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Biomedical subjects

T Lauritzen

Publications and source records attributed to T Lauritzen.

At least 91 records · Page 5Linked to original sources
PubMed1983

Effect of 1 year of near-normal blood glucose levels on retinopathy in insulin-dependent diabetics.

30 insulin-dependent diabetic patients with background retinopathy were randomised to conventional treatment (UCT) or treatment with continuous subcutaneous insulin infusion (CSII). They were followed prospectively for 1 year with fortnightly seven-sample home blood glucose measurements and retinal examinations every 6 months. Mean blood glucose and stable haemoglobin A1c during months 3-12 were significantly lower in the CSII than the UCT group. Retinal morphology deteriorated during the year with no significant differences between UCT and CSII groups. The frequency of deterioration was highest in the CSII group, especially among the 10 patients with best glycaemic control. Proliferative retinopathy developed in 3 patients--2 of these were CSII treated. Retinal function (oscillatory potential, macular recovery time, and posterior vitreous fluorophotometry) improved significantly with CSII treatment and deteriorated significantly with UCT. Changes in retinal function were most pronounced in patients with the best and the poorest regulated glycaemic control.

Adult↗
PubMed1983

Pharmacokinetics of continuous subcutaneous insulin infusion.

One of the reasons for the variability of blood glucose regulation in Type 1 (insulin-dependent) diabetic patients is the huge variation in subcutaneous absorption of intermediate-acting insulin. We have investigated the variation in insulin absorption during continuous subcutaneous insulin infusion in eight such patients. The content of insulin in the subcutaneous tissue was measured using 125I-labelled insulin. The concentration of free serum insulin and blood glucose was followed from 1 h before and from 7 h after breakfast on two consecutive days. The amount of insulin absorbed during 24 h differed in all cases by less than 3% from the daily insulin dose given by the pumps. Mean insulin absorption rates and mean free insulin concentration showed peak values 30-90 min after meal bolus injections; this was sufficient to maintain near-normal blood glucose. Mean free serum insulin correlated strongly with disappearance of insulin from the subcutaneous tissue (r = 0.98). From the insulin absorption rates and free insulin concentrations during basal constant insulin infusion, the half-time of serum insulin was calculated as 6 min. Compared with the known large variability in the absorption of intermediate-acting insulin, continuous subcutaneous insulin infusion offers a precise and reproducible way of insulin administration resulting in post-prandial serum insulin peaks sufficient to maintain near-normal blood glucose levels. The half-time of serum insulin during subcutaneous infusion corresponds to values for intravenous infusion given in the literature, indicating that local degradation of insulin in subcutaneous tissue is of minor importance.

Adult↗
PubMed1982

Absorption of isophane (NPH) insulin and its clinical implications.

Absorption of 125I-NPH insulin (125I-isophane insulin) (40 IU/ml) was studied in eight diabetics given 50% and 150% of their normal daily dose of insulin. Insulin absorption correlated with plasma insulin (r = 0.97, p less than 0.001) and blood glucose (r = -0.87, p less than 0.01) concentrations. Absorption was slower at higher doses, so that trebling the insulin dose only doubled the amount absorbed over the first 24 hours. The plasma elimination half time (t12) of insulin was about five minutes. Thus, the disappearance of radiolabelled insulin is a reliable and quantitative index of insulin absorption; subcutaneous degradation, if present, is minimal and constant. Changes in dise of intermediate-acting insulin further increases the large variation in insulin absorption. This implies that minor adjustments of intermediate insulin dosage are probably futile.

Absorption↗
PubMed1982

Glycosylated haemoglobin and steady-state mean blood glucose concentration in Type 1 (insulin-dependent) diabetes.

Since glucose control and glycosylated haemoglobin varies asyncroneously, we have studied the steady-state relationship between these two factors. In Type 1 (insulin-dependent) diabetic patients with a constant haemoglobin A1c during the preceding 2 years, 15 ambulatory blood glucose profiles during a 5-week period showed a constant glucose level and provided a precise estimate of the mean blood glucose concentration. In addition, we studied 15 non-diabetic subjects who provided three glucose profiles and had one haemoglobin A1c determination performed. A good correlation was found for a curvilinear relationship (haemoglobin A1c = 2.07 X mean blood glucose0.596, r = 0.98). This close relationship indicates that glycosylated haemoglobin is a valuable, but not very sensitive, index of glucose control.

Adolescent↗
PubMed1982

Diet versus average Danish food in insulin-dependent diabetes mellitus. An evaluation during treatment with an artificial betacell.

Ten randomly selected insulin-dependent diabetics with minimal betacell function were studied during treatment with an artificial betacell during two consecutive 24-hour periods. Patients were randomly served diabetic diet for one 24-hour period and average Danish food during the other 24-hour period. No significant (P greater than 0.05) difference was found between the mean blood glucose concentrations, nor insulin requirements on average Danish food compared to diet. However, the mean amplitude of glucose excursions was significantly higher on average Danish food than on diabetic diet (median 3.6 versus 2.7 mmol/l, P less than 0.05). Thus insulin-dependent patients not following their diabetes diet will show increased blood glucose fluctuations.

Adolescent↗
PubMed1982

Diurnal pattern of insulin requirements in insulin-dependent diabetics.

A total of 35 experiments in which insulin-dependent diabetics were connected to an artificial beta cell (Biostator) for feedback control of blood glucose during at least 24 h, were evaluated. Only 14 experiments, however, were available for analysis, since interruptions of more than 45 min/24 h in feedback control due to clots in analyser tubing occurred in those remaining. In these 14 experiments the 24-h insulin-infusion pattern was analysed. Basal insulin requirements (BIR), (between 01.00 and 04.00 hours) was found to be 0.178 +/- 0.044 (SD) mU/kg X min. Insulin requirements increased in the early morning (04.00-07.00 hours) to 0.231 +/- 0.084 mU/kg X min (P less than 0.01). A significant correlation between BIR and 24-h insulin requirement was found (r = 0.53, P less than 0.05). Insulin requirements per kJ following breakfast were higher than after lunch, 0.57 +/- 0.20 muU/kg X min X kJ versus 0.41 +/- 0.29 muU/kg X min X kJ (P less than 0.05).

Adult↗
PubMed1980

Importance of insulin absorption, subcutaneous blood flow, and residual beta-cell function in insulin therapy.

The interaction between variation in insulin absorption and beta-cell function was studied as well as the possible relation between subcutaneous blood flow through the region of injection and the variability in insulin absorption. The results indicate that the dose of insulin, the type of insulin preparation and the local blood flow influence the insulin absorption. Residual endogenous insulin secretion, governed by the blood glucose values, serves as a modulator.

Adult↗
PubMed1979

Variation in 125I-insulin absorption and blood glucose concentration.

The absorption of monocomponent porcine 125I-insulin Monotard and Isophane was studied in six insulin dependent diabetic patients over a period of 12 days. The absorption of insulin was measured as the disappearance of radioactivity from sites of injection. The daily 125I-insulin doses ranged from 20 to 48 IU between patients. The insulin absorbed varied considerably within and between patients. The range of individual daily absorbed insulin varied from 19 to 104 per cent of the 125I-insulin dose. A significant correlation (p less than 0.05) was found between insulin absorption and blood glucose concentration. Insulin absorption rates were relatively high before all hypoglycaemic episodes and reactive hyperglycaemia was only observed when relatively low insulin absorption rates followed the hypoglycaemic attack. The results show that lability in some insulin dependent diabetics is explained by variation in insulin absorption.

Absorption↗
PubMed1977

Long-term prognosis of duodenal ulcer: follow-up study and survey of doctors' estimates.

In 1976 we reviewed a randomly selected cohort of 227 patients with duodenal ulcer first diagnosed in 1963. The cohort comprised cases diagnosed in both hospitals and general practice. Fifty patients had died, 12 had emigrated, and 154 (93%) of the remaining patients were interviewed. Fifty-seven medically treated patients had no symptoms, 44 had mild symptoms, and 19 had more severe symptoms. The remaining 34 patients had been treated surgically. Cases diagnosed in hospital had a more severe prognosis than those diagnosed in general practice. A random sample of 65 general practitioners and 78 medical and surgical gastroenterologists tried to predict the results of this study. The range of the predictions was very wide showing that individual prognostic estimates were highly unreliable. The mean prediction by all doctors differed little from the actual result, suggesting that the collective experience of the medical profession is more reliable. The predictions of general practitioners, physicians, and surgeons showed small systematic differences, presumably reflecting the different types of patients they treat.

Adolescent↗
PubMed1977

Common duct stones in patients with acute cholecystitis.

In a retrospective survey of 202 patients with acute cholecystitis 40 patients (19,8%) were found to have common duct stones. No close correlation between common duct stones and either serum bilirubin or serum alkaline phosphatase could be demonstrated. Therefore it was concluded that peroperative cholangiography is necessary in operations for acute cholecystitis.

Acute Disease↗