Mechanisms to conserve glucose in lactating women during a 42-h fast

Starvation Ketoacidosis on the Acute Medical Take: An Easily Missed Complication of the Keto Diet

Starvation ketoacidosis represents one of the three forms of metabolic acidosis caused by the accumulation of ketone bodies within the blood stream. It can be easily missed in patients who present acutely and are found to have an unexplained or profound metabolic acidosis. Here, we present a life-threatening case of severe ketoacidosis in a breast-feeding mother without diabetes who was on a strict ketogenic diet. Although a ketogenic diet has been previously considered to be safe in non-pregnant individuals, its safety in breast-feeding mothers in the post-partum period is less known and may be associated with greater harm. Health professionals and mothers should be aware of the potential risks associated with a strict ketogenic diet when combined with breast-feeding, especially in the earlier stages of the post-partum period. Prompt investigation, diagnosis and immediate management is vital to avoid life-threatening complications. We report a case admitted on the acute medical take with starvation ketoacidosis associated with ketogenic diet and adequate calorie consumption who was breast-feeding at the time of admission.

LEARNING POINTS

Always check ketones in patients with an unexplained metabolic acidosis; there can be overlap between starvation, alcohol-related and lactic acidosis.Management of starvation ketoacidosis is often empirical, involving close monitoring of fluid status and electrolytes.Clinicians should discuss the risk of ketoacidosis associated with the ketogenic diet in women who plan to breast-feed and lose weight following pregnancy.

Glycemia and Gluconeogenesis With Metformin and Liraglutide: A Randomized Trial in Youth-onset Type 2 Diabetes

OBJECTIVE

Elevated rates of gluconeogenesis are an early pathogenic feature of youth-onset type 2 diabetes (Y-T2D), but targeted first-line therapies are suboptimal, especially in African American (AA) youth. We evaluated glucose-lowering mechanisms of metformin and liraglutide by measuring rates of gluconeogenesis and β-cell function after therapy in AA Y-T2D.

METHODS

In this parallel randomized clinical trial, 22 youth with Y-T2D-age 15.3 ± 2.1 years (mean ± SD), 68% female, body mass index (BMI) 40.1 ± 7.9 kg/m2, duration of diagnosis 1.8 ± 1.3 years-were randomized to metformin alone (Met) or metformin + liraglutide (Lira) (Met + Lira) and evaluated before and after 12 weeks. Stable isotope tracers were used to measure gluconeogenesis [2H2O] and glucose production [6,6-2H2]glucose after an overnight fast and during a continuous meal. β-cell function (sigma) and whole-body insulin sensitivity (mSI) were assessed during a frequently sampled 2-hour oral glucose tolerance test.

RESULTS

At baseline, gluconeogenesis, glucose production, and fasting and 2-hour glucose were comparable in both groups, though Met + Lira had higher hemoglobin A1C. Met + Lira had a greater decrease from baseline in fasting glucose (-2.0 ± 1.3 vs -0.6 ± 0.9 mmol/L, P = .008) and a greater increase in sigma (0.72 ± 0.68 vs -0.05 ± 0.71, P = .03). The change in fractional gluconeogenesis was similar between groups (Met + Lira: -0.36 ± 9.4 vs Met: 0.04 ± 12.3%, P = .9), and there were no changes in prandial gluconeogenesis or mSI. Increased glucose clearance in both groups was related to sigma (r = 0.63, P = .003) but not gluconeogenesis or mSI.

CONCLUSION

Among Y-T2D, metformin with or without liraglutide improved glycemia but did not suppress high rates of gluconeogenesis. Novel therapies that will enhance β-cell function and target the elevated rates of gluconeogenesis in Y-T2D are needed.

A Case of Severe Lactation Ketoacidosis in a Nondiabetic Mother on a Ketogenic Diet

Lactation ketoacidosis is a rare yet severe metabolic emergency that has been reported in breastfeeding mothers. Reduced carbohydrate intake during breastfeeding has been reported as a common trigger for ketoacidosis. We report the case of a 31-year-old mother without diabetes who presented with life-threatening lactation ketoacidosis after following a ketogenic diet while exclusively breastfeeding her newborn baby. She was managed in the intensive care unit with dextrose and insulin infusion to reverse ketoacidosis. With prompt treatment, the patient's ketoacidosis resolved within 24 hours, and she was discharged well 3 days later. We further discuss the underlying increased metabolic demand in lactating women that puts them at risk of ketoacidosis, underlining the importance of early recognition of lactation ketoacidosis and nutritional education for lactating women.

Maternal adaptations of the pancreas and glucose homeostasis in lactation and after lactation

During lactation, the maternal physiology adapts to bear the nutritional requirements of the offspring. The exocrine and endocrine pancreas are central to nutrient handling, promoting digestion and metabolism. In concert with prolactin, insulin is a determinant factor for milk synthesis. The investigation of the pancreas during lactation has been scattered over several periods. The investigations that laid the foundation of lactating pancreatic physiology and glucose homeostasis were conducted in the decades of 1970-1980. With the development of molecular biology, newer studies have revealed the molecular mechanisms involved in the endocrine pancreas during breastfeeding. There has been a surge of information recently about unexpected changes in the pancreas at the end of the lactation period and after weaning. In this review, we aim to gather information on the changes in the pancreas and glucose homeostasis during and after lactation and discuss the outcomes derived from the current discoveries.

Metabolic acidosis in a lactating woman induced by a deliberate ketogenic diet

ABSTRACT

This article describes a rare case of lactation ketoacidosis in a patient who started a ketogenic diet while nursing an infant and toddler. The patient presented to the ED with a history of nausea, vomiting, and postural dizziness, and was found to have a significant metabolic acidosis and elevated lipase level. The metabolic changes induced in this patient could occur in anyone with high metabolic demands who also is on a strict ketogenic diet. The case highlights the importance of a dietary history in patients with unexplained metabolic derangements.

The Role of Short-Chain Fatty Acids in Mediating Very Low-Calorie Ketogenic Diet-Infant Gut Microbiota Relationships and Its Therapeutic Potential in Obesity

As the very low-calorie ketogenic diet (VLCKD) gains increased interest as a therapeutic approach for many diseases, little is known about its therapeutic use in childhood obesity. Indeed, the role of VLCKD during pregnancy and lactation in influencing short chain fatty acid (SCFA)-producing bacteria and the potential mechanisms involved in the protective effects on obesity are still unclear. Infants are characterized by a diverse gut microbiota composition with higher abundance of SCFA-producing bacteria. Maternal VLCKD during pregnancy and lactation stimulates the growth of diverse species of SCFA-producing bacteria, which may induce epigenetic changes in infant obese gene expression and modulate adipose tissue inflammation in obesity. Therefore, this review aims to determine the mechanistic role of SCFAs in mediating VLCKD-infant gut microbiota relationships and its protective effects on obesity.

Maternal Supplementation with Cow's Milk Naturally Enriched with PUFA Alters the Metabolism of Sows and the Fatty Acid Profile of the Offspring

The study aimed to evaluate the supplementation of gilts with cow's milk naturally enriched with n-3 and n-6 polyunsaturated fatty acids (PUFA) on reproductive outcomes, and the serum biochemical and FA profile of swine females and their offspring. During 316 days, 30 gilts were distributed into three groups: (1) Control, fed a basal diet + milk from cows without oil; (2) n-3, fed a basal diet + milk from cows fed a diet enriched with linseed oil; (3) n-6, fed a basal diet + milk from cows fed a diet enriched with soybean oil. The gilts receiving the diets containing PUFA had higher serum urea and very-low-density lipoprotein levels and lower serum total protein and low-density lipoprotein levels compared to the Control group. Females supplemented with n-3 presented higher serum palmitic acid and γ-linolenic acid levels than those fed n-6. Piglets from the Control group were heavier at birth than those from females supplemented with enriched milk. The piglets from females receiving enriched milk had 140 g higher body weight from 1 to 21 days old compared to the Control group, and greater average daily weight gain from 7 to 14 days old. The serum eicosapentaenoic acid level of piglets fed n-3 was 69% higher than those fed n-6, which reduced the AA/EPA ratio. Gilts supplemented with PUFA-enriched cow's milk showed changes in their serum palmitic and γ-linolenic acid levels, in addition to improved performance, EPA concentration and consequently reduced AA/EPA ratio in their piglets, demonstrating beneficial results for their progeny.

A Comparative Review of the Extrinsic and Intrinsic Factors Regulating Lactose Synthesis

Milk is critical for the survival of all mammalian offspring, where its production by a mammary gland is also positively associated with its lactose concentration. A clearer understanding of the factors that regulate lactose synthesis stands to direct strategies for improving neonatal health while also highlighting opportunities to manipulate and improve milk production and composition. In this review we draw a cross-species comparison of the extra- and intramammary factors that regulate lactose synthesis, with a special focus on humans, dairy animals, and rodents. We outline the various factors known to influence lactose synthesis including diet, hormones, and substrate supply, as well as the intracellular molecular and genetic mechanisms. We also discuss the strengths and limitations of various in vivo and in vitro systems for the study of lactose synthesis, which remains an important research gap.

Lactation Versus Formula Feeding: Insulin, Glucose, and Fatty Acid Metabolism During the Postpartum Period

Milk production may involve a transient development of insulin resistance in nonmammary tissues to support redistribution of maternal macronutrients to match the requirements of the lactating mammary gland. In the current study, adipose and liver metabolic responses were measured in the fasting state and during a two-step (10 and 20 mU/m²/min) hyperinsulinemic-euglycemic clamp with stable isotopes, in 6-week postpartum women who were lactating (n = 12) or formula-feeding (n = 6) their infants and who were closely matched for baseline characteristics (e.g., parity, body composition, and intrahepatic lipid). When controlling for the low insulin concentrations of both groups, the lactating women exhibited a fasting rate of endogenous glucose production (EGP) that was 2.6-fold greater and a lipolysis rate that was 2.3-fold greater than the formula-feeding group. During the clamp, the groups exhibited similar suppression rates of EGP and lipolysis. In the lactating women only, higher prolactin concentrations were associated with greater suppression rates of lipolysis and lower intrahepatic lipid and plasma triacylglycerol concentrations. These data suggest that whole-body alterations in glucose transport may be organ specific and facilitate nutrient partitioning during lactation. Recapitulating a shift toward noninsulin-mediated glucose uptake could be an early postpartum strategy to enhance lactation success in women at risk for delayed onset of milk production.

Lactation ketoacidosis: an easily missed diagnosis

Ketoacidosis is uncommon in non-diabetic women, but occurs in the postpartum period as a rare complication of continuing to breastfeed during periods of acute illness. We report a case of a lactating woman who presented with severe symptomatic ketoacidosis in the early postpartum period. We also review the pathophysiology and management of lactation ketoacidosis.

Ketogenic Diet-Induced Severe Ketoacidosis in a Lactating Woman: A Case Report and Review of the Literature

The ketogenic diet (KD) is a high-fat, adequate-protein, and low-carbohydrate diet that leads to nutritional ketosis and weight loss. It is known to induce ketosis but is not an established cause of clinically significant ketoacidosis. Lactation ketoacidosis is well established in bovine literature but remains a rare phenomenon in humans. Here we present a life-threatening case of severe ketoacidosis in a nondiabetic lactating mother on a strict ketogenic diet. We review the available case reports of lactation ketoacidosis in humans and the mechanisms thereof. Although ketogenic diet has been shown to be safe in nonpregnant individuals, the safety of this diet in lactating mothers is not known. Health professionals and mothers should be made aware of the potential risk associated with a strict ketogenic diet when combined with lactation. Prompt diagnosis and immediate treatment cannot be overemphasized. To our knowledge, this is the first reported case of life-threatening lactation ketoacidosis associated with ketogenic diet while consuming an adequate number of calories per day.

How do pregnant and lactating women, and young children, experience religious food restriction at the community level? A qualitative study of fasting traditions and feeding behaviors in four regions of Ethiopia

Maternal and child feeding behaviors are often rooted in family and sociocultural context, making these an important point of inquiry for improving nutrition and health over the life course. The present study explored the practice of fasting during religious periods in relation to eating patterns of pregnant and lactating women and young children in four regions of Ethiopia, a nation which has experienced rapid economic growth and marked improvement in health and nutrition outcomes over the last two decades. Qualitative data collection and analysis at community level illustrated conflicting areas of understanding and practice related to diets of children and pregnant and lactating women during fasting times, potentially leading to gaps in nutrition. Community participants described different understandings of fasting requirements for these vulnerable populations and associated social norms and doxa, not always in accordance with religious texts or published guidance. Useful behavior change strategies may be developed through these results to address the potential barriers to appropriate feeding patterns for pregnant and lactating women and young children in Ethiopia. This will include continuing to work with communities and religious leaders to clarify that religious doctrine promotes improved nutrition outcomes.

A rare cause of metabolic acidosis: ketoacidosis in a non-diabetic lactating woman

Ketoacidosis occurring during lactation has been described infrequently. The condition is incompletely understood, but it appears to be associated with a combination of increased metabolic demands during lactation, reduction in carbohydrate intake and acute illness. We present a case of a 27-year-old woman, 8 weeks post-partum, who was exclusively breastfeeding her child whilst following a low carbohydrate diet. She developed gastroenteritis and was unable to tolerate an oral diet for several days. She presented with severe metabolic acidosis on admission with a blood 3-hydroxybutyrate of 5.4 mmol/L. She was treated with intravenous dextrose and intravenous sodium bicarbonate, and given dietary advice to increase her carbohydrate intake. She made a rapid and full recovery. We provide a summary of the common causes of ketoacidosis and compare our case with other presentations of lactation ketoacidosis.

Obtaining accurate glucose measurements from wild animals under field conditions: comparing a hand held glucometer with a standard laboratory technique in grey seals

Glucose is an important metabolic fuel and circulating levels are tightly regulated in most mammals, but can drop when body fuel reserves become critically low. Glucose is mobilized rapidly from liver and muscle during stress in response to increased circulating cortisol. Blood glucose levels can thus be of value in conservation as an indicator of nutritional status and may be a useful, rapid assessment marker for acute or chronic stress. However, seals show unusual glucose regulation: circulating levels are high and insulin sensitivity is limited. Accurate blood glucose measurement is therefore vital to enable meaningful health and physiological assessments in captive, wild or rehabilitated seals and to explore its utility as a marker of conservation relevance in these animals. Point-of-care devices are simple, portable, relatively cheap and use less blood compared with traditional sampling approaches, making them useful in conservation-related monitoring. We investigated the accuracy of a hand-held glucometer for 'instant' field measurement of blood glucose, compared with blood drawing followed by laboratory testing, in wild grey seals (Halichoerus grypus), a species used as an indicator for Good Environmental Status in European waters. The glucometer showed high precision, but low accuracy, relative to laboratory measurements, and was least accurate at extreme values. It did not provide a reliable alternative to plasma analysis. Poor correlation between methods may be due to suboptimal field conditions, greater and more variable haematocrit, faster erythrocyte settling rate and/or lipaemia in seals. Glucometers must therefore be rigorously tested before use in new species and demographic groups. Sampling, processing and glucose determination methods have major implications for conclusions regarding glucose regulation, and health assessment in seals generally, which is important in species of conservation concern and in development of circulating glucose as a marker of stress or nutritional state for use in management and monitoring.

Life-Threatening Lactation or "Bovine" Ketoacidosis: A Case Report

Lactation or "bovine" ketoacidosis is a rare cause of raised anion gap metabolic acidosis whereby a perfect storm of negative calorie balance (starvation/glucose preferentially used for milk production) and insulin resistance (counter regulatory stress hormone release/infection) leads to a dysregulated ketogenic state. We present a case of life-threatening lactation-related ketoacidosis in a patient 9 weeks postpartum, who presented to the emergency department with an arterial pH of 6.88, HCO3 of 5.8 mmol/L and blood ketone level of 5.8 mmol/L. Treatment consists of aggressive glucose loading, triggering supraphysiologic endogenous insulin release, and subsequent inhibition of ketone body formation.

Measurements of Gluconeogenesis and Glycogenolysis: A Methodological Review

Gluconeogenesis is a complex metabolic process that involves multiple enzymatic steps regulated by myriad factors, including substrate concentrations, the redox state, activation and inhibition of specific enzyme steps, and hormonal modulation. At present, the most widely accepted technique to determine gluconeogenesis is by measuring the incorporation of deuterium from the body water pool into newly formed glucose. However, several techniques using radioactive and stable-labeled isotopes have been used to quantitate the contribution and regulation of gluconeogenesis in humans. Each method has its advantages, methodological assumptions, and set of propagated errors. In this review, we examine the strengths and weaknesses of the most commonly used stable isotopes methods to measure gluconeogenesis in vivo. We discuss the advantages and limitations of each method and summarize the applicability of these measurements in understanding normal and pathophysiological conditions.

Ketoacidosis in a non-diabetic woman who was fasting during lactation

Ketoacidosis is a potential complication of type 1 diabetes. Severe ketoacidosis with a blood pH below 7.0 is only rarely seen in other diseases.

Three weeks after delivery, a young woman was admitted because of tachypnoe and tachycardia. Blood gas analysis showed a severe metabolic acidosis with a high anion gap. Further workup revealed the presence of ketone bodies in the urine with normal blood glucose and no history of diabetes. The patient reported that she had not eaten for days because of abdominal pain. After initial treatment in the ICU and immediate re-feeding, the patient’s condition rapidly improved.

While under normal circumstances fasting causes at most only mild acidosis, it can be dangerous during lactation. Prolonged fasting in combination with different forms of stress puts breast feeding women at risk for starvation ketoacidosis and should therefore be avoided.

Lactation and appetite-regulating hormones: increased maternal plasma peptide YY concentrations 3-6 months postpartum

Breast-feeding is associated with maternal hormonal and metabolic changes ensuring adequate milk production. In this study, we investigate the impact of breast-feeding on the profile of changes in maternal appetite-regulating hormones 3-6 months postpartum. Study participants were age- and BMI-matched lactating mothers (n 10), non-lactating mothers (n 9) and women without any history of pregnancy or breast-feeding in the previous 12 months (control group, n 10). During study sessions, young mothers breast-fed or bottle-fed their babies, and maternal blood samples were collected at five time points during 90 min: before, during and after feeding the babies. Outcome parameters were plasma concentrations of ghrelin, peptide YY (PYY), leptin, adiponectin, prolactin, cortisol, insulin, glucose and lipid values. At baseline, circulating PYY concentrations were significantly increased in lactating mothers (100·3 (se 6·7) pg/ml) v. non-lactating mothers (73·6 (se 4·9) pg/ml, P=0·008) and v. the control group (70·2 (se 9) pg/ml, P=0·021). We found no differences in ghrelin, leptin and adiponectin values. Baseline prolactin concentrations were over 4-fold higher in lactating mothers (P<0·001). Lactating women had reduced TAG levels and LDL-cholesterol:HDL-cholesterol ratio, but increased waist circumference, when compared with non-lactating women. Breast-feeding sessions further elevated circulating prolactin (P<0·001), but induced no acute effects on appetite-regulating hormones. In summary, one single breast-feeding session did not acutely modulate circulating appetite-regulating hormones, but increased baseline PYY concentrations are associated with prolonged lactation. PYY might play a role in the coordination of energy balance during lactation, increasing fat mobilisation from maternal depots and ensuring adequate milk production for the demands of the growing infant.

[Starvation ketosis in a breastfeeding woman]

INTRODUCTION

Bovine ketosis is a rare cause of metabolic acidosis. It is a starvation ketosis that appears in lactating woman.

CASE REPORT

A 29-year-old woman had a previous gastric surgery one month ago while breastfeeding her 6-month child. She presented to emergency with dyspnea, fatigue, weight loss and anorexia. The explorations revealed a serious metabolic acidosis with a high anion gap, for which all other causes have been eliminated.

CONCLUSION

A restrictive diet in lactating patients is a major risk of ketosis or bovine ketosis. Medico-surgical treatment of obesity during lactation seems unreasonable. Breastfeeding should be systematically sought before a medical and surgical management of obesity. With the spread of bariatric surgery, starvation ketosis is a cause of metabolic acidosis not to ignore.

Precursors of hexoneogenesis within the human mammary gland

The human mammary gland is capable of de novo synthesis of glucose and galactose (hexoneogenesis); however, the carbon source is incompletely understood. In this study, we investigated the role of acetate, glutamine, lactate and glycerol as potential carbon sources for hexoneogenesis. Healthy breastfeeding women were studied following a 24-h fast on two occasions separated by 1-3 wk. Five women were infused with [U-¹³C]lactate or [1,2-¹³C₂]glutamine and five women with [U-¹³C]glycerol or [1,2-¹³C₂]acetate. Enrichments of ¹³C in plasma and milk substrates were analyzed using GC-MS. Infusion of labeled lactate, glycerol, glutamine, and acetate resulted in plasma glucose being 22.0±3.7, 11.2±1.0, 2.5±0.5, and 1.3±0.2% labeled, respectively. Lactate, glutamine, or acetate did not contribute to milk glucose or galactose (0-2%). In milk, ¹³C-free glycerol enrichment was one-fourth that in plasma but free glycerol concentration in milk was fourfold higher than in plasma. Using [U-¹³C]glycerol and by accounting for tracer dilution, glycerol alone contributed to 10±2 and 69±11% of the hexoneogenesis of milk glucose and galactose, respectively. During [U-¹³C]glycerol infusion, the ratio of M₃ enrichment on 4-6 carbons/M₃ on 1-3 carbons of galactose was higher (P<0.05, 1.22±0.05) than those of glucose in plasma (1.05±0.03) and milk (1.07±0.02). Reanalysis of samples from a previous study involving [U-¹³C]glucose infusion alone suggested labeling a portion of galactose consistent with pentose phosphate pathway (PPP) activity. We conclude that, although lactate contributed significantly to gluconeogenesis, glycerol alone provides the vast majority of substrate for hexoneogenesis. The relative contribution of the PPP vs. the reversal Embden-Meyerhof pathway to hexoneogenesis within the human mammary gland remains to be determined.

Gene regulation of UDP-galactose synthesis and transport: potential rate-limiting processes in initiation of milk production in humans

Lactose synthesis is believed to be rate limiting for milk production. However, understanding the molecular events controlling lactose synthesis in humans is still rudimentary. We have utilized our established model of the RNA isolated from breast milk fat globule from seven healthy, exclusively breastfeeding women from 6 h to 42 days following delivery to determine the temporal coordination of changes in gene expression in the carbohydrate metabolic processes emphasizing the lactose synthesis pathway in human mammary epithelial cell. We showed that milk lactose concentrations increased from 75 to 200 mM from 6 to 96 h. Milk progesterone concentrations fell by 65% at 24 h and were undetectable by day 3. Milk prolactin peaked at 36 h and then declined progressively afterward. In concordance with lactose synthesis, gene expression of galactose kinase 2, UDP-glucose pyrophosphorylase 2 (UGP2), and phosphoglucomutase 1 increased 18-, 10-, and threefold, respectively, between 6 and 72 h. Between 6 and 96 h, gene expression of UDP-galactose transporter 2 (SLC35A2) increased threefold, whereas glucose transporter 1 was unchanged. Gene expression of lactose synthase no. 3 increased 1.7-fold by 96 h, whereas α-lactalbumin did not change over the entire study duration. Gene expression of prolactin receptor (PRLR) and its downstream signal transducer and activator of transcription complex 5 (STAT5) were increased 10- and 2.5-fold, respectively, by 72 h. In summary, lactose synthesis paralleled the induction of gene expression of proteins involved in UDP-galactose synthesis and transport, suggesting that they are potentially rate limiting in lactose synthesis and thus milk production. Progesterone withdrawal may be the signal that triggers PRLR signaling via STAT5, which may in turn induce UGP2 and SLC35A2 expression.

The evolutionary benefit of insulin resistance

Insulin resistance is perceived as deleterious, associated with conditions as the metabolic syndrome, type 2 diabetes mellitus and critical illness. However, insulin resistance is evolutionarily well preserved and its persistence suggests that it benefits survival. Insulin resistance is important in various states such as starvation, immune activation, growth and cancer, to spare glucose for different biosynthetic purposes such as the production of NADPH, nucleotides in the pentose phosphate pathway and oxaloacetate for anaplerosis. In these conditions, total glucose oxidation by the tricarboxylic acid cycle is actually low and energy demands are largely met by fatty acid and ketone body oxidation. This beneficial role of insulin resistance has consequences for treatment and research. Insulin resistance should be investigated at the cellular, tissue and whole organism level. The metabolic pathways discussed here, should be integrated in the accepted and valid mechanistic events of insulin resistance before interfering with them to promote insulin sensitivity at any cost.

A severe case of iatrogenic lactation ketoacidosis

Lactation ketosis is a recognised disorder in postpartum lactating cows where a negative energy balance develops because the energy demands of milk production exceed the energy capacity of the animal. Rarely, nursing women can develop problems with lactation ketosis when their glycogen stores are depleted, causing the body to turn to gluconeogenesis as an energy substrate for galactopoiesis. The authors describe the case of a breastfeeding woman admitted to hospital and made nil per os (NPO) to treat a bowel obstruction. She did not receive intravenous glucose and 3 days postadmission developed a dangerous starvation ketosis (venous pH of 6.64). She was treated with intravenous dextrose, bicarbonate as well as cessation of breastfeeding and recovered quickly. Only four previous reports describe human lactation ketosis and this is the first iatrogenic case reported to our knowledge. It highlights the importance of addressing the unique caloric requirements of nursing women, especially when they are kept NPO.

Galactose promotes fat mobilization in obese lactating and nonlactating women

BACKGROUND

Galactose consumption as the only carbohydrate source results in little increase in plasma glucose and insulin concentrations when compared with fasting. Lower insulin might promote endogenous lipolysis during meal absorption, which may facilitate fat loss.

OBJECTIVE

The objective was to test the hypothesis that consumption of an isocaloric, isonitrogenous galactose drink will result in higher rates of lipolysis and fat oxidation than consumption of a glucose drink in obese lactating and nonlactating women.

DESIGN

Seven healthy, obese, exclusively breastfeeding women and 7 healthy, obese, nonlactating women were studied on 2 occasions according to a randomized, crossover, single-blinded design. Subjects received drinks providing ≈70% of the daily estimated energy requirement, of which 60% was either glucose or galactose. The primary outcomes were the rate of appearance (Ra) of glycerol and palmitate, and the secondary outcomes were glucose Ra, milk production, energy expenditure, and substrate oxidation.

RESULTS

Plasma glucose and insulin concentrations were lower (P < 0.05) and those of glycerol, palmitate, free fatty acids, and triglycerides were higher (P < 0.05) during galactose than during glucose feeding in both nonlactating and lactating women. During galactose feeding, glucose Ra was lower (P < 0.01) and glycerol, palmitate, and free fatty acid Ra were higher (P < 0.01) in both groups. During galactose feeding in all women combined, fat oxidation was higher (P = 0.01) and protein oxidation was lower (P < 0.01). Milk production, energy expenditure, and carbohydrate oxidation were similar between glucose and galactose feeding.

CONCLUSIONS

Galactose consumption is associated with higher endogenous fat mobilization and oxidation during meal absorption. Long-term studies are required to determine whether galactose as an exclusive carbohydrate source would promote body fat loss in obese subjects.