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P Pontuch

Publications and source records attributed to P Pontuch.

8 recordsLinked to original sources
PubMed1992

Urinary excretion of retinol-binding protein in type 1 (insulin-dependent) diabetic patients with microalbuminuria and clinical diabetic nephropathy.

The urinary excretion of retinol-binding protein (RBP) was studied in 101 insulin-dependent diabetic patients allocated to three groups according to 24-h urinary albumin excretion rate (UAE) (median of three urine collections): group 1 (n = 45), normal UAE less than 30 mg/24 h; group 2 (n = 27), microalbuminuria (UAE 30-300 mg/24 h); and group 3 (n = 29), clinical diabetic nephropathy (UAE greater than 300 mg/24 h). We used 23 healthy subjects as controls. Fractional clearance of RBP (FC-RBP) and its 24-h urinary excretion rate (URBP) were higher in each diabetic group than in healthy subjects, the highest values being found in group 3. Groups 1 and 2 did not differ in URBP and FC-RBP. There was a correlation between FC-RBP and haemoglobin A1c in both the total diabetic cohort (P less than 0.001) and in diabetic patients in groups 1 and 2 with a glomerular filtration rate of more than 90 ml/min (P less than 0.05). No correlation was found between FC-RBP and UAE and/or duration of diabetes in any of the diabetic groups. We conclude that the increased urinary excretion of RBP, indicating proximal tubular dysfunction, is already present in normoalbuminuric insulin-dependent diabetic patients and correlates with metabolic control. Further deterioration in proximal tubular function was not observed in microalbuminuric patients, but is a late event in clinical diabetic nephropathy.

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PubMed1991

[The importance of albuminuria in the detection of diabetic nephropathy and its relation to the development of retinopathy and autonomic neuropathy in type I diabetes].

A series of 72 type I diabetics was grouped according to the mean value of 24-h albuminuria (AU) determined from three 24-h urine collections: group A (n = 49, normoalbuminuria, AU less than or equal to 26 mg/24 h), group B (n = 16, microalbuminuria, AU less than or equal to 26 mg/24 h), group C (n = 7, clinically significant proteinuria, AU greater than 260 mg/24 h). Glycosylated hemoglobin (GHb) was examined five times in three-month intervals. Systolic and diastolic blood pressure (BPs and BPD) were determined from four values taken in the course of one year. Glomerular filtration (GF) was established a single examination of 24-h creatinine clearance. Fluorescent angiography was used to examine the fundus of the eye. The function of the cardiovascular autonomic nervous system was assessed on the basis of three tests: variation of heart rate during deep respiration, response of heart rate to upright position, Valsalva's maneuver. Group C had the longest duration of diabetes, the highest GHb, the lowest GF, and the highest BPS and BPD values. The number of diabetics with different findings on the fundus of the eye (normal finding/simple retinopathy/preproliferative and proliferative retinopathy) was as follows: group A--15/31/3, group B--9/6/1, group C--0/3/4. Group C exhibited the most pronounced derangement of the cardiovascular autonomic nervous system, whose extent depended on the length of diabetes duration and on the quality of metabolic compensation. Between the groups A and B no significant differences were found in any of the parameters studied.(ABSTRACT TRUNCATED AT 250 WORDS)

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PubMed1989

[Comparison of the glomerular filtration rate using renal plasma clearance of 51Cr-EDTA and biochemical methods].

In 22 patients (age 19 to 73 years) the authors examined the glomerular filtration by assessing the renal clearance of 51Cr-EDTA in addition to the plasmatic method with several blood samples, methods with a smaller number of blood samples and external assessment of the radioactivity, or else by estimation of the creatinine clearance by biochemical methods. They used as the reference method assessment of the renal plasma clearance of 51Cr-EDTA by means of a one-compartment model from the radioactivity of blood samples collected during the 60th, 120th and 180th minute. It was revealed that for the normal value of glomerular filtration (GF = 1.8 ml/s) and for its reduced value (GF = 0.5 ml/s), as compared with the reference method RP, the highest external and internal accuracy, i.e. the best agreement with the reference method and the closest interval estimates, are obtained by the single sample method RE (blood sample during the 120th minute), supplemented by three external assessments of radioactivity during the 50th-70th, 110th-130th and 170th-190th minute. The regression relationship of these methods is expressed by the following equations: RE = -8.9 + 1.06 . RP; RP = 8.47 + 0.94 . RE. The biochemical methods were, as compared with the radionuclide ones, less accurate. Their accuracy declined in the order from the calculated creatinine clearance according to Cockcroft and Gault via the inverse value of the serum creatinine concentration towards the 24-hour creatinine clearance.

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PubMedDate not supplied

Effect of the exercise test on albuminuria, blood pressure and blood glucose in type I (insulin-dependent) diabetic patients.

Twenty-nine male type I diabetic patients (age range 16-46 years) and thirteen healthy men (age range 18-43 years) were exercised on a cycling ergometer at 75 W and 100 W after having achieved a steady state of water diuresis. Diabetic patients were subdivided into Group A (n = 19, resting urinary albumin excretion rate - UAER less than or equal to 16 micrograms/min) and Group B (n = 10, 16 less than resting UAER less than 126 micrograms/min). The groups were comparable in weight, serum creatinine, duration of diabetes and glycosylated hemoglobin. Group B showed the highest elevation of UAER at the work load of 100 W, with no correlation between increase in UAER and increase in systolic blood pressure (SBP) at both work loads. The only correlation between these parameters was found in Group A at the work load of 100 W (p less than 0.05). No correlation was found between exercise UAER and actual blood glucose in either group. The difference in UAER between healthy subjects and Group B patients (p less than 0.001) remained on the same level during exercise as at rest, but the difference between Group A and Group B (p less than 0.001) decreased with increasing work load (p less than 0.05). The highest exercise-induced systolic and diastolic blood pressure (DBP) was found in Group B, although there was no difference between the diabetic groups in pre-exercise blood pressure and in mean SBP and DBP from previous outpatient check-ups. Blood glucose did not change significantly during exercise in either diabetic group. Working capacity of diabetic patients was lower than that of healthy subjects. The test revealed some diabetic patients with strong elevation of UAER and with abnormally raised systolic and diastolic BP during exercise. The value of the findings reported is to be clarified in a further longitudinal study.

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PubMedDate not supplied

Relationship between nephropathy, retinopathy, and autonomic neuropathy in patients with type I diabetes.

Seventy-two Type I diabetic patients were divided into three groups according to 24 hour urinary albumin excretion (UalbV, mean of three urine collections): normoalbuminuric group 1 (n = 49, UalbV less than or equal to 26 mg/24 h), microalbuminuric group 2 (n = 16, 26 less than UalbV less than or equal to 250 mg/24 h), proteinuric group 3 (n = 7, UalbV greater than 250 mg/24 h). Fluorescein angiography and three cardiovascular autonomic tests were performed. Relative frequencies of ocular findings (no retinopathy/simplex retinopathy/preproliferative and proliferative retinopathy) were determined in each group: group 1 (0.31/0.63/0.06), group 2 (0.56/0.38/0.06), and group 3 (0/0.43/0.57). The most severely affected autonomic function was observed in group 3 (p less than 0.01 vs. group 1). Significant partial correlations were found between UalbV and retinopathy (p less than 0.01), UalbV, and autonomic neuropathy (p less than 0.05), retinopathy and autonomic neuropathy (p less than 0.01), and blood pressure and UalbV and/or autonomic neuropathy (p less than 0.01). No correlation was found between the variables and the previous 15 months' metabolic control. The results suggest that nephropathy, retinopathy, and autonomic neuropathy are signs of a generalized diabetic microangiopathic process whose progression may be influenced by factors other than diabetes duration and metabolic control.

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