothers spent a greater proportion of the night-time in the target range of 4.0-10.0 mmol/l (p = 0.01). Symptomatic hypoglycaemia occurred two or three times per week at 1, 2 and 6 months postpartum in both breastfeeding mothers and the control women. Severe hypoglycaemia was reported by one mother (3%) during the 6 month postpartum period and by one control woman (3%) in the previous year (p = 0.74). In breastfeeding mothers at 1 month, the insulin dose was 18% (-67% to +48%) lower than before pregnancy (p = 0.04). In total, carbohydrate was not consumed in relation to 438 recorded night-time breastfeeds, and CGM <4.0 mmol/l within 3 h occurred after 20 (4.6%) of these breastfeeds.

CONCLUSIONS/INTERPRETATION

The percentage of night-time spent in hypoglycaemia was low in the breastfeeding mothers with type 1 diabetes and was similar in the control women. Breastfeeding at night-time rarely induced hypoglycaemia. The historical recommendation of routine carbohydrate intake at night-time breastfeeding may be obsolete in mothers with type 1 diabetes who have properly reduced insulin dose with sufficient carbohydrate intake.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02898428.

The physiological and glycaemic changes in breastfeeding women with type 1 diabetes mellitus

The World Health Organisation recommends exclusive breastfeeding for the first six months of life (Australian institute of health and welfare, 2011). Breastfeeding confers many short- and long-term benefits for infants and mothers, including reduced childhood obesity and lower maternal body weight (Infant feeding survey, 2010; CDC National immunization surveys, 2012 and 2013; Sorkio et al., 2010; Hummel et al., 2014; Finkelstein et al., 2013). Exclusive breastfeeding is also recommended in women with type 1 diabetes mellitus (T1DM), for at least four months (Nucci et al., 2017). However, the impact of breastfeeding on mothers with T1DM, and, conversely, the impact of maternal T1DM on breastfeeding, is not clear. This review summarizes current knowledge regarding the epidemiology and physiology of breastfeeding in women with T1DM. In particular, it highlights the relationship between breastfeeding and glycaemia. Potential areas for future research are also identified.

Glycaemic behaviour during breastfeeding in women with Type 1 diabetes

AIM

To describe glycaemia in both breastfeeding women and artificially feeding women with Type 1 diabetes, and the changes in glycaemia induced by suckling.

METHODS

A blinded continuous glucose monitor was applied for up to 6 days in eight breastfeeding and eight artificially feeding women with Type 1 diabetes 2-4 months postpartum. Women recorded glucose levels, insulin dosages, oral intake and breastfeeding episodes. A standardized breakfast was consumed on 2 days. A third group (clinic controls) were identified from a historical database.

RESULTS

Carbohydrate intake tended to be higher in breastfeeding than artificially feeding women (P = 0.09) despite similar insulin requirements. Compared with breastfeeding women, the high blood glucose index and standard deviation of glucose were higher in artificially feeding women (P = 0.02 and 0.06, respectively) and in the clinical control group (P = 0.02 and 0.05, respectively). The low blood glucose index and hypoglycaemia were similar. After suckling, the low blood glucose index increased compared with before (P < 0.01) and during (P < 0.01) suckling. Hypoglycaemia (blood glucose < 4.0 mmol/l) occurred within 3 h of suckling in 14% of suckling episodes, and was associated with time from last oral intake (P = 0.04) and last rapid-acting insulin (P = 0.03). After a standardized breakfast, the area under the glucose curve was positive. In breastfeeding women the area under the glucose curve was positive if suckling was avoided for 1 h after eating and negative if suckling occurred within 30 min of eating.

CONCLUSIONS

Breastfeeding women with Type 1 diabetes had similar hypoglycaemia but lower glucose variability than artificially feeding women. Suckling reduced maternal glucose levels but did not cause hypoglycaemia in most episodes.

Continuous glucose monitoring during breastfeeding in women with recent gestational diabetes mellitus

AIMS

This study monitored blood glucose profiles in normotolerant breastfeeding women, with and without previous gestational diabetes, in real life in order to identify normal blood glucose fluctuations during breastfeeding.

SUBJECTS AND METHODS

Two groups were studied: (1) 18 women with recent gestational diabetes mellitus but normotolerant postpartum (pGDM-N group) and (2) 15 women normotolerant both during pregnancy and postpartum (pN-N group). All participants underwent continuous glucose monitoring during which they recorded their main daily activities and three standardized events: "suckling," "meal," and "meal and suckling." Other than these three events, these women were essentially on an "ad lib" diet. Data were expressed as median and SD values. Student's t test and Fisher's test were used to compare mean, variances, and percentages. Differences were significant with P<0.05. Clustering analysis was used to determine the normal range of glucose values.

RESULTS

The two groups were matched for age, follow-up duration, and monitoring measurements but not for body mass index. Blood glucose levels and variances were higher in the pGDM-N group, particularly during daytime and the three standardized events, and were not related to body mass index. Suckling had no direct effect on glucose profile during both the non-fed and the fed state. Blood glucose levels that best represent the normal breastfeeding population were between 50 and 126 mg/dL (from 2.8 to 7.0 mmol/L).

CONCLUSIONS

Three months after delivery, normotolerant women with recent gestational diabetes had higher daily blood glucose levels than women who were always normotolerant, with no direct effect of suckling. The blood glucose profiles of healthy subjects could be representative of the normal range of the population during breastfeeding.