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Biomedical subjects

B F Clarke

Publications and source records attributed to B F Clarke.

At least 145 records · Page 8Linked to original sources
PubMed1977

Peripheral and autonomic nerve function in newly diagnosed diabetes mellitus.

Peripheral and autonomic nerve function was assessed in 10 newly diagnosed male diabetics (six insulin-treated and four sulfonylurea-treated) with repeated observations over the subsequent six months. There was significant impairment of motor-conduction velocity in the common peroneal nerve at diagnosis in both treatment groups, with improvement following treatment in only the insulin-treated patients. In contrast, although the blood glucose level fell in both groups, the mean level was significantly lower in the sulfonylurea-treated patients at two months and at each subsequent visit. In the autonomic function tests significant abnormality was found in the electrocardiographic R-R-interval (beat-to-beat) variation in resting heart rate in two of the insulin-treated patients and all of the sulfonylurea-treated group, with improvement in only one of the latter. One patient in the sulfonylurea-treated group also showed an abnormal response to the Valsalva maneuver (expressed as the Valsalva ratio), and this remained abnormal throughout the period of study. All other patients had normal responses to the Valsalva maneuver and sustained handgrip test. None of the patients had postural hypotension. Abnormalities in autonomic nerve function in diabetics at diagnosis have not been previously reported.

Adolescent↗
PubMed1976

Plasma renin activity in diabetic autonomic neuropathy.

Postural changes in plasma renin activity were studied in three groups of age and duration-matched male diabetics (potent, impotent and with postural hypotension) and in non-diabetic control subjects. Those diabetic subjects with postural hypotension due to automatic neuropathy had no increase in plasma renin activity to the erect posture whereas both the potent and impotent groups had similar plasma renin activity responses to the control subjects. There was a significant inverse correlation between the rise in plasma renin activity on standing and the postural drop in blood pressure (r = 0.476, P less than 0.01) but no correlation with other tests of autonomic reflex function such as the Valsalva manoeuvre and blood pressure response to sustained handgrip. The results suggested that the lesion responsible for the postural hypotension is in the efferent sympathetic pathway. However, neuropathy per se did not wholly explain the decreased postural plasma renin activity response. Diabetic nephropathy, with involvement of cells of juxtaglomerular apparatus, may also be implicated.

Adult↗
PubMed1976

Peripheral and autonomic nerve function in diabetic ketoacidosis.

Peripheral and autonomic nerve function was assessed at intervals over a 3-month period in seven diabetics after ketoacidosis. There was marked improvement in motor conduction velocity and terminal latency of both ulnar and common peroneal nerves in all patients. Five had one or more abnormal autonomic function tests but there were no consistent changes during the same period. It is postulated that peripheral nerves may be more susceptible to acute metabolic damage than autonomic fibres.

Adolescent↗
PubMed1976

Therapeutic experience with fludrocortisone in diabetic postural hypotension.

Fourteen patients with diabetic postural hypotension were treated with fludrocortisone for a mean 12 months (range 6-30 months). The mean daily dose of fludrocortisone was 0.2 mg (range 0.1 mg-0.4 mg). Standing systolic and diastolic blood pressures increased significantly (P less than 0.001) after treatment with fludrocortisone and the postural hypotension decreased significantly (P less than 0.001). Thirteen patients noted considerable symptomatic improvement. Fludrocortisone should be used cautiously in patients with congestive cardiac failure or the nephrotic syndrome.

Adult↗
PubMed1976

Mortality in diabetic autonomic neuropathy.

Thirty-seven diabetics with symptoms and clinical features suggestive of autonomic neuropathy were followed up for 33 months. Of the twenty with abnormal Valsalva or handgrip tests initially, ten (50%) died. There were no other features at presentation that differentiated those who subsequently died from those who survived. The causes of death were renal failure (six patients), cerebrovascular accident (two patients), hypoglycaemic coma (one patient), and "sudden death" (one patient). Of the survivors whose autonomic-function tests were repeated 18 months to 2 years later, five had new or worsening symptoms of autonomic neuropathy with corresponding deterioration of their autonomic-function tests; while two, with initially normal tests, had improved symptomatically. It is concluded that in diabetics with the clinical features of autonomic neuropathy simple autonomic-function tests give a good guide to prognosis, and that abnormal tests are associated with a high mortality.

Adult↗
PubMed1976

Experience of coronary care in diabetes.

During 1968-1973, 94 patients with diabetes were admitted to a coronary care unit (CCU) on 99 occasions with proved myocardial infarction. Altogether 24 of them (25-5%) died, giving an overall mortality at the time of discharge of 24% for the total admissions. This was just significantly higher than the 19% mortality recorded among non-diabetics treated in the same period but was much lower than that among diabetics treated for myocardial infarction before the advent of CCUs. No definite correlation was found between the type of anti-diabetic treatment and either mortality or the incidence of primary ventricular fibrillation. Patients with "poor" control of the diabetes before admission showed a significantly higher mortality than those with "good" control, but there was no significant difference in mortality between those with previous good control and non-diabetics.

Aged↗
PubMed1976

Diabetic retinopathy with normal glucose tolerance.

A case is reported of a patient with typical diabetic retinopathy, but with normal glucose tolerance. Previously reported cases are reviewed and it is concluded that in such patients the diabetes is probably latent, the retinopathy being discovered during a period of natural or induced remission.

Diabetes Mellitus↗
PubMed1976

Peripheral motor nerve function in diabetic autonomic neuropathy.

Motor conduction velocity was measured in the median, ulnar and common peroneal nerves of 32 diabetics with clinical features of autonomic neuropathy. The responses to the Valsalva manoeuvre and sustained handgrip, and the postural fall in blood pressure were used to assess the integrity of the autonomic nervous system. Abnormalities in the three autonomic function tests were significantly correlated with the forearm conduction velocity of the ulnar nerve, the conduction velocity and motor latency of the common peroneal nerve, and the H reflex. These results show that, in diabetics with autonomic neuropathy, abnormalities in the autonomic nervous system parallel changes in the peripheral nerves. Any diabetic with peripheral neuropathy should be examined for evidence of autonomic nervous system involvement.

Adult↗
PubMed1975

[Duration of effective hypoglycaemic action of glipizide given once daily (author's transl)].

The clinically effective duration of blood glucose lowering action of a new hypoglycaemic sulphonylurea, glipizide, given in single before breakfast dosage (up to 20 mg) has been studied in 20 apparently insulin-independent diabetics. All, on diet only, had persistent overnight 1-2% glycosuria, fasting glycaemia in excess of 150 mg/100ml, random mid-morning glycaemia of at least 250 mg/100ml and associated clinical symptoms. Eighteen were satisfactorily controlled over the observation period of six months by single daily dosage (mean 10 mg daily); in addition considerable improvement in glucose tolerance occurred. Complementary in-patients indicated that, within the range of dosage studied, there was no therapeutic advantage in taking glipizide twice daily.

Administration, Oral↗
PubMed1975

Long-term comparative trial of glibenclamide and chlorpropamide in diet-failed, maturity-onset diabetics.

The long-term clinical effectiveness of glibenclamide was compared with chlorpropamide in highly comparable groups of three hundred and twenty-one diet-failed, non-obese, maturity-onset, newly diagnosed diabetics. The overall primary failure-rate in the chlorpropamide-treated patients was significantly less (p<0.05), and more patients were on chlorpropamide at the end of two years than were on glibenclamide (p<0.01). Although there were fewer secondary failures with chlorpropamide treatment, this difference was not significant. The final blood-glucose and change in body-weight were similar in patients from both treatment groups still taking the original sulphonylurea agent 2 years later. Hypoglycaemic episodes were more common and severe in the glibenclamide-treated patients.

Adult↗
PubMed1975

Continuous electrocardiographic recording during exercise in young male diabetics. A computer study.

Forty selected young patients with diabetes of medium to long duration and 26 control subjects without clinical evidence of ischaemic heart disease were studied using a new and sensitive technique of electrocardiographic recording during exercise with continuous computation of the time course of the ST-T segment changes to detect possible early ST depression indicative of ischaemia. Although no such evidence was found, significant differences in the diabetics were observed in the heart rate and ST-T segment, the latter changes having not been previously reported but which may be attributed to ischaemia or alternatively to autonomic neuropathy in the "presymptomatic" phase.

Adult↗
PubMed1975

RR interval variations in young male diabetics.

The beat-to-beat (RR interval) variation in resting heart rate was used to detect possible autonomic nerve damage in a group of 42 young asymptomatic male diabetics, employing a sensitive electrocardiographic computer technique. Compared with 25 age-matched controls, the diabetics showed both a significantly smaller mean RR interval (P less than 0.005) and less RR interval variation (P less than 0.001). Whereas only 4 of the diabetic subjects had shorter mean RR intervals, 22 (52%) of the diabetics had RR interval variations that were less than any of the normal subjects. This reduction in heart rate variation has not been previously reported in diabetics without clinical features of autonomic neuropathy and might provide a sensitive method of assessing early autonomic nerve involvement in diabetes.

Adult↗
PubMed1975

9-Alpha-fluorohydrocortisone in the treatment of postural hypotension in diabetic autonomic neuropathy.

A double-blind crossover study of fludrocortisone, 0,1 mg. twice daily, and placebo is reported in six diabetics with troublesome symptoms of postural hypotension due to autonomic neuropathy. During treatment with the active preparation there was an increase in the lying and tilted systolic blood pressure, a decrease in orthostatic tachycardia, and in increase in the total plasma volume and body weight, but with no change in plasma or urine osmolality; The symptoms of postural hypotension improved in four patients, while two patients with a low serum albumin developed ankle edema during treatment with fludrocortisone. It is concluded that fludrocortisone is effective in diabetics with symptomatic postural hypotesnion, but should be used with caution in patients with a low serum albumin.

Adult↗
PubMed1975

Comparison of injection techniques for soluble and protamine zinc insulins in diabetes mellitus.

Soluble and protamine zinc insulins were given to six insulin-dependent diabetic patients using three different techniques of administration to determine whether the recommended single injection of the insulins, from separate syringes with the needle redirected, compared more closely with separate injections or with a single injection from the same syringe. It was shown that the mixture of the two insulins in the same syringe resulted in both a significant loss of the initial rapid effect of soluble insulin and an increased protamine zinc action with the risk of late night-time hypoglycaemia. A single injection of the insulins, using separate syringes and redirecting needle, gave at least as satisfactory control of the 24-hour blood glucose profile as when they were given by separate injections.

Adolescent↗
PubMed1974

Testicular pain sensation in diabetic autonomic neuropathy.

Testicular sensation was examined in 32 male diabetics with symptoms suggestive of autonomic neuropathy to evaluate its usefulness as a clinical sign in this condition. Vascular reflex responses to the Valsalva manoeuvre and sustained handgrip and blood pressure fall on standing were measured as objective tests of autonomic involvement. Absent or diminished testicular sensation correlated well both with the clinical features of autonomic neuropathy, except where impotence occurred alone, and with abnormal vascular reflexes. Most patients with impotence alone had normal testicular sensation and normal vascular reflexes. It is concluded that this sign is useful in diabetics with impotence, the presence of intact testicular sensation indicating that the impotence is unlikely to be due to autonomic neuropathy.

Achilles Tendon↗