The C-peptide response to a standard mixed meal in a group of Brazilian type 1 diabetic patients

In order to analyze the different parameters used in the interpretation of C-peptide response in a functional test, we compared a group of 26 type 1 diabetics aged 21.1 + 8.2 years, with a diabetes duration of 7.9 + 6.7 months, with a group of 24 non-diabetic subjects aged 25.0 + 4.4 years. A standard mixed meal of 317 kcal was used as a stimulus. Blood sampling for C-peptide determinations was performed at regular intervals. Although all the studied C-peptide variables were significantly lower in the diabetic group (P<0.0001), some overlapping of parameters was observed between the two groups. The highest degree of overlapping was found for basal value (BV) (30.8 percent) and percent increase (42.31 percent), and the lowest for incremental area, absolute increase, peak value (PV) (3.8 percent), and total area (7.7 percent) (X2 = 31.6, P<0.0001). We did not observe a definite pattern in the time of maximum response among the 21 diabetics who showed an increase in C-peptide levels after the stimulus. In this group, however, there was a highly significant number of late responses (120 min) (X2 = 5.7, P<0.002). Although BV showed a significant correlation with PV (rs = 0.95, P<0.0001), the basal levels of C-peptide did not differentiate the groups with and without response to the stimulus. We conclude that the diabetic group studied showed delayed and reduced C-peptide responses, and that the functional test can be an important tool for the evaluation of residual beta cell function.

Influence of first morning urine volume, fasting blood glucose and glycosylated hemoglobin on first morning urinary albumin concentration

The aim of the present study was to evaluate the effect of first morning urinary volume (collected on three different non-consecutive days), fasting blood glucose (determined on the first and third days of urine collection), and glycosylated hemoglobin (determined on the first and third days of urine collection) on the albumin concentration in first morning urine samples collected on three different days. We found 3.6 per cent asymptomatic bacteriuria in the urine samples; therefore, every urine sample must be tested to exclude infection. One hundred and fifty urine samples were provided by 50 IDDM patients aged 21.9 ñ 7 (l2-38) years with a disease duration of 6.8 + 5.8 (0.4-31) years attending the Diabetes Clinic at the State University Hospital of Rio de Janeiro. There were no differences in albumin concentration (6.1 vs 5.8 vs 6.2 mug/ml; P = NS) or urinary volume (222.5 vs 210 vs 200 ml) between the three samples. In addition, there were no differences in fasting blood glucose (181.9 + 93.6 vs 194.6 + 104.7 mg per cent; P = NS) or glycosylated hemoglobin (HbA 1) (8.4 ñ 1.3 vs 8.8 ñ 1.5 per cent; P = NS) between the first and third blood samples. Six patients (group 1) had a mean urinary albumin concentration of more than 20 mug/ml for the three urine samples. This group was compared with the 44 patients (group 2) with a mean urinary albumin concentration for the three urine samples of less than 20 mug/ml. No difference was found between groups 1 and 2 in relation to fasting blood glucose (207.1 ñ 71.7 vs 187.6 ñ 84.6 mg/dl), HbA 1 (8.1 ñ 0.9 vs 8.6 ñ 1.1 per cent) or urinary volume [202 (48.3-435) vs 246 (77.3-683.3) ml]. Stepwise multiple regression analysis with albumin concentration of first morning urine samples as the dependent variable, and urinary volume, fasting blood glucose and glycosylated hemoglobin as independent variables, showed that only 12 per cent (P = 0.01) of the albumin concentration could be accounted for by the independent effect of morning urine volume on the first day of urine collection. No urine samples showed a change in the cutoff level of 20 mug/ml of albumin concentration as the result of volume. Fasting blood glucose and glycosylated hemoglobin did not influence the urinary albumin concentration. Considerable variability in urinary albumin concentration was found in the three morning urine samples with a mean intraindividual coefficient variation of 56 per cent. In conclusion, in the present study, urinary volume...

Hiperplasia supra-renal congenita. Efeito do tratamento sobre o crescimento estatural e a secrecao de somatotropina. / Congenital adrenal hyperplasia. The effect of the treatment of stature growth and somatotropina secretion

Os autores apresentam oito casos de pacientes com sindrome adrenogenital por hiperplasia suprarenal congenita devida a deficiencia de 21-hidroxilase tratados com corticosteroides. Analisam o efeito do tratamento sobre o desenvolvimento estatural e sobre os niveis serivos de hormonio do crescimento, discutindo os resultados em face dos possiveis mecanismos fisiopatologicos em causa