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Biomedical subjects

H Keen

Publications and source records attributed to H Keen.

At least 217 records · Page 12Linked to original sources
PubMed1979

Clinical application of pre-programmed insulin infusion: continuous subcutaneous insulin therapy with a portable infusion system.

Strict control of blood glucose was achieved by continuous subcutaneous insulin infusion with a specially adapted Mill Hill Infuser for 3-4 days. This led to normalisation of some of the intermediary metabolites. In a few patients, subcutaneous infusions have been carried out for periods up to 3 months with home monitoring of blood glucose, without infection or lipodystrophy. Short-term improvement of metabolic control was associated with recovery of abnormal renal glomerular permeability to albumin.

Alanine↗
PubMed1979

Technology of pre-programmable insulin delivery systems: continuous subcutaneous insulin infusion.

Dual-rate continuous subcutaneous insulin infusion was performed with a specially adapted Mill Hill Infuser. The infuser delivers 2 rates, a slow rate of ca. 50 microliter/h and an eightfold higher rate, designed to cover the increased requirement during meals. The high rate is engaged by pressing a button on the side of the pump, and returns automatically to the basal level after 17 min. Insulin is delivered to the subcutaneous side by a nylon cannula.

Blood Glucose↗
PubMed1979

Fluorescein angiography in borderline diabetics.

Fluorescein angiography was performed in twenty three men with impaired oral glucose tolerance (borderline diabetics) and sixteen matched, normoglycaemic controls. Retinal abnormalities (microaneurysms and leakage of dye) were observed in 18.7% of the controls, 41.6% of sustained borderline diabetics and 54.4% of initially borderline diabetics who subsequently "worsened to diabetes". Qualitatively the abnormalities were similar in each group. Although the difference in frequency between the sustained borderline diabetics and the controls does not achieve conventional statistical significance, other studies quoted support the conclusion that moderate impairment of glucose tolerance is associated with a raised frequency of minor retinal abnormalities. The significance of these remains to be determined.

Blood Pressure↗
PubMed1978

Continuous subcutaneous insulin infusion: an approach to achieving normoglycaemia.

A study was performed to examine the feasibility of achieving long periods of near-normoglycaemia in patients with diabetes mellitus by giving a continuous subcutaneous infusion of insulin solution from a miniature, battery-driven, syringe pump. Twelve insulin-dependent diabetics had their insulin pumped through a subcutaneously implanted, fine nylon cannula; the basal infusion rate was electronically stepped up eightfold before meals. The blood glucose profile of these patients was closely monitored during the 24 hours of the subcutaneous infusion and compared with the profile on a control day, when the patients were managed with their usual subcutaneous insulin. Diet and exercise were standardised on both days. In five out of 14 studies the subcutaneous insulin infusion significantly lowered the mean blood glucose concentration without producing hypoglycaemic symptoms; in another six patients the mean blood glucose concentration was maintained. As assessed by the M value the level of control was statistically improved in six out of 14 studies by the infusion method and maintained in six other patients. To assess the effects of blood glucose control on diabetic microvascular disease it will be necessary to achieve long-term normoglycaemia in selected diabetics. The results of this preliminary study suggest that a continuous subcutaneous insulin infusion may be a means of maining physiological glucose concentrations in diabetics. Though several problems remain--for example, in determining the rate of infusion--longer-term studies with the miniature infusion pumps are now needed.

Adult↗
PubMed1978

Increased glomerular permeability to albumin induced by exercise in diabetic subjects.

The urinary excretion of albumin was measured in insulin-dependent diabetics under ordinary conditions of life and in response to exercise. Possible mechanisms of exercise induced albuminuria in diabetics were also investigated. Under ordinary conditions of life the insulin-treated diabetics, as a group, had a higher mean urinary albumin excretion than normal controls; however, half of the diabetics had albumin excretion rates within the control range. A given exercise load (600 kpm/min for 20 min) produced an exaggerated albumin excretion in diabetics, particularly evident in the post-exercise period. The elevated urinary albumin excretion was due to an increased transglomerular passage of albumin, not to reduced tubular reabsorption. The increase was not associated with differences in blood pressure or urine flow between controls and diabetics. This exercise test has proved to be a suitable provocation test to unmask abnormalities in the glomerular handling of albumin that might not be recognisable at rest.

Albuminuria↗
PubMed1978

Glucose tolerance and blood pressure in two population samples: their relation to diabetes mellitus and hypertension.

The relationship between blood pressure and the blood sugar concentration measured two hours after a 50 g oral glucose load has been examined in two population surveys-the Whitehall and Bedford Surveys. In the Whitehall Survey, which was conducted in men above the age of 40, there was a positive, significant correlation between blood sugar and blood pressure (systolic and diastolic) which was independent of common associations with age, body mass index (BMI) and heart rate. In the Bedford Survey, systolic blood pressures were significantly higher in newly detected diabetics and borderline diabetics, both men and women, than in normoglycaemic controls after adjustment of blood pressures for age and BMI. However, in the stratified random sample of the cooperating Bedford population, only amongst women was the blood sugar significantly and independently correlated with the systolic blood pressure. Evidence is presented and discussed that autonomic, neurohumoral factors may play some part in the pathogenesis of maturity onset diabetes.

Adult↗
PubMed1978

The relation between insulin and adipocyte insulin receptors during treatment of human obesity.

Seventeen obese patients were submitted to 1 week's severe then 3 months moderate dietary restriction. The glycaemic and insulinaemic response to oral glucose was measured at baseline, after 1 week and at 3 months, and the results related to adipocyte insulin receptors estimated from fat biopsies taken on each occasion and to the weight lost. Adipocyte insulin binding was found to be significantly inversely correlated with the insulinaemic response to oral glucose (r = -0.54, P less than 0.05), an inverse relationship maintained even after weight loss had been achieved and displayed within as well as between subjects. Variation of 125I-insulin binding to adipocytes was related to receptor number and not to receptor affinity and could not be accounted for by differences in 125I-insulin degradation. Adipose cell size did not correlate significantly either with the insulinaemic response or with cell surface receptor density. The findings suggest: (1) that a significant proportion of obese subjects are not hyperinsulinaemic and that their metabolic response to weight reduction may differ from that of those who are hyperinsulinaemic; (2) that reduced insulin binding to adipocytes in the obese reflects hyperinsulinaemia, when present, and not adiposity as such; (3) that the degree of insulinaemia is a major determinant of the cell surface receptor density.

Adipose Tissue↗
PubMed1978

Partial lipodystrophy and insulin-resistant diabetes.

The coexistence of partial lipodystrophy of unusual distribution (limbs, back and head) with insulin-resistant diabetes and severe retinal, renal, neurological and arterial complications is reported. The lipodystrophy followed juvenile arthritis (Still's disease) and the diabetes, initially asymptomatic, became insulin dependent and technically insulin resistant (200 - 300 units insulin/day). Severe hyperlipidaemia has been a feature of this syndrome, probably contributing to the conspicuous peripheral arterial disease. The mother was diabetic but three sisters had normal glucose tolerance and there is no lipodystrophic member of the family. Underlying mechanisms of this syndrome remain obscure.

Adolescent↗
PubMed1977

Treatment of borderline diabetes: controlled trial using carbohydrate restriction and phenformin.

A five-year therapeutic trial of carbohydrate restriction with or without phenformin (50 mg/day) was performed in men with borderline diabetes. The aim of treatment was to diminish the enhanced risk of cardiovascular disease and deterioration of glucose tolerance. Cardiovascular morbidity and mortality were not significantly affected by any form of treatment, alone or in combination. The predominant risk factor for cardiovascular morbidity and mortality and for overall mortality was the initial blood pressure level. The baseline plasma cholesterol concentration significantly predicted the onset of intermittent claudication. One implication of the results is that hypotensive treatment, supplemented when necessary with hypolipidaemic treatment, may be more effective in preventing the progression of arterial disease in people with mild to moderate glucose intolerance than conventional antidiabetic therapy.

Blood Glucose↗
PubMed1977

Myocardial ischaemia, risk factors and death from coronary heart-disease.

Mortality follow-up is now complete for 5 years in the 18 403 male civil servants aged 40-64 who were examined between 1967-69 in the Whitehall Study of British civil servants. During this period, 277 of them died of coronary heart-disease (C.H.D.); half of these deaths were in subjects in whom the findings at initial screening had suggested early myocardial ischaemia (angina or history of possible infarction according to standard questionnaire, or electrocardiographic evidence of ischaemia). The finding of suspect ischaemia had greater predictive power than the "primary" coronary risk factors, from which it was generally independent. At each level of the primary risk factors, the risk of death from C.H.D. was much greater in the presence of suspect ischaemia; and, with the possible exceptions of glucose tolerance and physical activity, the main risk factors still operated even at the stage of early ischaemia. These findings have implications for future studies of the effects of intervention.

Adult↗
PubMed1976

Smoking and other risk factors for coronary heart-disease in British civil servants.

A five-year follow-up of 18 403 male British civil servants between the age of 40 and 64, who had been the subject of an earlier clinical survey found 277 deaths from coronary heart-disease (C.H.D.). After adjusting for age, current cigarette smoking, systolic and diastolic blood-pressure, and blood-cholesterol were shown to be related to both the prevalence of one or more indices of cardiac ischaemia and to the risk of cardiac death. Neither blood-glucose two hours after a 50 g load nor weight/height showed any such simple linear association with mortality. Multivariate analysis confirmed that the main risk factors were independently related to cardiac morbidity and mortality. Irrespective of blood-pressure or plasma-cholesterol, current cigarette smokers thus had a higher risk of C.H.D. death than those not smoking cigarettes.

Adult↗
PubMed1976

Hyperglycaemia and diabetes mellitus.

Recommended criteria for the diagnosis of maturity-onset diabetes mellitus based on glucose tolerance tests vary considerably; none are derived from long-term observations of the further development of different degrees of glucose intolerance. Evidence from several epidemiological investigations suggests that the risk of specific diabetic complications becomes important only in people with capillary whole-blood sugar concentrations exceeding 200 mg/dl 2 hours after a 50 g oral glucose load, who have overnight fasting blood-sugar concentrations usually exceeding 110 mg/dl. Lesser degrees of glucose intolerance may, nevertheless, indicate an additional risk of atherosclerotic arterial disease. Assessment of "borderline diabetics" should, therefore, include and evaluation of other known risk factors for arterial disease and any treatment programme should be determined in the light of these as well as by the degree of glycaemia.

Adult↗