The effect of insulin-induced hypoglycaemia on cerebral blood flow was examined using the intravenous xenon-clearance technique in 9 patients with Type 1 (insulin-dependent) diabetes (aged 20 to 43 years) and 9 age-matched control subjects before, during and after hypoglycaemia. Cerebral blood flow rose in both groups. The mean basal cerebral flood flow values were not significantly different and during hypoglycaemia mean cerebral blood flow increased by 17% (p = 0.008) in the diabetic patients and by 21% (p = 0.0003) in the control subjects. The results suggest that in young diabetic patients without autonomic neuropathy or microangiopathy cerebral vessels dilate normally in response to hypoglycaemia. The physiological importance of an increase in cerebral blood flow during hypoglycaemia is uncertain; but glucose availability is increased.

No abstract

Summary. Urinary albumin excretion during pregnancy has been studied using a sensitive radioimmunoassay. One hundred pregnant women attending a high‐risk antenatal clinic and 14 normal pregnant women were investigated serially, during pregnancy and post‐partum. The normal subjects showed a small but significant rise in albumin excretion in the third trimester, which was sustained pre‐delivery and in the first postnatal week. Twenty‐six women were classified as having mild pre‐eclampsia and 44 as having chronic hypertension without evidence of superimposed pre‐eclampsia. In neither group was there evidence of proteinuria by conventional testing, nor was the median albumin excretion different from normal antenatally; in the first week after delivery a significant increase was observed, but this regressed to normal 6 weeks later. Eight patients developed severe pre‐eclampsia, of whom one had evidence of underlying renal disease. Three presented with proteinuria already established. In the remaining five patients, the shift from normal to high albumin excretion occurred rapidly, usually preceded by a rise in uric acid and a decrease in the platelet count. These data suggest that proteinuric pre‐eclampsia, as defined by relatively insensitive routine laboratory measurement, is not preceded by a phase of increasing albumin loss which can be detected by more sensitive assays.

1.Two groups of patients with non-insulin-dependent diabetes mellitus (NIDDM), with dietary advice randomized between a low-carbohydrate (LC) diet and a modified-fat (MF) diet, were followed to determine the effect of diet on phospholipid fatty acid composition of platelets and on development of retinopathy in the 7 years following diagnosis. There was a tendency for retinopathy to occur more frequently in those randomiEd to the LC diet. This difference was not statistically significant, and fatty acid composition of platelets did not differ significantly in those with and without retinopathy.2. Linoleic acid values from platelet phospholipid fatty acids were significantly higher in NIDDM on an MF diet compared with an LC diet.3. There was no difference between the two dietary subgroups with respect to platelet arachidonic acid, but this was lower in the whole diabetic population when compared with non-diabetics.4. The arachidonic acid values correlated with neither glycosylated haemoglobin nor mean glycaemia. 5. Significant correlation between the fatty acid values for platelets and plasma cholesterol esters was found only for 16:O.