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Biomedical subjects

R J Jarrett

Publications and source records attributed to R J Jarrett.

At least 109 records · Page 6Linked to original sources
PubMed1981

The effects of a low-dose intravenous insulin infusion upon plasma glucose and non-esterified fatty acid levels in very obese and non-obese human subjects.

After an overnight fast, the effects of a 30-min low-dose intravenous insulin infusion (2.6 units/h) upon plasma glucose and non-esterified fatty acids were compared in 29 very obese patients and 17 non-obese controls. The dose of insulin was chosen so as to have its sole or predominant hypoglycaemic effect upon hepatic glucose release. The proportional fall from basal values at 30 min of both plasma glucose and non-esterified fatty acids was significantly greater in the controls and there was no difference between males and females. In the controls the fall in plasma glucose and non-esterified fatty acids was significantly and inversely correlated with the basal plasma insulin level. Neither index of insulin sensitivity was significantly related with the basal plasma insulin in the obese subjects. Weight lost in the obese subjects led to increased insulin sensitivity; in particular, the degree of change in insulin-induced non-esterified fatty acids was significantly related to the percentage change in weight. Despite their extreme degree of obesity, the distributions of basal plasma insulin levels and the indices of insulin sensitivity in the obese subjects overlapped with those of the non-obese controls.

Adult↗
PubMed1981

Effect of a long-term fat-modified diet on serum lipoprotein levels of cholesterol and triglyceride in patients on home haemodialysis.

1. Changes in serum total and lipoprotein fraction triglyceride and cholesterol levels were studied in 24 adults on home haemodialysis. Half the patients were randomly allocated to a low cholesterol (mean 200 mg/day), fat-modified diet (mean polyunsaturated/saturated fat ratio of 1.0 with a mean of 43% of the total energy content derived from fat). 2. Before dietary manipulation, triglyceride levels in all lipoprotein fractions were significantly higher (P less than 0.02) than in a control group of age and sex matched normal subjects. Total cholesterol, very-low-density-lipoprotein (VLDL) and low-density-lipoprotein (LDL) cholesterol were also significantly raised (P less than 0.02), but high-density-lipoprotein (HDL) cholesterol was normal. In the patients on a fat-modified diet triglyceride levels did not alter in any of the lipoprotein fractions. Total cholesterol and LDL cholesterol levels fell significantly into the normal range (P less than 0.002 and less tha 0.001 respectively) but VLDL and HDL cholesterol levels did not change. 3. Hypertriglyceridaemia is the most common lipid abnormality in patients with renal failure and a long-term fat-modified diet is, therefore, of limited therapeutic importance in these patients unless there is a low HDL/LDL cholesterol ratio.

Adolescent↗
PubMed1981

Hyperglycemia and arterial disease.

Clinical and autopsy evidence support the increased risk of atherosclerotic disease in diabetes mellitus (DM). However, mechanisms other than arterial occlusion may also contribute to clinical syndromes often assumed to be atherosclerotic in origin. There is considerable geographical variability in the frequency of arterial disease in the diabetic. Glucose intolerance short of unequivocal DM is found in some (though not all) populations to carry increased atherosclerotic risk. Morbidity and mortality data suggest that women are particularly vulnerable (as with DM). The Whitehall prospective study of cardiovascular mortality shows that risk does not rise smoothly with increasing degrees of glucose intolerance but that it doubles sharply at the 95th percentile of the 2-h post-glucose blood sugar distribution.

Adult↗
PubMed1980

Human insulin produced by recombinant DNA technology: safety and hypoglycaemic potency in healthy men.

Human insulin synthesised by recombinant DNA technology was compared with highly purified porcine insulin in healthy men. Intracutaneous injection over a wide range of concentrations of both insulins into five subjects gave rise to no local reactions over a 48 h period. The glycaemic response to standard subcutaneous injection at high and low dose levels was measured with both insulins in each of six men. Plasma glucose decrement with the two insulins was similar but human insulin was perhaps slightly more potent than porcine insulin at the low dose, and slightly less so at the high. The glycaemic response to the isulins, each infused intravenously at high and low concentrations for 1 h in a further six subjects, showed a similar trend. Depression of glycaemia with human insulin slightly exceeded that with porcine insulin at the low concentration infusion and fell slightly short of it at the high. Genetically synthesised human insulin seems to be safe and effective in man. Its dose-response relationship may differ from that of porcine insulin.

Adult↗
PubMed1980

Coronary-heart-disease risk and impaired glucose tolerance. The Whitehall study.

In the Whitehall Study of 18,403 male civil servants aged 40--64 years, 7 1/2 year coronary-heart-disease (CHD) mortality has been examined in relation to blood-sugar concentration 2 h after a 50 g oral glucose load. CHD mortality was approximately doubled for subjects with inpaired glucose tolerance (IGT), defined as a blood-sugar above the 95th centile (greater than or equal to 96 mg/dl). There was no trend of CHD mortality with blood-sugar below the 95th centile. Within the IGT group, age, systolic blood-pressure, and ECG abnormality (Whitehall criteria) were significantly predictive of subsequent CHD mortality. These findings are relevant to discussions on the criteria for diabetes which include the definition of an IGT category with increased risk of large-vessel disease, but without the high risk of small-vessel disease as occurs in diabetes mellitus.

Adult↗
PubMed1980

Pet ownership, distemper antibodies and multiple sclerosis.

The incidence of cat or dog ownership was similar in 64 multiple sclerosis (MS) patients in south-east England and age- and sex-matched controls. 86% of both groups had owned a cat or dog before the date of onset of MS in the index case so that it would be difficult to detect an association between pet ownership and MS. The titres of neutralising antibody to canine distemper virus were higher in the MS patients (mean 48 +/- 68) than the controls (32 +/- 35), a significant difference (P < 0.05). This difference is not necessarily explained by a cross-reaction with measles antibody of which the titre was much higher in MS (610 +/- 560) than in the controls (320 +/- 330, P < 0.001).

Animals↗
PubMed1979

Haemostatic variables associated with diabetes and its complications.

To study the possible role of an "increased thrombotic tendency" in the vascular complications of diabetes several tests of haemostatic function were carried out on 91 men and 63 women with diabetes aged 35-54 years and the results compared with findings in 686 men and 393 women of the same age in the Northwick Park Heart Study. Mean values for factors VII and X, fibrinogen, and platelet adhesiveness were higher in the diabetics, but mean fibrinolytic activity and whole blood platelet counts were lower. Antithrombin III values were also higher in the diabetics, which may have constituted a protective response to other changes favouring the onset of vascular disease. Diabetics with retinopathy had higher factor VII and antithrombin III values, and those with proteinuria had higher values for factor VII, fibrinogen, and platelet adhesiveness than those without these complications. These findings suggest a potentially important association between a thrombogenic tendency and vascular disease in diabetes. Nevertheless, prospective data are needed to clarify whether the haemostatic abnormalities precede the onset of clinically manifest vascular complications or are a consequence of them.

Adult↗
PubMed1979

Does the nephrotic syndrome increase the risk of cardiovascular disease?

Cardiovascular mortality and morbidity were assessed, after a mean follow-up period of 5 years, in an unselected series of 159 adults presenting with the nephrotic syndrome between 1972 and 1975. 60% of the deaths were attributed to terminal renal failure, and the incidence of deaths from ischaemic heart-disease (IHD) was not significantly above normal. The proportion of patients experiencing angina and intermittent claudication and the prevalence of ischaemic electrocardiographic changes did not differ significantly from those of a London control population. At follow-up, hypertension was significantly more common (p less than 0.001) in male nephrotic patients than in controls. Earlier reports of a greatly increased incidence of IHD in unselected patients with the nephrotic syndrome were not confirmed. Routine treatment of hyperlipidaemia in the nephrotic syndrome is not, therefore, recommended.

Adolescent↗