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S P Silveiro

Publications and source records attributed to S P Silveiro.

8 recordsLinked to original sources
PubMed1998

Urinary albumin excretion rate and glomerular filtration rate in single-kidney type 2 diabetic patients.

OBJECTIVE: To evaluate the urinary albumin excretion rate (UAER) and the glomerular filtration rate (GFR) of single-kidney type 2 diabetic patients (SKD) and of single-kidney non-diabetic patients (SKN). RESEARCH DESIGN AND METHODS: Patients who had only one kidney for at least 5 years, with no renal disease or hypertension at the time of the nephrectomy and with no calculus or systemic disease at the time of the evaluation, were included in this controlled cross-sectional study A total of 20 SKD (8 men, age 62 +/- 9 years; diabetes duration 8.5 +/- 7 years), 17 SKN (2 men, age 57 +/- 13 years), and 184 type 2 diabetic patients who were matched to the single-kidney diabetic group for age, sex, and BMI were studied. UAER was measured by immunoturbidimetry in timed 24-h sterile urine, and GFR was determined by the 51Cr-EDTA single-injection method. RESULTS: SKD patients presented a higher proportion (8 of 20, 40%) of microalbuminuria (UAER 20-200 microg/min) than SKN patients (3 of 17, 17.6%) and type 2 diabetic patients (37 of 184, 20%). SKD patients presented a higher proportion of macroalbuminuria (UAER >200 microg/min; 6 of 20, 30%) than SKN patients (1 of 17, 6%) but were similar to type 2 diabetic patients (43 of 184, 23%). The GFRs of normoalbuminuric SKN (71.7 +/- 21.4 ml x min(-1) x 1.73 m(-2)) and SKD patients (73.0 +/- 21.5 ml x min(-1) x 1.73 m(-2)) were similar but higher than the one-kidney GFR (GFR / 2) of the age-, sex-, and BMI-matched normal individuals (50.5 +/- 9.0 ml x min(-1) x 1.73 m(-2)) and normoalbuminuric type 2 diabetic patients (54.0 +/- 11.6 ml x min(-1) x 1.73 m(-2)). CONCLUSIONS: Increased GFR related to single-kidney status confers an increased risk of developing renal disease in the presence of diabetes.

Adult↗
PubMed1997

Hypothyroidism in a Brazilian kindred due to iodide trapping defect caused by a homozygous mutation in the sodium/iodide symporter gene.

A 36 year old man with a large goiter was suspected of having iodide (I-) transport defect based on low thyroidal and salivary gland radioiodide uptake. Thyroid surgery was performed, because thyroid cytology could not exclude a malignancy. Sequencing of the entire Na+/I- symporter (NIS) cDNA derived from thyroidal mRNA revealed a homozygous substitution of the normal cytosine in nucleotide (nt) 1163 with an adenine, resulting in a stop (TGA) at codon 272. This nonsense mutation produces a truncated NIS with undetectable I- transport activity when expressed into COS-7 cells. Genotyping confirmed that the propositus was homozygous for the mutation whereas his unaffected mother, son, and paternal aunt were heterozygous. This nt substitution was not detected in any of 50 normal individuals, ruling out a polymorphism. While the homozygous mutant NIS-272X causes congenital hypothyroidism, expression of one normal allele in the heterozygote (C272X) is sufficient to maintain active thyroidal I- uptake and function.

Adult↗
PubMed1996

Five-year prospective study of glomerular filtration rate and albumin excretion rate in normofiltering and hyperfiltering normoalbuminuric NIDDM patients.

OBJECTIVE: To evaluate the evolution of glomerular filtration rate (GFR) and albumin excretion rate (AER) of normofiltering (NF) and hyperfiltering (HF) normoalbuminuric NIDDM patients. RESEARCH DESIGN AND METHODS: A longitudinal study of 32 normoalbuminuric (AER < 20 micrograms/min) NIDDM patients and 20 age-, sex-, and BMI-matched normal individuals was done. Subjects had their GFR (51Cr-labeled EDTA single-injection method) measured at entry and after 40 and 60 months. At entry, 13 NIDDM patients had GFR values above the upper limit of the normal range in our laboratory (> 137 ml.min-1 x 1.73 m-2) and were considered as HF. In NIDDM patients, the 24-h AER (radioimmunoassay), HbA1c, urinary urea, and mean arterial blood pressure (MBP) were analyzed at entry and after 40 and 60 months. RESULTS: There was a significant decline of GFR in NIDDM patients and normal subjects at 60 months. The decline was significantly greater in HF patients (-0.61 ml.min-1.month-1; P = 0.001) than in NF (-0, 18) and control subjects (-0, 14); the rate of change in NF and control subjects was the same (P > 0.05). In stepwise multiple regression analysis, with GFR decline as the dependent variable and GFR and AER at baseline, age and change in MBP, change in urinary urea, change in HbA1c, and change in therapy as independent variables, only baseline GFR (R2 = 0.19, P = 0.002) and age (R2 = 0.31, P = 0.048) were significantly related to the outcome. At 60 months, AER raised > 20 micrograms/min in three HF and in four NF patients. In logistic regression analysis, only higher initial AER (although still in the normal range; P = 0.037) and an increase in urinary urea (P = 0.021) were significantly related to the later development of microalbuminuria. CONCLUSIONS: The GFR of normoalbuminuric NIDDM patients declines significantly over 60 months. This decline is associated to baseline GFR and age. HF NIDDM patients show a faster decline in GFR than NF patients, whose GFR falls at a rate that is compatible with the age-related change observed in normal control subjects. The development of microalbuminuria is related to higher baseline AER and to increases in urinary urea and is similar in NF (4 of 19) and HF (3 of 13) NIDDM patients (P > 0.05).

Adult↗
PubMed1993

Glomerular hyperfiltration in NIDDM patients without overt proteinuria.

OBJECTIVE--To evaluate the frequency and correlates of glomerular hyperfiltration in NIDDM patients without overt proteinuria. RESEARCH DESIGN AND METHODS--A cross-sectional study was conducted. Seventy-one consecutive NIDDM patients attending an outpatient clinic, with Albustix-tested negative urine and a 24-h AER < 200 micrograms/min, were examined for long-term complications of diabetes. We measured their GFR (51Cr-EDTA single-injection method), 24-h AER (RIA), plasma creatinine, HbA1c, total cholesterol, triglycerides, urinary glucose, and urea. RESULTS--GFR above the upper limit of the normal range for age-matched control subjects (137.1 ml.min-1 x 1.73 m2) was present in 15 of 71 (21%) NIDDM patients. Subjects with normal and hyperfiltration did not differ in terms of age, sex distribution, BMI, duration of NIDDM, BP, AER, or frequency of long-term complications. Plasma glucose was significantly higher in subjects with hyperfiltration (mean [range]: 12.8 [4.3-18.7] vs. 8.7 [2.6-17.5] mM). HbA1c failed to reach statistical significance, although it tended to be higher in the group with hyperfiltration (10.4 [6.7-13.9] vs. 9.4 [4.2-16.5]%, P = 0.10). Age (rS -0.37, P = 0.002), FPG (rS 0.45, P < 0.0005), total cholesterol (rS -0.31, P = 0.008), and glycosuria (rS 0.40, P = 0.001) correlated significantly with GFR. In a stepwise multiple regression analysis, FPG, age, and total cholesterol emerged as significant correlates of the dependent variable GFR. CONCLUSIONS--Hyperfiltration occurred in 21% of NIDDM patients without overt proteinuria. FPG and age significant correlates of the GFR in these patients. Cholesterol is significantly (although only modestly) correlated with the GFR.

Blood Glucose↗
PubMed1993

Risk factors for development of proteinuria by type II (non-insulin dependent) diabetic patients.

1. Renal involvement in non-insulin dependent diabetes mellitus patients is the single most important cause of renal failure. The aim of this study was to evaluate the clinical features and to assess the risk factors for the development of proteinuria by non-insulin dependent diabetic patients. 2. Risk factors (expressed as an odds ratio) were calculated by multiple logistic regression analysis taking into account age, sex, body mass index, known duration of diabetes, presence of arterial hypertension, fasting plasma glucose, cholesterol and triglycerides as independent variables and proteinuria as the dependent variable. Sixty-four normoalbuminuric (24-h albumin excretion rate < 30 micrograms/min, 27 females, mean age 53.7 years) and 53 proteinuric (24-h proteinuria > 0.5 g, 31 females, mean age 59.3 years) were studied. 3. Proteinuric patients were older, with a longer mean known duration of diabetes (12.4 vs 5.6 years), higher mean fasting plasma glucose (214 vs 168 mg/dl) and plasma creatinine (1.5 vs 1.1 mg/dl) and more frequently presented diabetic retinopathy (94% vs 23%), peripheral neuropathy (94% vs 23%) and arterial hypertension (73% vs 16%) than normoalbuminuric patients. Age > 50 years, body mass index > 28.6 kg/m2, known duration of diabetes > 10 years, presence of arterial hypertension, and fasting plasma glucose > 160 mg/dl were significantly and independently associated with development of proteinuria.

Adult↗
PubMed1992

Effect of age and sex on glomerular filtration rate measured by 51Cr-EDTA.

1. The effect of age and sex on glomerular filtration rate (GFR) was measured by the 51Cr-EDTA radioisotopic method in 76 normal individuals (43 women and 33 men). 2. Age has a significant effect on GFR. Subjects aged 41 to 60 years have GFR values [104.5 +/- 16.5 ml min-1 (1.73 m2)-1, N = 43] lower than younger individuals aged 20 to 40 years [116.6 +/- 11.2 ml min-1 (1.73 m2)-1, N = 33]. GFR decreases after 40 years of age by approximately 6.0 ml min-1 (1.73 m2)-1 per decade. 3. GFR values in women [105.9 +/- 16.0 ml min-1 (1.73 m2)-1, N = 43] were lower when compared to men [114.8 +/- 14.3 ml min-1 (1.73 m2)-1, N = 33]. 4. We conclude that the effect of sex and age must be taken into account when establishing reference values for GFR.

Adult↗