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Biomedical subjects

R J Corrall

Publications and source records attributed to R J Corrall.

At least 73 records · Page 4Linked to original sources
PubMed1986

The prevalence of autonomic neuropathy in insulin-dependent diabetes mellitus: a controlled study based on heart rate variability.

Autonomic function was investigated by tests of heart rate variation in 506 unselected insulin-dependent diabetics aged 12 to 85 years. Heart rate variability was measured by a computerised technique during rest and in response to a single deep breath, the Valsalva manoeuvre and standing. Changes in heart rate were compared with age-related normal ranges derived from 310 non-diabetic control subjects aged 18 to 87 years. Heart rate responses were found to be below the 5th centile control value in 13 to 23 per cent of diabetics. Impaired heart rate variability occurred more frequently in response to a single deep breath than to the other procedures. Results from all four procedures were combined in each subject to give an 'autonomic score', varying from 0 to 4. This score was greater than 1 in only five of 310 (1.6 per cent) non-diabetic control subjects. A score of 2 or more was therefore defined as abnormal and indicative of cardiac autonomic denervation. Abnormal autonomic scores were found in 84 diabetics (16.6 per cent). In diabetic subjects the autonomic score correlated most closely with heart rate variability at rest and in response to a single deep breath. Abnormal autonomic scores correlated significantly with duration of diabetes (p less than 0.0001) but not with age (p = 0.06). The frequency of abnormal autonomic scores was greatest in diabetics aged 40 to 49 years (24.5 per cent) and those with diabetes of 20 or more years duration (30.7 per cent).

Adult↗
PubMed1985

Hypoglycemia during adrenergic beta-blockade: evidence against mediation via a deficiency of lactate for gluconeogenesis.

Acute hypoglycemia was induced using intravenous inulin in three groups of normal volunteers: (1) seventeen control subjects, (2) six subjects under beta-adrenergic blockade with propranolol, and (3) eight subjects given propranolol plus sodium lactate as an exogenous substrate for gluconeogenesis. Under propranolol blockade the recovery from hypoglycemia was significantly impaired. This impairment was not prevented by the infusion of sodium lactate despite the production of an adequate elevation of blood lactate concentrations. These findings suggest that the impaired recovery from hypoglycemia during beta-adrenergic blockade is not mediated via a deficiency of lactate as substrate for hepatic gluconeogenesis.

Adult↗
PubMed1985

Oesophageal function in diabetes mellitus and its association with autonomic neuropathy.

We have evaluated oesophageal function in 34 diabetics and in 16 non-diabetic controls by a timed bolus transit method derived from dynamic oesophageal scintiscans (water transit time: WTT) and barium swallow. The diabetics were screened for autonomic neuropathy using standard cardiovascular responses and 10 patients were classified as abnormal. WTT was significantly prolonged in autonomic neuropaths compared with other diabetics (p less than 0.01) and controls (p less than 0.001). Abnormal peristalsis on barium swallow was seen more frequently in autonomic neuropaths (9/10) than in other diabetics (11/24, p less than 0.002). WTTs from all diabetic patients correlated with abnormal heart rate responses at rest (Rs = - 0.49, p less than 0.005), on deep inspiration (Rs = -0.48, p less than 0.005), and on standing (Rs = -0.39, p less than 0.025) but not with the Valsalva manoeuvre. A weaker correlation was found between the postural fall in blood pressure (Rs = 0.3, p less than 0.05). Diabetics with autonomic neuropathy frequently have asymptomatic oesophageal dysfunction which may result from a vagal neuropathy in view of its association with abnormalities of vagally mediated cardiovascular responses.

Adult↗
PubMed1985

Factitious diabetic instability.

Factitious diabetic instability is described in four patients. In three the predominant problem was recurrent hypoglycaemia. The fourth presented with apparent insulin resistance and episodes of ketoacidosis. The methods used to make the diagnosis are described, and the factors which contribute to this type of diabetic instability are discussed.

Adult↗
PubMed1984

Papilloedema in diabetes: an ischaemic optic mononeuropathy.

Five diabetic patients had acute visual impairment due to papilloedema, which was bilateral in two patients. The clinical features and subsequent course were compatible with ischaemic optic mononeuropathy presumed to result from ischaemia in a posterior ciliary artery. This cause should always be considered in the differential diagnosis of papilloedema in a diabetic patient to avoid the instigation of inappropriate and invasive investigations. In general the condition has a good prognosis.

Adult↗
PubMed1984

Clinical and neurophysiological studies with the aldose reductase inhibitor, sorbinil, in symptomatic diabetic neuropathy.

The effect of sorbinil (200 mg daily for 4 weeks) was examined in 13 patients, mean age 59.7 years (range 42-72 years), with symptomatic diabetic neuropathy of mean duration 6 year (range 1-18 years). In this double-blind, placebo-controlled crossover trial, studies were made of motor, sensory and autonomic nerve function, severity of painful symptoms and duration of sleep. One patient was withdrawn because of an adverse reaction to sorbinil. In the other 12, constant mean values for glycosylated haemoglobin A1 between 11% and 12% indicated stable though not ideal diabetic control throughout the study. Example values for nerve conduction velocity on placebo and active treatment were: 44.3 +/- 5.9 and 44.8 +/- 5.1 metres/s (mean +/- SD) for median motor nerve, 38.4 +/- 8.2 and 37.2 +/- 7.7 metres/s for median sensory nerve. Thus there was no significant effect of sorbinil on conduction velocity in these or any other of the motor and sensory nerves tested. Abnormal autonomic function was not improved by sorbinil. Subjective pain scores on a 10 cm visual analogue scale were 4.2 +/- 2.4 on placebo and 4.3 +/- 2.4 after sorbinil. Duration of sleep on placebo and active treatment was 6.1 +/- 1.6 and 6.2 +/- 1.7 h/night, respectively. We were not able to detect any beneficial effect of sorbinil on painful diabetic neuropathy in our patients.

Adult↗
PubMed1984

Autonomic neural control mechanisms and the release of adrenal steroids after hypoglycaemia in man.

The changes in blood glucose, plasma potassium, plasma renin activity, aldosterone, cortisol, corticosterone and ACTH were measured in 11 normal subjects, 6 tetraplegic subjects (pre-ganglionic sympathectomy) and 6 tetraplegic subjects given atropine (sympathectomy with cholinergic blockade), in response to acute insulin-induced hypoglycaemia. After hypoglycaemia, blood glucose recovery was impaired only in the tetraplegic group given atropine in whom ACTH secretion was delayed and the peak cortisol and corticosterone concentrations were lower compared with the other groups. Plasma renin activity rose both in the normal and the tetraplegic subjects; the aldosterone rise and the fall in potassium were similar in all three groups. Aldosterone release after hypoglycaemia appears to occur independently of stimulation of the sympatho-adrenal system and cholinergic blockade, and may result from activation of the renin-angiotensin system, rather than from ACTH stimulation. Activation of ACTH secretion in response to hypoglycaemia may involve a cholinergic mechanism at the hypothalamic level, with a consequent reduction in the increments of plasma cortisol and corticosterone after atropine administration.

Adrenal Cortex Hormones↗
PubMed1984

The influence of adrenergic denervation on the response to feeding of the gastroenteropancreatic system in man.

The effect of adrenergic denervation on the metabolic and hormonal response to a standard meal was studied in six tetraplegic subjects (pre-ganglionic sympathectomy) and compared with six normal subjects. Gastric emptying, estimated by isotope scintiscanning, was similar in both groups. Following the meal the mean blood glucose and plasma insulin rose in both groups, but were higher and remained elevated for longer in the tetraplegic subjects. There were no significant differences in the secretion of pancreatic glucagon, enteroglucagon, gastric inhibitory peptide (GIP) and neurotensin between the two groups. The mean basal and post-prandial levels of pancreatic polypeptide and motilin were significantly higher in the tetraplegic group. This study confirms the presence of mild glucose intolerance in tetraplegic subjects which is not explicable on the basis of abnormal insulin or pancreatic glucagon secretion or abnormal gastric emptying. In addition the results provide evidence for a sympathetic inhibitory influence on the secretion of pancreatic polypeptide and motilin in man, which is probably adrenergically-mediated.

Adult↗
PubMed1983

Cholinergic manifestations of the acute autonomic reaction to hypoglycaemia in man.

1. The effects of insulin-induced hypoglycaemia on pupil size, parotid salivary secretion and sweating were studied in seven normal volunteers. 2. Hypoglycaemia was associated with an acute stimulation of parotid salivary secretion and of sweating, synchronous in onset with the rise in heart rate. There was no clear evidence of concurrent pupillary constriction.

Acute Disease↗
PubMed1983

Peripheral blood cell changes in response to acute hypoglycaemia in man.

Peripheral white and red blood cell changes were studied in response to acute insulin-induced hypoglycaemia in six normal, six splenectomized and five sympathectomized (tetraplegic) subjects. The normal subjects were restudied during beta (propranolol) and beta 1-selective (metoprolol) adrenergic blockade. In the normal subjects a lymphocytosis immediately followed the acute hypoglycaemic reaction (R) with a neutrophilia 2 h later. The early lymphocytosis was absent in sympathectomized subjects (P less than 0.001) and reduced under beta blockade (P less than 0.02) in normal subjects, indicating mediation via an adrenergic mechanism. The later neutrophilia from R + 60 min was not abolished by adrenergic blockade or preceding sympathectomy; the enhanced response with propranolol was associated with an elevated plasma cortisol. Haemoglobin, packed cell volume and total erythrocyte count rose maximally at R in all groups except the sympathectomized subjects in whom all parameters declined progressively from basal values. These peripheral erythrocytes changes appear to be mediated via an adrenergic mechanism which is unaffected by beta adrenergic blockade and which does not involve splenic contraction.

Acute Disease↗
PubMed1982

Is testicular endocrine function abnormal in young men with spinal cord injuries?

Plasma concentrations of FSH, LH, testosterone and prolactin have been studied in seventeen men, aged 19 to 38 years, with traumatic paraplegia. Plasma testosterone, FSH and LH values were normal in all patients. The median LH concentration in patients was significantly higher (P less than 0.05) than in controls but there was no difference for FSH or testosterone. Plasma prolactin was high in five patients and the median prolactin concentration in patients was significantly greater (P less than 0.001) than in controls. It is concluded that there is no evidence of primary testicular failure in young paraplegics but it is possible that testicular hypofunction in some paraplegics may be related to increased prolactin production.

Adult↗
PubMed1982

The effect of adrenergic and cholinergic mechanisms on the secretion of pancreatic polypeptide and gastrin following hypoglycaemia in man.

The changes of plasma pancreatic polypeptide (PP) and plasma gastrin following acute insulin-induced hypoglycaemia (0 . 15 U/kg) were examined in six normal subjects, six tetraplegic subjects (preganglionic sympathectomy) and six tetraplegic subjects given atropine (combined adrenergic denervation and cholinergic blockade). Adequate hypoglycaemia was achieved in all three groups. The normal rise of plasma PP following hypoglycaemia was present in the tetraplegic group without atropine but was abolished in the tetraplegic subjects given atropine. There was no significant rise in plasma gastrin following hypoglycaemia except in the tetraplegic group given atropine. These results confirm that the secretion of PP in response to acute hypoglycaemia is mediated via cholinergic activity, while gastrin secretion appears to be inhibited in normal subjects by a vagal cholinergic mechanism.

Adult↗