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Biomedical subjects

J S Yudkin

Publications and source records attributed to J S Yudkin.

At least 19 recordsLinked to original sources
PubMed1992

Developing a district diabetic register.

OBJECTIVES: To compile a district wide diabetic register of all diabetic patients registered with general practitioners in the catchment area of a single district general hospital and to compare different approaches to identifying patients. DESIGN: Information for a register was obtained from general practitioners' practice registers, the Prescription Pricing Authority, and hospital diabetic clinic records. SETTING: Catchment area of an inner London district general hospital with a large diabetic clinic. SUBJECTS: All patients with a diagnosis of diabetes resident in or attending general practitioners or hospital clinics in the district or its catchment area. MAIN OUTCOME MEASURES: Prevalence of diabetes, population of patients elicited by different approaches, proportion attending the local district general hospital, cost of using prescription returns for identifying diabetic patients. RESULTS: 4674 patients with diabetes were identified from all sources of information, which corresponds to a mean of 22.4 patients per general practitioner and the prevalence of known diabetes of 1.17%. 39.4% of patients identified had Prescription Pricing Authority returns and 42.8% of patients appeared on practices' diabetic registers. Only 56.5% of patients identified attended the district general hospital. For practices where all sources of information were available, practice registers included 60.4% of all patients, and prescription returns and the clinic register identified 64.9% and 40.6% respectively. The cost of using prescription returns to identify patients not detected in other ways was 6.37 pounds per patient. CONCLUSION: The task of developing district diabetic registers may prove, even in one cross sectional attempt, a major task in many inner city health districts.

Catchment Area, Health↗
PubMed1992

An algorithm for tight glycaemic control in diabetic infarct survivors.

An algorithm has been developed to provide predictable control of blood glucose for 48 h following acute myocardial infarction. In 29 diabetic patients intravenous infusion of soluble insulin was started upon admission to hospital and the rate adjusted hourly on the basis of bedside capillary glucose estimations. Insulin infusion rates related to glycaemia were higher in obese patients and those with severe cardiac failure. For all patients mean admission glucose levels were reduced from 18.3 +/- 5.9 mmol l-1 to 9.1 +/- 3.3 mmol l-1 at 4 h and to 8.8 +/- 2.5 mmol l-1 at 6 h. Mean glucose concentrations for 48 h after admission were 8.2 +/- 1.3 mmol l-1 for all patients. Admission glucose levels were slightly higher in patients with severe, compared to those without or mild, cardiac failure (P less than 0.1), but levels over the following 48 h were similar. Doubling insulin infusion rates before meals did not achieve tighter glycaemic control. Hypoglycaemia (glucose less than 3 mmol l-1) occurred on 11 occasions in six patients; only two episodes were symptomatic and only two episodes occurred when the insulin rates were doubled before meals. This algorithm produced tighter glycaemic control than previously published protocols, particularly in patients with severe cardiac failure. Hypoglycaemia is uncommon and the algorithm easy to administer by nursing staff.

Algorithms↗
PubMed1992

A comparison of the relationships of the glucose tolerance test and the glycated haemoglobin assay with diabetic vascular disease in the community. The Islington Diabetes Survey.

We have compared the relationships of fasting and 2 h blood-glucose during a 75 g oral glucose tolerance test, and those of an affinity chromatography assay of glycated haemoglobin, with the presence of vascular complications of diabetes mellitus in 223 subjects without known diabetes aged over 40 years selected from a community screening study population. The subjects included 15 (6.9%) with newly diagnosed diabetes and 52 (24.1%) with impaired glucose tolerance. Employing receiver operating characteristic analysis, the tests were similar in their relationship with three cases of retinopathy, 19 of microalbuminuria and six of peripheral neuropathy. The prevalence of coronary heart disease, defined as angina, myocardial infarction, or electrocardiographic changes of ischaemia, increased linearly across all four quartiles of both 2 h blood glucose and glycated haemoglobin concentration, but using logistic regression analysis, 2 h blood glucose was a better predictor of coronary heart disease than glycated haemoglobin. Receiver operating characteristic analysis also showed that 2 h blood glucose generally performed better than any of four assays of glycated haemoglobin in classifying those subjects with coronary heart disease.

Aged↗
PubMed1992

'Spontaneous' platelet aggregation in whole blood in diabetic patients with and without microvascular disease.

Consistent abnormalities of agonist-induced platelet aggregation, in either whole blood or platelet rich plasma, have not been demonstrated in diabetic patients without microvascular disease. In the present study platelet aggregation in the absence of exogenous agonists ('spontaneous' aggregation) was compared between 22 non-diabetic subjects and 23 Type 1 diabetic patients with (n = 12) and without (n = 11) microvascular disease. 'Spontaneous' aggregation was determined by measuring the percentage fall in single platelet number in aliquots of whole blood shaken for 60 min. Diabetic patients without microvascular disease had fewer single platelets remaining (greater aggregation) than non-diabetic subjects at all time-points (69.7 +/- 6.6 vs 82.3 +/- 7.3% at 60 min p less than 0.001), but more platelets remaining than in diabetic patients with microvascular disease at all time-points (69.7 +/- 6.6 vs 61.0 +/- 7.8% at 60 min p less than 0.02). No significant correlations were observed between platelet aggregation and plasma glucose, blood cell counts, or glycated haemoglobin levels. The study suggests that platelet abnormalities antedate the appearance of microvascular disease in diabetic patients.

Adult↗
PubMed1992

Hypertension and coronary artery disease in non-insulin dependent diabetes--cause and effect?

There is a log-linear increase in the risk of coronary heart disease with elevation of levels of blood pressure. Allowing for the phenomenon of regression dilution bias, this corresponds to around a 20 to 25% increase in risk for each 5 to 6 mm Hg elevation in usual diastolic blood pressure. In diabetic subjects, a similar relationship occurs, but of somewhat lesser degree. Recent overviews of therapy suggest that in nondiabetics, reducing blood pressure reverses around 50% of the excess coronary heart disease risk, but this has not yet been conclusively shown in patients with diabetes. The reduction in risk with therapy is a prerequisite to defining the antecedent as a causal influence on outcome, but it is as likely that the incomplete reversibility of excess risk represents other pathways of connection between hypertension and coronary heart disease as a consequent of iatrogenic effects of current treatments. Several alternative mechanisms are outlined, and the suggestion is made that only in the context of randomized controlled studies could the possible benefits on coronary heart disease of agents influencing such mechanisms be assessed.

Adult↗
PubMed1992

Effect of vitamin C on glycosylation of proteins.

Twelve nondiabetic subjects consumed 1 g/day vitamin C for 3 mo. A fasting blood sample was taken at the start of the study and at the end of each month for the measurement of plasma and intraerythrocyte glucose, vitamin C, glycosylated hemoglobin (affinity chromatography and electrophoresis), and glycosylated albumin (affinity chromatography). Although there were no significant changes in fasting glycemia, glycosylated hemoglobin (affinity chromatography) decreased 18%, from 6.18 +/- 0.48% (mean +/- SD) at the start to 5.05 +/- 0.50% (P less than 0.0001) after 3 mo, whereas, HbA1 measured by electrophoresis increased 16%, from 6.17 +/- 0.61 to 7.16 +/- 0.59% (P less than 0.0001) in this period. Glycosylated albumin decreased 33%, from 1.56 +/- 0.24 to 1.04 +/- 1.01% (P less than 0.0001) after 3 mo. This discrepancy between glycosylated hemoglobin measured by electrophoresis and affinity chromatography was due to methodological differences between the two techniques, with affinity chromatography measuring "true" glycosylated hemoglobin. The greater decrease found with glycosylated albumin was probably due to the different distribution of vitamin C between plasma and within the erythrocyte, levels after 1 mo of supplementation being 109 +/- 19 and 59 +/- 9 microM, respectively (P less than 0.001). This indicates that administration of oral vitamin C may inhibit the glycosylation of proteins in vivo by a competitive mechanism.

Administration, Oral↗
PubMed1992

Microalbuminuria: a genetic link between diabetes and cardiovascular disease?

Non-insulin-dependent diabetes is associated with a 2-3 fold increased risk of cardiovascular disease. The poor relationship between this risk and either glycaemic control or diabetes duration suggests that some other aspect of the diabetic state, and not hyperglycaemia per se, mediates this risk. This other aspect of diabetes does not comprise alterations in recognized cardiovascular risk factors such as blood pressure or lipids, as the major component of the excess risk is in those diabetics with low levels of the other risk factors. It thus appears that there may be some factors that predispose both to diabetes and to cardiovascular disease. In insulin-dependent diabetics most of the excess risk of cardiovascular disease occurs in subjects with proteinuria, and microalbuminuria or proteinuria in non-insulin-dependent diabetics also substantially increases cardiovascular risk. Although changes in recognized risk factors in diabetics with nephropathy may partly explain these observations, we and others have shown that microalbuminuric non-diabetics also have a markedly increased prevalence of cardiovascular disease and substantially increased cardiovascular mortality. The observations that in insulin-dependent diabetics nephropathy shows family clustering and that these patients have elevated sodium lithium counter-transport rate, a possible genetic marker for the vascular complications of hypertension, have led to the suggestion that microalbuminuria may be a marker of a genetic predisposition to vascular disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Albumins↗
PubMed1991

Misclassification of diabetic subjects may account for the increased vascular risk of impaired glucose tolerance: the Islington Diabetes Survey.

We have studied the associations of macrovascular disease and hypertension with impaired glucose tolerance in a recall sample of 223 subjects selected from a population aged greater than or equal to 40 years who had been screened for diabetes using two separate glucose tolerance tests. Blood pressure was higher in subjects with diabetes, but not in those with impaired glucose tolerance, than in normals. Coronary heart disease, based on ECG criteria and history, was more frequent both in subjects with impaired glucose tolerance (odds ratio 1.94, 95% CI 1.02-3.69) and those with diabetes (odds ratio 3.88, 95% CI 1.33-11.97) than in normals, but the excess in the impaired glucose tolerance group was reduced, and was no longer significant, when adjusted for other variables (odds ratio 1.29, 95% CI 0.62-2.66). Peripheral vascular disease was more frequent in subjects with diabetes, but not in those with impaired glucose tolerance. When the subjects with impaired glucose tolerance on a single test were reclassified according to the results of a separate glucose tolerance test, the prevalence of coronary heart disease increased significantly with increasing degrees of glucose intolerance. Subjects with impaired glucose tolerance on both tests had an adjusted odds ratio of coronary heart disease of 0.90 (95% CI 0.42-1.94) compared with normal subjects. The excess of macrovascular disease in subjects with impaired glucose tolerance may result, at least in part, from the admixture of 'false negative diabetics' in that class.

Adult↗
PubMed1991

Platelet function and conjugated diene concentrations in diabetic and non-diabetic survivors of acute myocardial infarction.

STUDY OBJECTIVE: The aim was to compare platelet function in diabetic and non-diabetic survivors of acute myocardial infarction and to relate it to an index of free radical activity in these patients. DESIGN: In vivo and in vitro indices of platelet function and diene conjugate molar ratios were measured in diabetic and non-diabetic infarct survivors on admission to hospital and sequentially for 72 h. PATIENTS: The patients were 17 diabetics (age 61.9 years, range 32-74) and 12 non-diabetics (60.8 years, range 39-75) admitted to hospital with acute myocardial infarction confirmed according to WHO criteria. MEASUREMENTS AND MAIN RESULTS: Agonist induced platelet aggregation, beta thromboglobulin levels, and linoleic acid 18:2(9,11)/18:2(9,12) molar ratios did not differ between diabetic and non-diabetic patients on admission. Concentrations of adrenaline producing 50% maximum platelet aggregation (EC50) in whole blood on admission were lower than non-infarct controls in both patient groups. The EC50 values in platelet rich plasma in both groups fell during the 72 h following admission (increases in platelet sensitivity). beta Thromboglobulin concentrations fell following admission in the diabetic group. Diene conjugate molar ratios were higher at 12 h and 24 h compared to admission in diabetic patients. Increases in diene conjugate ratios between admission and 24 h correlated with peak aspartate transaminase levels in both patient groups. No correlations were observed between platelet aggregation, beta thromboglobulin levels, or diene conjugate molar ratios. CONCLUSIONS: During 72 h following myocardial infarction there is a reduction in platelet activation in vivo and an increase in platelet sensitivity to exogenous agonists in vitro. Free radical generated isomers of linoleic acid increase in relation to infarct size, but are unrelated to platelet function. There were no differences in platelet function between diabetic and non-diabetic subjects.

Acute Disease↗
PubMed1991

Factors influencing threshold and choice of treatment for hypertension in NIDDM. Cardiovascular factors.

In nondiabetic populations, there is an approximately 40% increase in stroke risk and a 25% increase in coronary heart disease (CHD) risk with every 6-mmHg increase above 75 mmHg in usual diastolic blood pressure. Diabetes increases the risk of both conditions by two- to threefold, and in diabetic patients, hypertension further increases these risks. The benefits of lowering blood pressure in nondiabetic subjects have been subjected to meta-analysis, which has demonstrated benefits equivalent to 100% reversal of the excess risk for stroke but with only approximately 50% of CHD risk reversible after 2-3 yr of treatment. In these analyses, the benefit of treating diastolic blood pressure is similar at all levels greater than 90 mmHg. If these results are extrapolated to diabetic patients, possible benefits of therapy for mild hypertension could be two to three times greater than in nondiabetic subjects, but this could still correspond to 300 person-yr of treatment to prevent one nonfatal stroke and 2500 person-yr of treatment to prevent one CHD death, with treatment that may deleteriously affect quality of life in 36% of all diabetic patients. There may also be risks in treating patients with mild hypertension who have existing CHD or left ventricular hypertrophy, which are more common in diabetes. Despite the theoretical risk of deleterious changes in several cardiovascular risk factors with thiazides or beta-blockers, most of the newer agents have not yet been demonstrated to produce similar benefits to the large prospective studies in which the aforementioned agents have been used.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiovascular Diseases↗
PubMed1990

A study of the effect of diet on glycosylated haemoglobin and albumin levels and glucose tolerance in normal subjects.

As factors other than the degree of glucose tolerance or ambient blood glucose may determine glycosylated haemoglobin levels, we have investigated the effects of dietary glucose and soluble fibre supplementation on glucose tolerance, glycosylated haemoglobin and glycosylated albumin in non-diabetic subjects. Eleven non-diabetic subjects (7 M, 4 F; age 26.5 +/- 6.5 (+/- SD) yr; BMI 21.6 +/- 3.1 kg m-2) followed a high-soluble-fibre (5 g guar gum thrice daily)/low-glucose diet, or a low-soluble-fibre/high-glucose (500 ml glucose drink providing 100 g glucose per day) diet, each for 6 weeks, in randomized order. A 75 g oral glucose tolerance test was performed at recruitment and after each diet period, and fasting blood was assayed for glycosylated albumin by affinity chromatography, and glycosylated haemoglobin by four different methods. Adherence to guar and glucose supplementation was assessed at 89.5 +/- 7.5% and 97.1 +/- 3.5%, respectively. There was no significant effect of either diet on mean fasting, 1-h or 2-h plasma glucose concentration, or glycosylated haemoglobin levels by any assay. Glycosylated albumin was 1.71 +/- 0.35% at entry, fell to 1.33 +/- 0.30% (p less than 0.01) with high-fibre and rose to 1.95 +/- 0.23% (p less than 0.02) after a high-glucose diet. Insulin, total- and HDL-cholesterol and triglyceride levels were unaffected by either diet. A high-glucose diet increases, and a high-soluble-fibre diet decreases, levels of glycosylated albumin without effects on glucose tolerance or glycosylated haemoglobin.

Adult↗
PubMed1979

The relationship between concentrations of glycosylated haemoglobins and of serum high-density-lipoprotein cholesterol in diabetic patients.

1. Concentrations of high-density-lipoprotein cholesterol and of glycosylated haemoglobins [HbA1(a+b+c)] were measured in non-fasting blood samples taken from 171 diabetic patients. 2. Mean concentrations of high-density-lipoprotein cholesterol were lower in men, and in patients not requiring insulin. 3. There was no correlation between concentrations of high-density-lipoprotein cholesterol and of HbA1(a+b+c) in the patients as a whole, but a significant positive correlation was found between these values in male diabetics not requiring insulin. 4. Changes in the concentrations of HbA1(a+b+c) were not correlated with changes in concentrations of high-density-lipoprotein cholesterol.

Cholesterol↗
PubMed1978

Changing patterns of resource allocation in a London teaching district.

The health plans of the Tower Hamlets district management team were studied to determine what effects the report of the Resource Allocation Working Party and the White Paper "Priorities in the Health and Social Services" have had on resource allocation in a teaching district. The study showed that at present acute services are allocated a greater proportion of the district budget than occurs nationally, while geriatrics, mental health, and community services receive proportionately less. In the next three years spending on acute services is expected to decrease, while spending on geriatric facilities and community services will increase. Nevertheless, cuts in acute services will take place mainly through a reduction in the number of beds serving a community function, concentrating all acute services in the teaching hospital. Services to the district might be better maintained by creating a community hospital to meet the needs of patients who would otherwise need to be accommodated in acute beds with unnecessarily expensive support services.

Community Health Services↗
PubMed1978

Provision of medicines in a developing country.

In many developing countries the money spent on drugs could often be used more effectively to prevent disease. A large proportion of the drug budget of one developing country is spent on expensive proprietary preparations for use mainly in the larger hospitals, draining resources from health care in rural areas. A major factor in determining the country's expenditure on drugs is the promotional activities of pharmaceutical companies; the number of drug company representatives in the country is proportionately five times that in Britain. Many drugs are promoted for diseases for which they are not indicated and in which their use may be hazardous, and information on side-effects and contraindications is inadequate. Information supplied by drug firms to health workers in different countries must be standardised and the purchase and use of drugs in Third-World countries made more appropriate to their needs.

Costs and Cost Analysis↗