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Biomedical subjects

B Feldt-Rasmussen

Publications and source records attributed to B Feldt-Rasmussen.

107 records · Page 6Linked to original sources
PubMed1985

Exercise as a provocative test in early renal disease in type 1 (insulin-dependent) diabetes: albuminuric, systemic and renal haemodynamic responses.

The value of exercise as a provocative test for early renal disease in Type 1 (insulin-dependent) diabetes was re-evaluated. Three carefully characterized groups of males were studied: 10 non-diabetic controls, 16 diabetic patients (group 1) with normal urinary albumin excretion (less than 15 micrograms/min) and 14 Albustix-negative diabetics (group 2) with increased urinary albumin excretion (15-122 micrograms/min). Assignment to a study group was made on the basis of three 24-h urine collections, and the groups were well matched for age, weight, height, and serum creatinine concentration. The two diabetic groups were similar with regard to duration of disease (13 +/- 6 versus 16 +/- 3 years), metabolic control (HbA1c: 8.4 +/- 1.4 versus 8.7 +/- 1.3%) and degree of diabetic complications (beat-to-beat variation and retinopathy). An exercise protocol of 450 and 600 kpm/min workloads was employed. In the resting state group 2 patients had elevated systolic blood pressure compared with the normal subjects (132 +/- 13 versus 119 +/- 9 mmHg), and their glomerular filtration rate was significantly reduced compared with group 1 (123 +/- 19 versus 138 +/- 15 ml/min per 1.73 m2, p less than 0.05). During exercise the urinary albumin excretion rate increased significantly in all three groups (normal subjects: 6 +/- 0.7 to 8 +/- 1.3 (microgram/min); group 1: 6 +/- 0.6 to 9 +/- 1 microgram/min and group 2: 48 +/- 10 to 113 +/- 23 micrograms/min), the relative increase being higher in group 2 (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Short-term inhibition of prostaglandin synthesis has no effect on the elevated glomerular filtration rate of early insulin-dependent diabetes.

Glomerular filtration rate and renal plasma flow (constant infusion technique using 125I-iothalamate and 131I-hippuran) were measured twice within a 1-week interval in nine young males with insulin-dependent diabetes of short duration (2-5 years). The study was performed in a randomized double-blind design, with the patients receiving either indomethacin (150 mg/day) or placebo for 3 days before the study. Measures of metabolic control did not change. No differences were found in glomerular filtration rate (144 +/- 9 versus 144 +/- 9 ml/min X 1.73 m2, mean +/- S.E.M.) or renal plasma flow (579 +/- 43 versus 560 +/- 52 ml/min X 1.73 m2), when measured during placebo or indomethacin treatment, respectively. It is concluded that the steady-state enhancement of glomerular filtration rate and renal plasma flow found in early insulin-dependent diabetes is not due to an excessive activity of the prostaglandin system.

Adult↗
PubMed1985

Kinetic models for plasma disappearance of insulin in normal subjects.

Three theoretical kinetic models for plasma disappearance of insulin were examined in six normal men. The models allowed for the existence of non-saturable and/or saturable mechanisms. Constant infusion of porcine insulin at different rates was used to achieve different levels of steady state plasma insulin concentrations, while normoglycaemia was secured by a glucose clamp technique. Appropriate validation procedures demonstrated that one of the three models was superior to the others in describing the relationship between the exogenous insulin infusion rate Iex and the steady state plasma insulin concentration C: Iex = -Iend + k2 X C/(k3 + C), where Iend is the endogenous post-hepatic insulin delivery rate. Thus, only saturable mechanism(s) could be demonstrated. The median value of k2 (the maximal insulin disappearance rate) and k3 (the plasma insulin concentration at which the insulin disappearance rate is half maximal) were 7.31 nmol X min.-1 and 3.89 nmol X 1-1. The median value of k2/k3 (the clearance rate of insulin for infinitesimal plasma insulin concentrations) was 25.0 ml X kg-1 X min.-1. Thus, at physiological levels of plasma insulin concentrations the metabolic clearance rate of insulin is higher than insulin clearance estimates previously reported in studies based on the assumption of first order kinetics.

Adolescent↗
PubMed1985

The effect of metabolic control on hemodynamics in short-term insulin-dependent diabetic patients.

Hemodynamics variables (heart rate, arterial blood pressure, cardiac output, hepato-splanchnic blood flow, forearm blood flow, and plasma catecholamines) were measured during good (median blood glucose 4.7 mmol/L) and poor (median blood glucose 16.3 mmol/L) metabolic control in eight young, short-term, insulin-dependent diabetic patients. The measurements were performed twice within 2 wk, in random order. Continuous subcutaneous insulin infusion (CSII) was applied for 1 wk in order to obtain good control. All eight patients had elevated cardiac output (median 9%) and forearm blood flow (median 34%) during poor compared with good metabolic control, P less than 0.01. In contrast, hepato-splanchnic blood flow was lower (median 12%) during poor compared with good metabolic control, P less than 0.05. Heart rate remained unchanged, while mean arterial blood pressure was slightly higher during poor control, P less than 0.05. Five of six patients had elevated plasma noradrenaline concentration during poor metabolic control. Due to the small number of patients investigated, no valid conclusion regarding the activity of the sympathoadrenal system can be drawn. Our study suggests that both increased cardiac output and reduced hepato-splanchnic blood flow (redistribution) contribute to the elevated blood flow previously demonstrated in various other organs and tissues in diabetic patients during poor metabolic control.

Adult↗
PubMed1985

Enzyme immunoassay: an improved determination of urinary albumin in diabetics with incipient nephropathy.

An enzyme linked immunoadsorbent assay for urinary albumin using commercially available reagents is described. The assay range is 2.5-120 micrograms/l. When samples are analysed in two standard dilutions, the assayable albumin concentration range is 2.5-240 mg/l, covering the clinical range from normoalbuminuria to overt clinical nephropathy. Intra-assay variation was 2.1% and interassay variation 8.3%. Recovery of added albumin to urine was 95%-106% and dilution of urine was linear. The correlation to urinary albumin determined by immunodiffusion was excellent (n = 80, r = 0.99). Intraindividual variation of the 24 h urine albumin excretion of different days was high in patients with incipient diabetic nephropathy (51.5%) and was only slightly reduced by taking the variation of creatinine excretion into account (39.5%). No correlation was found between albumin excretion, and HbA1c or urine glucose excretion, indicating that minor metabolic variations are not responsible for the huge intraindividual day-to-day variations of UalbV. The study shows that more than one UalbV measurement must be done before classifying patients into groups with or without incipient diabetic nephropathy.

Adolescent↗
PubMed1984

Impaired autoregulation of glomerular filtration rate in type 1 (insulin-dependent) diabetic patients with nephropathy.

The effect of acute lowering of arterial blood pressure upon kidney function in nephropathy was studied in 13 patients with long-term Type 1 (insulin-dependent) diabetes. Ten normal subjects (six normotensive and four hypertensive) and five short-term Type 1 diabetic patients without nephropathy served as controls. Renal function was assessed by glomerular filtration rate (single bolus 51Cr-EDTA technique) and urinary albumin excretion rate (radial immunodiffusion). The study was performed twice within 2 weeks, with the subjects receiving an intravenous injection of either clonidine (225 micrograms) or saline (0.154 mmol/l). The arterial blood pressure was similar in the diabetic patients with nephropathy (mean 136 +/- 11 divided by 88 +/- mmHg) and in the non-diabetic control subjects (mean 140 +/- 25 divided by 92 +/- 15 mmHg). The clonidine injection induced similar reductions in mean arterial blood pressure in all three groups (16-18 mmHg). While glomerular filtration rate and urinary albumin excretion rate remained unchanged in both control groups after clonidine injection, glomerular filtration rate diminished from 78 to 71 ml/min per 1.73 m2 (p les than 0.01), and urinary albumin excretion declined from 1707 to 938 micrograms/min (p less than 0.01) in the patients with diabetic nephropathy. Our results suggest that an intrinsic vascular (arteriolar) mechanism underlying the normal autoregulation of glomerular filtration rate, i.e. the relative constancy of glomerular filtration rate that occurs in response to rather wide variations in perfusion pressure, is defective in diabetic nephropathy.

Adult↗
PubMedDate not supplied

The role of hypertension in the development of nephropathy in type 1 (insulin-dependent) diabetes mellitus.

Which comes first when developing clinical diabetic nephropathy, the blood pressure rise or the increasing urinary albumin excretion? This issue is discussed based on recent literature of studies in humans with Type 1 (insulin-dependent) diabetes mellitus. We conclude that hypertension has a central role in the progression of diabetic nephropathy and has deleterious effects on the life expectancy of patients who already have signs of diabetic renal disease in terms of elevated urinary albumin excretion. However, blood pressure is preceded by small increments of urinary albumin excretion rates, an indicator of universally increased vascular leakiness, and thus does not seem to be the cause of diabetic nephropathy.

Blood Pressure↗
PubMedDate not supplied

Hypertension in the course of insulin dependent diabetes mellitus and its pathogenetic mechanisms.

All IDDM patients without late complications have blood pressures similar to the nondiabetic background population, and those who develop clinical nephropathy in Denmark have no familial predisposition to hypertension. Blood pressure remains normal until after development of microalbuminuria, indicating no primary role for hypertension in the pathogenesis of nephropathy. When microalbuminuria is present it does, however, play a crucial role in the progression of nephropathy. Sodium retention, possibly induced by hyperinsulinemia, and perhaps glucose-coupled sodium reabsorption in insulin treated patients, seem to play a central role in elevating the blood pressure, but this needs further clarification.

Causality↗
PubMedDate not supplied

Microalbuminuria: an important diagnostic tool.

The concept of microalbuminuria is reviewed. Measuring the urinary albumin excretion rate and testing for microalbuminuria is well established in the control and treatment of patients with insulin-dependent diabetes mellitus. Microalbuminuria predicts nephropathy and early cardiovascular death. In the presence of microalbuminuria frequent examinations are warranted for early detection of retinopathy, blood-pressure rise, and for optimizing the glycemic control. In patients with non-insulin-dependent diabetes, the independent value of microalbuminuria as a cardiovascular risk factor is not yet clarified. The urinary albumin excretion rate should be measured at diagnosis, because the indications are that presence of microalbuminuria reinforces the urge to intervene against other well-documented cardiovascular risk factors (hypertension, dyslipidemia, tobacco, and obesity). In the nondiabetic population, there is accumulating evidence that an elevated urinary albumin excretion rate is associated with early cardiovascular morbidity and mortality. Large scale cross-sectional and prospective studies are needed in order to clarify further the role of microalbuminuria as an independent risk factor in the background population.

Albuminuria↗
PubMedDate not supplied

Microalbuminuria in insulin-dependent diabetes: prevalence and practical consequences.

Urinary albumin excretion in a representative sample of 679 patients with Type I (insulin-dependent) diabetes, 18 to 50 years of age, was investigated. Patients on antihypertensive therapy were excluded. Urinary albumin excretion was examined in one 24 hour urine sample using an ELISA technique. Twenty-three per cent of the patients had microalbuminuria, i.e., 30-300 mg albumin/24 h. The prevalence of microalbuminuria was independent of sex, age, insulin dose and diabetes duration. In the majority of those cases in which microalbuminuria was found during the first 10 years of diabetes, the concentrations were in the lower range, i.e., 30-50 mg/24 h. The prevalence of incipient nephropathy (urinary albumin excretion in a single urine sample of 51-300 mg/24 h) increased with diabetes duration. In patients with incipient nephropathy hemoglobin A1c tended to be, and blood pressure was, elevated compared with age, sex, and duration matched patients with normal urinary albumin excretion rates (p = 0.08 and p less than 0.001, respectively). Urinary albumin excretion and blood pressure were significantly correlated in the total group (n = 401, r = 0.2, p less than 0.001). On the basis of these findings practical guidelines for the handling of patients with microalbuminuria are proposed.

Adult↗
PubMedDate not supplied

Comparison of overnight, morning and 24-hour urine collections in the assessment of diabetic microalbuminuria.

With the aim of comparing different urine collection periods in the assessment of micro-albuminuria, urinary albumin excretion rates (AERs) were measured in samples from 24 h, overnight, and morning urine collections in 54 patients aged 17 to 62 years with insulin-dependent diabetes mellitus with a mean duration of 15 years. The AER in overnight urine was found to be reduced by 25% compared to the rate in 24 h and morning urine. Assessing the ability to predict a 24 h AER within the microalbuminuric range (20-200 micrograms/min) we found a sensitivity of 90% and a specificity of 88% for both overnight and morning urine samples. These values were slightly improved by relating AER to the excretion of creatinine and it is concluded that overnight as well as morning urine collections can be used when diagnosing microalbuminuria in insulin-dependent diabetics. Furthermore the results show that the albumin to creatinine ratio in morning urine is a reliable estimate of 24 h AER and better than measurement of the albumin concentration alone.

Albuminuria↗
PubMedDate not supplied

Elevated albumin excretion and retinal changes in children with type 1 diabetes are related to long-term poor blood glucose control.

All diabetic children (n = 113) under 19 years old and with more than 2 years of diabetes attending the Steno Memorial Hospital in 1987 were studied. Normal urinary albumin excretion (less than 30 mg 24 h-1) was found in 96 patients (85%), 15 had microalbuminuria (30-300 mg 24 h-1) (13%), and 2 patients were proteinuric (greater than 300 mg 24 h-1) (2%). Retinal morphology was evaluated by colour fundus photography. Background retinopathy was more frequent in the group with elevated albumin excretion (71%) than in a matched normoalbuminuric group (20%, 2p less than 0.001). Long-term blood glucose control was assessed from all previous HbA1c measurements in the hospital records, an average of nine per patient. The mean observation period was 48 (3-76) months. Children with elevated albumin excretion had a higher mean HbA1c than children with normal urinary albumin excretion (10.3 +/- 1.9 vs 9.2 +/- 1.3% (+/- SD), 2p less than 0.05). Children with retinopathy had an HbA1c of 9.9 +/- 1.7 vs 9.0 +/- 1.2% in patients without retinopathy (2p less than 0.01).

Adolescent↗
PubMedDate not supplied

Hypertension in diabetes as related to nephropathy. Early blood pressure changes.

We measured the blood pressure under standardized conditions in three groups of patients with type I (insulin-dependent) diabetes: group 1, patients with Albustix-negative urine and normal urinary albumin excretion rate below 20 micrograms/min; group 2, patients with Albustix-negative urine and elevated urinary albumin excretion rate 20 to 200 micrograms/min; and group 3, patients with Albustix-positive urine at the time of diagnosis of diabetic nephropathy, that is, proteinuria greater than 0.5 g/24 hr on four consecutive visits with an interval of more than 1 month. We also studied blood pressure data at the time of diagnosis of diabetes in patients with type I diabetes who later died with severe nephropathy (n = 84), and in those who survived their disease for more than 40 years (n = 256). Patients subsequently developing diabetic nephropathy could not be identified on the basis of systolic and/or diastolic blood pressure during the first 2 to 10 years of diabetes. Our study also demonstrated that the blood pressure in group 3 (147/93 mm Hg) was significantly higher than that in group 2 (135/86 mm Hg), which again was higher than that in group 1 (128/79 mm Hg). We concluded that arterial hypertension is an early feature in the developing of diabetic nephropathy, with blood pressure rising before the presence of clinical proteinuria.

Adolescent↗
PubMedDate not supplied

A prospective, randomized multicenter study comparing APD and CAPD treatment.

OBJECTIVE: The goals for maintenance dialysis treatment are to improve patient survival, reduce patient morbidity, and improve patient quality of life. This is the first randomized prospective study comparing automated peritoneal dialysis (APD) and continuous ambulatory peritoneal dialysis (CAPD) treatment with respect to quality of life and clinical outcomes in relation to therapy costs. DESIGN: A prospective, randomized multicenter study. SETTING: Three Danish CAPD units. PATIENTS: Thirty-four adequately dialyzed patients with high or high-average peritoneal transport characteristics were included in the study.Twenty-five patients completed the study. INTERVENTIONS: After randomization, 17 patients were allocated to APD treatment and 17 patients to CAPD treatment for a period of 6 months. Medical and biochemical parameters were evaluated at monthly controls in the CAPD units. Quality-of-life parameters were assessed at baseline and after 6 months by the self-administered short-form SF-36 generic health survey questionnaire supplemented with disease- and treatment-specific questions. Therapy costs were compared by evaluating dialysis-related expenses. MAIN OUTCOME MEASURES: Quality-of-life parameters, dialysis-related complications, dialysis-related expenses. RESULTS: The quality-of-life studies showed that significantly more time for work, family, and social activities was available to patients on APD compared to those on CAPD (p < 0.001). Although the difference was not significant, there was a tendency for less physical and emotional discomfort caused by dialysis fluid in the APD group. Sleep problems, on the other hand, tended to be more marked in the APD group. Any positive effect of APD compared to CAPD on dialysis-related hospital days or complication rates could not be confirmed. With larger patient samples, it is possible, however, that a significant difference might have been achieved. The running costs for APD treatment were US $75 per day and for CAPD treatment US $61 per day. CONCLUSION: If APD treatment can help to keep selected patients vocationally or socially active, paying the extra cost seems reasonable.

Denmark↗