Prevalence of nocturnal hypoglycemia in first trimester of pregnancy in patients with insulin treated diabetes mellitus.

BACKGROUND: Excellent metabolic control before conception and during diabetic pregnancies is the aim in order to avoid malformations and perinatal morbidity. Since an inverse correlation between median blood glucose concentration (BG) and hypoglycemia as well as a high prevalence of nocturnal hypoglycemia have been described, we investigated the frequency of nocturnal hypoglycemia and the predictive value of bedtime blood glucose concentration for development of this condition in insulin treated diabetic patients. METHODS: During hospitalization, with no other changes in the patients' normal schedules, hourly blood samples were drawn from an iv-cannula from 22.00 h to 07.00 h for one night. BG (venous whole blood) and hemoglobin A1c were determined the following day. RESULTS: Fifty-three patients participated; subsequently ten were excluded due to discontinuation of blood sampling during the night, caused by either discomfort or cannula problems. Of the remaining 43 patients, 16 (37%) had at least one blood glucose <3.0 mmol/l. The duration of hypoglycemia was 2.4 (1-7) h with the highest prevalence at 05 h. Only one patient felt hypoglycemic during the night. Hemoglobin A1c was similar in patients with (7.1+/-1.2%, mean+/-s.d.) and without (6.8+/-0.8%) nocturnal hypoglycemia. Women with nocturnal hypoglycemia had significantly lower BG before bedtime compared to patients without hypoglycemia, 6.4+/-3.6 mmol/l vs. 7.9+/-2.4 mmol/l, p<0.05. The best predictive value for nocturnal hypoglycemia was a BG below 6.0 mmol/l at 23.00, which resulted in a risk of nocturnal hypoglycemia of 71%. Conversely, if the BG was > or =6.0 mmol/l, the chance of avoiding nocturnal hypoglycemia was 83%. CONCLUSION: Nocturnal hypoglycemia was seen with a prevalence of 37% during a night in the first trimester of pregnancy in insulin treated patients. Only one patient registered the hypoglycemia. Nocturnal hypoglycemia could be predicted in the majority of patients by measurements of BG before bedtime.

Oral hypoglycaemic agents in 118 diabetic pregnancies.

AIMS: To assess maternal and neonatal complications in pregnancies of diabetic women treated with oral hypoglycaemic agents during pregnancy. METHODS: A cohort study including all consecutively registered, orally treated pregnant diabetic patients set in a diabetic obstetrical service at a university hospital: 50 women treated with metformin, 68 women treated with sulphonylurea during pregnancy and a reference group of 42 diabetic women treated with insulin during pregnancy. RESULTS: The prevalence of pre-eclampsia was significantly increased in the group of women treated with metformin compared to women treated with sulphonylurea or insulin (32 vs. 7 vs. 10%, P < 0.001). No difference in neonatal morbidity was observed between the orally treated and insulin-treated group; no cases of severe hypoglycaemia or jaundice were seen in the orally treated groups. However, in the group of women treated with metformin in the third trimester, the perinatal mortality was significantly increased compared to women not treated with metformin (11.6 vs. 1.3%, P < 0.02). CONCLUSION: Treatment with metformin during pregnancy was associated with increased prevalence of pre-eclampsia and a high perinatal mortality.

Differential molar heat capacities to test ideal solubility estimations.

PURPOSE: Calculation of the ideal solubility of a crystalline solute in a liquid solvent requires knowledge of the difference in the molar heat capacity at constant pressure of the solid and the supercooled liquid forms of the solute, delta Cp. Since this parameter is not usually known, two assumptions have been used to simplify the expression. The first is that delta Cp can be considered equal to zero; the alternate assumption is that the molar entropy of fusion, delta Sf, is an estimate of delta Cp. Reports claiming the superiority of one assumption over the other, on the basis of calculations done using experimentally determined parameters, have appeared in the literature. The validity of the assumptions in predicting the ideal solubility of five structurally unrelated compounds of pharmaceutical interest, with melting points in the range 420 to 470 K, was evaluated in this study. METHODS: Solid and liquid heat capacities of each compound near its melting point were determined using differential scanning calorimetry. Linear equations describing the heat capacities were extrapolated to the melting point to generate the differential molar heat capacity. RESULTS: Linear data were obtained for both crystal and liquid heat capacities of sample and test compounds. For each sample, ideal solubility at 298 K was calculated and compared to the two estimates generated using literature equations based on the differential molar heat capacity assumptions. CONCLUSIONS: For the compounds studied, delta Cp was not negligible and was closer to delta Sf than to zero. However, neither of the two assumptions was valid for accurately estimating the ideal solubility as given by the full equation.

Dimensional stability of thermosensitive gutta-percha.

The expansion and shrinkage of four commercial brands of endodontic thermosensitive gutta-percha were evaluated. A modified volume dilatometry technique was used; the dilatometric system (DS) consisted of Pyrex glass capillary tubes and a specimen chamber. Each sample was weighed to 10(-4) mg, placed in the specimen chamber, and subjected to vacuum for 45 min to eliminate moisture or gases. The DS was gradually heated from 24 degrees C to 80 degrees C and then cooled to 24 degrees C using a well-agitated temperature-controlled water bath. In a parallel set of experiments, the DS was heated in the same manner but cooled to body temperature (37 degrees C) in the water bath and the temperature kept stable at 37 degrees C for 24 h. The level of the mercury meniscus within the DS was monitored to determine the percent volume change of each sample at 2 degrees C intervals. All samples expanded as the temperature was elevated and shrank during cooling. The percent volume change for each of the four gutta-percha products, as the temperature was raised to 80 degrees C, ranged from an expansion of +11.62 to +12.25. As the temperature was lowered from 80 degrees C to 24 degrees C, the percent volume change representing shrinkage ranged from -2.22 to -3.53. When the temperature was lowered from 80 degrees C to 37 degrees C, the products continued to exhibit shrinkage for a range of time between 45 min and 10 h before stabilizing at a fixed volume. The final percent volume change for each experiment, with each product, was positive, ranging from +5.50 to +7.20, with discernible differences between products.

Congenital malformations in offspring of diabetic women treated with oral hypoglycaemic agents during embryogenesis.

A markedly increased risk (50%) of congenital malformations in the offspring of women treated with oral hypoglycaemic agents during the first trimester has recently been reported. With this background, the medical records of a consecutive sample of 25 pregnant Type 2 diabetic women treated with oral hypoglycaemic agents during embryogenesis between 1966 and 1991 in the diabetic service of a university hospital, were studied retrospectively. None of the infants had major congenital malformations disclosed in the neonatal period (0%, 97.5% confidence interval 0.0-13.7%), but one minor congenital malformation was found (4.0%, 95% confidence interval 0.1-20.3%). Although this study, due to the limited number of pregnancies examined, does not exclude an association between treatment with oral hypoglycaemic agents at the time of embryogenesis and major congenital malformations in the offspring, the previously reported association was not confirmed. Thus we find no obvious indication for therapeutic abortions in patients who have accidentally been treated with oral hypoglycaemic agents during embryogenesis. On the contrary it seems reasonable to reassure these women with respect to their risk of having a malformed baby, stop the treatment with oral hypoglycaemic agents and initiate insulin treatment.

Polystyrene bezoar in a patient with polystyrenomania.

A 35-yr-old man with hematemesis, epigastric pain, and no predisposing factors to delayed gastric emptying was found to have a gastric bezoar. Surgical removal was required. Pathological and biochemical examination revealed a mass composed of polystyrene. This represents an unusual composition and a newly recognized predisposing factor to bezoar formation, "polystyrenomania" from ingestion of styrofoam cups.