Selective SGLT2 inhibition by tofogliflozin reduces renal glucose reabsorption under hyperglycemic but not under hypo- or euglycemic conditions in rats.

To understand the risk of hypoglycemia associated with urinary glucose excretion (UGE) induced by sodium-glucose cotransporter (SGLT) inhibitors, it is necessary to know the relationship between the ratio of contribution of SGLT2 vs. SGLT1 to renal glucose reabsorption (RGR) and the glycemic levels in vivo. To examine the contributions of SGLT2 and SGLT1 in normal rats, we compared the RGR inhibition by tofogliflozin, a highly specific SGLT2 inhibitor, and phlorizin, an SGLT1 and SGLT2 (SGLT1/2) inhibitor, at plasma concentrations sufficient to completely inhibit rat SGLT2 (rSGLT2) while inhibiting rSGLT1 to different degrees. Under hyperglycemic conditions by glucose titration, tofogliflozin and phlorizin achieved ≥50% inhibition of RGR. Under hypoglycemic conditions by hyperinsulinemic clamp, RGR was reduced by 20-50% with phlorizin and by 1-5% with tofogliflozin, suggesting the smaller contribution of rSGLT2 to RGR under hypoglycemic conditions than under hyperglycemic conditions. Next, to evaluate the hypoglycemic potentials of SGLT1/2 inhibition, we measured the plasma glucose (PG) and endogenous glucose production (EGP) simultaneously after UGE induction by SGLT inhibitors. Tofogliflozin (400 ng/ml) induced UGE of about 2 mg·kg⁻¹·min⁻¹ and increased EGP by 1-2 mg·kg⁻¹·min⁻¹, resulting in PG in the normal range. Phlorizin (1,333 ng/ml) induced UGE of about 6 mg·kg⁻¹·min⁻¹ and increased EGP by about 4 mg·kg⁻¹·min⁻¹; this was more than with tofogliflozin, but the minimum PG was lower. These results suggest that the contribution of SGLT1 to RGR is greater under lower glycemic conditions than under hyperglycemic conditions and that SGLT2-selective inhibitors pose a lower risk of hypoglycemia than SGLT1/2 inhibitors.

Developmental pattern of urinary bile acid profile in preterm infants.

BACKGROUND: Bile acid metabolism in preterm infants is yet to be fully characterized. We compared the developmental pattern of urinary bile acid profiles in ten infants born at gestational ages from 25 to 33 weeks with previous data from full-term infants from birth to about 7 months of age. METHODS: Gas chromatography-mass spectrometry was performed on serial samples. RESULTS: Total urinary bile acid concentrations gradually increased until 1 to 2 months of age. After this peak of excretion (30 to 60 micromol/mmol creatinine), total urinary bile acid concentrations gradually decreased to less than 20 micromol/mmol creatinine. The percentage of usual bile acids (mainly cholic acid) relative to total urinary total bile acids gradually deceased from approximately 30% at birth to less than 15% at 7 months of age. On the other hand, 1beta-hydroxylated bile acids (mainly 1beta,3alpha,7alpha,12alpha-tetrahydroxy-5beta-cholan-24-oic acid) relative to total urinary bile acids were increased gradually from 60% at birth to reach 70% to 80% at 1 month of age. The percentage of 1beta-hydroxylated bile acids relative to total urinary bile acids then remained stable at a high percentage (70% to 90%) until the age of 7 months. CONCLUSION: Physiological cholestasis in preterm infants persists longer than in full-term infants. Moreover, as large amounts of cholic and 1beta,3alpha,7alpha,12alpha-tetrahydroxy-5beta-cholan-24-oic acids were detected in urine from preterm infants during this study, the 25-hydroxylation pathway may be particularly important for bile acid synthesis in early preterm infants.

[Prevalence of ketotic hypoglycaemia among schoolchildren in the village of Ahoué in Côte-d'Ivoire]. / Prévalence de l'hypoglycémie cétosique chez les enfants d'âge scolaire dans le village d'Ahoué en Côte-d'Ivoire.

To determine the prevalence of ketotic hypoglycemia among schoolchildren, a descriptive cross-sectional study was conducted in preschools and schools in rural areas that involved 102 schoolchildren, from 4 to 7 years old, comprised 51 girls and 51 boys. Index WHZ was used to evaluate the children's nutritional status. The sampling was obtained by a drop of capillary blood in the pulp of the finger. The determination of glucose was realized by glucose oxidase method using an ultra sensitive and fast (One Touch Ultra) glucometer, and ketonuria was detected by dipstick "Ketodiastix." The clinical results revealed that most of children had a normal birth weight with an average of 2.885 g, a good Apgar's score superior to 7, and then the nutritional index WHZ revealed 3% of severe malnutrition and 34% of moderate malnutrition. Ten children (9.8%) had a hypoglycemia with a median of 0.51 g/l and extreme values going from 0.42 to 0.59 g/l. Seven children had a hypoglycemia associated with ketonuria. The prevalence of ketotic hypoglycemia was 7% in this study, and more frequent in the children between 4 and 5 years with 57% of cases in this age group. Thus, this condition, found in Western countries is a reality in Côte d'Ivoire, where the diathesis of malnutrition (37% of the population of the study) is a favorable factor. Therefore, it is useful to prevent protein-energy malnutrition by a balanced food by avoiding fasting before school by diet management.

Urine glucose concentration: A useful parameter as a surrogate for glycaemia on the first day of life in canine neonates.

INTRODUCTION: Hypoglycaemia is a well-known risk factor in neonatal puppies and kittens; glycaemia control is crucial during the first days of life. Kidneys immaturity provokes the presence of physiological glycosuria during the first 2-3 weeks of life in small animals. OBJECTIVES: The aim of this study was to evaluate the potential of glycosuria as a predictor of glycaemia in neonatal puppies during the first two weeks of life. METHODS: Prospective study. Thirty-three client-owned healthy neonatal puppies admitted to the Veterinary Teaching Hospital, Autonomous University of Barcelona, were included in the study and divided into four different groups according to the day of sampling (1, 4, 7, and 11 days post-delivery). Glucose levels in blood and urine samples were evaluated and compared between groups. Correlation between glucose levels in blood and urine was also determined. RESULTS: Hypoglycaemia was diagnosed in 17.14% of the puppies and only on day 1 after delivery. A positive and significant correlation between blood and urine glucose concentration on day 1 after delivery was observed. No significant correlation between blood and urine glucose was observed on days 4, 7 and 11 after delivery. CONCLUSIONS: Urine concentration of glucose is a useful parameter to establish glycaemic status on the first day of life in canine puppies.

Urine cortisol/creatinine ratio in controlled insulin-induced hypoglycemia.

An elevated urine cortisol/creatinine ratio has been presented as a simple laboratory method to detect nocturnal hypoglycemia. The present study examines the time course of the rise and fall of the urine cortisol/creatinine ratio in 11 patients following insulin-induced hypoglycemia. The mean urine cortisol/creatinine ratios at 1 and 3 h after the onset of symptomatic hypoglycemia were 170 +/- 103 and 62 +/- 23, respectively. These were significantly greater (P less than 0.01) than the basal ratio of 13 +/- 7. By 5 h, the ratio had fallen to 19 +/- 11, which was similar to basal values. The study documents the sensitivity of the urine cortisol/creatinine ratio in detecting hypoglycemia but indicates that after 3 h, the ratio may return to normal despite a previous hypoglycemic episode.

Nocturnal cortisol release during hypoglycemia in diabetes.

Nocturnal hypoglycemia in insulin-treated diabetic persons is often difficult to recognize clinically. It has been suggested that a useful biochemical test to demonstrate this would be the increased excretion of cortisol in the urine during the overnight period. However, of six diabetic persons who had nocturnal hypoglycemia (less than or equal to 2.5 mmol/L), plasma cortisol profiles and overnight urinary cortisol-creatinine ratios were abnormal in only one. In four others the plasma cortisol levels and cortisol excretion indices were indistinguishable from either a normal control group or a group of five diabetic subjects who did not develop nocturnal hypoglycemia. The remaining patient had a raised urinary cortisol-creatinine ratio, but did not show increased plasma levels of cortisol, growth hormone, or glucagon during the hypoglycemic phase. These data do not support the usefulness of the urinary cortisol-creatinine index as a marker of nocturnal hypoglycemia in diabetes.

Prolonged elimination of tolbutamide in a premature newborn with hyperinsulinaemic hypoglycaemia.

So far, gestational diabetes treated with tolbutamide has never been associated with severe hypoglycaemia in the newborn when the mother's diabetes was well controlled. We report a case of a premature neonate, gestational age 34 weeks, with severe and long-standing hypoglycaemia from birth. The mother had well-controlled gestational diabetes, treated with tolbutamide from the 24th week of gestation until delivery. The neonate had inappropriately high levels of serum proinsulin, insulin and C-peptide relative to blood glucose concentrations. From day 19 after birth, the levels were normalized. Serum tolbutamide was 140.6 micromol/l (38 microg/ml) at 3 h after birth. Zero-order kinetics were seen during the first 90 postnatal hours. The half-life of serum tolbutamide decreased from 46 to 6 h. It is suggested that tolbutamide, when given to the mother until delivery, may cause severe and prolonged hyperinsulinaemic hypoglycaemia in premature neonates. The initially prolonged tolbutamide half-lives and zero-order kinetics suggest immaturity of hepatic elimination during the first 2 days of postnatal life.

Hyperprolactinaemia is associated with a higher prevalence of pituitary-adrenal dysfunction in non-functioning pituitary macroadenoma.

In non-functioning pituitary macroadenoma (NFMA), hyperprolactinaemia (hyperPRL) is considered to be a sign of hypothalamic-pituitary dysregulation, but it is unknown whether hyperPRL is associated with an increased frequency of pituitary hormone deficiencies. Forty consecutive patients with histology-proven NFMA were studied and hyperPRL was defined as serum prolactin (PRL) > 200 mIU/l in men and > 600 mIU/l in women. The pituitary-adrenal axis was evaluated by measurement of urinary free cortisol (N = 38), peak cortisol to insulin-induced hypoglycaemia (IIH, N = 36) and to human corticotrophin-releasing hormone (hCRF, N = 40) and by urinary tetrahydrol 11-deoxycortisol (H4S, N = 39), plasma androstenedione increment (N = 39) and serum 11-deoxycortisol (N = 1) after metyrapone. Central hypothyroidism, gonadotrophin deficiency and growth hormone (GH) reserve were also assessed. Twenty patients had hyperPRL (serum PRL 331 (223-1120) mIU/l (median, range) in men and 932 (660-3927) mIU/l in women): urinary free cortisol excretion (p < 0.03) and peak serum cortisol in response to IIH (p < 0.02) were lower in hyperPRL than in normoPRL patients; peak serum cortisol after hCRF was not different between groups but occurred later in hyperPRL patients (at 60vs 30 min, p < 0.03); urinary H4S excretion and androstenedione response after metyrapone were lower in hyperPRL than in normoPRL patients (p < 0.05 for both): 60% of hyperPRL patients and 15% of normoPRL patients had an abnormal H4S response (p < 0.025): central hypothyroidism (overt + subclinical) was present in 74% of hyperPRL and in 60% of normoPRL patients (NS); 78% of hyperPRL and 55% of normoPRL patients had gonadotrophin deficiency (NS): growth hormone (GH) deficiency was present in 83% of hyperPRL and in 89% of normoPRL patients (NS); 73.3% of 75 evaluable pituitary hormone axes were abnormal in hyperPRL patients compared to 53.8% of 78 hormone axes in normoPRL patients (by metyrapone test to examine adrenal function, p < 0.025); and no significant differences in tumour grade and stage distribution were found between hyperPRL and normoPRL patients. It is concluded that hyper-prolactinaemia in NFMA is associated with a higher prevalence of pituitary-adrenal dysfunction, which is likely to be explained at least in part by functional hypothalamic-pituitary interruption.

3-Hydroxyoctanoic aciduria: identification of a new organic acid in the urine of a patient with non-ketotic hypoglycemia.

A four-month-old child with non-ketotic hypoglycemia and rapidly progressive cirrhosis excreted in her urine large amounts of two unidentified organic acids in addition to a spectrum of saturated, unsaturated, and 3-hydroxy dicarboxylic acids in her urine. Gas chromatography/mass spectrometry of the trimethylsilyl derivative of one of the unknown compounds suggested the structure of 3-hydroxyoctanoic acid, which was confirmed by similar analysis of the authentic compound. The same organic acid was found in the child's plasma. The significance of 3-hydroxyoctanoic aciduria as a possible marker for a primary defect of 3-hydroxy fatty acid metabolism is discussed.

Non-ketotic C6-C10-dicarboxylic aciduria: biochemical investigations of two cases.

Two boys, who are not related, with hypoglycemia and C6-C10-dicarboxylic aciduria were investigated. Besides substantial amounts of adipic, suberic and sebacic acids, the urinary metabolic profile of organic acids contained 5-OH-caproic acid and caproylglycine. During acute attacks the concentrations of adipic, suberic and sebacic acids were 300--530, 160--200 and 35--200 micrograms/mg creatinine, respectively, and the excretions of 5-OH-caproic acid and caproylglycine were 75--330 and 41--260 micrograms/mg creatinine, respectively. It is argued that the biosynthesis of adipic acid passes through an omega-oxidation, that the production of 5-OH-caproic acid is caused by an omega-1-oxidation, and that caproylglycine formation passes through a glycine-N-acylase catalysed conjugation of accumulated caproic acid in the patients. Suberic acid and sebacic acid are in the same way omega-oxidation products of accumulated caprylic acid and capric acid, respectively. From the excretion pattern presented it is hypothesized that the patients suffer from a defect in the dehydrogenation of fatty acids in the beta-oxidation pathway. The biological significance of the findings is discussed.

Relation between the urinary cortisol:creatinine ratio and hypoglycaemia.

The relationships between (i) urinary free cortisol and urinary creatinine concentrations and (ii) the urinary cortisol/creatinine ratio (UCCR) and various glycaemic levels were studied in three groups--normal, insulin-stressed and insulin-treated diabetic subjects. In non-hypoglycaemic subjects, there was a significant positive linear correlationship between urinary free cortisol and urinary creatinine excretion, but in the presence of hypoglycaemia, this relationship was lost. The highest mean urinary cortisol/creatinine ratio (UCCR) was found in subjects after an insulin tolerance test (ITT). The mean post-ITT UCCR was significantly greater than the mean for the pre-ITT samples. There was a significant negative correlation between capillary blood glucose levels at 03.00 and the UCCR of the overnight urine samples of insulin-treated diabetic subjects. We conclude that there is a definite increase in the UCCR after hypoglycaemia in subjects with adequate adrenocortical response to hypoglycaemia and that determination of the UCCR could be helpful in the detection of nocturnal hypoglycaemia.

The investigation of beta-hydroxybutyrate as a marker for sudden death due to hypoglycemia in alcoholics.

The purpose of this study was to determine if the ketone body beta-hydroxybutyrate (beta-HBA) is a useful positive marker for sudden deaths in chronic alcoholics, thought to be due to hypoglycemia. Beta-HBA can be reliably measured in postmortem samples of vitreous humour and urine. In fatalities where there is a history of chronic alcoholism and routine investigations, including autopsy and routine toxicology, yield only a fatty liver as positive findings, a raised level of beta-HBA can be used as an indicator for alcoholic ketosis. Alcoholic ketosis is often associated with antemortem hypoglycemia. Caution should be observed in attributing the significance of ketosis exclusively to alcohol in those conditions where it would otherwise be expected (i.e. diabetic ketoacidosis and chronic starvation). A measurement of this marker of alcoholic ketosis may also help in the investigation of cases where hypothermia or alcohol withdrawal fits are suspected.

Multifactorial intervention in individuals with type 2 diabetes and microalbuminuria: the Microalbuminuria Education and Medication Optimisation (MEMO) study.

AIMS: To determine whether tighter cardiovascular risk factor control with structured education in individuals with type 2 diabetes (T2DM) and microalbuminuria benefits cardiovascular risk factors. METHODS: Participants from a multiethnic population, recruited from primary care and specialist clinics were randomised to intensive intervention with structured patient (DESMOND model) education (n=94) or usual care by own health professional (n=95). PRIMARY OUTCOME: change in HbA1c at 18months. SECONDARY OUTCOMES: changes in blood pressure (BP), cholesterol, albuminuria, proportion reaching risk factor targets, modelled cardiovascular risk scores. RESULTS: Mean (SD) age and diabetes duration of participants were 61.5 (10.5) and 11.5 (9.3) years, respectively. At 18months, intensive intervention showed significant improvements in HbA1c (7.1(1.0) vs. 7.8(1.4)%, p<0.0001), systolic BP (129(16) vs. 139(17) mmHg, p<0.0001), diastolic BP (70(11) vs. 76(12) mmHg, p<0.001), total cholesterol (3.7(0.8) vs. 4.1(0.9) mmol/l, p=0.001). Moderate and severe hypoglycaemia was 11.2 vs. 29.0%; p=0.001 and 0 vs. 6.3%; p=0.07, respectively. More intensive participants achieved ≥3 risk factor targets with greater reductions in cardiovascular risk scores. CONCLUSIONS: Intensive intervention showed greater improvements in metabolic control and cardiovascular risk profile with lower rates of moderate and severe hypoglycaemia. Intensive glycaemic interventions should be underpinned by structured education promoting self-management in T2DM.

[Late onset 3-HMG-CoA lyase deficiency: a rare but treatable disorder]. / Déficit en 3-HMG-CoA lyase à révélation tardive : savoir reconnaître une maladie rare mais traitable.

3-Hydroxy-3-methylglutaric aciduria is a rare autosomal recessive genetic disorder due to a deficiency of the 3-hydroxy-3-methylglutarylCoA lyase (HMG-CoA lyase), a mitochondrial enzyme involved in ketogenesis and in the final step of l-leucine catabolism. HMG-CoA lyase deficiency can lead, in particular circumstances, such as fever, prolonged fasting or digestive disorders, to brutal and severe hypoglycemia with metabolic acidosis and sometimes fatal coma. We report on a new case of 3-hydroxy-3-methylglutaric aciduria particular by its late onset in a 3-year-old patient. Molecular investigation identified two new sequence modifications in the HMGCL gene: c.494G>A (p.Arg165Gln) and c.820G>A (p.Gly274Arg). We remind about this case report that the therapeutical is mainly preventive and allows a very good prognosis for this disease. Long-term treatment consists in limited fasting time, continuous low protein diet and l-carnitine supplementation. Preventive measures are essential: prevention of fasting and emergency treatment during intercurrent infections.