West Indian diabetic population of a large inner city diabetic clinic

West Indians form a sizable minority of diabetics attending many inner city diabetic clinics. There are 554 diabetics of West Indian origin on our computer files--7% of the total recorded clinic population. Of these 554 patients (56% female, 44% male), 70% have been diagnosed within the past five years; and only 9% have had diabetes for over 10 years; in only five (1%) was diabetes diagnosed before the age of 20. Sixteen per cent were taking insulin, but only 4% of the total West Indian population were truly insulin dependent. Of 65 patients admitted in hyperglycaemic coma or precoma over the past three years, 10 were of West Indian origin; eight of these 10 had hyperosmolar coma compared with only six of the remaining 55. We conclude that diabetics of West Indian origin attending our clinic show differences in the distribution of age and duration of diabetes from the caucasian population. Most are non-insulin dependent, and the frequency of hyperosmolar coma is higher than that of ketoacidosis. Diabetics of West Indian origin may have a different pattern of disease from the rest of the clinic population.

Circulating prostanoid levels, both basal and during the chlorpropamide alcohol flush, in non-insulin dependent diabetes

Circulating basal levels of prostanoids were measured in non-insulin dependent diabetics (NIDDs) who showed chlorpropamide alcohol flushing (CPAF), with and without diabetic complications, and in non-diabetic controls. Prostanoids were also measured during CPAF in those diabetics in whom CPAF is or is not blocked by indomethacin and also in CPAF-negative patients. There was no significant difference in circulating prostanoids between diabetics with and without severe vascular disease. The level of prostaglandin F, however, was significantly higher in the diabetic than in the non-diabetic subjects (mean +/- SEM PGFM 521 +/- 23 v. 414 +/- 18 pmol/l respectively P less than 0.01). In the group in whom CPAF could be blocked by indomethacin there was a significant rise in thromboxane during CPAF when compared with basal values (mean +/- SEM 905 +/- 48 v. 688 +/- 46 pmol/l respectively P less than 0.01) which was abolished by prior administration of indomethacin. There was no significant rise in prostacyclin or PGF. The group in which CPAF could not be blocked by indomethacin and the CPAF negative group showed no rise in any of the prostanoids measured. These findings support the concept of at least two different groups of CPAF positive NIDDs, one in which prostanoids are involved in CPAF and one in which they are not. It is the group in which prostanoids are involved in CPAF who seem to be highly protected against vascular disease.

Blood concentrations of acetaldehyde during chlorpropamide-alcohol flush

To test the suggestion that chlorpropamide-alcohol flushing (CPAF) resembles the disulfiram effect and might be mediated by acetaldehyde, the initial metabolite of alcohol, blood concentrations of acetaldehyde were measured after a drink of alcohol in controls and diabetics positive and negative for CPAF. The CPAF-positive diabetics had significantly greater blood acetaldehyde concentrations after alcohol than the CPAF-negative diabetics both with a single dose of chlorpropamide and after two weeks' chlorpropamide treatment. Concentrations in the CPAF-positive group after chlorpropamide were also significantly greater than after a placebo tablet. There was also a clear separation in the increase in facial temperature after two weeks of chlorpropamide between the CPAF-positive and CPAF-negative groups (although there was some overlap after a single tablet). There was no difference in plasma chlorpropamide or alcohol concentrations between CPAF-positive and CPAF-negative diabetics. These findings show that CPAF is distinct from alcohol flushing and that the acetaldehyde concentration in the blood provides an objective measure of CPAF. The difference between flushing and non-flushing diabetics cannot be accounted for by differences in blood concentrations of chlorpropamide or alcohol.

Metabolic studies in unaffected co-twins of non-insulin-dependent diabetics

Forty-eight out of 53 non-insulin-dependent diabetic identical twin pairs were concordant for diabetes. In the five discordant pairs the diabetic twin had only recently been diagnosed. Oral glucose tolerance tests were carried out on the unaffected twins of the five pairs and on matched controls. Fasting concentrations of blood glucose (5.5 +/- 0.6 v 3.7 +/- 0.3 mmol/l; 99.1 +/- 10.8 v 66.6 +/- 5.4 mg/100 ml), haemoglobin A1 (mean 9.1%, range 8.8-9.2% v mean 7.9%, range 7.4-8.4%), lactate, alanine, and glycerol (0.090 +/- 0.017 v 0.045 +/- 0.008 mmol/l); and the lactate: pyruvate ratio were significantly higher in the twins than controls. After glucose challenge blood glucose, lactate, alanine, and glycerol concentrations and lactate: pyruvate ratio were increased in the twins. Insulin response was severely impaired, being almost absent in four of the five twins. The non-diabetic members of the discordant non-insulin-dependent diabetic pairs showed noticeable metabolic abnormalities which would later presumably deteriorate to frank diabetes. These findings, taken with the high concordance rate for non-insulin-dependent diabetic twins, suggest that non-insulin-dependent diabetes is predominantly, possibly entirely, inherited.

Soliciting Accurate Evaluations of Public Goods

Among the many problems faced by policy makers in attempts to use public funds efficiently, none is more troublesome than that of inducing users of public goods to reveal their demand prices. The difficulty in attempts to solicit demand prices falls under the general rubric of the free-rider problem, and is manifest in the propensity of users to behave strategically when asked to reveal evaluations. Several preference revelation devices have been proposed to surmount this problem, but all of these schemes are seriously flawed. This article presents a device which overcomes some of the flaws contained in previous work. The preference revealing mechanism proposed here is a bidding mechanism which takes advantage of the commonly found trait of risk-aversion to discourage strategic revelations.

Blockade of chlorpropamide-alcohol flushing by indomethacin suggests an association between prostaglandins and diabetic vascular complications

Chlorpropamide/alcohol flushing (CPAF), found in many patients with non-insulin-dependent diabetes (NIDD), can be blocked by indomethacin in most patients who are free of vascular complications but not in those with such complications. Since indomethacin is a prostaglandin inhibitor this finding suggests that prostaglandins may be involved in the aetiology of vascular diseases in NIDD. All 6 pairs of identical twins with CPAF, of whom 2 pairs were disocrdant for diabetes, were concordant for indomethacin blocking, which suggests that the block has a genetic basis. The difference in the response of CPAF to indomethacin in diabetic patients with and without vascular complications is probably the first indication of a metabolic difference between these two types of patient.

Chlorpropamide-alcohol flushing and large-vessel disease in non-insulin-dependent diabetes

A total of 220 non-insulin-dependent diabetics aged over 45 (139 with a history of chlorpropamide-alcohol flushing and 81 without such a history) were examined for the prevalence of large-vessel disease. Large-vessel disease was significantly more common in the group without a history of flushing (41% v 24% of the two groups respectively; p < 0.05). A history of myocardial infarction was found in 14 (17%) of the patients without flushing but in only 10 (7%) patients with flushing. Similar differences were detected in the prevalences of angina, intermittent claudication, and absent foot pulses. There were, however, no significant differences in the prevalence of cerebrovascular disease or hypertension between the two groups. These results suggest that patients with non-insulin-dependent diabetes who flush in response to chlorpropamide and alcohol are significantly less likely to develop large-vessel disease than those who do not. Hence such flushing is probably related to the pathogenesis not only of small-vessel but also of large-vessel disease.

Management of premature labour in diabetic pregnancy

The practical management of premature labour is described, illustrated by ten cases. All the patients were treated with beta-sympathomimetic infusion, either salbutamol (0.4-1.6 mg/h) or ritodrine hydrochloride (2-6 mg/h), to stop uterine contractions, and with intramuscular dexamethasone 4 mg eight hourly to accelerate foetal lung maturity. Satisfactory control of blood glucose was achieved (range 2-10 mmol/l) by using high rates of insulin infusion (range 8-32 units per hour). Delivery was postponed in eight cases and seven healthy babies were born. There were three foetal deaths from multiple congenital abnormalities. Beta-sympathomimetic infusion caused few maternal side-effects and there were no foetal problems. Maternal plasma potassium decreased in all cases studied, the mean fall being from 4.5 mmol/l to 2.7 mmol/l.

Can insulin-treated diabetics be given beta-adrenergic blocking drugs?

Lack of awareness of hypoglycaemia leading to loss of consciousness is a serious problem in some insulin-treated diabetics, and beta-blocking drugs may increase this hazard. A prospective study was therefore carried out over eight months to determine the incidence of hypoglycaemic episodes in 50 insulin-treated diabetics taking beta-blockers, as compared with 100 diabetic controls matched for age, sex, and duration of diabetes. The incidence of loss of consciousness from hypoglycaemia was the same in both groups and was unrelated to the dose of beta-blocking drug used. Five patients taking beta-blockers and 10 controls had episodes of unconsciousness, but four of these patients taking beta-blockers had had similar episodes in the two years preceding treatment. It is concluded that beta-blocking drugs are generally safe in insulin-treated diabetics and that hypoglycaemic unconsciousness resulting from their use is rare.

Mini-pump: method of diabetic control during minor surgery under general anaesthesia

A simple method for maintaining diabetic control during and after minor surgery requiring a general anaesthetic was studied in 20 insulin-treated diabetics. Long-acting insulin was omitted on the night before the operation, and a mini-pump delivering insulin at a rate of 0.5 units/h was strapped to the arm early on the morning of the operation regardless of the time of operation. Insulin was infused at this rate throughout the day, the usual evening dose of insulin given and followed by supper, and the pump then stopped. In all 20 patients studied blood glucose concentrations fell steadily throughout the day. Hypoglycaemia did not occur. The mini-pump is simple to use and with the same standard insulin dose for all patients maintains satisfactory blood glucose concentrations throughout the day of operation.

Effect of bromocriptine on maturity onset diabetes

The effect of the dopamine agonist, bromocriptine, and the dopamine antagonist, metoclopramide, on glucose tolerance was examined in maturity onset diabetics and normal subjects. After bromocriptine there was a lowered fasting blood glucose and improved glucose tolerance in the diabetics. The controls showed an initial improvement in glucose tolerance. A reduction in insulin levels and a marked fall in plasma prolactin was observed in all subjects. Growth hormone concentrations were low and unaffected in the diabetics, and there was an inconsistent rise in the normals. After metoclopramide there was some impairment in glucose tolerance in the normal subjects, but this was not significant in the diabetics. There was also a marked prolactin release in all subjects, but no significant effect on insulin or growth hormone. It is concluded that bromocriptine lowers the blood glucose and improves glucose tolerance in maturity onset diabetics. This action may be the result of the lowered prolactin which occurred without a concomitant rise in growth hormone.

Chlorpropamide alcohol flushing and diabetic retinopathy

"Mason-type" diabetics (mild diabetes which is dominantly inherited) are relatively free of retinopathy. Alcohol almost invariably causes facial flushing in these patients when they are given chlorpropamide (chlorpropamide alcohol flush, C.P.A.F.). 291 non-insulin-dependent diabetics were examined to see whether there was a difference in frequency of retinopathy between C.P.A.F. positive and negative cases who were of comparable age and duration of diabetes. Retinopathy was commoner and often severe in CPAF negative patients. Blindness from retinopathy was almost confined to C.P.A.F.-negative cases. Lens opacities, on the other hand, were equally common in both groups. Since C.P.A.F. is an inherited trait, retinopathy in non-insulin-dependent diabetics is to a considerable extent, although not entirely, determined by genetic factors.