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.

Microalbuminuria and associated clinical features among Brazilians with insulin dependent diabetes mellitus.

With the objective to determine the frequency of microalbuminuria, macroalbuminuria and the associated clinic and metabolic features among insulin dependent diabetes mellitus (IDDM) Brazilian patients attending at a general University Hospital, a total of 50 outpatients, aged 21.9 +/- 7 years with IDDM duration of 6.8 +/- 5.8 years were studied cross-sectionally. Urinary albumin excretion rate (AER) was determined in timed overnight urine samples. Microalbuminuria was defined when two out of three urine samples had AER ranging 20-200 micrograms/min. Microalbuminuria was present in 12% of our patients. No macroalbuminuric patient was found. Among patients with diabetes duration < or = 5 years (n = 24), 8.3% (n = 2) had microalbuminuria. Retinopathy was strongly associated with microalbuminuria (P = 0.004) although no proliferative retinopathy was noted. No difference was observed concerning FBG and HBAI between normo and microalbuminuria patients. Univariate analysis has revealed no influence of these variables in AER. Systolic blood pressure (sBP) was high in microalbuminuria patients and stepwise multiple regression analysis has shown that it was the only significant independent variable to influence AER. (R = 0.42 r2 = 0.18 P = 0.002). In conclusion, the frequency of microalbuminuria in this sample of IDDM Brazilian patients was similar to other populational groups and was associated with retinopathy and sBP.

[Lipids, microalbuminuria and systemic blood pressure in patients with insulin-dependent diabetes mellitus]. / Perfil lipídico, microalbuminúria e pressão arterial sistêmica em pacientes com diabetes insulino-dependente.

PURPOSE: To determine the association between lipids, microalbuminuria and systemic blood pressure. Urinary albumin excretion rate (AER) was determined in timed overnight urine samples by radioimmunoassay. Microalbuminuria was defined when two out of three urine samples had AER ranging 20-200 micrograms/min. Lipids were determined by colorimetric methods (total cholesterol, HDL cholesterol and triglycerides). METHODS: Fifty patients with insulin dependent diabetes mellitus (28 females, 22 males) aged 21.9 +/- 7 years and with diabetes duration of 6.8 +/- 5.8 years attending the outpatients diabetes clinic were studied cross-sectionally. RESULTS: Microalbuminuria was present in 12% of our patients. A high systolic blood pressure (SBP) was found in microalbuminuric patients (p = 0.003). No difference concerning serum lipids were found in comparison between normo and microalbuminuric patients, although 20% of all patients had increased cholesterol and LDL cholesterol and 4% had high HDL cholesterol and triglycerides levels. Stepwise multiple regression analysis showed that SBP was the only significant independent variable to influence AER (r = 0.42 r2 = 0.18 p = 0.002). CONCLUSION: Although in our study, microalbuminuria was associated only with SBP, the independent alteration of lipids in young IDDM patients must be considered as a possible additional risk factor for cardiovascular disease.

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%) and percent increase (42.31%), and the lowest for incremental area, absolute increase, peak value (PV) (3.8%), and total area (7.7%) (chi 2 = 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) (chi 2 = 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.

Estudo da funçäo tireóidea na síndrome de Down / Study of the thyroid function in Down syndrome

Os autores investigam o funcionamento da tireóide em 43 crianças com síndrome de Down e 48 controles em faixas etárias entre três meses e 18 anos, através de dosagens séricas de T3 livre (T3L), T4 L livre (T4L), tireotropina (TSH), T3 reverso (rT3) e anticorpos antimicrossomais (AcAM) e antitireoglobulina (AcAT). A idade óssea e as habilidades intelectuais também foram estimadas. Das 43 crianças com síndrome de Down, uma tinha hipotireoidismo clínico e em 12 havia hipotireoidismo subclíníco (27,9 por cento). A percentagem de AcAM titulável no grupo dos Down foi de 37,2 por cento. Em 25,6 por cento dos pacientes submetidos a radiografia de maos e punhos havia retardo na idade óssea. As médias hormonais dos casos de síndrome de Down sem disfunçao tireóidea detectável, quando comparadas às dos controles, mostraram-se significativamente mais elevadas quanto ao TSH e mais reduzidas quanto ao rT3. É possível que o déficit relativo de rT3 na síndrome de Down, confirmado neste trabalho, represente tao somente mais uma manifestaçao do hipotireoidismo. O rendimento intelectual dos casos de síndrome de Down com hipotireoidismo exclusivamente subclínico revelou-se comparável ao daqueles sem alteraçoes hormonais, embora o paciente com hipotireoidismo clínico mostrasse importante déficit mental. Crianças com síndrome de Down têm elevado risco de desenvolver hipotireoidismo, devendo portanto ser submetidas a estudos laboratoriais especializados, objetivando a prevençao de danos progressivos à funçao intelectual.