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Biomedical subjects

R W Bilous

Publications and source records attributed to R W Bilous.

At least 55 records · Page 3Linked to original sources
PubMed1989

Mean glomerular volume and rate of development of diabetic nephropathy.

We studied kidney glomerular structure and function in two groups of type I (insulin-dependent) diabetic subjects with 14-16 yr (group 1, n = 16) and 24-26 yr (group 2, n = 13) duration of diabetes and compared them to a group of 18 nondiabetic subjects with similar age ranges. Within each diabetic group, subjects were selected for normal kidney function (urinary albumin excretion less than 40 mg/24 h, normal blood pressure, creatinine clearance greater than 90 ml.min-1.1.73 m-2) or for nephropathy (urinary albumin excretion greater than 200 mg/24 h). Morphometric analysis of glomeruli revealed a significantly larger mean glomerular volume in subjects with nephropathy (group 2). Mesangial volumes were significantly greater in the nephropathic than the normoalbuminuric diabetic subjects in each group, but filtration surface per glomerulus was constant among all subjects. The percentage of sclerosed glomeruli was also significantly increased in the nephropathic subjects compared with the subjects with normal kidney function, in whom sclerosed glomeruli did not exceed 8%. In addition, there was a significant correlation between percentage of globally sclerosed glomeruli and glomerular volume in group 2 (rs = .79, P less than .01) but not group 1 (rs = -.20, NS) subjects. Thus, glomerular size or individual capacity for glomerular expansion may determine the rate of progression of the loss of kidney function in subjects destined to develop diabetic nephropathy.

Adolescent↗
PubMed1989

The relationship between glomerular structure and function in insulin-dependent diabetes.

Diabetic nephropathy affects up to 40% of insulin dependent patients for reasons that are unclear. This review briefly describes the methodology of histological quantitative morphometry as applied to the human renal glomerulus and what the results tell us about the glomerular structural determinants of GFR. A case is made for the use of renal biopsy as an important part of studies of the diabetic kidney.

Anthropometry↗
PubMed1988

The epidemiology of hypothyroidism--an update.

Comparison of studies of the prevalence and incidence of hypothyroidism is hampered by differing definitions and population samples. Using a uniform set of diagnostic criteria, the prevalence of previously undiagnosed, spontaneous, overt hypothyroidism in community-based studies has been estimated between 2-4/1000 total population world-wide. If all cases of previously diagnosed hypothyroidism, previous thyroid surgery and radioiodine treatment are included, this prevalence rises to approximately 10/1000, and if subclinical cases are included, then the prevalence is probably over 50/1000 total population. The annual incidence of overt hypothyroidism is between 1-2/1000 for female and around 2/10,000 for males, with individuals having previously elevated TSH and positive circulating thyroid autoantibodies, being particularly at risk. The question of widespread population screening for hypothyroidism is unsettled, but it is probably not cost-effective unless incorporated as part of a screening programme for other conditions such as cervical cancer, or targeted at high risk groups such as post-menopausal women. The combination of serum TSH estimation and a high clinical index of suspicion should detect most patients with thyroid dysfunction, although detailed studies on the use of the more sensitive assays in the detection of both hyper- and hypothyroidism have yet to be published.

Female↗
PubMed1985

Conference on insulin pump therapy in diabetes. Multicenter study of effect on microvascular disease. Recruitment, Randomization, and baseline characteristics of the treatment groups.

The general and ophthalmologic eligibility criteria were applied in the course of formal screening of selected members of clinic populations at the six treatment centers between August 1980 and November 1981. Patients eligible on the grounds of the history and general physical examination underwent a detailed ophthalmologic examination and determination of C-peptide status. Initial rates of recruitment were slow, which occasioned modifications of the eligibility criteria and a prolongation of the recruitment phase. All six clinics approached their goal of at least six patients in each of the continuous subcutaneous insulin infusion (CSII) and conventional insulin treatment (CIT) groups, with a final total of 70 randomized subjects. The method of paired randomization was acceptable, but led to some delay during periods of slow recruitment activity. Data from two patients who chose to drop out of the study shortly after randomization are included in the baseline characteristics. There was no difference between treatment groups with respect to age or duration of known diabetes, body weight, systolic blood pressure, proportion of cigarette smokers, retinopathy level as assigned by analysis of stereofundus photographs, or microaneurysm counts performed on fluorescein angiograms. A trend toward milder retinopathy in the CIT group proved to be statistically insignificant. Subsequent assessment of stereofundus photographs at the Fundus Photograph Reading Center indicated that six patients were misclassified by treatment center ophthalmologists with respect to ophthalmologic eligibility. We conclude that recruitment goals were met and randomization was successful.

Adolescent↗
PubMed1985

Eight-month correction of hyperglycemia in insulin-dependent diabetes mellitus is associated with a significant and sustained reduction of urinary albumin excretion rates in patients with microalbuminuria.

Persistent Albustix-positive proteinuria and subsequent chronic renal failure are frequently encountered in insulin-dependent diabetes mellitus (IDDM). Rates of decline of renal function may be modified by treatment of accompanying hypertension, but studies of the effects of long-term continuous subcutaneous insulin infusion (CSII) on deterioration of renal function provide no statistically significant evidence of benefit of near-normoglycemia. However, short-term studies in IDDM subjects with negative Albustix tests but subclinically raised levels of albumin excretion rate (AER) have shown that treatment with CSII significantly reduces this microalbuminuria. The prospective, controlled 8-mo Kroc Collaborative Study therefore offered the opportunity of examining more protracted effects of CSII-induced metabolic correction upon microalbuminuria. Twenty-four-hour urine collections obtained at baseline, 4, and 8 mo were available from 59 Albustix-negative patients. Beta 2-microglobulin excretion was normal. The 39 normoalbuminuric (AER less than 12 micrograms/min) patients did not differ from the 20 microalbuminuric (AER elevated between 13.2 and 192.6 micrograms/min) with respect to distributions of age, sex, and duration of diabetes. In both the normoalbuminuric and the microalbuminuric groups studied at 4 and 8 mo, percent glycosylated hemoglobin (%HbA1) and mean blood glucose were significantly decreased during CSII compared with baseline values, whereas no change occurred in the group continuing their conventional insulin therapy (CIT). AER did not differ between CIT and CSII treatments in the normoalbuminuric group. AER fell significantly in the CSII-treated microalbuminuric patients at 4 (P less than 0.05) and 8 (P less than 0.01) mo but showed no consistent change in the CIT microalbuminuric group.(ABSTRACT TRUNCATED AT 250 WORDS)

Albuminuria↗
PubMed1984

Metabolic effects of physical exercise in insulin-dependent diabetics controlled by continuous subcutaneous insulin infusion or conventional injection therapy.

The metabolic and hormonal response to moderately severe exercise 2 h after breakfast was assessed in 8 insulin-dependent diabetics during conventional insulin injection therapy and after 3 weeks of continuous sc insulin infusion. Blood glucose fell from 12.1 to 4.4 mmol/l on injection therapy; this was accompanied by a significant rise (P less than 0.05) in free insulin to 57 mU/l. On infusion therapy plasma glucose fell and stabilised at 3.6 mmol/l from pre-exercise levels of 7.1 mmol/l, while free insulin level was unchanged at the end of the exercise period (31 mU/l). The fall in blood glucose on injection therapy was accompanied by an exaggerated growth hormone response to exercise that was normalised by 3 weeks of infusion therapy. Basal and post-prandial levels of intermediary metabolites, catecholamines and glucagon were comparable on the two insulin regimens. Responses during exercise were generally similar and no different from those of normal subjects, with the exception of plasma NEFA levels which became abnormally suppressed. Good metabolic control of diabetes is thus accompanied by nearly normal hormonal and metabolic response to moderately severe exercise.

Adult↗
PubMed1983

Severe diabetic microangiopathy with normal glucose tolerance and pituitary infarction.

Blood glucose concentrations in a woman with severe retinopathy, nephropathy, and neuropathy were found to be within the normal range. A high random blood glucose concentration was recorded only once, six months before her initial presentation. At necropsy the anterior lobe of the pituitary gland showed old, extensive infarction. Occult pituitary hypofunction may explain severe diabetic microangiopathy in patients with normal glucose tolerance.

Adult↗
PubMed1983

Long term correction of hyperglycaemia and progression of renal failure in insulin dependent diabetes.

The effect of long term correction of hyperglycaemia on the rate of deterioration of renal function was studied in six insulin dependent diabetics with proteinuria due to diabetic nephropathy. After a planned run in observation period of 10 to 24 months patients entered a programme of continuous subcutaneous insulin infusion for up to 24 months. Glycaemic control was promptly and significantly improved and optimal glycaemic values sustained throughout the study. Blood pressure was maintained stable. A control group of six nephropathic diabetics was studied receiving conventional insulin injection treatment but also with blood pressure control over the same period.Despite greatly improved metabolic control in the infusion treated group no significant change in the rate of decline of glomerular filtration rate could be shown, the plasma creatinine concentrations continued to increase, and the fractional clearance of albumin and IgG rose progressively, indicating progression of glomerular damage. The conventionally treated control group behaved similarly. In a single patient receiving the continuous infusion the rate of decline of the glomerular filtration rate slowed considerably, suggesting that the response to strict diabetic control may differ in some patients.These findings suggest that by the time glomerular function has started to fail in diabetic nephropathy the process culminating in end stage renal failure has become self perpetuating and is little influenced by the degree of metabolic control. A new definition of potential clinical diabetic nephropathy is proposed that will permit identification of patients at risk and earlier intervention by glycaemic correction in an attempt to arrest diabetic renal disease.

Adult↗
PubMed1983

Monitoring glomerular function in diabetic nephropathy. A prospective study.

Glomerular function was monitored prospectively in 13 patients with insulin-dependent diabetes and diabetic nephropathy for up to 51 months. Glomerular filtration rate, measured by 51Cr-EDTA clearance, showed a linear decline in all patients. Rates of fall ranged between 0.63 and 2.4 ml/minute per month (mean +/- SEM 1.2 +/- 0.16). Plasma creatinine concentration proved to be an insensitive marker of glomerular function, especially in the early phase of nephropathy. A good correlation was found between the rate of change of 51Cr-EDTA glomerular filtration rate and that of inverse creatinine levels when plasma creatinine concentrations exceeded 200 mumol/liter. Inverse plasma beta 2-microglobulin concentrations, however, showed a highly significant correlation (r = 0.93; p less than 0.001) with 51Cr-EDTA glomerular filtration rate over the whole range of values, making it sensitive in screening for early impairment of renal function. A significant relationship (r = 0.85; p less than 0.01) was found between the rates of change of the 51Cr-EDTA glomerular filtration rate and of inverse beta 2-microglobulin levels for plasma beta 2-microglobulin concentrations above 3 mg/liter. A progressive increase in the fractional clearance of albumin, IgG, and beta 2-microglobulin was noted as the glomerular filtration rate fell, indicating an evolving defect in the renal handling of proteins. The rate of decline of the glomerular filtration rate was unrelated to age, sex, duration of diabetes, duration of diabetes before onset of proteinuria, glomerular filtration rate, initial albumin clearance, blood glucose control, and arterial pressure, when diastolic values were below 100 mm Hg. The effect of therapeutic intervention (e.g., blood glucose, blood pressure, or diet) on the progression of diabetic nephropathy can be reliably evaluated by precise measures of rate of decline of glomerular filtration rate and changes in fractional clearance of plasma proteins. The factor(s) determining the individual rate of decline of renal function still remain obscure.

Adult↗
PubMed1982

Safety of continuous subcutaneous insulin infusion: metabolic deterioration and glycaemic autoregulation after deliberate cessation of infusion.

To assess the rate of metabolic deterioration and potential risks of failure of continuous subcutaneous insulin infusion during basal insulin delivery, we deliberately stopped infusion in nine insulin dependent diabetics. Plasma glucose, blood 3-hydroxybutyrate and plasma free insulin were measured for 9 h whilst the patients remained supine and fasting. Mean plasma glucose remained unchanged at normal fasting levels for the first hour, then rose to plateau at about 10 mmol/l until the end of the experiment. The final plateau level of glucose varied from patient to patient; two C-peptide secreting diabetics plateaued at low glucose levels. In contrast, blood 3-hydroxybutyrate rose progressively, without plateauing. PLasma free insulin concentrations fell during the withdrawal period and there was a highly significant negative correlation between free insulin and 3-hydroxybutyrate. No patient was more than mildly unwell after 9 h of insulin deprivation. We conclude that under these experimental conditions there is glycaemic autoregulation and that ketones may sometimes be a more appropriate monitor of insulin deficiency or loss of diabetic control than is glucose. Accidental failure of continuous subcutaneous insulin infusion and interruption of basal delivery in resting and fasting diabetics will probably not cause dangerous metabolic or clinical deterioration.

3-Hydroxybutyric Acid↗
PubMed1982

Proteinuria in diabetes mellitus: role of spontaneous and experimental variation of glycemia.

The excretion rates of albumin, IgG and beta 2-microglobulin were studied in insulin-dependent diabetic patients with (Albustix positive) and without (Albustix negative) clinical proteinuria and in a group of nondiabetic controls. In patients negative for clinical proteinuria, the mean excretion rate of albumin and IgG was increased but that of beta 2-microglobulin was normal. HbA1, a measure of excess glycemia, was positively correlated with both albumin and IgG urinary excretion rates. Vigorous correction of glycemic control significantly reduced IgG excretion in nine patients. In patients positive for clinical proteinuria, albumin and IgG clearances were inversely correlated with GFR, the filtration of IgG increasing relatively more than that of albumin as GFR declined. A negative hyperbolic correlation was found between GFR and beta 2-micro-globulin excretion. In this group HbA1 was unrelated to excretion rates or clearances of albumin and IgG. In clinically proteinuric patients, long-term correction of hyperglycemia by continuous subcutaneous insulin infusion failed to check the increasing albumin and IgG filtration. The microproteinuria of diabetes is glomerular in origin, is influenced by prevailing glycemia, and is reversible by vigorous glycemic control. In the clinically proteinuric phase, by contrast, selectivity is progressively lost and, as GFR falls, proteinuria becomes of a mixed glomerular and tubular origin. There is no evident association with prevailing glycemia, and metabolic near-normalization dose not appear to affect progression over the period of observation considered. This study suggests that clinical proteinuria denotes the installation of a self-maintaining process, largely independent of the diabetic metabolic disturbance which gave rise to it. Prevention of clinical diabetic nephropathy by metabolic correction may be achievable only in the phase of early microproteinuria.

Adult↗
PubMed1981

Patient reactions to long-term outpatient treatment with continuous subcutaneous insulin infusion.

Fourteen of the first 15 insulin-dependent diabetics to be treated in our unit by three weeks or more of outpatient continuous subcutaneous insulin infusion with a portable syringe pump completed a questionnaire about their reactions to the system. Motivation was more important to a favourable response than occupation or intelligence. Most patients thought that diabetic control was better with the pump than conventional injection treatment and several felt subjectively better. Features such as the greater flexibility of diet and insulin delivery rates during continuous subcutaneous infusion were appreciated. The most consistent adverse criticism was about the size of the device used, nearly all patients thinking that smaller and lighter infusion systems should be developed. Psychological reactions to the infusion and difficulties with interpersonal relationships were identified; these must be clearly appreciated and discussed with patients and family before and during treatment. Nine of the 14 patients said they would undertake continuous subcutaneous infusion for one year and a further two said they would do so if the infuser was smaller. These results provide guidance on future technological development of continuous subcutaneous insulin infusion and indicate that the major constraint to long-term trials of the present system is the size of the pump.

Activities of Daily Living↗
PubMed1981

Management of severely brittle diabetes by continuous subcutaneous and intramuscular insulin infusions: evidence for a defect in subcutaneous insulin absorption.

Severely brittle diabetes is defined as a rare subtype of insulin-dependent diabetes with wide, fast, unpredictable, and inexplicable swings in blood glucose concentration, often culminating in ketoacidosis or hypoglycaemic coma. To assess the role of inappropriate type, amount, or timing of insulin treatment and the route of administration as a cause of severe brittleness six patients with continuous subcutaneous insulin infusion, which provides a high degree of optimisation of dosage with exogenous insulin in stable diabetics. The glycaemic control achieved during continuous subcutaneous insulin infusion was compared with that during continuous intramuscular insulin infusion. Six patients with non-brittle diabetes were also treated by continuous subcutaneous insulin infusion. These patients achieved the expected improvement in glycaemic control (mean +/- SD plasma glucose concentration 5.1 +/- 2.3 mmol/l (92 +/- 41 mg/100 ml)), but not the patients with brittle diabetes remained uncontrolled with continuous subcutaneous infusion (13.6 +/- 5.8 mmol/1 (245 +/- 105 mg/100 ml) compared with 10.3 +/- 4.1 mmol/l (186 +/- 74 mg/100 ml) during treatment with optimised conventional subcutaneous injections). During continuous intramuscular infusion, however, glycaemic control in five of the patients with brittle diabetes was significantly improved (7.7 +/- 2.6 mmol/l (139 +/- 47 mg/100 ml). The remaining patient with brittle diabetes, previously safely controlled only with continuous intravenous insulin, did not respond to continuous intramuscular infusion. It is concluded that in five of the six patients with brittle diabetes studied here impaired or irregular absorption of insulin from the subcutaneous site played a more important part in their hyperlability than inappropriate injection strategies. This absorption defect was presumably bypassed by the intramuscular route.

Absorption↗
PubMed1981

Correction of exercise-induced microalbuminuria in insulin-dependent diabetics after 3 weeks of subcutaneous insulin infusion.

The effect of metabolic near-normalization, induced by continuous subcutaneous insulin infusion, on the exaggerated microalbuminuria of exercise was studied in eight insulin-dependent diabetic men selected for normal resting albuminuria. Patients were studied in randomized order during the ordinary glycemic control of conventional insulin treatment (CIT) and after 3 wk of "super-control" with continuous subcutaneous insulin infusion (CSII). Seven age-matched healthy men were used as controls. In the diabetics the albuminuric response to fixed-load bicycle exercise (600 kpm/min for 20 min) during CIT greatly exceeded that of the normal controls (P less than 0.01). After 3 wk of optimal plasma glucose control, urinary albumin excretion rates in response to the same exercise load were significantly reduced (P less than 0.02) in the diabetics and became statistically indistinguishable from that of the normal controls. The urinary excretion rate of beta 2-microglobulin, an index of tubular function, was not increased significantly by exercise either during CIT or CSII. The plasma glucose fall after exercise was greater (P greater than 0.001) on CIT (8.5 +/- 0.9 mmol/L) than on CSII (4.0 +/- 0.6 mmol/L). The pulse rate acceleration in response to exercise was significantly reduced after 3 wk of CSII (P less than 0.05). The exercise-induced systolic blood pressure rise was similar in controls and diabetics on both therapeutic regimens. Thus, a period of metabolic near-normalization in the diabetic corrects the abnormal transglomerular passage of albumin induced by moderately strenuous muscular exercise and reduces the exercise tachycardia. Improved control with CSII appears to reduce greatly the risk of exercise-induced hypoglycemia, despite much tighter glycemic control.

Adult↗