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Biomedical subjects

U Adamson

Publications and source records attributed to U Adamson.

At least 19 recordsLinked to original sources
PubMed1992

Arterial, arterialized venous, venous and capillary blood glucose measurements in normal man during hyperinsulinaemic euglycaemia and hypoglycaemia.

The purpose of this study was to evaluate the effectiveness of the warm-air box method on the arterialization of venous blood during euglycaemia and hypoglycaemia. Six healthy male volunteers were studied using an i.v. infusion of insulin (144 mU.kg-1.h-1). Arterial blood glucose was clamped at the baseline level for the first 30 min and subsequently reduced to 3.2 and to 2.5 mmol/lf or 20 min. At each stage, including prior to insulin infusion, arterial, arterialized venous (heating the hand in a warm-air box set to 55-60 degrees C), venous and capillary blood samples were taken simultaneously for analyses of blood glucose and oxygen saturation (not for capillary blood). The oxygen saturations in arterialized blood were approximately 3% below the arterial values. The arterial-arterialized difference of blood glucose was about 0.1 mmol/l (the 95% confidence interval: from -0.19 to 0.41 mmol/l), which tended to correlate with the difference in oxygen saturations between the arterial and arterialized blood samples (r = 0.25, p = 0.08). During the test the forearm venous blood oxygen saturation increased by 9% and the arteriovenous difference in blood glucose ranged from 0.2 to 0.5 mmol/l which correlated significantly with the difference in oxygen saturations (r = 0.48, p less than 0.001). Capillary glucose was similar to the arterialized value. Rectal temperature was stable during the experiment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Stressful life events and Graves' disease.

The role of stressful life events in the onset of Graves' disease (toxic diffuse goitre) is controversial. However, the numerous early clinical reports that supported such an association were not adequately controlled and specificity of the diagnosis could be questioned. Later studies have not shown a causal relation, but these studies were small, did not have proper controls, or epidemiological methods were inappropriate. To assess possible associations between life events, heredity, social support, and Graves' disease, we have done a population-based case-control study in a defined area with about 1 million inhabitants. Over 2 years, 208 (95%) of 219 eligible patients with newly-diagnosed Graves' disease and 372 (80%) of all selected matched controls answered an identical mailed questionnaire about marital status, occupation, drinking and smoking habits, physical activity, familial occurrence of thyroid disease, life events, social support, and personality. Compared with controls, patients claimed to have had more negative life events in the 12 months preceding the diagnosis, and negative life-event scores were also significantly higher (odds ratio 6.3, 95% confidence interval 2.7-14.7, for the category with the highest negative score). Individuals who had relatives with thyroid disease (especially first-degree and second-degree relatives) were more likely to have Graves' disease (3.6, 2.2-5.9). Slightly more patients than controls were divorced (1.8, 1.0-3.3) and reported a less frequent intake of alcohol (0.4, 0.2-0.8). When results were adjusted for possible confounding factors in multivariate analyses, risk estimates were almost unchanged. These findings indicate that negative life events and hereditary factors may be risk factors for Graves' disease.

Adult↗
PubMed1991

Insulin absorption is faster when keeping the infusion site in use for three days during continuous subcutaneous insulin infusion.

To evaluate the possible influence of regular infusion site changes on insulin absorption, fifteen type 1 diabetic patients using continuous subcutaneous insulin infusion (CSII) were studied on four occasions: the first day after an infusion site was settled, again the first day after a new infusion site was utilized and the two fourth days after the two infusion sites had been used for three days. A bolus of insulin (1 U/10 kg of body weight) was infused by the pump in the lower para-umbilical region. Plasma free insulin and blood glucose levels were determined before and during 240 min of the study at 30-min intervals. It was found that the peak times extracted from the individual insulin curves were shorter in 17 out of 23 curves when the fourth day was compared with the first day and the mean value of peak time of the fourth day was significantly shorter than that of the first day (56 +/- 11 vs 110 +/- 15 min, P less than 0.01). The mean area under the insulin curves during the first hour of the study tended to increase on the fourth day compared to that of the first day (25 +/- 2.2 vs 21 +/- 2.1 mU.l-1.min, P = 0.12). The decremental area of blood glucose on the fourth day was larger than on the first day (405 +/- 111 vs 82 +/- 160 mmol.l-1.min, P less than 0.05). We conclude that during CSII, the absorption rate of the injected insulin bolus is faster when the infusion site has been in use continuously for three days.

Absorption↗
PubMed1991

Insulin clearance during hypoglycemia in patients with insulin-dependent diabetes mellitus.

Eight male patients with insulin-dependent diabetes mellitus (IDDM) without residual beta-cell function were studied on two occasions in random order. In one experiment hypoglycemia was induced by a constant rate iv infusion of insulin (0.034 U/kg/h) during 150 minutes. At the other occasion an identical infusion of insulin was given, but this time euglycemia was maintained by a variable iv infusion of glucose. Plasma levels of free insulin were almost identical during the two experiments indicating that insulin clearance is not influenced by hypoglycemia in patients with IDDM.

Adult↗
PubMed1991

Experience of long-term intraperitoneal insulin treatment using a new percutaneous access device.

A pilot study was conducted to determine the efficacy of a new percutaneous device, designed to help to deliver insulin from an external, multiprogrammable pump to the abdominal cavity in patients with Type 1 (insulin-dependent) diabetes. Six patients received intraperitoneal insulin therapy for 15-24 months, a total experience of 9.4 patient-years. Glycosylated haemoglobin stabilized at 7.6 +/- 0.7% with no change in insulin dose. Four patients had to submit to reimplantation after 30 to 60 weeks. One patient met with inconvenient location of the device and three had blockage of the system. In four patients treatment had to be interrupted due to blockage of the intraperitoneal catheter by omental-tissue encapsulation. In two of those patients this blockage was combined with deeper infections. In another patient treatment had to be interrupted due to chronic, local, subcutaneous infection.

Adult↗
PubMed1991

A high concentration of circulating insulin suppresses the glucagon response to hypoglycemia in normal man.

In an attempt to clarify whether circulating insulin per se exerts an inhibitory effect on the hormonal responses to hypoglycemia, with special emphasis on glucagon secretion, nine healthy volunteers were exposed to low dose (244 pmol/kg.h) and high dose (1034 pmol/kg.h) iv insulin infusions for 3 h on two separate occasions. A close to identical arterial hypoglycemia of about 3.4 mmo/L was obtained in both tests by glucose clamping during the high dose test. The corresponding glucose concentration in the venous blood was significantly lower in the high dose test (2.5 +/- 0.1 vs. 3.0 +/- 0.1 mmol/L; P less than 0.01), while the plasma free insulin level was 4 times higher in the high dose test (897 +/- 50 vs. 208 +/- 14 pmol/L). Plasma glucagon was elevated in both experiments, but its rise was reduced during the high dose test after 1 h, yielding an incremental area under the glucagon curve that was significantly smaller than that obtained during the low dose test (213 +/- 70 vs. 348 +/- 81 ng/L.h; P less than 0.05). The plasma adrenaline, noradrenaline, GH, C-peptide, pancreatic polypeptide, and somatostatin profiles were similar in the two tests. We conclude that an inhibitory effect of circulating insulin on the glucagon response to hypoglycemia can be demonstrated in normal man during an infusion of insulin yielding a plasma concentration of about 900 pmol/L. The responses of other hormones studied are not significantly influenced by the circulating insulin level.

Adult↗
PubMed1990

Permanent neuropsychological impairment after recurrent episodes of severe hypoglycaemia in man.

Seventeen Type 1 (insulin-dependent) diabetic patients with a history of recurrent and severe hypoglycaemia and Type 1 diabetic patients with no severe hypoglycaemia were compared as regarded performances in tests of neuropsychological functioning. To test the hypothesis that recurrent severe hypoglycaemia gives rise to permanent cognitive impairment, the study group was selected among those patients who had met with repeated attacks over the last three years or more as identified by a questionnaire among almost 600 insulin-treated diabetic patients. The comparison group without known severe reactions were comparable to the study group with respect to type of diabetes, sex, age, age at onset, duration of diabetes, socio-economic parameters, and prevalence of neuropathy and retinopathy. The results indicate that Type 1 diabetic patients with recurrent severe hypoglycaemia scored lower than those without severe hypoglycaemia in tests of motor ability, short-term and associative memory and visuospatial tasks assessing ability in general problem-solving. Type 1 diabetic patients with severe hypoglycaemia also displayed a higher frequency of perspective reversals suggesting frontal-lobe involvement. These data can be interpreted in two ways. One interpretation implies that the cognitive impairment of Type 1 diabetic patients with severe hypoglycaemia reflects a selection factor, the other that recurrent episodes of severe hypoglycaemia result in permanent cognitive impairment.

Cognition↗
PubMed1990

Exogenous somatostatin raises plasma insulin levels in patients with insulin-dependent diabetes mellitus.

The effect of cyclic somatostatin on circulating insulin levels was studied in eight patients with insulin-dependent diabetes mellitus (IDDM). The study was performed after an overnight fast when their subcutaneous depots of insulin had been depleted during i.v. insulin substitution for 18 hours. A constant rate i.v. insulin infusion (0.4 mU/kg/min) was given for 240 min and somatostatin was co-infused between 60-120 min (100 micrograms/h) and 180-240 min (250 micrograms/h) respectively. Plasma insulin, blood glucose and hematocrit were measured at 15 min intervals. Hematocrit fell from 41.7 to 38.3% during the study period. Somatostatin increased the plasma insulin levels, corrected for the changes of hematocrit, by approximately 8% in the low dose (P less than 0.05) as well as in the high dose (P less than 0.05) period. It is concluded that somatostatin interferes with the clearance of insulin thereby increasing the circulating plasma insulin levels in IDDM patients without residual insulin secretion.

Adult↗
PubMed1990

Prevalence of anti-insulin antibodies and its relation to severe hypoglycaemia in insulin-treated diabetic patients.

The prevalence of anti-insulin antibodies (AIABs) and their association with clinical parameters, metabolic control and severe hypoglycaemia were investigated in a geographically defined population of insulin-treated diabetic patients. Eighty per cent of the patients (479) delivered venous blood samples and answered a questionnaire on severe hypoglycaemic problems during a 12-month period. Circulating AIABs were demonstrable in 78% of the patients, being more common among those with type 1 diabetes and in long-duration patients. High levels of AIABs were also more frequent in patients in whom insulin treatment had been initiated prior to the era of highly purified insulins. The AIABs did not correlate to metabolic control, insulin dose or severe hypoglycaemia. It is concluded that AIABs is not a risk factor for severe hypoglycaemia in insulin-treated diabetic patients.

Adult↗
PubMed1990

A comparative study on the hormonal responses to insulin-induced hypoglycaemia using semisynthetic human insulin and pork insulin in patients with type 1 diabetes mellitus.

In order to enlighten the controversy on whether human and pork insulin result in different hormonal responses to insulin-induced hypoglycaemia, eight C-peptide negative, diabetic patients without measurable circulating insulin-binding antibodies were exposed to insulin-induced hypoglycaemia in random order with highly purified pork insulin (Actrapid) and semisynthetic human insulin (Actrapid Human). Hypoglycaemia was provoked by a constant rate IV infusion of insulin (0.034 U kg-1 h-1) for 3 h after which the blood glucose recovery was assessed for an additional period of 60 min. Both insulin preparations gave close to identical responses for glucose, glucagon, growth hormone, adrenaline, and somatostatin. The circulating noradrenaline levels were higher during the infusion of pork insulin which also yielded a more prominent response of pancreatic polypeptide and, after cessation of the insulin infusion, plasma cortisol was also higher following pork insulin. It is concluded that human and pork insulin induce close to identical responses of the important counter-regulatory hormones during hypoglycaemia in Type 1 diabetic patients.

Adult↗
PubMed1990

Muscle strength in hyperthyroid patients before and after medical treatment.

Ten hyperthyroid patients were assessed for muscle strength before and after a period of medical treatment that averaged 12 months. The subjects did not change their habitual level of physical activity between the two test occasions. Maximal voluntary isokinetic knee extensor muscle strength was determined during various concentric, eccentric and isometric conditions. Average increases in strength from before to termination of treatment ranged from 25 to 41% for the concentric and isometric tests (P less than 0.01, n = 10), and from 19 to 35% for the eccentric tests (P less than 0.01, n = 6). The present study demonstrates that medical treatment of hyperthyroid patients results in a marked increase in muscle strength.

Adult↗
PubMed1990

Combined insulin-glibenclamide therapy of NIDDM patients in primary health care. A follow-up study of its compliance and efficacy and a review of the literature.

Twenty non-insulin-dependent diabetic (NIDDM) patients with secondary failure to sulphonylureas were given combined insulin-glibenclamide therapy. After discharge they were followed for the following 12 months at different primary care centres. In the 19 patients who completed the combined therapy, the mean glycosylated haemoglobin A1c (HbA1c) level decreased from 11.2 +/- 0.5% to 9.1 +/- 0.3% at 2 months (p less than 0.001), and remained at 9.1 +/- 0.4% at 12 months. The reduction of HbA1c was positively correlated with the HbA1c value and inversely with the initial body weight (both p less than 0.05). There was a slight rise in the body mass index (BMI) from 26.9 +/- 0.9 to 28.2 +/- 0.7 at 12 months (p less than 0.001), which was inversely correlated with the BMI value at 0 month (p less than 0.05). The insulin doses were similar at 2 and 12 months. A review of the literature since 1985 identified ten double-blind, controlled studies on combined insulin-sulphonylurea therapy, comprising 156 NIDDM patients followed for 8-52 weeks. Improved glycaemic control and endogenous insulin secretion were documented in nine of these studies in parallel with a decrease of insulin requirement in six studies. We conclude from our own experience and the literature that combined insulin-glibenclamide therapy is an efficient and compliant therapeutic regimen.

Aged↗
PubMed1989

The prevalence of impaired glucose counter-regulation during an insulin-infusion test in insulin-treated diabetic patients prone to severe hypoglycaemia.

Among 603 patients over the age of 18, with insulin-treated diabetes mellitus, a questionnaire identified 98 patients who during a 12-month period had experienced severe hypoglycaemia, defined as an event which required the help of another person. Twenty of these patients had repeatedly suffered from such episodes, without any obvious reason, for a period of at least three years. The capacity to counter-regulate a standardized, insulin-infusion test (0.034 U.kg-1.h-1 given for 3 h unless severe neuroglucopenia developed) was evaluated in 14 of these patients. In 12, an impaired glucose counter-regulation was registered, defined as blood-glucose values below -2 SD of healthy subjects. In all but one of these patients, a combined deficiency of glucagon and adrenaline was documented, and was believed to be the likely cause of their inclination towards hypoglycaemia. In patients with severe hypoglycaemia, but not in diabetic patients without severe hypoglycaemia or in healthy subjects, a significant relationship between insulin disappearance and glucose rise was found. It is concluded that in insulin-treated diabetic patients, the prevalence of recurrent attacks of severe hypoglycaemia amounts to about 4%. In such patients, a combined deficiency of adrenaline and glucagon responses to hypoglycaemia is the predominant finding and the disappearance rate of insulin becomes critical for recovery of blood glucose after hypoglycaemia.

Blood Glucose↗
PubMed1989

Fasting for 72 h decreases the responses of counterregulatory hormones to insulin-induced hypoglycaemia in normal man.

We have evaluated the influence of fasting on the response of counterregulatory hormones to insulin-induced hypoglycaemia. Eight healthy, non-obese volunteers were studied after an overnight fast and again after a 72-h fast period. Levels of blood glucose were higher after overnight fasting (4.59 +/- 0.10 mmol/l) than after 72 h of fasting (3.38 +/- 0.12 mmol/l). Hypoglycaemia was induced by a constant insulin infusion (2.4 mU/kg/min) and clamped between 2.1 and 2.3 mmol/l of glucose by a variable glucose infusion. Hypoglycaemia evoked stimulation of glucagon release after the overnight fast but did not alter release after 72 h of fasting. The response of other counterregulatory hormones were also influenced by the longer fasting period: the normal rise in adrenaline levels during hypoglycaemia was delayed and attenuated and the normal rise in cortisol levels was absent; paradoxically, cortisol levels decreased during hypoglycaemia. Seventy-two hours of fasting, therefore, profoundly alters hormonal responses to hypoglycaemia.

Adult↗
PubMed1988

Transient insulin resistance following infusion of adrenaline in type 1 (insulin-dependent) diabetes mellitus.

Insulin resistance was assessed after an intravenous infusion of adrenaline (50 ng.kg-1.min-1) or saline (control study) given between 08.00 and 08.30 hours in nine patients with Type 1 (insulin-dependent) diabetes mellitus. The blood glucose level during a somatostatin (100 micrograms/h)-insulin (0.4 mU.kg-1.min-1)-glucose (4.5 mg.kg-1.min-1)-infusion-test performed between 10.30 and 14.30 hours served as an indicator of the total body insulin resistance. Blood glucose was maintained around 7 mmol/l between 08.00 and 10.30 hours by a constant infusion of regular insulin (0.57 mU.kg-1.min-1) and a variable infusion of a 20% glucose solution. The infusion of adrenaline raised plasma adrenaline to 2.7 +/- 0.3 nmol/l (mean +/- SEM) at the end of the infusion; thereafter it returned to its basal level within 30 min. The plasma levels of free insulin, glucagon, cortisol and growth hormone were similar in the adrenaline and the control studies from 08.00 to 14.30 hours. In comparison with the control study the infusion of adrenaline decreased the need for intravenous glucose significantly over the initial 2 h. Furthermore, during the somatostatin-insulin-glucose infusion test the blood glucose rose significantly (p less than 0.05) over the initial 2 h; thereafter no significant differences between the two studies were seen. It is concluded that a short term infusion of adrenaline, resembling the adrenergic hormone response to hypoglycaemia, induces a diabetogenic effect which subsides within 6 h after omission of the adrenaline infusion.

Adult↗