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Biomedical subjects

D J Ewing

Publications and source records attributed to D J Ewing.

At least 73 records · Page 4Linked to original sources
PubMed1985

Assessment of erectile function in diabetic and non-diabetic impotence by simultaneous recording of penile diameter and penile arterial pulse.

Simultaneous monitoring of penile diameter and penile arterial pulse during laboratory-based erotic stimulation with film and fantasy, has been used to compare diabetic and non-diabetic impotent men with non-impotent controls. The degree of erection to erotic film distinguished between organic and psychogenic aetiologies. The diabetic group showed smaller penile pulse amplitude changes than the other two groups. Amongst the diabetics, severe autonomic neuropathy was associated with impaired erectile and penile pulse amplitude responses. Severe retinopathy was associated with smaller baseline penile pulse amplitude as well as smaller amplitude response. Blood pressure response to erotic stimuli did not differ between the three groups. An analysis of the temporal relationship between penile diameter change and pulse amplitude change revealed differences between the groups that may prove to have diagnostic as well as theoretical implications.

Adult↗
PubMed1984

New method for assessing cardiac parasympathetic activity using 24 hour electrocardiograms.

Cardiac parasympathetic activity was assessed using 24 hour electrocardiographic recordings by measuring the incidence of larger changes in successive RR intervals, which in normal subjects occur frequently but irregularly. In 25 normal subjects the mean number of times per hour in which the change in successive RR interval was greater than 50 ms was 150-250 during waking and 350-450 during sleeping. By contrast, 30 diabetics with medically denervated hearts (12 with cardiovascular reflex evidence of parasympathetic damage and 18 with additional sympathetic damage) and six cardiac transplant patients with surgically denervated hearts had extremely low counts. Additionally, of 20 diabetics with normal cardiovascular reflexes, about half had abnormally low counts, suggesting that this method is better than currently available reflex tests in detecting early cardiac parasympathetic damage. This technique provides a valid and sensitive way of monitoring cardiac parasympathetic activity over prolonged periods.

Adult↗
PubMed1984

Breathing, sleep, and diabetic autonomic neuropathy.

Sudden, unexplained deaths are relatively common in diabetic autonomic neuropathy. As disturbed autonomic function has been associated with sleep apnea, and sleep apnea with sudden death, we recorded breathing patterns, arterial oxygen saturation, and EEG during sleep in 8 male diabetic subjects with severe autonomic neuropathy and 8 age-matched, male diabetic subjects without autonomic neuropathy. None of the patients with autonomic neuropathy had more than 11 apneic episodes per night, and there were no significant differences between the two groups in the number of sleep apneas, the duration of individual apneic episodes, the total duration of irregular breathing during sleep, or the duration and quality of sleep. The arterial oxygen saturation when awake and the lowest arterial oxygen saturation during sleep were also similar in both groups. Thus, diabetic patients with severe autonomic neuropathy have normal breathing patterns and oxygenation during sleep, and it is unlikely that sleep apnea causes these unexpected deaths.

Adult↗
PubMed1983

Sexual responsiveness in diabetic women.

Sexual responsiveness in 82 Type 1 (insulin-dependent) diabetic women was compared with that of 47 normal control subjects, using an interview method for rating various aspects of sexual response, and attitude questionnaires. The diabetic women were questioned about symptoms of autonomic neuropathy, and cardiovascular autonomic nerve function tests were performed. There were differences between the two groups in the reports of vaginal lubrication, but in most other respects the groups were similar. The diabetic women were not less orgasmic, and reported significantly fewer unpleasant feelings during sexual intercourse. They saw themselves and their husbands as less 'potent' than did the normal subjects. The possible enhancing effect of diabetes on the marriage of some diabetic women possibly counteracted the relatively mild physiological deficits involved. There was very little difference in sexual response between women with and without symptomatic autonomic neuropathy.

Adult↗
PubMed1983

A controlled trial of sorbinil, an aldose reductase inhibitor, in chronic painful diabetic neuropathy.

A double-blind, randomized, placebo-controlled cross-over trial of the aldose reductase inhibitor sorbinil was undertaken in 15 patients (age 35-68 yr) with chronic painful diabetic neuropathy. Treatment was evaluated by subjective pain responses, clinical examination, vibration perception threshold, motor and sensory nerve electrophysiology, and cardiovascular reflex tests of autonomic nerve function. Among the many measurements, only pain, tendon reflex scores, and sural sensory potential amplitude improved significantly during sorbinil administration, while scores of clinical sensory examination deteriorated. Four patients experienced an idiosyncratic reaction that rapidly recovered on discontinuing the drug. This study suggests that aldose reductase inhibitor treatment with suggests that aldose reductase inhibitor treatment with sorbinil may have an effect on symptomatic diabetic neuropathy in man.

Adult↗
PubMed1983

Abnormalities of ambulatory 24-hour heart rate in diabetes mellitus.

Twenty-one normal subjects and 64 diabetics with varying severity of autonomic damage underwent 24-h ambulatory EKG monitoring. No diabetics had the "sick sinus syndrome," and the frequency of arrhythmias was no higher than in the normal subjects. The diabetics had higher mean hourly heart rates, and with increasing autonomic damage there was reduction in diurnal heart rate variation. The mean waking and sleeping heart rates were higher in the diabetics. The maximum heart rates were not significantly different, but the minimum heart rates were significantly higher in the diabetics. These previously unrecognized abnormal 24-h heart rate patterns provide further evidence of damage to the heart rate-controlling mechanisms in diabetes mellitus.

Adult↗
PubMed1983

Nerve function and metabolic control in teenage diabetics.

Peripheral somatic and autonomic nerve function have been studied in 79 teenage (16-19 yr) diabetics and 20 age- and sex-matched normal controls. Almost three-quarters of the diabetics (72%) had abnormal peripheral somatic nerve function tests, and one-third (31%) had abnormal cardiac parasympathetic tests. Both motor and sensory peripheral somatic nerve abnormalities were related to poor prevailing glycemic control (HbA1) and duration of diabetes. Thus, the 27 patients with three or more (maximum six) peripheral nerve abnormalities had significantly higher HbA1 levels (P less than 0.001) and longer duration of diabetes (P less than 0.01) than the 22 with no abnormalities. Individual peripheral somatic nerve tests almost invariably correlated only with HbA1 (median motor, P less than 0.05; peroneal motor, P less than 0.001; sural sensory, P less than 0.001) or duration of diabetes (median sensory, P less than 0.001). Sensory potential amplitude, as well as conduction velocity, was frequently reduced, implying axonal involvement. These findings suggest that abnormal peripheral and autonomic nerve function are common in young insulin-dependent diabetics and that poor metabolic control is a major determinant of the damage. DIABETES 32:142-147, February 1983.

Adolescent↗
PubMed1982

Autonomic control of the immediate heart rate response to lying down.

1. The initial heart rate response to lying down was analysed in 18 younger (23-36 years) and 10 older (48-67 years) normal subjects, and consisted of an immediate shortening of the R-R interval reaching a maximum around the third or fourth beat after lying, followed by a lengthening beyond the resting value to reach a steady level around beats 25-30. In six diabetic patients with autonomic neuropathy, no cardiac acceleration occurred and the deceleration was markedly diminished. 2. In eight young normal subjects the pattern of response was altered by atropine, which abolished the initial shortening of the R-R interval over the first 10 beats. Thereafter slow but steady lengthening of the R-R interval occurred. With additional propranolol the later part of the response was further attenuated. Propranolol alone did not affect the normal pattern of response. 3. Six young normal subjects performed short periods of muscular exercise, lying, sitting and standing, and the heart rate patterns were compared with that after lying down. After both manoeuvres R-R interval shortened and then lengthened back to the resting level within 10-15 beats. Thereafter it remained steady after muscular exercise, but continued to lengthen after lying down. 4. In four young normal subjects, no initial R-R interval shortening occurred during fast or slow "passive' tilting from the 80 degrees head-up position to horizontal, whereas shortening was seen both with fast and slow "active' lying down. 5. It is concluded that the immediate part of the heart rate response to lying down (during the first 10 beats) is under vagal control and the later part predominantly under sympathetic control. The first part of the response is probably due to a "muscle-heart' reflex which occurs during the change in posture.

Adult↗
PubMed1982

Preservation of the hypoxic drive to breathing in diabetic autonomic neuropathy.

1. Unexplained cardiorespiratory arrests have been reported in patients with diabetic autonomic neuropathy and these could be due to denervation of the carotid chemoreceptors. 2. We have studied the ventilatory response to transient hypoxia (Ve/Peto2) during exercise in 22 male diabetic patients, six with symptomatic and cardiovascular evidence to suggest diabetic autonomic neuropathy (DAN+) and 12 without these features (DAN-). 3. There was no difference in the ventilatory response to transient hypoxia between the different groups of diabetic patients (Ve/Peto2 in DAN+ patients = -0.9 +/- 0.2 litre min-1 kPa-1; Ve/Peto2 in DAN- patients = -1.2 +/- 0.6 litres min-1 kPa-1) even allowing for differences in the level of exercise achieved (CO2 production in DAN+ patients = 743 +/- 103 ml/min; CO2 production in DAN- patients = 800 +/- 144 ml/min). These results fell within our normal range for ventilatory response to transient hypoxia at this level of exercise. 4. The heart rate response to transient hypoxia varied within the groups but was significantly (P less than 0.05) less in the patients with established diabetic autonomic neuropathy. 5. We conclude that the peripheral chemoreceptors are intact in diabetic autonomic neuropathy and that other mechanisms must be implicated in the unexpected cardiorespiratory arrests seen in these patients.

Adult↗
PubMed1982

The clinical features of diabetic impotence: a preliminary study.

Twenty-seven diabetic men with erectile impotence were given physical and psychosexual assessments. Physical assessment included vascular and neurological evaluation. Psychosexual assessment was by means of a semi-structured interview. Seven potent diabetic men formed a control group. Patients with erectile failure had a varied clinical picture which differed from the stereotype of diabetic impotence: morning erections were preserved in over a half (55 per cent), eight patients (30 per cent) had intact spontaneous erections, and sexual interest was reduced in 12 patients (44 per cent). In 13 patients (48 per cent) ejaculation was disturbed and a further four patients (15 per cent) described unusual disorders of sexual function. Within the group there were no differences in clinical picture between those with and without autonomic neuropathy, retinopathy or potential psychogenic factors.

Adult↗
PubMed1981

Heart rate changes in diabetes mellitus.

Resting heart rates were measured lying, sitting, and standing in 61 diabetics with varying degrees of cardiovascular reflex abnormalities. Those with parasympathetic abnormalities alone had the highest heart rates, while those with both parasympathetic and sympathetic involvement had slightly less rapid heart rates, which were still faster than those in diabetics with normal cardiovascular reflexes. 38 other diabetics in whom autonomic function tests had been done at least three times had a similar pattern of resting heart rate. 25 had unchanged tests: those with parasympathetic involvement alone had the highest heart rates. The other 13 subjects whose autonomic function changed from normal to abnormal showed a sequential increase in heart rate as cardiac parasympathetic damage developed, followed by a fall in heart rate, but not back to normal, as sympathetic damage developed as well. The increased resting heart rates in diabetics may be due in some patients to cardiac parasympathetic damage alone and in others to combined parasympathetic and cardiac sympathetic damage. The sequential heart rate changes support the view that the vagus nerve is affected before the cardiac sympathetic nerves.

Adolescent↗