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Biomedical subjects

L J Duncan

Publications and source records attributed to L J Duncan.

At least 37 records · Page 2Linked to original sources
PubMed1983

Effect of dietary compliance on metabolic control in insulin-dependent diabetics.

One hundred and seventy eight insulin dependent diabetics (IDDM) have been studied regarding their understanding of and compliance with a controlled carbohydrate diet. Forty per cent could not remember their dietary prescription, 35 per cent did not estimate carbohydrate and many scored badly in a 'quiz' on the carbohydrate content of common foods. Quiz scores were significantly associated with HbA1 levels (P less than 0.001). One hundred and thirty six patients completed a seven-day food record from which the pattern of eating was established. Of these 75 were injecting twice daily short and intermediate acting insulin; in this group there were significant relationships between HbA1 and both care with carbohydrate estimation and eating pattern (P less than 0.05). Thus, in IDDM, the understanding of a controlled carbohydrate diet and adherence to it are associated with better glycaemic control but adequate compliance is rare. Future dietary recommendations for insulin taking diabetics should be simple, easy to understand, acceptable in practice and of proven effectiveness if they are to appreciably influence the quality of diabetic control.

Adolescent↗
PubMed1983

Non-insulin-treated ICA positive and negative diabetics are equally insulin resistant.

Insulin action was assessed in 5 cytoplasmic islet cell antibody (ICA) positive non-diabetics, 8 ICA positive (type I) non-insulin-treated diabetics, 7 ICA negative insulin-treated diabetics by measurement of steady state plasma glucose (SSPG) levels during a combined intravenous infusion of propranolol, adrenaline, glucose and insulin. SPPG values of ICA positive and negative non-diabetics were similar and their combined value (4.0 +/- 0.5 mmol/l) was significantly lower (p less than 0.01 and less than 0.01) than those (11.5 +/- 1.9 and 11.3 +/- 2.2 mmol/l) of ICA positive and negative diabetics, indicating that both groups of diabetics were similarly insulin resistant. Similar correlations were observed between SSPG and HbA1 levels when considering all ICA positive subjects (r = 0.89, p less than 0.001) and all ICA negative subjects (r = 0.73, p less than 0.01). Conventional insulin treatment (2.6 months) in 4 ICA positive diabetics improved insulin action in each case with a reduction in mean SSPG concentration from 14.0 +/- 2.3 to 8.5 +/- 3.4 mmol/l. Thus, ICA positive and negative diabetics, of equivalent degree of carbohydrate intolerance, are equally insulin resistant. Insulin treatment may improve, but appears not to normalise, insulin action in ICA positive (type I) diabetics.

Adult↗
PubMed1983

Humoral immunity in type 1 diabetes mellitus: a prospective study.

Cytoplasmic islet cell antibodies, as detected by anti-IgG (ICAb), and circulating immune complexes (AgAb), detected by the solid phase C1q test (C1qSP), were evaluated in 153 insulin dependent diabetics (IDD) at diagnosis and subsequently in 88 of these patients who were studied prospectively at regular intervals for up to 3 yr. AgAb detected by the conglutinin (KgBt) and Raji cell (RAJI) techniques were also studied at diagnosis in 34 and 50 diabetics respectively. Normal controls were included in the AgAb studies. Complement fixing islet cell antibodies (CF-ICAb) were evaluated in 30 randomly selected diabetics both at diagnosis and after 6 months. Viral antibodies (VAb) were measured in 30 IDD at diagnosis and in 30 matched controls. Insulin antibodies (IBC) were measured 9 months after diagnosis in 35 diabetics and HLA studies (B8 and B15) performed in 115 patients. In the prospective study the ICAb positivity declined from 50% at diagnosis to 45, 38, 36, 31, 26, 19 and 17% at 1, 3, 6, 9, 12, 24 and 36 months after diagnosis respectively. CF-ICAb were found in 30% of the diabetics at diagnosis and in 23% at 6 months. All patients with CF-ICAb at diagnosis were ICAb positive whilst only 47% of patients with ICAb also had CF-ICAb in the serum. AgAb were found at diagnosis in 35% of patients by C1qSP (p less than 0.001 vs. normals), in 35% by KgBt (p less than 0.001) and in 54% by RAJI (p less than 0.002). Eighty-four patients were studied at diagnosis by more than one AgAb method and of these 57% had at least one positive AgAb result. AgAb by C1qSP declined to less than 20% within 6 months of diagnosis. AgAb, as measured by C1qSP and RAJI techniques, correlated with ICAb at diagnosis whereas there was no correlation with VAb levels, IBC values, nor with the HLA antigens. There was no correlation between AgAb (C1q) and CF-ICAb. HLA B15 positive patients tended to form higher IBC levels than B15 negative patients. Thus, AgAb presence seems to parallel that of ICAb in the early stages of diabetes and both phenomena may be primarily or secondarily involved in the development of the disease.

Adult↗
PubMed1982

Alpha 2-macroglobulin and proliferative retinopathy in type 1 diabetes.

Serum alpha 2-macroglobulin (alpha 2m) and total glycosylated haemoglobin (HbA1) concentrations were measured in 110 insulin dependent Type 1 diabetics with minimal or no fundoscopic retinopathy, referred to as non-retinopaths, and in 52 proliferative retinopaths. Proteinuria was recorded in 8 (7%) non-retinopaths and 29 (56%) retinopaths and was accompanied by elevated alpha 2m concentrations in both groups of diabetics but only significantly so in the non-retinopaths. Diabetics without proteinuria showed a significant correlation between alpha 2m concentration and duration of diabetes, HbA1 and age (being higher at extremes of age). Alpha 2m concentrations were significantly higher in retinopaths than in non-retinopaths without proteinuria when allowance was made for the influence of age and duration of diabetes on alpha 2m. This difference may be attributed to the higher HbA, levels found in retinopaths than in non-retinopaths and was no longer evident when account was taken of the prevailing HbA1 concentration in individual patients.

Adult↗
PubMed1982

HLA antigens and other risk factors in the development of retinopathy in type 1 diabetes.

Factors possibly influencing the development of diabetic retinopathy were studied in 112 randomly selected type 1 diabetics having no or minimal retinopathy (group A) and in 82 type 1 diabetics with known severe diabetic retinopathy. The latter comprised those with severe background retinopathy (group B, n = 17) and those having proliferative retinopathy without (group C, n = 38) and with group D, n = 27) diabetic nephropathy. Nonretinopaths (group A) were of similar sex ratio, body weight, and age at diagnosis of diabetes but had been diabetic longer (p less than 0.001) and were thus older (p less than 0.001) than retinopaths (groups B-D). The distribution of HLA antigens of the A, B, and C loci was similar in nonretinopaths and retinopaths with the exception that HLA B7 showed a reduced (p less than 0.05) prevalence in the retinopaths (6% versus 17%) and was singularly underrepresented in group D, where no patients had this antigen. Mean postprandial plasma glucose and HbA1 concentrations were higher (p less than 0.01 and p less than 0.001) and cigarette smoking was more prevalent (p less than 0.01) in the retinopathy groups B-D than in group A. Systolic and diastolic blood pressures were similar in groups A-C, with higher (p less than 0.001) values only in group D. There was no association between insulin antibody binding in the serum or measurable plasma C-peptide immunoreactivity and retinopathy status. The risk of development of diabetic retinopathy in type 1 diabetes may be related to HLA-associated genetic factors and to cigarette smoking.

Adult↗
PubMed1981

Diabetic control in patients treated with once or twice-daily insulin injections, including a comparison of conventional beef and highly purified pork insulins.

Twenty patients were changed from a single daily injection of beef insulin (a mixture of soluble and protamine zinc insulin) to two daily injections (mixtures of soluble and isophane insulins). This was associated with a reduction, one month later, in the concentration of glycosylated haemoglobin (HbA1) and in the degree of late evening glycosuria. A reduction was shown 6 months later in antibody binding of beef and pork insulin by serum. Subsequent conversion to a twice daily regime of highly purified pork insulin was not associated with further improvement in diabetic control, but was associated after 1 month with a reduction in daily insulin dose, and after 5 months with a further reduction in antibody binding of beef and pork insulin by serum. Patients failing to show a C-peptide response to intravenous glucagon had a fall in HbA1 after conversion from a once to a twice daily insulin regime, which correlated inversely with insulin antibody binding estimated at the beginning of the study.

Adolescent↗
PubMed1981

Relationship of glycosylated haemoglobin to C-peptide secretory status and antibody binding of insulin in insulin-dependent diabetes.

Diabetic control, assessed by measuring the concentration in venous blood of total glycosylated haemoglobin (HbA1), endogenous insulin secretion, as estimated by the C-peptide response (delta C-P) to intravenous glucagon, and serum beef insulin antibody binding were measured in 50 juvenile onset insulin dependent diabetics (IDDM) receiving a single daily injection of soluble and protamine zinc insulin. The delta C-P correlated inversely with duration of diabetes (tau = -0.27, p less than 0.01) and daily insulin requirement (tau = -0.22, p less than 0.05) in the 50 IDDM studied of whom 28 exhibited a measurable delta C-P. In C-peptide nonresponders, but not in the C-peptide responders, and inverse regression (t = 2.19, p less than 0.05) was observed between beef insulin antibody and HbA1. In the 25 IDDM having the lowest insulin antibody binding, and inverse correlation (tau = 0.36, p less than 0.02) was observed between delta CP and HbA1, which was not found (tau = 0.05) in the remaining 25 IDDM who had the highest insulin antibody binding. These findings suggest that, in the absence of endogenous insulin secretion, diabetic control in IDDM receiving a single daily injection of conventional beef insulin is better in patients with high beef insulin antibody binding. Conversely, in patients with low beef insulin antibody binding, diabetic control appears to be better in those with persisting endogenous insulin secretion.

Adolescent↗
PubMed1980

Driving and insulin-dependent diabetes.

A survey of 250 patients with insulin-dependent diabetes (IDD) holding a full motor vehicle driving licence revealed that 107 (42.8%) had not declared IDD on their application for a driving licence. 70 of these (28% of entire group) claimed that they were unaware of the statutory requirements. There was no difference in the declaration-rate between men and women. 159 patients (66%) declared IDD for their motor insurance. 86 patients (34.4%) had had severe or frequent hypoglycaemia in the preceding six months, during which they had been driving regularly. 34 patients (13.6%) admitted involvement in a driving accident since commencing treatment with insulin, and 13 of these patients were aware that hypoglycaemia had been an important causal factor. The prevalence of diabetic retinopathy and cataracts was considerable, but few patients (2.4%) had severe impairment of vision in both eyes.

Accident Prevention↗
PubMed1980

Serum alpha 2-macroglobulin levels in diabetes.

Serum alpha 2-macroglobulin levels have been determined in diabetic patients by quantitative radial immunodiffusion and compared with those observed in age- and sex-matched controls. In addition, the results in diabetics have been analysed with respect to such variables as the age and sex of the patient, the duration of disease, treatment, control, and the occurrence of retinopathy or nephropathy. The alpha 2-macroglobulin levels in diabetic patients were found to be significantly higher than in age- and sex-matched controls, thus confirming previous observations. However, these differences were most apparent in the more extreme age groups. Multiple regression analysis also revealed that the only variables contributing significantly to the regression apart from age and sex were control and retinopathy.

Adolescent↗
PubMed1980

Glucose and insulin responses to oral glucose in overt non-insulin-dependent diabetics with and without the islet cell antibody.

Plasma insulin, glucose, and insulin/glucose responses to a 50-g oral glucose tolerance test (OGTT) were compared in 14 islet cell antibody (ICAb) positive non-insulin-dependent diabetics (NIDDM), 14 matched ICAb negative NIDDM, and 14 ICAb negative nondiabetic controls. Both groups of NIDDM exhibited marked carbohydrate intolerance with insulinopenia. Despite having significantly higher plasma glucose concentrations during the study, the ICAb positive NIDDM had significantly lower insulin levels, and thus lower insulin/glucose ratios, than the ICAb negative NIDDM both in the fasting state and in response to the OGTT. Similarily, ICAb positive NIDDM had higher integrated glucose responses (delta G), lower integrated insulin responses (delta I), and lower delta I/delta G values than ICAb negative NIDDM. Three ICAb negative and seven ICAb positive NIDDM subsequently required insulin treatment. These findings show that ICAb positive NIDDM suffer from a greater disturbance of B-cell function than do matched ICAb negative NIDDM.

Adult↗
PubMed1980

Fatal coma in diabetes.

Analysis of causes of death in a population of 3,113 diabetics was carried out for a period of eight years and those patients dying of some form of diabetic coma identified. Of 1,274 deaths, only 22 (1.73%) were primarily due to coma; 7 hypoglycaemia, 8 ketoacidosis, 3 hyperosmolar coma and 4 lactic acidosis. Three of the ketoacidosis patients may have died from other causes. Most deaths occurred in patients with long-standing diabetes. In the hypoglycaemic group all were on insulin and several had been difficult to control for many years. Infection was an important precipitating factor for ketoacidosis and hyperosmolar coma. Phenformin was the cause of all cases of fatal lactic acidosis. It is reassuring that death from coma is a comparatively rare event in known treated diabetic patients.

Adult↗